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BULLETIN OF 
THE BRITISH MUSEUM 
(NATURAL HISTORY) 


GEOLOGY 
VOL. 20 
197I—1972 


TRUSTEES OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 
LONDON : 1974 


DATES OF PUBLICATION OF THE PARTS 


No. 
No. 
No. 
No. 
No. 
No. 
No. 


1. 28 January 
23 April 
28 April 
22 June 
22 June 
15 July 
28 January 


WATE Wy 


PRINTED IN GREAT BRITAIN 
BY JOHN WRIGHT & SONS LIMITED, AT 


1971 
1971 
1971 
1971 
1971 
1971 
1972 


THE STONEBRIDGE PRESS, BRISTOL BS4 5NU 


CONTENTS 
GEOLOGY VOLUME 20 


The Lower Palaeozoic stratigraphy and faunas of the Taurus Moun- 
tains near Beysehir, Turkey. II. The trilobites of the Seydisehir 
formation (Ordovician). W.T. DEAN 

[Part I published as Bull. Br. Mus. nat. Hist. (Geol.), Vol. 19, 8, 1970: 
411-426] 


Lower Cretaceous ammonites from north-east England : the Hauteri- 
vian genus Simbirskites. P. F. RAwson 


Review of Peramus tenuivostris Owen (Eupantotheria, Mammalia). 
W. A. CLEMENS & J. R. E. Mitts 


The Ordovician trilobite faunas of the Bluith—Llandrindod Inlier, 
Central Wales. Part II. C. P. HUGHES 
[Part I published as Bull. Br. Mus. nat. Hist. (Geol.), Vol. 18, 3, 


1969 : 39-103] 


Palaeozoic coral faunas from Venezuela, I. Silurian and Permo- 
Carboniferous corals from the Mérida Andes. C. T. SCRUTTON 


The earliest goats and other antelopes from the Samos Hipparion 
fauna. A. W. GENTRY 


Stratigraphy of the Jurassic and Lower Cretaceous rocks and Jurassic 
ammonites from northern areas of West Pakistan. A. N. FATMI 


Index to Volume 20 


25 


87 


II5 


183 


229 


297 


381 


INDEX TO VOLUME 20 


New taxonomic names and the page numbers of the principal references are printed in bold type. 
An asterisk (*) denotes a figure. 


Abbottabad formation 315 
Acanthodiscus 71, 372, Fig. 6 
Spp. 72 
vadiatus (zone) Fig. 6 
Acanthohalysites 186, 221, 222 
australis 221 
sp. 191, 221-2; Pl. 5, figs. 5-6 
Addax nasomaculatus 261, 275 
Aegialodon 89, 110-11 
Aeglina sicardi 14 
Aegocrioceras 28, 33, 36, 72-3, 75 
bicarinatum 33, 35 
capitanet 70-1 
capricornu 70-1, 75; see also capricoynu zone 
seeleyi 32, 36, 64, 73, 70; see also seeleyi zone 
Spp. 36, 54 
Agarikophyllum 201-2 
Agnostidae 6-7 
Agnostus sidenbladhi 6 
Ailoceras 324 
Alleynia 194-5 
Alocolytoceras Fig. 6 (facing 362) 
Amblotherium 90 
pusillum 108 
Ammonites anceps 334 
bipinnatus 64 
clypeiformis 62-3 
concinnus 28, 35, 48 
cryptoceras 71 
dechent 38 
discofalcatus 55, 59 
discus 63 
duvalti 64 
exoticus 329 
fasciatofalcatus 50, 52 
frequens 346 
hyphaisis 358 
INVEYSUS 43 
lamberti 61, Fig. 6 (facing 362) 
lippiacus 54 
marginatus 28, 65 
nuculeus 352 
phillips 61 
picteti 38, 65 
pottingeri 342 
ptychoicus 328 
stlesiacus 328 


speetonensis 28, 35, 47, 50, 63, 69 
spetonensis 50 
teutobergensis 39 
trifurcatus 58 
umbonites 65 
venustus 28, 35, 50-1 
versicolor 43, 46 
wallicht 353 
(Olcostephanus) inversus 43 
lippiacus 54 
versicolor 46 
Ammonites, associated with Simbirskites 
Hauterivian 36 
Ammonitida 330-59 
Ammonitina 37—69 
Ammonitoceras Fig. 4 
sp. cf. pavlowt 324 
sp. Figs. 3, 4 
Ammonoidea 328-59 
Ammotragus 278-81 
leyvia 261, 280 
Amphitherium 89, 106-10, 112 
prevosti 106 
restoration of upper molars 107* 
Amplexocarinia 194 
muralis 194 
tovtuosa 194 
Amplexocariniidae 192, 194 
Amplitherium 106-8 
Ampyx 3 
nasutus 7 
villebyunt 8, 22 
? sp. 7-8, 22; Pl. 1, fig. 5 
Ampyxina ? villebruni 8 
Anakashmirites 313 
Anavirgatites 370 
palmatus zone Fig. 6 
Ancyloceras beds 64 
Ancyloceras duvalit 64 
Anebolithus 120, 138-40 
simplicioy 139 
sp. 137, 139; Pl. 4, figs. 3, 5 
angulicostata zone (Tethys) 77, 80-1 
Antelopes from Samos Hipparion fauna 229-96 
Antelopes, spiral-horned 261—75 
horn-cores 265*, 267* 
skull proportions 268*, 269* 


in 


382 INDEX 


teeth-row lengths 266* 
Antidorcas ? gaudryi 265 
Antilope 287, 288* 
avdea 281 
cantleyt 277 
cervicapra 261, 265*, 267*, 268-9*, 274-5, 
286-8, 293 
lindermayeri 261, 269, 271-2 
pallasi 233, 236 
vothi 261 
sivalensis 277 
speciosa 239 
‘Antilope d’espéce indéterminée’ of Gaudry 233, 
241 
Antilopini 231, 261-2, 288* 
spiral-horned 285-9 
phylogeny of 288-9 
Antilospira licenti 289 
Aphyllostylus 216 
Aptychi of ammonites 359 
Aptychus latus 359 
Ayvaeodon 106 
‘arc’ (trinucleid trilobites) 117 
Archaeotrigon 106, 110 
Arctostvea sp. 316 
Argenticevas noduliferum Fig. 6 (facing 362) 
Arisphinctes 321, 340, Fig. 6 
orientalis Fig. 6 
asaphid trilobite, gen. & sp. undetermined 18-19, 
Ppp IAL, By ty TA, fy 9 ©, ws IPL «1, ils Th, 
3-4, 6, 9; Pl. 5, figs. 2, 7 
fragments 22 
Asaphidae 14-19, 21 
Asaphus 19 
angustifyons 17 
palprebrosus 12-13 
(Neoasaphus) 19 
Aspidoceras (Aspidoceras) 368-70, Fig. 6 
iphiceroides 348 
mombasense 348 
sp. indet. 348, 3590 
spp. 319, 361, Fig. 3 
(Pseudowaagenia) 364; see also Pseudowaagenia 
sp. indet. 348-9; Pl. 9, figs. 2a—b 
Sp. 319, 361 
Aspidoceratidae 337-50 
Aspidoceratinae 347-9 
Ataxioceras 367 
Aulacosphinctes 308, 361, 365, 369-70, 372 
moerikeanus 359 
spitiensis 319, 359; Pl. 11, figs. 2a—b, 3a—b 
toryquatus 344 
tvansitovius 37% 
sp. 321, Figs. 3, 4, 6 
Aulacosphinctoides 333, 344-5, 347, 354, 361, 
363-6, 368-71 
hazaraensis 325, 343-4, 345; Pl. 8, figs. 1a—b, 
2a—b 
hundesianus 344 
infundibulus 344-5 


uhligt 325, 333, 344-5, 361; Pl. 8, figs. 3a—b 
willist 345 
sp. indet. 319, 325, 345, Figs. 3, 6; Pl. 8, 
figs. 4a—b 
Aulacostephanus 367 
pseudomutabilis zone Fig. 6 


Bajocian 360 
Baluchistan 362-3 
Baroch Limestone 309-10 
Barrandeophyllum 194-6, 199 
bohemicum 195 
cantabricum 199 
parvum 199 
perplexum 193 
Barremian, boundary with MHauterivian in 
NW Europe 77*, 80-1 
Bathonian 360 
Beckles, S. H., collection of Purbeckian mammals 
89 
Belemnite bed 308—10 
Belemnopsis 318, 363 
gevavdi 307, 318-19, 321-2, 361, 365-0, 
Figs. 3-4, 6 
gvantana 316, 364, Figs. 3-4 
uhligi 365-6, Fig. 6 
SP. 322, 326 
Bergamia 120, 131-2, 139-51 
etheridget 145 
gibbsi 145 
hibernicus 145 
inquilium 145, 151 
maturva 145 
praecedens 140, 145, 151 
prima 140-6, 142*, 147-8, 151; Pl. 4, figs. 1-2, 
6; Pl. 5; Pl. 6, figs. 1-6, 8 
vhodesi 139, 145 
sedgwickt 145 
whittardi 139-40, 145, 146-51, 147*, 149*; 
Pl. 4, fig. 7; Pl. 7; Bl. 8, figs: 1-9, 11; Pl 9; 
figs. 1-2 
? sp. 145-6 
Berriasella 356, 367-9, 371 
aspera 355, 371 
boissievi 371, Fig. 6 
chapevi 355-6, 371; subzone Fig. 6 
ciliata zone Fig. 6 
delphinensis 371; subzone Fig. 6 
gvandis zone 372, Fig. 6 
malbosi 356, 371 
pavamimouna 371 
sp. 320, Fig. 3 
Berriasellidae 353-9 
Berriasellinae 353-6 
Berriasian 361-2 
Bettonia 120, 152, 158-67 
chamberlaini 158, 159-67, 162*, 163*; Pl. 11, 
figs. 9-11, 13-15; Pl. 12; Pl. 13; Pl. 14, 
figs. 1-5, 8-10 
frontalis 159-60, 163* 


INDEX 383 


gibbosa 159 
iregularis 159-60, 163* 
paucipuncta 159-60, 163*, 164 
aff. superstes 158-9, 167; Pl. 11, fig. 11 
Beysehir, Turkey, Ordovician trilobites from 1-24 
district 4*, 5* 
Ordovician succession of 21* 
bivalves Fig. 3 (facing 312) 
Blanfordia 353-4, 357 
Blanfordiceras 308, 321, 361, 365, 369, 371, 
Figs. 4, 6 
acuticosta 310, 355, 369 
cf. boehmi 355 
cf. latidomus 354; Pl. 10, figs. 6a—b, 7a—b 
cf. wallicht 319, 353—4, 361; Pl. ro, figs. 4a—b, 
5a—b 
sp. indet. 354-5, Fig. 3; Pl. ro, figs. 8a—b 
Bochianites 369-70, Fig. 6 
Boopsis sinensis 289 
Boselaphini 243, 277, 284, 292 
Botriodes 121-2 
Bouleiceras 307, 310, 312-15, 317, 360, 362-3, 
367-8, 370, Figs. 4, 6 
chakdallaense 314, 331-2, Figs. 3-4; Pl. 3, 
figs. 2a—b, 4 
elegans 331-2 
nitescens 314, 330-1, 332, 360, Figs. 3-4; Pl. 3, 
figs. Ia—b, 3a—b 
tumidum 332 
sp. indet. 332 
Bouleiceratinae 330-2 
bovid faunas, Eurasian 231, 292 
relationships 288* 
Bovidae 231-93 
Bovini 278 
brachiopods Fig. 3 (facing 312) 
Brachyelasma 207-8 
primum 207 
Byancatherulum 106, 110-11 
tendagurense I10 
Brancoceras 324, Fig. 3 
indicum 309 
sp. Fig. 3 
Budorcas 282, 288*, 292 
taxicolor 289 


Cal Tepe, Turkey 5* 

Cambrian of 4 
Calliphylloceratinae 328-9 
Calliptychoceras 319, Fig. 6 
Callovian 360 
Calymena arago 8 
Calymenid—Trinucleid province 20 
Calymenidae 8-11, 21 
Campylites Fig. 6 (facing 362) 
Cantrillia 216 
Camparo Formation (Venezuela Palaeozoic) 

188*-9g1 
Capra 253*, 277-81, 288*, 293 
aegagvus 259*, 260*, 278, 281 


caucasica 261, 278, 281 
falconeri 261, 278, 281 
ibex 278 
sibivica 259*, 278 
walie 277 
Capricornis 281 
capricoynu zone (N. Germany) 48, 50, 53-4, 75, 77 
Caprini 231, 235, 261, 277-81, 288*, 292-3 
Cardioceras covdatum zone Fig. 6 (facing 362) 
Caspianites Figs. 3, 4 
sp. nov. cf. wassillewsky 324 
cephalon, cephalic length, width 118 
Cephalopoda 328-59 
ceratite ammonites Fig. 3 (facing 312) 
Chak Jabbi Limestone 311, 313-14 
cheirurid ? trilobite, gen. & sp. indet. 11-12, 22; 
Pl. 2, figs. 2, 5 
Cheiruridae ? 11-12 
Chemnitzia 307 
Chichali formation 311-12, 318 
Chilotherium 235 
Choffatia 360, 369, Fig. 3 
cobra 338 
sakuntla 338 
sp. indet. 316, 337-8 
CLEMENS, W. E. and Mitts, J. R. E. 87-113 
Cleonicervas 324 
daviesi 309 
Clydoniceras discus zone Fig. 6 (facing 362) 
clypeiformis zone 63 
Cnemidopyge bisecta 132 
Cochliorrhoe 139-40 
Coenites 186, 218-19 
juniperinus 218 
laminatus 219 
sp. 191, 219; Pl. 4, figs. 10-11 
Coenitidae 218-19 
collignoniceratid ammonite Fig. 4 (facing 316) 
Colpocoryphe 3, 11, 21, 23 
avago 8 
thorali 8 
sp. 8-9, 22; Pl. 1, figs. 2, 9-10 
Colpocoryphidae 21 
Colpocoryphinae 8—9 
Columnariina 213-15 
Columnaxon 186, 199, 200-1 
angelae 186, 191, 199-201, 200%; Pl. 1, 
figs. 9-12 
concinnus subzone 50, 54, 68, 73 
Coprolite Bed 31 
Corals, Silurian and Permo-Carboniferous, from 
Mérida Andes 183-227 
Corbula Fig. 4 
lyvata 307, 317, 368, Figs. 3, 6 
Corongoceras 371 
alternans Fig. 6 
Costidiscus vecticostatus 81; zone Fig. 6 (facing 
362) 
Costonia 119 
ultima 168 


384 INDEX 


Craspedites gottschet 56 
Craspedodiscus 28, 37-8, 55-64, 69 
discofalcatus 59 
gottschet 56 
Crassilasma 207 
Cretaceous rocks, Lower, in northern West 
Pakistan : 
biostratigraphical correlation of Fig. 4* 
(facing 316) 
lithological sections of Fig. 3* (facing 312) 
stages 361-2 
stratigraphy 312-25 
‘Crioceras duvalit’ 35 
crioceratid ammonites 81, 310 
Crioceratites 28, 33, 36, 72, Fig. © (facing 362) 
beant group 73 
duvali 80; zone Fig. 6; see also duvali zone 
emevicianus zone Fig. 6 
hildesiense 75; see also hildesiense zone 
nolani Fig. 6 
weymbteri group 35, 75 
Crioceratitidae 36 
Criotherium 240, 288*, 290-1 
argalioides 239, 289-91, 293 
Cryptolithinae 119, 120, 152-67 
Cryptolithoides 119 
Cryptolithus 120, 121, 152-9 
abductus 157 
chamberlaini 159 
gibbosus 159 
imopinatus 156 
instabilis 152-7, 155*; Pl. 9, figs. 4-6, 8; 
Pl. 10; Pl. 11, figs. 5, 12 
intertextus 156, 159 
lloydi 156 
vadiatilis 156-7 
tessellatus 152 
sp. A 157; Pl. 11, figs. 1, 4, 6 
?, sp. B 157-8; Pl. 11, figs. 2, 7 
?, sp. C 158; Pl. 11, figs. 3, 8 
sp., of Whittard 159 
Ctenostreon proboscideum 308, 321 
Cutch 363-5 
Cuyaniceras transgrediens Fig. 6 (facing 362) 
Cyathaxonia 199 
prolifera 202 
siluriensis 195 
Cyathaxoniicae 192-206 
Cymatelasma 191, 213-14, 215 
aricaguaense 186, 191, 214-15, 215*; Pl. 3, 
figs. 9-15; Pl. 4, fig. 1 
cavinatum 213, 215 
corniculum 213 
Cymatoceras sp. 310 
Cystihalysites 186, 219-20, 221 
brownsportensis 191, 220-1; Pl. 5, figs. 1-4 
mirabilis 219 
Cystiphyllina 216-8 


Dactylioceras tenuicostatum zone Fig. 6 (facing 362) 


Damalavus 285, 288* 
boroccot 284 
Damaliscus 285 
Darsamand 320 
Datta formation 311-15 
Davlatmar Limestone 315 
Dean, W. T. 1-24 
dechent zone 50, 52, 57, 60, 65, 67, 69 
(Russia) 77, 78, 79*, 80-1 
Deperetia ardeus 281 
Desmoceras 324 
Dhosaites 370 
Dicerocardium 307 
Dichotomites bidichotomus Fig. 6 (facing 362) 
Dichotomosphinctes 319, 321, 341, Fig. 6 
Didelphis 101 
Didymograptus bifidus zone 158 
muyrchisoni zone, shales 137-8, 151-2, 157, 161 
speciosus zone 139, 158, 161 
Dinophyllum 207, 213 
Dipoloceras 325 
discofalcatus zone, subzone 57, 60, 63 
(Russia) 77, 78, 79*, 80 
Discosphinctes Fig. 6 (facing 362) 
Distoloceras 362, 369, 372, Fig. 6 
sp. 320 
Ditoecholasma 207 
Dolevasaphus 15-16, 19 
laevis 15 
Dorcadoryx altidens 284 
lagreli 284 
triquetricornis 284 
Douvilleiceras 307, 325, Fig. 4 
mammillatum 309, 324, Figs. 3-4 
aff. monile 307 
sp. Fig. 3 
dryolestid mammals 106, 110 
Dufrenoyia Fig. 3 (facing 312), Fig. 4 (facing 316) 
{n. gen. aff.] 324 
Durangites Fig. 6 (facing 213) 
Durlston Bay 91 
duwvalii zone (Tethys) 77, 80 
Dybowskia prima 207 


echinoids Fig. 3 (facing 312) 
Echinospatangus Bed 31 
Edgellia 121-2 

fimbriatus 121-2 
Eivelithus 120 
Elburz Mountains 367 
Endemoceras 41, 71, 78 

amblygonius 71 

novicum zone 75 

vegale 33, 71-2; see also vegale zone 
Endotherium 110-11 
Enterolasma 214 

stvictum 214 

waynense 214 
Entomostracites extenuatus 17 
Eocerus 234 


INDEX 385 


Eomiodon Fig. 4 
indicus 307, 317, Fig. 3 
Eopecten velata 307 
Eotragus 234-5, 284 
Epimayaites 366, Fig. 6 
Epipeltoceras bimammatum zone Fig. 6 (facing 
362) 
Evymnoceras covonatum zone Fig. 6 (facing 362) 
Euaspidoceras 367-70, Figs. 4, 6 
varians 348 
cf. wagurense 321, 347-8 
Sp. indet. 321 
Eupantotheria 87-113 
Eurasian bovid faunas 231, 292 
Euryptychites 39 
Exogyra arduennensis 308 
fourtaui 308 


Fatt, A. N. 297-380 
Favositina 218-19 
jissicostatum zone 74, 76-7 
(N. Germany) 76-7, 81 
France, southern 370-3 
furrows (trilobites), articulating 119 
axial 119 
glabellar 118 
occipital 118 


Galbagnostus 7 
Galdanian formation 315 
Garantiana garantiana zone Fig. 6 (facing 362) 
gastropods Fig. 3 (facing 312) 
Gazella bennetti 289 
capricornis 284 
deperdita 265, 284 
vodleri 284 
stehlini 284 
Gazellospiva 288* 
torticornis 289 
Gentry, A. W. 229-96 
Geragnostella tullbergi 7 
Geragnostus 3, 6-7, 23 
? explanatus 7 
lycaonicus 3, 6-7, 22; Pl. 1, figs. 1, 3-4, 7, 8 
occitanus 7 
sidenbladhi 6 
tullbergi 7 
Germany, north, Speeton Clay strata correlated 
with 74-7, 77* 
Giumal Limestone, Sandstone 307-8 
glabella (trilobites) 118-19 
glabellar furrows 118-19 
length 118 
node, median 119 
Globotruncana ventricosa Fig. 4 (facing 316) 
sp. 309 
Glochiceras 364, 367-9 
Glyptagnostus 7 
Glyptograptus tevetiusculus zone 141, 157-8, 167 
Goats from Samos Hipparion fauna 229-96 
Golden Oolite 309 


gotischei zone 57, 72, 73, 77, 80 
Gracilisphinctes progracilis zone Fig. 6 (facing 
362) 
Graecoryx 234 
Grayiceras 42, 366, Fig. 6 
immami Fig. 4 
sp. Fig. 3 
Gregoryceras transversavium zone Fig. 6 (facing 
362) 
Gryphaea 305, 319-21 
balli 308, 321 
SP. 323 


Halysites australis 221 
brownsportensis 220-1 
catenularia brownsportensis 220 
Halysitidae 219-22 
Halysitina 219-22 
Hamites 325 
Hanchungolithus 21 
primitivus 169 
Haploceras 370 
Haploceratacea 332-3 
Haploceratidae 332-3 
Harpoceras falcifey zone Fig. 6 (facing 362) 
Hauterivian, boundary with Barremian in NW 
Europe 77*, 80-1 
stratigraphy, NE England 29-36, 30* 
Hazara 306-7, 315, 317, 322, 325-6 
Helicelasma 207-8 
Helicoceras fraasti 265 
votundicorne 261, 265 
Helicophora rotundicornis 265, 267 
Helicotragus 262 
fraasii 265 
votundicornis 261, 265 
Heligoland, Hauterivian Simbirskites 85-6 
Hemilytoceras vex 330 
Hemistrepsiceros 262 
zitteli 262-3 
Hemitragus 278-81, 288* 
Hertleinites 38 
Hesperoceras merlae 282 
Heteroceras astierianum zone Fig. 6 (facing 362) 
Heterophrentinae 207 
Hetevrophrentis 207 
Hibolites 318-21, 361, 363 
jaculoides 34, 69 
pistilliformis 363 
subfusiformis 310, 363 
sp. 323, Fig. 3 
hildesiense zone (N. Germany) 54, 75-6, 77 
Hildoceras bifrons zone Fig. 6 (facing 362) 
Hildoceratacea 330-2 
Hildoceratidae 330-2 
Hildoglochiceras 361, 365, 370, Figs. 3-4, 6 
grossicostatum 368 
hobelli 333, 361, 369 
latistrigatum 333 
propinoum 333 


386 INDEX 


sp. indet. 319, 332-3; Pl. 3, fig. 5 
Himalayites 308, 321, 354, 356, 361, 365, 369, 371, 
Figs. 3-4, 6 
celebvans 358 
cf. depressus 321, 357 
cf. hyphaisis 319, 358-9, 372; Pl. 9, figs. 5a-b 
middlemissi 357; Pl. 9, figs. 6a—b 
sp. indet. 319, 358, 372 
Himalayitinae 357-9 
Hipparion fauna, Samos, goats and antelopes 
from 229-96 
Hippotragini 231, 233-5, 261, 275-7, 284, 293 
Hippotragus 234, 249, 253*, 276-9 
equinus 259*, 200*, 275-6 
gigas 270 
hopasst 234-5, 245, 249 
nigey 259*, 260*, 275-6 
Holacanthia 216 
Holcodiscidae 36 
Holcodiscus subastievia Fig. 6 (facing 362) 
Holcophylloceras 369-70, Fig. 6 
aff. polyolcum 328 
silesiacum 319, 328, 361; Pl. 1 
Hollisites 38 
Holoclemensia 89, 110-13 
Homomya cf. gibbosa 316 
Hoplites amblygonius 71 
michaelis 355 
(Blanfordia) latidomus 354 
middlemisst 357 
wallicht 353 
Hoplocriocevas fissicostatum 74, 70-7; see also 
fissicostatum zone 
Hubertoceras 337, 367-9, Fig. 6 
dhosaense 337 
mutans 337 
sp. indet. 337; Pl. 5, figs. 3-6 
SPP. 309, 316, 360, Fig. 3 
HuaGueEs, C. P. 115-82 
Hybonoticervas 364, 370 
beckeri (and zone) 364, Fig. 6 
ciliatum 350 
sp. nov. aff. hybonata, of Spath 350 
hybonotum zone Fig. 6 
kachensis 350 
pressulum 350 
sp. indet. 319, 349-50, 361 
Hypophylloceras 28, 71 
cf. perlobatum 36 


Idocevas 370, Fig 6. 
Incaia simplicior 138 
Indocephalites Fig. 6 
diadematus Fig. 6 
tvansitovius 310, 312 
Indopecten sp. 307, 314 
inter-radial ridge (trinucleid trilobites) 117 
inversum zone 35, 43, 46, 72, 75, 77-9 
subzone (Russia) 77, 78, 79* 
Iraq 367-8 


Jebel Tuwaiq 367 
Jubaland 370 
Jurassic ammonites, northern West Pakistan 
328-59 
Jurassic rocks, northern West Pakistan: 
biostratigraphical correlation of Fig. 4* 
(facing 316) 
lithological sections of Fig. 3* (facing 312) 
stages 360-1 
stratigraphy 312-25 
Jurassic/Cretaceous boundary 361 


Kala Chitta-Nizampur area 316-17, 320-2, 
324-5 
Kala Chitta Pahar, central 308 
Kala Chitta range 307-8, 313-14, 326 
Kamptokephalites magnumbilicatus 310, 312 
Katroliceras 364, Figs. 3, 4, © 
depressum 342 
cf. pottingeri 319, 342, 361; Pl. 7, figs. 4a—b 
pingue 342 
zittelt 342 
sp. indet. 342 
Kawaghar formation 311-12 
Kemper, Dr E. 82, 85 
Kenophyllum 207, 211 
subcylindrvicum 211 
Khadimakh 320 
Kheraiceras 352 
Khmerophyllum 201-2 
Kilianella 356, 369, 372, Figs. 4, 6 
astatica 319, 362 
besairvei 319 
leptosma 320, 362 
pexiptycha Fig. 6 
voubaudiana (and zone) 362, Fig. 6 
Spp., SP. NOV. 319, 320, 362, Fig. 3 
Kimmeridgian, Lower 360-1 
Kingena sp. 310 
Kingriali formation 311, 313 
Kinkeliniceras 309, Fig. 6 
Kioto Limestone 306-7, 315 
Kaizilca 5*, 8, 19 
Kohat, western 314-16, 320, 324 
district 308-9, 326 
Koninchites 313 
Kossmatia 365-6, Fig. 6 
Kosmoceras jason zone Fig. 6 (facing 362) 
Kranaosphinctes 319, 339-40, 370, Fig. 6 
Kuehneotherium 89, 103-5, 107-13 
Kurdistan 367-8 
Kymatites 313 


Laccophyllidae 192 
Laccophyllum 194-5 

acuminatum 195 
Laevaptychus 319, 359, 361 
leintwardinensis zone 195 
Leioceras opalinum zone Fig. 6 (facing 362) 
Lemuroceras 324 


INDEX 387 


Leolasma 190, 207, 210-11, 211-12 
kaljoi 186, 190, 211-12, 212*; Pl. 2, fig. 13; 
Pl. 3, figs. 1-8 
veimant 210-12 
Leopoldia 71, 362, 369, 372, Fig. © 
leopoldi Fig. 6 
sp. 320 
Leptobos 233 
Leptotragus 283-4 
pseudotragoides 283 
Lima (Plagiostoma) gigantea 307, 314 
Lindstroemia 192 
columnaris 192 
Lindstroemiidae 186, 192-4, 194-201 
Lithacocevas 368 
Lithographic Limestone, upper and lower 308 
Lloydolithus 132 
localities, fossil, in West Pakistan 326-7 
Lophamplexus 186, 205, 206 
eliast 205 
sp. 191, 205-6; Pl. 2, figs. 3-6 
Lophophyllidiidae 201-6 
Lophophyllidium 186, 199, 201-2, 203-5 
elongatum 205 
pelaeum 191, 202-3; Pl. 1, figs. 13-15 
plummeri 203-4 
prolifera 202 
wewokanum 203-4 
sp. cf. wewokanum 191, 203-4; Pl. 1, figs. 16-18 
sp. 191, 204-5; Pl. 2, figs. 1-2 
Lordshillia 140 
Lower Palaeozoic faunas, Taurus Mountains, 
Turkey 1-24 
Ludwigia murchisonae zone Fig. 6 (facing 362) 
Lumshiwal formation 311-12, 323 
Sandstone 309 
Lyelliceras 307, 325, Fig. 4 
lyelli 307, Figs. 3, 4 
Lyrielasma 214 
Lyrocerus satan 289 
Lyticoceras 362, 372, Figs. 3, 6 
pseudoregalis Fig. 6 
Sp. Nov. 320 
sp. indet. 320 
Lytoceras 28, 71 
cryptoceras 71 
exoticum 329 
jurense zone Fig. 6 (facing 362) 
cf. subfimbriatum 36 
aff. vogdti 36 
Lytocerataceae 329-30 
Lytoceratida 329-30 
Lytoceratidae 36, 329-30 
Lytoceratinae 329-30 


Macrocephalites 363 
dimerus Fig. 6 
macrocephalus (and zone) Fig. 6 
triangularis Fig. 6 

waagent 333 


Madagascar 368-9 
Main Sandstone series (Samana) 308—9 
Maira formation 315 
Makapania 288* 
broomi 290 
Mammal bed, Purbeckian of Durlston Bay 91 
Maragha 233 
marginatus zone 60, 66, 72, 73, 77, 80 
Marrolithinae 117, 119, 120, 167-79 
Marrolithoides 119 
Marrolithus 119, 121, 128, 167-9 
bureaut 168 
favus 174 
tmornatus 169 
ultimus 168 
sp. 168-9; Pl. 14, figs. 6-7 
Massif Central 370-3 
Mathacolestes 106 
Mayaites 360 
hitchent 333 
polyphemus 308 
cf. waageni 319, 333, 360; Pl. 3, figs. 6a—b, 
7a—b 
(Epimayaites) Fig. 6 
(Grayiceras) Fig. 6 
Mayaitidae 333 
Mazapilites Fig. 6 (facing 362) 
measurements, trinucleid trilobites 118*, 119 
Megalaspis (Paramegalaspis) immarginata 14 
Megalodon 307 
Megalovis 282, 288* 
avdea 282 
latifyons 256*, 259*, 260%, 281-3, 290, 293 
Megistaspidella extenuatus 17 
Megistaspis 3, 16-17, 23 
limbatus 16 
sp. 16-17; Pl. 4, fig. 5; Pl. 5, figs. 1, 3-4, 6, 10 
? sp. 22; Pl. 3, fig. 8 
(Megistaspidella) 17 
extenuatus 17 
Mérida Andes, Silurian and Permo-Carboni- 
ferous corals from 183-227 
Palaeozoic stratigraphy 188-90 
Palaeozoic successions 188* 
sample locations 187* 
Metaptychopyge 17 
truncata 18 
Metriophyllinae 193 
Metriophyllum 193 
Mianwali formation 311, 313-14 
Micracanthoceras 369, 371, Fig. © 
Microtragus 234, 283 
parvidens 266* 
Milanowskia 28, 37, 47-55; see also Simbirskites 
Mitts, J. R. E. 87-113 
Miotragocerus 234-5, 237, 239, 243, 250, 252-3, 
253*, 260, 284-5 
amalthea 239, 243 
valenciennest 284 
Miquelina miqueli 20 


388 INDEX 


Mojsisoviczia 325 

Monod, O. 4-5 

Muchuchachi formation (Venezuela Palaeozoic) 
188-91, 188* 

Myttonia 21 


Nautilus anceps 334 
Neaspidocevas wagurense 347 
Nebrodites 370 
Negrelicevas 319, 361, 371, Fig. 6 
Neithea attockensis 308, 325, Fig. 3 
Nejdia 368, Fig. 6 
Nemagraptus gracilis shales, zone 123, 168, 
174-5 
Neoasaphus 19 
Neocomites (Neocomites) 365, 369-70, 372, 
Figs. 4, 6 
pycnoptychus 319 
cf. teschites 319 
wichmanni Fig. 6 
sp. nov. 319, 362 
spp. 320, Fig. 3 
(Calliptychoceras) 365, Fig. 6 
spp. nov. 319, 362 
(Odontodiscoceras) 365 
similis 319, Figs. 4, 6; zone 362, 366 
(Parandiceras) 365, Fig. 6 
aff. indicus 319 
cf. vota 319 
theodorit 319, 362 
Neocosmoceras 307, 325, 365-6, 371-2, Figs. 
3-4, 6 
negregium Fig. 6 
octagonoides 307, 322 
octagonum 320 
Spitiensis 319, 361 
subradiatus 307, 319, 321-2, Fig. 3 
Neohoploceras (Neohoploceras) 362, 369, Fig. 6 
baumbergert 319, 356 
sp. indet. 319 
Neolissoceyas grasianum 320, 369 
Neotragocerus 234-5 
Nerinella 370 
Neseuretus 3, 9-10, 21-2 
avenosus 10 
brevisulcus 11 
gvandior 11 
parvifrons 10 
vamseyensis 9-10 
sexangulus 3, 9-10, 22; Pl. 1, figs. 6, 11-12 
? sp. 10-1, 22; Pl. 2, fig. 9 
Nicholsonia 194 
Nicklesia pulchella 81; see also pulchella zone 
Nileidae 12-4 
Nizampur 308, 313-14, 316-17, 326; see also 
Kala Chitta—Nizampur 


Obtusicostites 367-9, Figs. 4, 6 
buckmani 316, 335-6; Pl. 4, figs. 5a—b; Pl. 5, 
figs. 1a—b, 2a—b 


devi 336 
obtusicostata 336 
ushas 336 
waageni 336 
sp. indet. 336 
SPpp. 309, 316, 360, Fig. 3 
occipital furrow, ring, spine 118 
Ochetoceras (Campylites) Fig. 6 (facing 362) 
Odontodiscoceras 319, Fig. 6 
Otoceros 243, 273, 281, 284 
vodleri 284 
vothi 261, 264, 269 
wegnert 267, 273, 281 
Olcostephanidae 37-69, 350-3 
Olcostephanus 71, 318, Figs. 4, 6 
curvacoensis Fig. 6 
maidani Fig. 6 
subfilosus 72 
valanginites Fig. 6 
virgifer 68 
spp. Fig. 3 
(Olcostephanus) 365, 369-70, 372 
astierianus 309, Fig. 6 
fascigerus 320 
filosus 320, 372 
aff. geet 320 
pachycyclus 320 
vadiatus 320 
sakavalensis 320 
salinarius 319-20, Figs. 3-4, 6; zone 362, 
366, 372 
sublaevis 320 
sp. nov. 320 
spp. 362 
(Rogersites) 362, 365, 369, 372; see also 
Rogersites 
atherstoni 372 
schenki 320 
sp. nov. 320 
(Simbirskites) ; see also Simbirskites 
concinnus 48 
decheni 38, 57 
discofalcatus 56, 59 
fasciatofalcatus 50, 59 
inverSUS 43 
payeri 50-1 
progredicus 48, 50, 52 
speetonensis 50 
concinnus 48 
venustus 50 
subinversus 44 
umbonatus 35, 66 
venustus 50 
versicolor 46 
SP43 
Olonbulukia 283-4 
tsaidamensis 283 
Oppelia aspidoides zone Fig. 6 (facing 362) 
Oppeliidae 36 
Oveamnos americanus 277 


INDEX 389 


Oryx 233, 276, 281-3 
dammah 275 
gazella 275 
leucoryx 275 
Otoites sauzei zone Fig. 6 (facing 362) 
Ovibos 282, 288*, 292 
moschatus 289 é 
Ovibovini 231, 235, 262, 282, 288* 
Ovis 281 
ammon 261, 280 
canadensis 201, 277 
Owenites 313 
Oxfordian, Upper 360 
Oxyteuthis 76 
brunsvicensis 77 
pugio 35 
Oxytropidoceras 308, 324, Fig. 4 
aff. voissyanum 307 
spp. 325, Fig. 3 


Pachysphinctes 342, 364-5, 368-70, Figs. 3-4, 6 
bathyplocus 342 
major 342 
yobustus 319, 342-3, 361; Pl. 7, figs. 5a—b 
staffi 370 
2? Sp. 322 
Pachytragus 231, 233-5, 244-60, 253*, 271, 275, 
277-84, 292-3 
crassicornis 234, 242*, 244, 246*, 247*, 248*, 
252, 253-60, 254*, 255*, 256*, 259*, 260*, 276, 
278-81, 288*, 293; Pl. 4 
laticeps 242*, 244-53, 246*, 247*, 248*, 254-8, 
254*, 255*, 256%, 259*, 260, 276, 278-80, 
288*, 293; Pls. 2-3 
schlossevi 234-5, 253, 256-8 
Pakistan, West, northern areas of 303* 
biostratigraphical correlation of Fig. 4* 
(facing 316) 
fossil localities 326-7, 327* 
geological map 304* 
Jurassic ammonites 328-59 
Mesozoic rocks, lithological sections of Fig. 3* 
(facing 312) 
sequence 310-12 
stratigraphy of Jurassic and Lower Cretaceous 
rocks 312-25 
history 305-10 
stages 360-2 
Palaeophyllum 207 
Palaeorcas 231, 233, 262, 270, 271, 273, 285-6, 
290, 292 
lindermayeri 261, 265, 266*, 267*, 268-9, 
268*, 269*, 271, 272-5, 286-7, 288*, 289-92, 
293; Pl. 6, figs. 1, 2 (top) 
Palaeoryx 231, 233-5, 236, 237-41, 244-5, 251, 
275-7, 279, 284-5, 288*, 292-3 
athanasini 241 
boodon 233 
cordiert 233 
ingens 233, 237, 239 


laticeps 233, 236-8 
longicephalus 240 
MAajovi 233, 236-40 
pallasi 233, 236-41, 242*-4, 246*, 247*, 248*, 
251-2, 254*, 256*, 258, 259%, 260*, 276-80, 
281-3, 285, 290, 293; Pl. 1 
comparisons 240-1 
individual dentitions 239-40 
infraspecific variation 238 
tooth characters 239 
votundicornis 230-7 
sinensis 240 
speciosus 236 
stutzeli 258, 260 
cf. stiitzeli 253, 257-8 
woodwardt 230-7 
columnatus 236, 238-9 
Palaeoryx—Protoryx—Pachytragus group of 
antelopes: 
ancestors 284-5 
cheek teeth 253* 
horn cores 255*, 250* 
compression graph 246* 
percentage diagram 242* 
skull proportions 247*, 248*, 260* 
skulls, side view 254* 
teeth-row lengths 259* 
tribal classification 275-92 
Palmarito formation (Venezuela Palaeozoic) 
188*-9o1 
Pappotherium 89, 104, 110-13 
Paraboliceras 365-6 
Parabos 233 
boodon 233 
cordieri 233 
Paracrioceras 28 
denckmanni 81 
vavocinctum 70-1, 76; see also vavocinctum zone 
statheri 36, 73 
stvombecki 74, 76; see also strombecki zone 
Pavadontoceras 368 
Paramegalaspis 3, 14-16, 19, 21, 23 
cf. frequens 15 
immarginata 14 
sp. 14-16, 22; Pl. 5, figs. 5, 8-9, 11 
Parandiceras 319, Fig. 6 
Paranorites 313 
Paraprotoryx 283 
Pavaptychopyge 17 
Parastievia peltoceroides 72 
Parkinsonia parkinsoni zone Fig. 6 (facing 362) 
Parurmiatherium 292 
rugosifrons 290 
Paurodon 106 
Paurodontidae 106 
Portuguese Kimmeridgian 106 
pavlovae subzone (Russia) 46, 77, 78, 79* 
Pecten 368, Fig. 4 
SP. 314, 316, 362, Fig. 3 
Pelicopsis 106 


390 INDEX 


Peltoceras Fig. 6 (facing 362) 
athleta, and zone Fig. 6 
Peltocevatoides Fig. 6 (facing 362) 
Pentacrinus 309 
Peramuridae 87-113; 108 
Pevamus tenuivostris 87-113 
ancestry IIO 
comparison with Amplitherium 106-8 
with late Jurassic mammals 108-10 
dental formula 112 
dentition, restorations of 102* 
descendants 110-12 
functional interpretations 101-6 
mandibles 91, 94-100, 97*; Pls. 3-4 
maxilla 91-4; Pls. 1-2 
occlusion 101-6 
teeth, postcanine 91 
variation, intrageneric 100-1 
‘cf. Peramus’ (Kimmeridgian of Portugal) tog-12 
Perisphinctaceae 37-69, 334-59 
Perisphinctes 308, 338, Figs. 4, 6 
biplicatus Fig. 6 
denseplicatus 346 
jelskit 339 
Raysevi 57 
MAZUVICUS 339 
obtusicostata 335-6 
orientalis 340 
plicatilis 340 
votoides 341 
virguloides 338 
sp. indet. 339; Pl. 6, figs. 3a—b 
(Avisphinctes) orientalis 340, 360 
(Aulacosphinctes) spitiensis 359 
torquatus 344 
(Dichotomosphinctes) 368 
antecedens 341 
aff. grossouvret 341 
jacki 341 
cf. votoides 319, 341, 360; PI. 7, figs. 1a—b, 2 
subhelenae 341 
sp. 319 
(2? Dichotomosphinctes) sp. indet. 341; Pl. 7, 
figs. 3a—b 
(Kvanaosphinctes) cymatophorus 340 
tvifidus 340 
sp. indet. 319, 339-40, 360; Pl. 6, figs. 4a—b 
(Virgatosphinctes) denseplicatus 346 
frequens 346 
Perisphinctidae 335-47, Fig. 3 
Perisphinctinae 338-41 
Persia 367 
Petyaia 193-4 
Phanerostephanus 367 
phillipsi zone 62 
Phylloceras ptychoicum 328 
silesiacum 328 
Phylloceratacea 328-9 
Phylloceratida 328-9 
Phylloceratidae 36, 328-9 


Physodocevas (Simaspidocervas) 364; see also 
Simaspidoceras 
sp. indet. 319, 349, 361 
Pikermi 233 
Plagiostoma 314 
Plesiaddax depereti 281, 290 
Plesiomegalspis 21 
Pleurocephalites habyensis 310 
Pleurotomaria sp. 321 
Plicatula spinosa 307 
Pliotvagus avdeus 281 
Polyptychites 66 
of gravesiformis group 39 
Portugal, Kimmeridgian mammals 106, 109 
preoccipital cephalic length (trilobites) 118 
Prodamaliscus gracilidens 243 
Prograyicevas Fig. 3 (facing 312) 
Proniceras 367-8, 371 
indicum 319, 350, 361, 368, 371, Fig. 6; Pl. 9, 
figs. 3a—b 
sp. Fig. 3 (facing 312) 
Proplanulites koenigi zone Fig. 6 (facing 362) 
Proplanulitinae 335-7 
Prosinotragus 243, 283 
Prososphinctes 300, 338-9 
MAZUVICUS 339 
virguloides 321, 338-9, 360; Pl. 6, figs. 1, 2a—b 
sp. indet. 321 
(Arisphinctes) orientalis 321 
(Dichotomosphinctes) sp. indet. 321 
Prostrepsiceros 231, 233, 261-2, 262-3, 263-73, 
275, 285-7, 289, 292-3 
fraasi 267 
houtumschindleri 261-2, 263-5, 265*, 266-8, 
266*, 267*, 268*, 269*, 271-5, 286-9, 288*, 
291, 293); Pl. 55 figs. 0, 3 
dentitions 264-5 
varieties 263-4 
mecquenemt 262-3 
votundicornis 265-9, 265*, 267*, 268*, 269%, 
271-4, 287-8, 288*, 293; Pl. 5, fig. 2; Pl. 6, 
fig. 2 (bottom) 
dentitions 268—9 
varieties 266-8 
woodwardi 261, 263-4 
Zitteli 263 
sp. 261-3 
Protacanthodiscus 356, 366, 371, Figs. 4, 6 
cf. michaelis 319, 355-6, 361; Pl. 11, figs. ta—b 
Sp. 319-20, 361, 372, Fig. 3 
? sp. indet. 356; Pl. 11, figs. 4a—b 
Protaconecervas 28 
sp. 36 
Protocardia Fig. 4 
gvandidieri 307, 317, 368, Figs. 3, 6 
Protogyvammoceras 368 
Protolloydolithus 119, 121, 169-74 
neintianus 174 
primitivus 169 
vamsayi 169, 173 


INDEX 391 


veticulatus 169-74, 171*; Pl. 15, figs. 1, 5-9, 
11; Pl. 16, fig. 2 
Protoryx% 231, 233-5, 241, 241-4, 249, 275-7, 279, 
281-5, 288*, 292-3 
cavolinae 233-5, 238, 241-3, 242*, 244-5, 
246*, 247*, 248*, 248-52, 254*, 256*, 259%, 
276, 279, 293; comparisons 243 
crassicoynis 234 
laticeps 234, 245 
CYASSICOYNIS 234, 245, 249 
gaudryt 233-4, 245, 250 
hentschelt 234, 245, 251-2 
tenuicoynis 234, 245, 251 
hippolyte 233-4, 245, 246*, 248*, 250 
laticeps 234, 245-7 
longiceps 233, 244-5, 247 
? Protoryx planifrons 243 
shansiensis 243 
yushensis 260 
SP. 243, 253 
Protophites 352 
Protvagelaphus 231, 233, 269, 272-3, 285-7, 289, 
293 
shouzesi 261-2, 265*, 266*, 267*, 268*, 269%, 
269-71, 274-5, 287-8, 288*, 289, 291, 293; 
Pl. 6, fig. 2 (middle) 
zitteli 261-3 
Protragoceyus 234-5, 284 
Provalanginites 351-2, 361, Figs. 3, 4 
howarthi 319, 353; Pl. 10, Figs. 2a—b 
rhodesi 319, 351, 352-3; Pl. to, figs. 1a—b, 
3a-b 
Provalanginitinae 351-3 
Pseudoinvoluticeras 370 
Pseudois 278-81 
nayauy 261 
Pseudolissoceras 367-8 
zitteli Fig. 6 
Pseudoperisphinctinae 337-8 
Pseudoptychopyge 17 
Pseudosphaerexochus (Pateraspis) inflatus 12 
Pseudothurmannia angulicostata 80-1; zone 77, 
80-1, Fig. 6 (facing 362) 
Pseudotragini 234-5, 249 
Pseudotragus 234, 283-4, 288* 
altidens 284 
capricornis 234-5, 253, 256-7, 283 
hippolyte 234-5, 245, 250 
lagreli 284. 
longicornis 234-5, 253, 257-8 
potwaricus 284 
Pseudowaagenia 319, 348-9, Figs. 4, 6 
hyanaldi 349 
micropla 349 
Ptenophyllidae 213 
Pterolytoceras exoticum 319-20, 329, 330, 365; 
Pl. 2, figs. 2a—b 
sp. indet. 320, 330; Pl. 2, figs. 3a—b 
Ptychophylloceras 369 


ptychoicum 319, 328-9, 361, Fig. 6; Pl. 2, 
figs. Ia—b 

tithonicum 329 
Ptychopyge 3, 17-18 

angustifrons 17 

lesntkovae 18 

sp. 17-18, 22; Pl. 4, fig. 7 

? sp. Pl. 4, fig. 8 
pulchella zone (Tethys) 81 
Putealiceras Fig. 6 (facing 362) 
Pycnactis 213 
pygidial length, width (trilobites) 119 


Quenstedtocevas lamberti zone Fig. 6 (facing 362) 
marviae zone Fig. 6 


vadiatus zone (Tethys) 77 
Raimondiceras 356 
vaimondi 356 
? salinarium 356 
Raphiophoridae 7-8 
varocinctum zone 69, 74, 77, 81 
(in N. Germany) 76, 77, 81-2 
Rawson, P. E. 25-86 
vegale zone 34, 72, 77, 79 
Reineckeia 335, 360, Fig. 4 
anceps 316, 334, 360, 367-8, Figs. 4, 6; Pl. 4, 
figs. I-3 
arthritica 335 
brancot 335 
vehmant Fig. 6 
cf. torulosus 316, 334-5; Pl. 4, figs. 4a—b 
sp. indet. 316, 335, Fig. 3 
Reineckeiidae 334-5 
Reineckeites torulosus 334 
Reuscholithus 119 
Rhabdacanthia 216 
rhynchonellid brachiopods 319, 362, Fig. 3 
Rhynchonelloidea avcuata 309, 314-15, Figs. 3-4 
ribs, density of primary and secondary, in 
Simbirskites (Speetoniceras) inversum 45* 
Rogersites 42, 320, Fig. 6 
laticostatum Fig. 6 
schenki Fig. 6; zone 362 
tenuicostatus Fig. 6 
Rogersites beds 369 
Rugosa (corals) 192-218 
Russia, Speeton Clay strata correlated with 
77-80, 77* 


Sabaneta formation (Venezuela Palaeozoic) 
188*—-191 

sagittal line (trilobites) 118-19 

Samana 320 

Samana beds, lowest 308-9 

Samana range 308-9 

Samana Suk Limestone 308-9, 311-13, 315 


302 INDEX 


Samos 231-3 
Hipparvion fauna, goats and antelopes from 
229-96 
Samotherium 235 
Samotvagus cvassicoynis 281 
Sarasinella 365, 369, Figs. 3, © 
spinosa 319, 362 
uhligt 319, Fig. 4; zone 362, 366 
Saudi Arabia 367 
sayni zone (Tethys) 77, 80-1, Fig. 6 (facing 362) 
Saynoceras vervucosum Fig. 6; zone 362 
Scrutton, C. T. 183-227 
seeleyi zone (N. Germany) 52, 57, 76, 77 
Selenopeltis-fauna 20 
Semiformiceras semiforme zone Fig. 6 
Seydisehir district (Turkey) 4*, 5* 
Ordovician succession of 21* 
Seydisehir shales, formation (Lr Ordovician) 4, 
5*, 6, 8-9, II-12, 14, 16, 18-19, 21* 
Shaikh Budin Hills 310, 327 
Sigaloceras calloviense zone Fig. 6 (facing 362) 
Simaspidoceras 319, 349, Fig. 6 
argobbae 349 
Simbirsk section, ammonite zones 78, 79* 
Simbirskites 25-86, 38-42, 64 
in Speeton Clay, distribution of species 72* 
arminius 69 
aurvacanus 42 
fasciatofalcatus 35, 50 
lorkshivensis 66 
moruenae 41 
nodocinctus 68 
payeri 51 
quadripartitus 42 
trifurcatus 57-8 
triplicatus 54, 69 
(Simbirskites) 37-8, 41, 64, 73, 78 
decheni 38, 40*, 41-2, 50, 57, 59, 66-8, 71, 
73, 76, 79, 82; see also decheni zone 
var. a 40* 
of decheni group 37, 67-8, 72, 75; Pl. 11, 
fig. 6; Pl. 12, figs. 1, 3-4, 6, 8-10 
elatus 39, 52-3, 67-8, 78-9 
kleint group, cf. kleini 41-2, 73 
howalewskii 40*, 41, 79 
marginatus 28, 37, 40*, 65-6, 71-3, 80; 
Pl. 12, figs. 13-14; see also marginatus 
zone 
paucilobus 54, 76 
pavlovae [= pavlovi] 78-9; see also pavlovae 
zone 
pavlovi [pavlowi] 39, 64, 66, 78-80 
pseudobarboti 67, 78-9 
aff. toensbergensis 35, 57, 59, 66-7, 69 
toensbergensis—yorkshivensis group 73-4 
umbonatiformis 40*, 41, 78-9 
umbonatus 35, 37-8, 40*, 41, 65, 66-7, 
78-80; Pl. 12, fig. 15; see also wmbonatus 
zone 
virgifer 76 


cf. virgifer 35, 37, 54, 68; Pl. 12, fig. 12 
yorkshivensis 35, 37, 40*, 59, 65, 66-7, 
69-73, 79-80; Pl. 12, figs. 2, 5, 7 
yorkshivensis—toensbergensis group 73-4 
spp. 69 
(Craspedodiscus) 35, 37-9, 41, 55, 56-64, 78 
barbotanus 69 
barboti 79 
carinatus 69, 86 
clypetformis 62-3, 70 
discofalcatus 35, 37-8, 55, 57, 59-60, 61-3, 
69-72, 74, 76, 78-80; Pls. 7-8; Pl. 9, 
figs. 1-2; Pl. 11, figs. 2-3, 5; see also 
discofalcatus zone 
extvemus 56 
gottschet 32, 37, 55, 56-7, 59-60, 62, 64, 71-3, 
76, 79-80; Pl. 2, figs. 2, 4-5; Pl. 5, fig. 1; 
see also gottschei zone 
juddi 28, 35, 37, 55, 62-3, 70, 74, 81; Pl. 10, 
figs. 1-2 
cf. kayseri 37, 55, 57 
phillipst 37, 57, 61-2, 63, 69-71, 79; Pl. 9, 
fig. 3 
sp. of phillipsi group 37, 62, 72-3, 86; 
Pl. 5, fig. 2 
tenuis 76; see also tenuis zone 
variabilis 28, 37, 55, 57-9, 62, 71-3, 81; 
Pl. 4, figs. 1, 3, 6; Pl. 5, figs. 3-4; see also 
variabilis zone 
sp. a 37, 63, 72, 80; Pl. 11, fig. 1 
sp. b 35, 37, 64, 74; Pl. 6 
spp. 81, 85-6 
(Milanowskia) 37, 39, 41, 47, 48-55, 60, 64, 73, 
78 
concinnus 28, 33, 35, 37, 40*, 46*, 47, 48-50, 
51, 53-4, 68, 71-3, 75, 79; Pl. 2, figs. 2-6, 
8; Pl. 12, fig. 11; see also concinnus zone 
thmensis 76 
lahuseni 48, 50, 79 
lippiacus 37, 47, 54-5, 81; Pl. 3, figs. 2, 5 
cf. ippiacus 37, 47, 55, 72-3; Pl. 3, fig. 3 
polivnensis 35, 69, 78-9 
progredicus 38, 40*, 47-8, 50, 52-3, 69-71, 
78-9; see also S. (M.) sp. 
speetonensis 28, 35, 37-8, 47, 50-2, 53-4, 59, 
63, 69-73, 78-9; Pl. 2, figs. 7, 9-11, 15; 
Pl. 11, fig. 4; see also speetonensis zone 
venustus 86 
staffi 37, 40*, 47, 53-4, 72-3, 75; Pl. 2, figs. 
14, 10; Pl" 3; figss 1,4 
venustus 28, 35, 50-1 
sp. 37, 47, 52-3; Pl. 2, figs. 12-13 
(Speetoniceras) 28, 33, 37-9, 41, 42-3, 44-7, 73 
agnessense 46 
coronatiformis 39, 64, 78-9 
inversilobatus 42; cf. inversilobatus 68 
inversum 33, 36, 40*, 42, 43-6, 45*, 46*, 47, 
50, 71-2, 78-9, 85; Pl. I, figs. 1, 3-4, 6, 7, 
9; Pl. 2, fig. 1; see also inversum zone 
subbipliciforme 36, 42, 43, 72; Pl. 1, figs. 2, 5 


INDEX 393 


subinversum 42-6, 69-71, 78-9; Fig. 6 
(facing 362); zone 69 
versicolor 37-9, 42, 46-7, 64, 70-1, 78-9, 85; 
Pl. 1, fig. 8; see also versicolor zone 
sp. 37, 47, 72; Pl. 1, fig. 10 
Simbirskites beds of Speeton Clay, zonation 
69-74, 71* 
simbirskitid ammonites 28 
Simbirskitinae 37—69 
Simoceratinae 349-50 
Sinophyllum 201 
Sinoryx 283 
bombifrons 240 
Sinotragus 243, 281, 283, 288* 
Sivacapra 281 
Sivatragus bohlini 277 
Sivoreas evemita 289 
Sivoryx sivalensis 277 
Sobova valley 5*, 6, 11-12, 14, 16, 18, 20 
Somaliland 370 
Somalirhynchia nobelis 316 
Sonninia sowerbyi zone Fig. 6 (facing 362) 
Spalacotheriidae 110 
Spalacotherium 108 
Speeton Clay 29-34 
belemnite zones 69 
zonation of Simbirskites beds 69-74, 71* 
speetonensis zone 35, 50, 52, 57, 69, 72-3, 75-9, 81 
subzone (Russia) 77, 78, 79* 
Speetoniceras 28, 37-8, 42-7; see Simbirskites 
(Spectoniceras) 
subbipliciforme 43 
(Milanowskia) lahuseni 48 
Spiriferina Fig. 4 
rostrata 368 
Sp. 314-15, Fig. 3 
Spirocerus 288* 
kiakhtensis 289 
wongi 289 
Spiti 365-6 
Spiti Shales 307-8 
Spiticeras 354, 365-6, 371 
bilobatus 351 
damesi Fig. 6 
multiforme 319, 350-1, 361, 371-2; Pl. 9, 
figs. 4a—b 
aff. scriptus 351 
subbilobatus 351 
uhligi Fig. 6 
Zivkeli Fig. 6 
sp. indet. 351, 361, Figs. 3-4 
(Spiticeras) aff. griesbachi 320 
cf. mojsvari 320 
(Negreliceras) negreli Fig. 6 
aff. subnegreli 319 
Spiticeratinae 350-1 
Spitidiscus 28, 71 
inflatiformis 36, 72 
votula 36, 70-1, 73 
Spongophyllidae 213-15 


Spongophylloides 213 
cocket 213 
pusillus 213 
Sporadotragus 234, 281, 283-4, 288, 288*, 291 
parvidens 266*, 269 
stiitzeli 258 
Stapeleyella 140 
Stauriidae 207 
Stephanoceras humphresianum zone Fig. 6 
(facing 263) 
Stephanoceratacea 333 
stephanoceratid ammonite Fig. 6 (facing 362) 
Steveolasma 192 
Stereostylus 201-2 
brushensis 202-3 
pelaeus 202-3 
Stewartophyllum polonicum 193 
Stoicoceras 38 
teutoburgensis 39 
Streblites 364, 369-70, Fig. 6 
tenuilobatus 364; zone Fig. 6 
Strenoceras subfurcatum zone Fig. 6 (facing 362) 
Streptelasma 206, 207-8, 209-10 
corniculum 207 
poulsemi 210 
shagami 186, 190, 208-10, 209*; Pl. 2, figs. 
7-10 
sp. 190, 210; Pl. 2, figs. 11-12 
Streptelasmatidae 206-7, 207-12 
Streptelasmatina 192-212 
Streptelasmatinae 206 
stvombecki zone (N. Germany) 60, 74, 76, 77, 
80-1 
Subastievia sulcosa 71-2 
Subdichotomoceras 370, Fig. 6 
sparsiplicatum 370 
Subkossmatia flemingi 309, 316, 364 
Subplanites vimineus zone Fig. 6 (facing 362) 
Subsaynella sayni 80; see also sayni zone 
Substeueroceras 367-8 
koenent Fig. 6 
Subthurmannia 318-19, 361, 365-6, 369, 371-2, 
Figs. 4, 6 
boissiert 320, 366, 371-2, Fig. 6 
densistriatus Fig. 6 
fermori 319-20, 355-6, 361, 371-2, Figs. 3-4 
lissonioides 319-20 
aff. pseudopunctata 320 
surgharensis 366 
tenocht Fig. 6 
spp. 319, Fig. 3 
Subvishnuites 313 
Sutneria 370 
suture-lines in Simbirskites spp. 40*, 45* 
Symphysurus 3, 12, 23 
angustatus 14 
blumenthali 3, 12-14, 22; Pl. 2, figs. 1, 3-4, 
6-8, Io 
palpebrosus 12-13 
Sp. 13, 22; Pl. 3, figs. 5-6, 10; Pl. 4, fig. 2 


394 INDEX 


Synhomalonotidae 21 
Syringaxon 186, 193, 194-6, 196-9 
acuminatum 197 
adaense 197 
arnoldi 186, 191, 196-7, 197*; Pl. 1, figs. 1-5 
bohemica bohemica 193 
cantabricum 198*, 199 
memorabilis 194 
parvum 198*, 199 
pinguis 193 
postsiluriense 193 
siluriense 193, 195; Pl. 1, fig. 6 
suripaense 186, 191, 197-9, 198*; Pl. 1, 
figs. 7-8 
wedekindt 197 
Syringaxoninae 193 


Tabulata (corals) 218-22 
Taihungshania 3, 19-21 
landayranensis 20 
miqueli 20 
shui 19-20 
sp. 19-20, 22; Pl. 3, fig. 3 
Taihungshaniidae 19-21 
Tanganyika 369-70 
Tavamellicevas 364, 3690, Fig. 6 
lithographicum zone Fig. 6 
Tathiodon 106 
Taurotvagus 261 
Taurus mountains, Turkey 4* 
Ordovician trilobites 1-24 
Tealby beds 34 
Clay, lower 34-5, 50, 67 
Limestone 35 
Telaeomarrolithus 119, 121, 174-9 
intermedius 128, 174-8, 176*; Pl. 15, figs. 
2-4, 10; Pl. 16, figs. 1, 4-9 
vadiatus 174, 178-9; Pl. 16, fig. 3 
sp. indet. of Whittard 178 
Tellurimya tellaris 316 
tenuis zone (N. Germany) 57, 60, 76, 77, 80 
terebratulid brachiopods 319, Fig. 3 
terminology, trinucleid trilobites 117 
Tethys, Speeton Clay strata correlated with 
* 
thoracic length, width, segment length (trilobites) 
119 
Thracia phillipsi 33 
Thurmanniceras 365, 369, 372, Figs. 4, 6 
boissievi, and zone Fig. 6 
novihispanicus Fig. 6 
pertrvansiens Fig. 6 
SP. 319-20, 362, Fig. 3 
Thysanatoceras 38 
picteti 38 
Tinodon 108 
Tithonian 361 
Tmetoceras scissum zone Fig. 6 (facing 362) 
Toarcian, Lower 360 


Tollia 39 
Torquatisphinctes 364, 369-70, Fig. 6 
Tossunnoria pseudibex 280, 288* 
Tragelaphini 231, 261-2, 285-6 
Tragelaphus 261 
houtumschindleri [houtum schindleri, etc.] 261, 
263 
nakuae 286 
Tragocerus 234, 285 
Tragoveas 284 
altidens 284 
lagrelt 284 
oryxoides 284, 292 
potwaricus 284 
Trans-Indus Salt Ranges 309, 312-13, 316, 
318-20, 323, 327 
Tredian Formation 311 
Tretaspis 140 
fimbriatus 122, 146 
praecedens 140 
seticornis 138 
Trigonia 305 
cressa Fig. 6 
schwartzi 370 
ventricosa 308, 321, 325, Figs. 3-4 
spp. 325, Fig. 3 
Trilobites limbatus 16 
Trilobites, Ordovician of Turkey 1-24 
Trinucleidae 21, 117, 118*, 119-79 
trinucleid (trilobite), gen. & sp. indet. 151-2; 
Pl. 8, fig. 10; Pl. 9, figs. 3, 7 
Trinucleinae 119, 121-52 
Trinucleoides 173 
veticulatus 169, 173 
veusst’ 173 
saltert 122, 132 
Trinucleus 119, 121-38 
abruptus 132-7, 135*, 138-9, 159; Pl. 3, 
figs. 2-4, 6-7 
cf. acutofinalis 131, 136, 137-8, 152; Pl. 3, 
fig. 5; Pl. 4, figs. 4, 7-8 
bronnt 132, 137 
cavactaci 121 
chamberlaini 132, 158-9 
etheridget 145 
fimbriatus 121, 122-32, 125*, 127*, 137, 141, 
145-6, 149, 177-8; Pls. 1-2; Pl. 3, fig. 1 
primus 131, 140, 146 
ultimus 122, 131 
foveolatus 131-3, 137 
intermedius 131 
gibbsi 145 
hibernicus 145 
oynatus favus 167 
primitivus 169 
vadiatus 174, 178 
vamsayi 169 
sedgwicht 145 
(Cryptolithus) gibbosus 159 
lloydt 156 


INDEX 395 


Tryplasma 186, 216, 217-18 

aequabile 216 

gracilis 218 

lonsdalet 218 

minor 218 

malvernense 216 

nordica 216-17 

sp. cf. nordica 191, 216-17; PI. 4, figs. 2-4 

sp. 191, 217-18; Pl. 4, figs. 5-9 
Tryplasmatidae 216-18 
Tsaidamotherium 290 

hedini 290 
Tulites subcontractus zone Fig. 6 (facing 362) 
Turkey, outline map 4* 


Uhligites 365, Fig. 6 
sp. indet. 319 
Ulyanovsk section, ammonite zones 78, 79* 
umbonatus subzone (Russia) 60, 67, 77, 78, 79*, 
80 
Umia Fig. 6 (facing 362) 
Urmiatherium group 288*, 290 
intermedium 290 
polaki 290 


Valanginian 362 
Valanginites 352-3 
nuculeus 352-3 
variabilis zone 35, 59-60, 63, 67, 72, 73-4, 77, 79, 
80-1 
Variegated Series, stage 307-8 
Velata velata 314, Fig. 3 
Sp. 315 


Venezuela, Silurian and Permo-Carboniferous 
corals from Mérida Andes 183-227 
versicoloy zone 46-7, 69 
(Russia) 77, 78, 79* 
subzone (Russia) 77, 78, 79*, 80 
Virgatosphinctes 347, 363, 365-71, Figs. 4, 6 
communis 310 
denseplicatus 325, 346, 361, 363; Pl. 8, figs. 
5a—b 
frequens 307, 325, 346-7, 361; Pl. 9, figs. 1a—b 
indistinctus 347 
mendozanus Fig. 6 
votunda 346 
subfrequens 347 
subquadratus 347 
transitorius 371; zone Fig. 6 
spp., sp. indet. 319, 347, Fig. 3 
Virgatosphinctinae 342-7 


Weerth, O., type Simbirskites of 85-6 

Wenlockia 216 

whorl-proportions in Simbirskites spp. 46*, 49* 

W [indhauseniceras| internispinosum Fig. 6 (facing 
362) 


Xenoceltites 313 
Xenodiscoides 313 


Zaphrenticae 206-12 
Zelleria sp. 310 
Zigzagiceras zigzag zone Fig. 6 (facing 362) 


THE LOWER PALAEOZOIC | 
STRATIGRAPHY AND FAUNAS © 
OF THE TAURUS MOUNTAINS 

NEAR BEYSEHIR, TURKEY. 

He TRILOGBIEES. OP THE 
SEYDISEHIR FORMATION 


(ORDOVICIAN) 
W. T. DEAN 
BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 
GEOLOGY Vol. 20 No. 1 


LONDON: 1971 


THE LOWER PALAEOZOIC STRATIGRAPHY 
AND FAUNAS OF THE TAURUS MOUNTAINS 
NEAR BEYSEHIR, TURKEY. IL THE TRILOBITES 

OF THE SEYDISEHIR FORMATION 
(ORDOVICIAN) 


BY 
WILLIAM THORNTON DEAN 


Geological Survey of Canada 


Ph. 1-24 ; 5 Plates, 3 Text-figures 


BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 
GEOLOGY Vol. 20 No. 1 
LONDON : 1971 


THE BULLETIN OF THE BRITISH MUSEUM 
(NATURAL HISTORY), ¢mstituted im 1949, 1s 
issued in five series corresponding to the Departments 
of the Museum, and an Historical series. 

Parts will appear at irregular intervals as they become 
veady. Volumes will contain about three or four 
hundred pages, and will not necessarily be completed 
within one calendar year. 

In 1965 a separate supplementary series of longer 
papers was instituted, numbered serially for each 
Department. 

This paper is Vol. 20, No. 1 of the Geological 
(Palaeontological) series. The abbreviated titles of 
periodicals cited follow those of the World List of 
Scientific Periodicals. 


World List abbreviation 
Bull. Br. Mus. nat. Hist. (Geol.). 


© Trustees of the British Museum (Natural History), 1971 


TRUSTEES OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 


Issued 28 January, 1971 Price £1.75 


THE LOWER PALAEOZOIC STRATIGRAPHY 
AND FAUNAS OF THE TAURUS MOUNTAINS 
NEAR BEYSEHIR, TURKEY. Il THE TRILOBITES 

OF THE SEYDISEHIR FORMATION 
(ORDOVICIAN) 


By W. T. DEAN 


CONTENTS 
Page 
I. INTRODUCTION AND ACKNOWLEDGMENTS 4 
II. SySTEMATIC DESCRIPTIONS ; 6 
Family Agnostidae M’Coy 6 
Geragnostus lycaonicus sp. nov. 6 
Family Raphiophoridae Angelin 7 
Ampyx ? sp. ; 7 
Family Calymenidae ‘Edwards 8 
Subfamily Colpocoryphinae Hupé 8 
Colpocoryphe sp. : 8 
Subfamily Symhomalonotinae Kobayashi 9 
Neseuretus sexangulus sp. nov. 9 
Neseuretus ? sp. ; : 2 : : ; so) 
? Family Cheiruridae Salter : : : : : ° II 
Cheirurid ? gen. et sp. indet. . ; : : : : II 
Family Nileidae Angelin . : é 5 , 6 : 12 
Symphysurus blumenthali sp. nov. . : ; ¢ 5 12 
Family Asaphidae Burmeister . ; : 4 : : 14 
Paramegalaspis sp. : ‘ ‘ : , : F 14 
Megistaspis sp... ; : : : : : : 16 
Ptychopyge sp. , : : : , F 17 
Asaphid gen. et sp. undetermined ; ‘ 4 ; ; 18 
Family Taihungshaniidae Sun _ . é : é : : 19 
Tathungshania sp. ‘ : : . 19 
III. AGE AND RELATIONSHIPS OF THE TRILOBITES : : . ; 20 
IV. REFERENCES : 2 : : . : : . 23 


SYNOPSIS 


Trilobites from the upper half of the Seydisehir Formation near Beysehir are described. Al- 
most all are represented only by disarticulated fragments but the following genera are identified : 
Gevagnostus, Ampyx ?, Colpocoryphe, Neseuretus, Symphysurus, Paramegalaspis, Megistaspis, 
Ptychopyge and Tathungshania. Three new species are described : Gevagnostus lycaonicus, 
Neseuretus sexangulus and Symphysurus blumenthali. The assemblage is of Lower Arenig age 
and mostly of Tethyan type, but some genera from the highest strata exhibit Balto-Scandinavian 
affinities. 


4 LOWER PALAEOZOIC STRATIGRAPHY 


I. INTRODUCTION & ACKNOWLEDGMENTS 


THE present paper is the first of a series describing the Lower Palaeozoic trilobites of 
that area of Turkey which lies between Beysehir and Seydisehir (see Fig. 1), some 
100 kilometres south-west of Konya. An earlier paper (Dean & Monod, 1970) intro- 
duced the reader to the succession of Cambrian and Ordovician strata there and gave 
a series of sketch-maps showing the position of fossil localities and their stratigraphical 
position, if known. 


woRTH ANATOLIAN Rang, 


Bakara 


Konya 
/ Bat 


Beysehir al 
Tos <7 
Seydisehir il 4 

| | 


| v™ 
Us wo 


Fic. 1. Outline map of Turkey showing the location of the Beysehir-Seydisehir district in 
relation to the Taurus Mountains (vertical shading) and other major structural units. 


The Seydisehir Formation, at least part of which is Lower Ordovician in age, forms 
by far the largest Lower Palaeozoic outcrops of the region (see Fig. 2), and comprises 
the Seydisehir Shales, silty shales more than 1000 metres thick with occasional 
resistant bands of brown-weathering, sandy limestone, followed by 20 metres of 
coarser beds, the Upper Greywackes. The rocks, often tectonically deformed, are 
largely barren, but at some localities, all of which represent levels in the upper half of 
the Seydisehir Formation, the harder bands have yielded fossils. The latter include 
graptolites which indicate an Arenig age, possibly both the Extensus and Hirundo 


AND FAUNAS OF THE TAURUS MOUNTAINS, II 5 


Zones of that series, together with a few brachiopods and molluscs, and the trilobites 
described in the following pages. The trilobite remains are almost always broken 
and comprise about fifty fragments, mostly pygidia and librigenae, in addition to the 
specimens now described ; they are difficult to determine specifically, but at least 


LAKE — BEYSEHIR 


post-Ordovician 


Ordovician 


5 
kms 
KIZILCA 
SVS ASG << 
Ss 5 
=. & D 
a C543 
Le 
E — 
I G Oya 
A my 0G eS 
FH C= 
A PAY. oO * 
=o A “4; 
= Q3 


=y = 

ee €.319 C.216 = 
_—————————— 320 aa €309 — 
—- = Or 
SS ae == 
SS SS SS === 
eS” SSSA = 
: C160 <a SEYDISEHIR 

1-7 €.206 
My : 
€.310,€.311, SS > 


———— . €.312 & 3124 


Fic. 2. Sketch-map showing the situation of fossil localities in the Seydisehir Formation 
of the district between Beysehir and Seydisehir. 


eleven genera have been collected. Fossils were found for the first time in the Sey- 
disehir Shales by M. Olivier Monod, who not only placed his material at my disposal 
but also introduced me to the geology of the Beysehir region during a visit in the 


6 LOWER PALAEOZOIC STRATIGRAPHY 


summer of 1968. I am much indebted to him for his co-operation and to Prof. 
H. B. Whittington who has kindly read and criticized the manuscript. 


II. SYSTEMATIC DESCRIPTIONS 


The terminology employed here is essentially that proposed by Harrington, 
Moore & Stubblefield in the Treatise on Invertebrate Paleontology (7m Moore 1959 : 
O 117-O 126), though that describing Geragnostus follows Whittington (1963 : 28). 


Family AGNOSTIDAE M’Coy 1849 
Genus GERAGNOSTUS Howell, 1935 


TYPE SPECIES. Agnostus sidenbladhi Linnarsson, 1869. 


Geragnostus lycaonicus sp. nov. 
Pho, figs,.1;°3, 457; & 


Dracnosis. Species of Geragnostus distinguished particularly by strongly convex 
pygidium with axis about five-sixths of total length. Anterior part of axis formed 
by two well-defined axial rings with median lobes joined to form a longitudinal lobe; 
remainder of axis scarcely defined, but with median tubercle near elliptical tip. 


HoLotyPe. BM. It.7992 (Pl. 1, figs. 3, 4, 8). 
PARATYPES. BM. It:7991 (PL x, fig: x); Uit7o93 (PI 1, figs): 


LOCALITY AND HORIZON. Sobova Valley, locality B.650, in the highest beds of the 
Seydisehir Shales, about 33 metres from the top of the Sobova Formation. 


DEscRIPTION. The cranidium has an elongated, semielliptical glabella that 
occupies two-thirds the length and half the basal breadth of the cranidium and is 
bounded by broad, shallow axial furrows. The glabella carries a small tubercle 
slightly in front of centre and in-line with a pair of slight indentations in the sides 
of the glabella. One specimen (PI. 1, fig. 1) shows these indentations linked to the 
median tubercle by shallow furrows which form a chevron, apex directed forwards, 
but it is not clear whether they are primary structures because similar furrows, 
almost certainly the result of crushing, diverge forwards from the median tubercle. 
The hindmost portion of the cranidium is imperfectly preserved but there are traces 
of a pair of subtriangular occipital lobes comparable with those found in other species 
of Geragnostus. Though incomplete, an otherwise broad border becomes slightly 
narrower posterolaterally and is delimited by a broad border furrow. 

The pygidium is strongly arched both longitudinally and transversely, has a 
maximum breadth slightly greater than the median length and is semiellipitical in 
plan. The anterior margin (excluding the articulating half-ring, which is missing) is 
transversely straight medially but then runs backwards slightly to the articulating 
facets ; these are bounded by furrows that coalesce with the lateral border furrow, 
which in turn delimits a narrow border. As far as can be seen, there are no postero- 
lateral border spines, but this part of the exoskeleton is imperfectly preserved. The 


AND FAUNAS OF THE TAURUS MOUNTAINS, II 7 


frontal breadth of the axis is equal to half, its median length about five-sixths, that 
of the pygidium. The frontal two-fifths of the axis is composed of two unequal axial 
rings, the anterior of which is slightly the smaller. The median quarter or so of this 
part of the axis is occupied by a longitudinal structure, formed by the fusion of the 
median lobes of the axial rings, and the posterior half was probably produced dorsally 
to form a blunt spine, judging by the broken surface remaining. The ring furrows 
curve forwards gently at inner and outer ends, and both they and the axial furrows 
are deep and broad. The remainder of the axis is poorly defined and the axial 
furrows are scarcely discernible, though they can be seen to curve gently to the 
semielliptical tip, just in front of which is a small median tubercle (see PI. 1, fig. 8). 
The posterior portion of the axis carries traces of a number of small pits like those 
on the pygidium of Glyptagnostus as described and figured by Opik (1961, text-figs 
15, 16) who termed them muscle spots. Apparently similar structures behind the 
pygidial axis of Galbagnostus have been described as muscle pits by Whittington 
(1965 : 308). 

Discussion. The cephalon of the new species has no obviously distinctive features 
to separate it from approximately contemporaneous members of Geragnostus, such as 
G. occitanus Howell (1935 : 231 ; see also Dean 1966 : 274) from the lower Arenig 
Series of southern France. The latter species has a distinctive pygidial axis in which 
the anterior, segmented portion is relatively much larger than that of G. lycaonicus. 
The axial furrows of the pygidium of G. occitanus display considerable variation and 
may become completely effaced. There is insufficient material of the new species to 
test for such variation, but similar effacement of the axial furrows affects only the 
posterior half of the pygidial axis of G. lycaonicus. In this respect it resembles G. 
tullbergi (Novak), from the Llanvirn Series of Bohemia (see Dean 1966 : 273) but the 
latter species may be readily distinguished by its narrower, slightly shorter axis with 
a proportionately smaller segmented portion of the axis. G. tullbergi was made the 
type species of Geragnostella Kobayashi 1939, to which G. lycaonicus would at one 
time have been assigned, but this genus has since been placed in the synonymy of 
Geragnostus. 

The pygidium of G. lycaonicus shares some features—the form of the axial rings, 
the small median tubercle, and the undefined posterior portion of the axis—with that 
of G. ? explanatus Tjernvik (1956 : 193, pl. I, figs. 13, 14), from the Lower Arenig of 
Sweden, but the Swedish species is distinguished by its wider border. 


Family RAPHIOPHORIDAE Angelin, 1854 
Genus AMPYX Dalman, 1827 


TYPE SPECIES. Ampyx nasutus Dalman, 1827. 


Ampyx ? sp. 
Pl. 1, fig. 5 


FIGURED SPECIMEN. BM. It.8658. 


8 LOWER PALAEOZOIC STRATIGRAPHY 


LOCALITY AND HORIZON. Locality C.543, 4:5 kms south of Kizilca, and in the 
upper half of the Seydisehir Shales. 


DESCRIPTION. A small, poorly-preserved cranidium approximately 5 mm wide 
is the only representative of the Raphiophoridae yet known from the Seydisehir 
Shales. The fixigenae are convex, almost quadrant-shaped in plan, and the narrow 
(exsag.) posterior border, separated from the fixigenae by a deep, broad (exsag.) 
posterior border furrow, curves gently forwards abaxially. There is a faint sug- 
gestion of wrinkle-like ornamentation on the test of the left fixigena. The glabella is 
broken but the remains of the external mould suggest that it was relatively short and 
extended only a little way in front of the fixigenae. 

Although detailed comparison of such inadequate material is not possible, perhaps 
the closest raphiophorid is Ampyx ? villebvunt Thoral (1935 : 307) from the Arenig 
Series of St. Chinian, southern France. In an earlier paper (Dean, 1966 : 281) it was 
suggested that the affinities of Thoral’s species lie with Ampyxina, and the same may 
be true of the Turkish specimen. 


- Family CALYMENIDAE Edwards, 1843 
Subfamily COLPOCORYPHINAE Hupé, 1955 
Genus COLPOCORYPHE Novak in Perner, 1918 


TYPE SPECIES. Calymene arago Rouault, 1849. 


Colpocoryphe sp. 
Pl.1, figs: 2,19, 10 


FIGURED SPECIMENS. BM. It.7994 (PI. 1, figs. 2, 5), It.7995 (PI. 1, figs. 9, 10). 


LOCALITY AND HORIZON. Sobova Valley, locality B.650, in the highest strata of 
the Seydisehir Shales, and about 33 metres below the summit of the Seydisehir 
Formation. 


DESCRIPTION. Two incomplete cranidia were found, both of which exhibit the 
bifid, ventrally-directed prolongations of the anterior border which have been inter- 
preted as vincular structures (Dean, 1966 : 308 ; 1966a : 135). The more completely- 
preserved glabella has straight sides which converge forwards at about 30 degrees ; 
the anterior margin of the frontal glabellar lobe is slightly concave forwards, whilst 
the posterior margin of the glabella is transversely straight. There are three pairs of 
glabellar lobes ; the Ip and 2p pairs are almost equisized in Pl. 1, fig. 2, but those of 
Pl. 1, fig. 10 are markedly unequal and perhaps less distorted. The 3p lobes and 
frontal glabellar lobe are of approximately equal length and about two-thirds the size 
ofthe 1pand zp lobes. Small, incomplete palpebral lobes are positioned opposite the 
2p furrows and the anterior part of the rp lobes. 

Only one other species of Colpocoryphe of Arenig age is known, C. thorali Dean 
(1966 : 304) from the Extensus Zone of southern France. The latter differs from 


AND FAUNAS OF THE TAURUS MOUNTAINS, II 9 


the Turkish form in having a bell-shaped glabellar outline that is slightly constricted 
in front of the 2p glabellar lobes, a conspicuously longer frontal glabellar lobe, and 
less well-defined 2p and 3p glabellar furrows. 


Subfamily SYMHOMALONOTINAE Kobayashi 1960 
Genus NESEURETUS Hicks, 1872 


TYPE SPECIES. Neseuretus ramseyensis Hicks, 1872. 


Neseuretus sexangulus sp. nov. 
Pint, fiesy6; a1, 12 


Diacnosis. Neseuretus with hexagonal glabellar outline, the sides parallel as far 
as 2p glabellar furrows but then converging forwards strongly to transversely straight 
frontal glabellar lobe. 1p and 2p glabellar furrows well developed ; traces only of 3p 
furrows. Swollen anterior border about one-fifth length of cranidium. Eyes set 
well forwards, opposite 3p glabellar lobes. Posterior portions of fixigenae relatively 
large. 


HoLotyPe. BM. It.7996. 


LOCALITIES AND HORIZONS. The holotype is from locality C.216, about 8 kms 
north-west of Seydisehir. A fragmentary cranidium at locality C.312, 6 kms west of 
Seydisehir, may represent the same species but is too poorly preserved for certain 
identification. Both localities are in the upper half of the Seydisehir Shales. 


DEscRIPTION. The distinctive cranidium is preserved as an internal mould. 
Although the fixigenae are slightly distorted, it is calculated that the median length 
of the specimen is approximately three-fifths of the maximum breadth, measured 
across the genal angles. The glabella, excluding occipital ring, is roughly hexagonal 
in outline, almost as long as wide, with subparallel sides extending forwards as far as 
the 2p glabellar furrows. In lateral view the glabella is of low convexity, and when 
viewed anteriorly the dorsal surface appears slightly flattened (see Pl. 1, fig. 11). 
The median third of the posterior margin of the glabella is transversely straight, set 
slightly in front of the outer thirds which form gentle curves, concave forwards, 
around the bases of the rp glabellar lobes. The anterolateral margins are almost 
straight and converge forwards at about 75 degrees so that the anterior margin, which 
has a slight median indentation, is equal to half the glabellar breadth. The main 
portion of the glabella, behind the convergent anterolateral margins, is divided into 
two pairs of glabellar lobes by deep glabellar furrows. The rp lobes are slightly the 
largest and occupy one-third of the total glabellar length; they have the “cat’s ear”’ 
outline found commonly in calymenaceids and are delimited anteriorly by deep, 
conspicuous Ip glabellar furrows that run inwards and back, expanding slightly at 
their inner ends but terminating so as to leave an unfurrowed median band one-third 
the breadth of the glabella. The 2p lobes are parallel-sided, bounded anteriorly by 
straight 2p glabellar furrows which diverge forwards at about 130 degrees. The 2p 


10 LOWER PALAEOZOIC STRATIGRAPHY 


furrows end adaxially in-line with the 1p furrows, whilst abaxially they become 
markedly shallow immediately before intersecting the axial furrows. The glabella 
in front of the 2p furrows forms an almost continuous structure, with only a pair of 
faint indentations to suggest the position of 3p glabellar furrows. The axial furrows 
are subparallel, deep and narrow as far forwards as the 2p glabellar furrows, where 
they become slightly broader and shallower. The median third of the occipital ring is 
parallel-sided, and the corresponding portion of the occipital furrow is shallow, but 
abaxially the furrow becomes conspicuously deeper and curves forwards around the 
bases of the Ip glabellar lobes. At the same time the occipital ring narrows markedly 
and ends in a poorly-defined pair of occipital lobes, the tips of which extend forwards 
adjacent to the basal part of the rp lobes. The anterior border, although slightly 
damaged, is evidently characteristic for the genus, swollen medially, separated from 
the glabella by a broad, shallow furrow and from the fixigenae by still broader 
furrows. The eye lobes are small, sited well forwards opposite the 3p lobes and at a 
distance outside the axial furrows equal to one-third the breadth of the glabella. The 
proportion of the fixigenae behind the eyes is thus relatively large for the genus. The 
remainder of the exoskeleton is unknown. 


Discussion. Whittard (1960 : 138 et seg.) has described the type and other 
species of Nesewretus from the Shelve Inlier of Shropshire and various parts of Wales. 
All, save one atypical species which should probably be excluded from the genus, are 
of Arenig age. In each case the combined anterior border and preglabellar furrow 
are appreciably longer than those of the Turkish species, and the latter differs also in 
the marked convergence of the axial furrows in front of the 2p glabellar furrows. 
Neseuretus arenosus Dean (1966 : 313) from the lower Arenig Series of southern 
France has generally similar glabellar proportions but is distinguished by the less 
angular outline of the front of the glabella, the smaller fixigenae, and the apparently 
less convex anterior border. The type species of Neseuretus, N. ramseyensis Hicks 
from the Lower Arenig of Wales (see Bates, 1969 : 22) has a more rounded glabellar 
outline and less distinct glabellar furrows than the Turkish species. N. parvifrons 
(M’Coy), also of Arenig age in Wales (Bates, 1969 : 26 ; Whittington, 1966 : 500), is 
distinguished by having a larger anterior border, and a glabellar outline that is more 
evenly convergent forwards. In both these species the posterior halves of the 
fixigenae are conspicuously smaller than those of N. sexangulus. 


Neseuretus ? sp. 
Pl..2;-fig. 9 

A single fragmentary pygidium, preserved as an internal mould, has the anterior 
margin strongly convex forwards, whilst the posterolateral margins are straight, and 
diverge forwards at about 130 degrees. The left and sole surviving side-lobe is 
smooth for the most part but has two pleural ribs and a trace of a third rib in addition 
to the articulating facet and anterior half-rib. The ribs are delimited by shallow 
pleural furrows which cross only two-thirds of the side-lobe so as to leave a broad, 
smooth border. The axis extends to within a short distance of the pygidial tip and is 
infundibular in plan, with a marked break in outline behind the third axial ring. 


AND FAUNAS OF THE TAURUS MOUNTAINS, Il II 


There are five well-defined axial rings and a sixth less well defined, followed by a small 
terminal piece with semielliptical tip. The ring furrows are transversely straight and, 
apart from the first two, do not quite attain the broad, shallow axial furrows. 

A similar axial outline has been described by Whittard (1960 : 142, 146) for 
Neseuretus grandior and N. brevisulcus, both from the Extensus Zone of the Arenig 
Series in the Shelve Inlier. In each case, however, the pygidial axis is parallel-sided 
behind the seventh axial ring, compared with the third ring in the Turkish form. 
The relative smoothness of the side-lobes, though it does not exclude the specimen 
from Neseuretus, is perhaps more suggestive of Colpocoryphe, but lack of the character- 
istic vincular furrows argues against such an identification. For the present I 
prefer to assign the pygidium questionably to Neseuretus. 


FIGURED SPECIMEN. BM. It.8o0or. 


LOCALITY AND HORIZON. Sobova Valley, locality B.650, in the highest portion of 
the Seydisehir Shales. 


? Family CHEIRURIDAE Salter 1864 
Cheirurid ? gen. et sp. indet. 


Pi 2 ies. 25 
FIGURED SPECIMEN. BM. It.8000. 


LOCALITY AND HORIZON. Loc. C.160, about 5:5 kms west of Seydisehir, in the 
upper half of the Seydisehir Shales. 


DESCRIPTION. A single, incomplete, poorly-preserved glabella of unusual type, 
with a fragment of the anterior border, is the only available, if doubtful, evidence for 
cheirurid trilobites in the Seydisehir Shales. The glabella is of inflated form, 
elliptical in plan, with breadth just over four-fifths of the maximum length. In 
lateral view the glabellar outline is tumid, strongly arched-down frontally, and there 
is evidence of at least two pairs, with a suggestion of a third pair, of glabellar furrows, 
preserved as narrow, lightly-impressed lines on the internal mould. Glabellar 
furrows interpreted as the Ip pair arch adaxially backwards towards, though they do 
not reach, the occipital furrow, whilst the 2p furrows are more transverse, only 
gently curved. The pairs of glabellar lobes so delimited are of large size, each about 
three-tenths of the length of the glabella. The axial furrows were evidently broad 
and deep, overhung on their adaxial sides by the tumid glabella. Traces of the 
anterior border show it was small and narrow, separated from the glabella by a furrow 
comparable in depth and breadth with the axial furrows. Only a fragment of the 
anterior branch of the facial suture remains, and meets the anterior margin of the 
cranidium at an obtuse angle. 

It is difficult to assign such fragmentary material to a family with any degree of 
certainty, but the swollen glabella, the course taken by the glabellar furrows and the 
form of the outer portion of the anterior border suggest the Cheiruridae. Cranidia 
of this type are unusual in the Arenig Series but some comparison may be made with 


12 LOWER PALAEOZOIC STRATIGRAPHY 


forms such as Pseudosphaerexochus (Pateraspis) inflatus Poulsen (1965 : 104, pl. 9, 
esp. figs. 1-4), from the Skelbro Limestone of Bornholm. This unusually early 
representative of the genus differs from the Turkish specimen in having a glabella 
that is less tumid in cross-section, a slightly larger anterior border, and more deeply- 
incised glabellar furrows. However, it shares enough features, such as the swollen 
glabella, conspicuously arched in lateral view and elliptical in plan, the position and 
direction of the glabellar furrows, and the shape of the anterior border, to suggest a 
possible affinity. 


Family NILEIDAE Angelin, 1854 
Genus SYMPHYSURUS Goldfuss, 1843 


TYPE SPECIES. Asaphus palpebrosus Dalman, 1827. 


Symphysurus blumenthali sp. nov. 
Pl. 2, figs. 1, 3, 4, 6-8, ro ; Pl. 3, figs. 5, 6, 10 
DiaGnosis. Symphysurus with large, strongly convex glabella about four-fifths 
as broad as long, expanding slightly at front. Median tubercle developed. Large 
palpebral lobes situated just behind centre, each equal to two-fifths of glabellar 
length. Pygidium about twice as broad as long, with posterior margin strongly 
curved. Straight-sided axis clearly visible only on internal mould. 


HororyrPe. BM.- lt7oo7(Pl 2) figs x, 7; 10); 
PARATYPES. BM. It.7998 (PI. 2, fig. 3) ; It.7999 (PI 2, figs. 4, 6, 8). 


LOcALITY AND HORIZON. All the type material is from locality B.650 in the 
Sobova Valley. The specimens were collected from a thin band of weathered sandy 
limestone about 33 metres below the summit of the Seydisehir Formation. 


DESCRIPTION. The exoskeleton is known only from disarticulated cranidia and 
pygidia. The cranidium is strongly convex both longitudinally and transversely, 
with projected length about two-thirds of the breadth. The glabella is large, occupies 
just over half the maximum basal breadth of the cranidium, and its sides are 
subparallel as far as the front of the palpebral lobes, beyond which the breadth 
expands by about one-quarter. Owing to its marked convexity, the front of the 
glabella appears rounded in plan, but when viewed anteriorly the margin of the 
frontal glabellar lobe is seen to be only slightly convex sagittally (see Pl. 2, fig. 7). 
The shallow axial furrows diverge forwards gently from the back of the cranidium 
until just in front of the posterior border furrow, where they become subparallel as 
far as the front of the palpebral lobes ; they then deepen and flex gently around the 
frontal glabellar lobe. Deep, slot-like anterior pits are sited in the axial furrows 
just in front of the palpebral lobes. There is no anterior border. A conspicuous 
tubercle is situated well behind the centre of the glabella. The occipital ring is not 
differentiated anteriorly from the glabella but its posterior margin projects back- 
wards in a broad curve, with a small notch, marking the position of the axial furrows, 


AND FAUNAS OF THE TAURUS MOUNTAINS, II 13 


situated at either end, beyond which the straight posterior margins of the posterior 
border run slightly back abaxially. The eyes and librigenae have not been found, 
but large, elongated, semielliptical palpebral lobes, which lack palpebral furrows, are 
sited immediately outside the axial furrows. When the cranidium is viewed later- 
ally in its presumed life attitude, the flat upper surface of the palpebral lobes is de- 
clined forwards at about 40 degrees. When the cranidium is viewed with the 
palpebral lobes horizontal, the latter appear equal to two-fifths of the glabellar length, 
with one-fifth of the latter behind them. The anterior branches of the facial suture 
run parallel to, and immediately outside, the anterolateral margins of the frontal 
glabellar lobe and then turn adaxially through slightly more than a right-angle so as 
to meet frontally in an unbroken gentle curve. The posterior branches run out- 
wards and slightly backwards from the rear of the eyes in almost straight lines, so 
that the posterior portions of the fixigenae are small and triangular. 

The hypostoma and thorax are not known. 

The pygidium is about twice as broad as long. The anterior margin arches for- 
wards gently while the posterior margin forms a stronger, parabolic curve, so that 
the two curves meet at almost a right-angle. In both side and posterior views the 
pygidium appears moderately convex, with the top of the axis almost continuous 
with that of the side-lobes. The front of the axis has a breadth equal to one-third 
of the maximum breadth of the pygidium. The axial furrows are straight, converg- 
ing backwards gently, and both they and the ring furrows are almost obsolete on the 
external surface of the test. On the internal mould the axial furrows appear deeper 
and at least three axial rings are visible, together with a small articulating half-ring, 
but it was not possible to examine the tip of the axis. The side-lobes have a pair of 
large articulating facets, just behind each of which is a broad (exsag.), shallow pleural 
furrow, visible only on the internal mould. 

The surface of the glabella is ornamented with numerous thin, anastomosing ridges 
which form a Bertillon pattern and are subparallel to the margins of the frontal 
glabellar lobe. The surface of the pygidium is smooth. 

A pygidium (PI. 3, fig. 6) from the type locality has the axis better.defined than 
that of S. blumenthali, but is slightly crushed ; its specific position is in doubt, and it 
is termed merely Symphysurus sp. Likewise a fragmentary specimen (PI. 3, figs. 5, 
10) that shows the doublure ornamented by subparallel terrace-lines, but is too in- 
complete for determination. Another pygidium of Symphysurus (PI. 4, fig. 2) from 
the Seydisehir Shales at locality C.312 has the appropriate outline and proportions 
for S. blumenthali. but the axis appears to be better-segmented and there are traces 
of more pleural ribs. 


Discussion. A modern diagnosis and modified illustration of the type species 
of Symphysurus, Asaphus palpebrosus Dalman 1827, have been published more 
recently by Poulsen (im Moore 1959 : O 358, Fig. 267, 8). They show that the 
Swedish species differs from S. blumenthali in having a relatively shorter glabella with 
axial furrows that are more divergent forwards, and eyes set farther forwards, so that 
the posterior portions of the fixigenae are proportionately larger. The pygidium of 
S. palpebrosus has a more rounded outline and an axis that is better defined and 
perhaps shorter, though this feature is hard to assess. 


14 LOWER PALAEOZOIC STRATIGRAPHY 


The pygidium of S. blumenthali appears to be very close to that of S. angustatus 
(Sars & Boeck) from the late Tremadoc and early Arenig Series of Norway and Sweden 
(Tjernvik 1956 : 211, pl. 2, figs. 24, 25). As far as can be judged from illustrations, 
both have an axis that is well defined on the internal mould but obsolete on the outer 
surface of the test. The cephalon of S. angustatus is less tumid and has a more 
straight-sided glabella that is relatively narrower. The slight carination of the 
glabella of S. angustatus is of dubious significance. The trilobite from the early 
Ordovician of the Montagne Noire, south-western France, described originally by 
Bergeron (1895 : 478, pl. 5, figs. 6-8) as Aeglina sicardi is clearly a Symphysurus and 
is sometimes cited as a variety of S. angustatus. The glabella is slightly shorter than 
that of S. blumenthali, the median tubercle and palpebral lobes are sited farther back, 
and the front of the glabella is more convex in plan. The pygidium attributed by 
Bergeron to the species is much longer than any of those considered above, with a 
wide, concave border and long, narrow axis ; probably it does not belong to the genus. 


Family ASAPHIDAE Burmeister, 1843 


Trilobites of generalized asaphid type are represented by locally abundant frag- 
ments in the resistant, thin bands of sandy limestone in the Seydisehir Shales. Such 
remains invariably pose problems of identification, particularly when the hypostoma 
is lacking. Consequently it has rarely proved possible to give more than a tentative 
generic assignment to the material. 


Genus PARAMEGALASPIS Thoral im Jaanusson, 1956 


Type spEcIES. Megalaspis (Paramegalaspis) 1mmarginata Thoral, 1935. 


Paramegalaspis sp. 
Pls, figs. 5, 8 Opie 

FIGURED SPECIMENS. BM. It.8016 (Pl. 5, fig. 8) ; It.8019 (Pl. 5, fig. 11) ; 
It.8020 (Pl. 5, fig. 5) ; It.8021 (Pl. 5, fig. 9). 

LOCALITIES AND HORIZONS. _It.8021 is from locality C.314, in the upper half of the 
Seydisehir Shales, about 8 kms north-west of Seydisehir. The other three specimens 
are from locality B.650, in the highest beds of the Seydisehir Shales in the Sobova 
Valley, south of Beysehir. 


DEscrRIPTION. A single incomplete cranidium (PI. 5, fig. 9) has the median length 
rather more than three-quarters of the basal breadth. The glabella is poorly defined 
but as far as can be seen the breadth is about five-eighths of the median length. The 
front of the glabella is almost semicircular and the sides are parallel except behind the 
palpebral lobes, where they are slightly digergent posteriorly. The anterior portion 
of the cranidium—frontal area of Harrington, Moore & Stubblefield 7m Moore 1959 : 
O 120—shows no distinct differentiation into preglabellar field and anterior border, 
but the marginal area corresponding to the anterior border is slightly flattened, 


AND FAUNAS OF THE TAURUS MOUNTAINS, II 15 


separated from the glabella by a broad (sag.), gently depressed area which corresponds 
to the preglabellar field. The occipital ring is almost indiscernible, although faint 
traces occur near the axial furrow, and there is a small median tubercle on the 
glabella in a position estimated to be immediately in front of the obsolete occipital 
furrow. There are traces of a narrow (sag.) doublure along the posterior margin of 
the occipital ring, and an apodeme is visible at the end of the right axial furrow. The 
eyes are positioned opposite the centre, and have a length (exsag.) equal to one- 
quarter, of the combined glabella and occipital ring. The flattened palpebral lobes 
are sub-semicircular in plan with no palpebral furrows, although the internal mould 
suggests a marginal thickening of the test. The anterior branches of the facial 
suture arch forwards and out from the eyes until half-way to the margin, at which 
point they are in-line abaxially with the centres of the palpebral lobes ; they then 
curve forwards and strongly inwards to meet at a blunted obtuse angle. The poster- 
ior branches run outwards and slightly back from the eyes in a very gentle curve, 
concave forwards, for a distance equal to nearly half the breadth of the glabella, and 
then turn backwards sharply to cut the posterior margin at almost a right-angle. 
The posterior area of each fixigena so formed is small, sub-triangular in plan, and 
carries a slightly curved posterior border furrow which runs parallel to the posterior 
margin and widens (exsag.) a little abaxially. 

An almost complete left librigena (Pl. 5, fig. 8) from the same locality as the above 
cranidium shows the facial suture following a generally similar course, though the 
anterior branch appears straighter in front of the eye, perhaps due to crushing. 
The anterolateral margin is straight for the most part but becomes curved both 
frontally and, more strongly, near the genal angle, which is produced to form a 
moderately-long, slim spine, directed backwards and slightly outwards. A hypostoma 
preserved as an internal mould (PI. 5, fig. 11) shows the characteristics of the genus 
and may be compared with one illustrated as Paramegalaspis sp. from the Lower 
Arenig Series of the Montagne Noire, southern France (Dean 1966 : 3206, pl. 18, fig. 9). 
A pygidium (PI. 5, fig. 5) preserved as an internal mould and exhibiting a uniformly 
narrow doublure has generally similar proportions to material illustrated from the 
Arenig Series of the Montagne Noire, for example Paramegalaspis cf. frequens Thoral 
(Dean 1966, pl. 18, figs. 2, 10, 13). The pleural ribs of the Turkish specimen appear 
to be slightly less well defined but further comparison is difficult with so little material. 


Discussion. According to the Treatise on Invertebrate Paleontology (Jaanusson 
in Moore 1959 : O 349) Paramegalaspis has no border on either cephalon or pygidium ; 
the frontal area is 0-2 to 0:25 of the cephalic length ; librigenal spines are present ; 
and the pygidium has a flattened axis and a narrow doublure. Material from the 
type area in southern France has been shown to exhibit a small amount of cephalic 
variation so that the anterior border may be moderately well defined (Dean 1966 : 
326) or almost obsolete, as is the case for the Turkish cranidium now figured. 
Jaanusson (loc. cit.) claimed Dolerasaphus, type species D. laevis Harrington & 
Leanza (1957 : 157), as a synonym of Paramegalaspis, but the illustrations of D. 
laevis show that it, like the Turkish cranidium now described, has a frontal area which 
occupies slightly less than the 0-2 to 0-25 of the cephalic length stipulated in the 
Treatise. Such small differences are probably not valid at generic level, particularly 


16 LOWER PALAEOZOIC STRATIGRAPHY 


when one is dealing with compressed specimens, and Dolerasaphus shows no other 
significant differences from Paramegalaspis as generally interpreted, though the 
hypostoma has not yet been described. 


Genus MEGISTASPIS Jaanusson 1956 


TYPE SPECIES. Tvilobites limbatus Boeck, 1838. 


Megistaspis sp. 
Pl. 3, fig. 8 ? 3 Ply) fig, 55 Biss fies. 1 304, 6,520 


FIGURED SPECIMENS. BM. It.8007 (PI. 3, fig. 8); It.8013 (Pl. 4, fig. 5) ; It.8014 
(PI. 5, fig. 1) ; It.8015 (Pl. 5, figs. 3, 4, 6) ; It. 8017 (PI. 5, fig. ro). 


LOCALITIES AND HORIZONS. In the area north-west of Seydisehir the genus was 
collected at localities C.310, 312 and, most commonly, C.314, all of them in the upper 
half of the Seydisehir Shales. It was found less commonly in the highest part of the 
shales at B.650, in the Sobova Valley. Fragments referred questionably to the 
genus were obtained at localities C.319 and C.320 in the Upper Greywackes. 


DESCRIPTION. Several fragmentary pygidia have been collected which corre- 
spond to the generic diagnosis given by Jaanusson (im Moore 1959 : O 347). The 
largest pygidium (PI. 5, fig. 10) is parabolic in plan, gently convex both longitudin- 
ally and transversely, with median length about five-sixths of the maximum breadth 
as measured across the anterolateral angles. The front of the axis of this specimen 
is more than one-third of the maximum breadth of the pygidium, and the sides are 
straight, converging backwards at approximately 25 degrees to the indistinct tip. 
The whole axis, excluding the small articulating half-ring, occupies four-fifths of the 
pygidial length. The axial furrows are broad, shallow and for the most part poorly 
defined on the outer surface, so that the distinction between axis and side-lobes is not 
clear except frontally. The side-lobes are of low convexity, with large facets cutting 
obliquely across the abaxial halves of the anterior half-ribs. There is almost no 
trace of other furrows and the pygidium is bounded by a broad (ér.) border which 
becomes still broader (sag.) between the axis and the tip of the pygidium. 

The above remarks apply only to the largest pygidium, and one of the best- 
preserved smaller specimens (PI. 5, figs. 3, 4, 6) shows slight differences. For example 
the length is about nine-tenths of the maximum breadth, though such proportions 
have been affected to a certain degree by compression, particularly in the large 
specimen noted above. Certainly the axis and side-lobes of the smaller pygidium 
show more evidence of segmentation, and some of the pleural ribs have traces of 
interpleural furrows (see also specimen It.8014, Pl. 5, fig. 1). The doublure appears 
to correspond in size to the smooth border. This pygidium (It.8015) is preserved as 
an internal mould and a partly-exfoliated smaller specimen (PI. 4, fig. 5) is of par- 
ticular interest as it demonstrates the lack of furrows on the outer surface of the test, 
while the internal mould shows evidence of ten axial rings and at least seven pairs of 
pleural ribs. 


AND FAUNAS OF THE TAURUS MOUNTAINS, II 17 


No corresponding cranidium has yet been found, but an incomplete right librigena 
(Pl. 3, fig. 8) is questionably referred to Megistaspis?. The genal angle is produced to 
form a short, sharp spine and part of the test is missing so as to reveal the narrow 
doublure. A fragment of another right librigena (Pl. 5, figs. 2, 7) represents one of 
the largest trilobite remains found in the Seydisehir Shales. It is unusually deep 
anteriorly and the ventral side shows conspicuous ridge-like structures running at 
right angles to the margin. The incomplete anterior branch of the facial suture 
suggests Megistaspis rather than any of the other asaphid genera found in the area, 
but the material is insufficient for certain identification. 

Megistaspis (Megistaspidella) of Jaanusson (1956: 71; im Moore 1959 : 348, 
Fig. 259, 3) has a broadly similar pygidium but the tip is slightly more pointed and 
the side-lobes and axis are smooth, except for two axial rings. The type species, 
Entomostracites extenuatus Wahlenberg 1821, was figured also by Schmidt (1906, pl. 7, 
figs. I, 2a, 3a) whose illustrations of the pygidium show it to be very like the Turkish 
specimens, though the border is more concave and wider near the bluntly pointed tip. 


Genus PTYCHOPYGE Angelin, 1854 


TYPE SPECIES. Asaphus angustifrons Dalman, 1827. 


Ptychopyge sp. 
Pl. 4-figs. 7, 8° 

In 1964 Balashova erected a new subfamily Ptychopyginae and included therein 
the type genus and three new genera, Metaptychopyge, Paraptychopyge and Pseudopty- 
chopyge. The present scanty material from the Seydisehir Shales does not lend 
itself to such detailed treatment and the specimens are referred merely to Ptychopyge 
sensu lato. 

An isolated hypostoma (Pl. 4, fig. 7) from locality C.310 lacks the anterior wings 
but the maximum breadth, measured across centre, is three-quarters of the median 
length. The median body is moderately convex, occupies slightly more than 
three-quarters of the median length of the hypostoma, and is an elongated ellipse 
in plan, two-thirds as broad as long. It is divided into two unequal lobes by a 
median furrow which becomes almost effaced medially, runs in a gentle curve, convex 
forwards, and forms deep notches at either end. The crescentic posterior lobe so 
formed occupies about one quarter of the length (sag.) of the median body. The 
front of the hypostoma is incompletely preserved, but the lateral border starts 
opposite the middle of the anterior half of the median body, and the lateral margins 
are gently convex abaxially. The lateral border is continuous with the posterior 
border, but the latter is broader (exsag.), slightly flattened, and has a short, narrow 
median notch. The border is separated from the median body by a broad, shallow 
border furrow. The overall appearance is similar to that of the hypostoma of 
Ptychopyge angustifrons (Dalman) (see Jaanusson 7m Moore 1959 : O 339, Fig. 250, 2c) 
but differs in having a narrower lateral border, whilst the posterior lobe of the 

B 


18 LOWER PALAEOZOIC STRATIGRAPHY 


median body is slightly longer and better differentiated. One may also compare the 
hypostoma of Ptychopyge lesnikovae Balashova (1964, pl. 1, fig. 6) but the latter has a 
slightly larger, more pointed median notch and the posterior lobe of the median body 
is almost continuous with both the anterior lobe and the posterior border. 

The pygidium from locality C.312a@ questionably assigned to Ptychopyge (Pl. 4, 
fig. 8) is subparabolic in plan, has a low convexity and a maximum breadth rather 
more than one and a half times the median length. The axis has a frontal breadth 
equal to two-sevenths that the pygidium and extends back for more than four-fifths 
of the pygidial length; in plan it has a slightly infundibular appearance owing to the 
converging of the sides at about 30 degrees for half the length, followed by their 
running parallel to the rounded tip. There are four rings on the anterior half, 
followed by two faint additional rings, and the rest of the axis is smooth. Outside 
the broad, shallow axial furrows are flattened side-lobes which merge imperceptibly 
with a smooth, concave border that widens posteriorly. The inner portion of the 
side-lobes is lightly furrowed with five pairs of ribs in addition to the anterior half- 
rib ; each rib, in turn, carries a faint interpleural furrow which divides it into anterior 
and posterior half-ribs, the latter slightly the larger. The furrowing of the pleural 
ribs is a feature not usually found in Ptychopyge, though it can occur in related genera 
as shown by the internal mould of a pygidium of Metaptychopyge truncata Nieszkowski 
sp. (Balashova 1964, pl. 8, fig. 7), the external surface of which exhibits smooth ribs. 


Asaphid gen. et sp. undetermined 


Pls 3) Migs, 12,045 7,10, Lk Plates, 35e4Oy G 
FIGURED SPECIMENS. BM. It.8002 (Pl. 3, figs. 1, 9, 11), It.8003 (Pl. 3, figs. 
2, 4, 7), It.8008 (PI. 4, figs. 1, 3, 4), It.8010 (Pl. 4, figs. 6, 9). 


LOCALITIES AND HORIZONS. Localities C.310 and C.312a, both 6 kms west of 
Seydisehir and in the upper half of the Seydisehir Shales ; also locality B.650 in the 
Sobova Valley, where it forms part of the highest Seydisehir Shales. 


DESCRIPTION. Certain asaphid fragments exhibit characters which exclude them 
from the other genera so far recorded from the Beysehir region but are inadequate 
for generic assignment. No undistorted cranidium has been found, but a well- 
preserved left librigena (Pl. 3, figs. I, 9, II) gives useful information regarding the 
course of the facial suture and the position of the eye. The palpebral lobe is semi- 
circular in outline, positioned relatively far forwards so that the projected length of 
the cephalon in front of the eye is 0-34 of the estimated median length. The length 
of the eye is 0.28 that of the cephalon. From this and other specimens the facial 
suture is seen to be of isoteliform type, with the anterior branches meeting frontally 
at an obtuse angle. There is a weakly-developed, low anterior border, bounded by a 
shallow furrow which curves evenly backwards abaxially to meet the lateral margins 
immediately in front of the conspicuous, broadly-rounded genal angles. Pl. 4, 
figs. 6, 9 shows another left librigena of apparently the same type but with part of 
the test removed to reveal the doublure, which is narrow, dorsally concave, except at 
its inner margin where it becomes slightly reflexed, and ornamented with closely- 
spaced, subparallel terrace-lines. 


AND FAUNAS OF THE TAURUS MOUNTAINS, II 19 


No corresponding cranidium has been found well preserved. PI. 3, fig. 4 shows the 
glabella and occipital ring to be continuous, bounded by broad, shallow, almost 
parallel axial furrows. The dorsally flattened palpebral lobes are slightly inclined 
abaxially, and are situated close to the sides of the glabella. Traces of a shallow 
furrow circumscribing the front of the glabella suggest the presence of an anterior 
border. 

Only six segments of the thorax have been found preserved (PI. 4, figs. 1, 3, 4) and 
are of asaphid type, with a broad, flattened axis occupying more than one-third of 
the breadth. The conjoined cephalon resembles the material already noted but the 
front is distorted by crushing. 


Discussion. The material agrees in most respects with specimens attributed to 
Paramegalaspis, as well as the type species of its subjective synonym Dolerasaphus. 
The latter (Harrington & Leanza 1957 : 157) was stated to have no anterior border, 
but was founded on only a single specimen. As noted earlier, this feature has been 
described as slightly variable in Paramegalaspis and consequently the anterior 
border alone should not exclude the Turkish specimen from the genus. However, a 
conspicuous feature of the present material is its possession of broadly-rounded genal 
angles, a character found in such genera as Asaphus, in which the glabellar lobation is 
quite different, and Asaphus (Neosaphus), the type species of which has the eyes set 
much farther back (Jaanusson in Moore 1959 : O 336), though other species attributed 
to the latter subgenus may have the eyes set farther forwards and possess librigenal 
spines (see Jaanusson 1953). Rounded genal angles have not been reported from 
Paramegalaspis or similar forms, but crushing and the fragmentary nature of the 
material from the Seydisehir Formation preclude more detailed comparison, and in 
the circumstances I prefer not to make a definite generic assignment. 


Family TAIHUNGSHANITIDAE Sun, 1931 
Genus TAIHUNGSHANIA Sun, 1931 


TYPE SPECIES. T. shut Sun, 1931. 


Taihungshania sp. 
Riva ties 3 
FIGURED SPECIMEN. BM. It.8004. 


LOCALITY AND SPECIMEN. Locality C.543, 4:5 kms south of Kizilca and in the 
upper half of the Seydisehir Shales. 


DESCRIPTION. The genus is represented in the Beysehir region by a single incom- 
plete pygidium which lacks both the posterior part of the axis and the posterior 
margin, but is estimated to have been approximately three-quarters as long as wide. 
The axis has straight sides, bounded by shallow axial furrows which converge back- 
wards at about fifteen degrees. Only the anterior half of the axis is preserved, on 
which there are six axial rings of uniform width (sag.), separated by shallow, trans- 


20 LOWER PALAEOZOIC STRATIGRAPHY 


versely straight ring furrows. The right side-lobe only is preserved and has six well- 
defined ribs and traces of two further ribs. The anterior half-rib is transversely 
straight for about one-third of its length (¢.) as far as a well-defined fulcrum, but 
then turns back through about forty-five degrees and is bounded anterolaterally by a 
large facet. From front to rear of the pygidium the ribs become progressively more 
strongly directed backwards, each rib being parallel-sided for half its length (é.) but 
then turning backwards and tapering before dying-out. The angle through which 
the ribs turn backwards becomes progressively less from front to rear of the pygidium, 
and those of the fifth pair are almost straight. The first three ribs extend across 
about three-quarters of the breadth of the side-lobe and then almost die out towards 
the pygidial margin. Although, according to Jaanusson (im Moore 1959 : 356), there 
is no pygidial border in Tathungshamia, nevertheless the specimen shows what appears 
to be a true, almost smooth border which becomes broader towards the tip of the 
pygidium. The pygidium of the type species 7. shut Sun (10931, pl. 2, figs. Ia, b) 
appears to be generally similar, though with more pleural ribs, and the supposed 
absence of a border may be more apparent than real owing to the state of preservation. 
The portion of the border in-line with the third rib is slightly swollen and the margin 
there is produced backwards to form a spine which is only partially preserved. Most 
of the surface of the test is smooth, but that of the axial rings and the posterior bands 
of the ribs is pitted. Similar pitting occurs also in the first two pleural furrows. 


Discussion. In the Montagne Noire, southern France, Tathungshania [Miquelina| 
muqueli (Bergeron) has been used as an index fossil for part of the Extensus Zone of 
the Arenig and has been recorded from China by Sheng (1958 : 192). The pygidium 
of T. miqueli was refigured by Dean (1966, pl. 16, figs. 3, 4), and differs from that of 
the present specimen in having a narrower axis and a greater number of ribs, as well 
as a narrower border upon which the pleural furrows are slightly more impressed. 
Tathungshania landayranensts (Thoral), also from the Lower Arenig of the Montagne 
Noire (Dean, 1966 : 331-332, pl. 16, fig. 7), has a number of ribs broadly comparable 
with that of the Turkish specimen but relatively smaller side-lobes. 


III. AGE AND RELATIONSHIPS OF THE TRILOBITES 


A generalized section through the Seydisehir Formation is given below (Fig. 3) 
together with the estimated stratigraphic levels of the principal localities known at 
present in the Seydishir-Sobova region (see Fig. 1). It must be emphasized that in 
strata of this type, which have undergone a considerable amount of folding, the 
horizons given can be no more than approximations. 

The trilobites of the Seydisehir Formation, although relatively sparse, show un- 
mistakable evidence of belonging, at least in part, to what has been termed variously 
the Calymenid—Trinucleid Province or the Selenopeltis—Fauna (Whittington 1966a). 
These names are sometimes difficult to apply owing to lack of the eponymous trilobite 
groups and I prefer to use the term Tethyan Province or Fauna (Dean 1967). Geo- 
graphically the Tethyan faunal province has been shown to have extended westwards 
from the Mediterranean to encompass the Anglo-Welsh area, south-east Newfound- 
land and Florida, if not still farther. To the east it extended at least as far as south- 
west China during Arenig times and probably beyond, into Australia. 


AND FAUNAS OF THE TAURUS MOUNTAINS, II 21 


The trilobite families and genera characteristic of the Mediterranean part of the 
Tethyan region during the early Ordovician are Asaphidae (Paramegalaspis, Plesiome- 
galaspis), Colpocoryphidae (Colopocoryphe), Synhomalonotidae (Neseuretus) [these 
two families are sometimes regarded as subfamilies of the Calymenidae], Taihung- 


JURASSIC & TRIASSIC LSTS 


Upper { 
Giiywackese> 


SOBOVA 
FM 
S 


SEYDISEHIR 
SHALES 
> 1000m 


ORDOVICIAN 
SEYDISEHIR FM 


CAMBRIAN 
CAL 
TEPE FM 


Fic. 3. Composite stratigraphical column for the Ordovician and adjacent rocks of the 
Beysehir-Seydisehir district, showing the approximate horizons of fossil localities in the 
Seydisehir Shales and Upper Greywackes. C.309 and C.543 have been omitted owing to 
even greater uncertainty regarding their horizon, though it is undoubtedly in the upper 
half of the Seydisehir Shales. 


shaniidae (Tathungshania) and Trinucleidae (Myttonia, Hanchungolithus). Of these 
the trinucleids, so useful in Ordovician stratigraphy, have unfortunately not yet 
been found in the higher Seydisehir Shales, but all the other families and most of 
the genera are represented, though never in large numbers. Other genera are present 


22 LOWER PALAEOZOIC STRATIGRAPHY 


which, as noted later, support Whittington’s (1966a) contention that the boundaries 
between Ordovician faunal provinces are sometimes difficult to draw. The few 
graptolites found at C.206 and C.310 (see Fig. 2) indicate an Arenig age (Toghill im 
Dean & Monod, 1970) and supplement the evidence provided by the trilobites. 

In a previous paper (Dean & Monod 1970) preliminary lists of trilobite identifica- 
tions were given for the known fossiliferous localities in the Seydisehir Formation. 
The foregoing descriptions enable a series of revised faunal lists to be compiled, as 
follows: 


Locality B.650. Asaphid gen. et sp. undetermined, Colpocoryphe sp., Geragnostus 
lycaonicus sp. nov., Megistaspis ? sp., Neseuretus ? sp., Para- 
megalaspis sp., Symphysurus blumenthali sp. nov., Symphysurus 
sp. 

Locality C.160. Cheirurid ? gen. et sp. indet., Pavamegalaspis ? sp. 

Locality C.216. Neseuretus sexangulus sp. nov., Parvamegalaspis sp. 

Locality C.309. Paramegalaspis sp. 

Locality C.310. Asaphid gen, et sp. undetermined, Megistaspis ? sp., Ptychopyge 
sp. 

Locality C.311. Paramegalaspis sp. 

Locality C.312. Megistaspis sp., Neseuretus? sp., Paramegalaspis sp., Sym- 
physurus sp. 

Locality C.312a. Asaphid gen. et sp. undetermined, Pavamegalaspis sp., Pty- 
chopyge ? sp. 

Locality C.314. Asaphid gen. et sp. undetermined, Megistaspis sp., Para- 
megalaspis sp. 

Localities C.319 

SaiC 7320. Asaphid fragments, possibly Megistaspis sp. 

Locality C.543. Ampyx ? sp., Tathungshania sp. 


Upper Cambrian and Tremadoc strata have not been found in this region, and the 
nature of the Cambrian—Ordovician boundary is not yet known. Certainly there 
are some hundreds of metres of clastic sediments lying between undoubted Middle 
Cambrian and Arenig strata, but so far there is no evidence for their age. The lower 
half, at least, of the Seydisehir Shales has not yet yielded identifiable fossils and the 
lowest fossiliferous horizon, at locality C.210, produced only unidentifiable fragments 
of uncertain affinities. Probably the oldest trilobites collected from the shales are 
from the upper part of the succession at C.160, where the Tethyan genus Paramegal- 
aspis is accompanied by a cheirurid which, though unidentifiable, nevertheless 
represents a group that is more Baltic than Tethyan in aspect, a suggestion that 
receives some support from the few brachiopods at the same locality. 

The small sample from C.543 is of particular interest as it includes the only specimen 
of Tathungshania yet known from the Seydisehir Shales. Although the latter is not 
identical with any of the species described from southern France or south-west 
China, it is accompanied here by a small raphiophorid apparently allied to Ampyx ? 
villebrunt, described by Thoral from the Arenig Series of the Montagne Noire. 

One of the youngest trilobite faunas, and also the most prolific, from the Seydisehir 


AND FAUNAS OF THE TAURUS MOUNTAINS, II 23 


Formation was collected at B.650 in the Sobova Valley, about 33 metres below the 
base of the overlying Sobova Limestone. Colpocoryphe and Neseuretus are typical 
Tethyan elements, and both genera had a long vertical range there, from Lower 
Arenig to Caradoc Series. Colpocoryphe is essentially a western Tethyan form, 
extending westwards to Florida and eastwards to Turkey but Neseuretus is more 
widespread in an easterly direction and is well known from the Lower Ordovician of 
south-west China. The Gevagnostus present belongs to a group of species found 
particularly in the Arenig and Llanvirn of the Mediterranean region and Bohemia. 
At least three asaphid genera are present, and although Pavamegalaspis is again of 
Tethyan type, Megistaspis and Symphysurus are northern European forms. The 
presence of Symphysurus at this point in the succession foreshadows the even greater 
abundance of the genus, together with additional Baltic elements, in the Sobova 
Limestone, and suggests at least a temporary break in the relatively uniform 
Tethyan Lower Arenig faunas, accompanied by the establishment of new faunal 
links with the Baltic region and Scandinavia. 


IV. REFERENCES 


BarasHova, E. A. 1964. Morphology, phylogeny and stratigraphical significance of the early 
Ordovician subfamily Ptychopyginae of the Baltic area. Vopvosy Paleont., Leningrad, 
4 : 3-56, pls 1-9, 3 tables [In Russian]. 

Bates, D. E.B. 1969. Some early Arenig Brachiopods and Trilobites from Wales. Bull. Br. 
Mus. nat. Hist., Geol., 18 : 1-28, 9 pls. 

BERGERON, J. 1895. Notes paléontologiques. Crustacés. Bull. Soc. géol. Fr., Paris, (3) 23 : 
405-481, pls 4, 5, 

Dean, W. T. 1966. The Lower Ordovician stratigraphy and trilobites of the Landeyran 

Valley and the neighbouring district of the Montagne Noire, south-western France. Bull. 

Br. Mus. nat. Hist., Geol., 12 : 245-353, 21 pls. 

1966a. A revision of the Ordovician Trilobite genus Plaesiacomia Hawle & Corda. Sb. 

nay. Mus. Praze, 22B : 133-142, 3 pls. 

1967. The distribution of Ordovician shelly faunas in the Tethyan region. Im “‘ Aspects 

of Tethyan Biogeography ”’, Publs Syst. Ass., London, 7 : 11-44, 5 figs. 

& Monon, O. 1970. The Lower Palaeozoic stratigraphy and faunas of the Taurus 

Mountains near Beysehir, Turkey. I. Introduction to Stratigraphy. Bull. Br. Mus. nat. 
Hist., Geol., 19: 413-426. 

HARRINGTON, H. J. & Leanza, A. F. 1957. Ordovician Trilobites of Argentina. Univ. 
Kansas, Lawrence, Dept. Geol. Spec. Pub., 1 : 1-276, 140 figs. 

Howe tt, B. F. 1935. Cambrian and Ordovician trilobites from Hérault, southern France. 
J. Paleont., Menasha, 9 : 222-238, pls. 22, 23. 

JAANUsSSON, V. 1953. Untersuchungen tiber baltoskandische Asaphiden. II. Revision der 

Asaphus (Neoasaphus)—Arten aus dem Geschiebe des siidbottnischen Gebietes. Ark. 

Miner. Geol., Stockholm, 1 (15) : 465-499, 6 pls. 

1956. Untersuchungen iiber baltoskandische Asaphiden. III. Uber die Gattungen 

Megistaspis n. nom. und Homalopyge n. gen. Bull. geol. Instn. Univ. Upsala, 36 : 59-77, 

I pl., 3 figs. 

Moore, R.C. 1959. Treatise on Invertebrate Paleontology. Part O.ArthropodaI,. xix + 560 
PP., 415 figs. Lawrence & Meriden. 

Oprx, A. A. 1961. Alimentary caeca of agnostids and other trilobites. Palaeontology, 
London, 3: 410-438, pls 68-70. 

POULSEN, V. 1965. An early Ordovician trilobite fauna from Bornholm. Meddr dansk. geol. 
Foren., Copenhagen, 16 : 49-113, 9 pls. 


24 LOWER PALAEOZOIC STRATIGRAPHY 


ScHMIDT, F. 1906. Revision der Ostbaltischen Silurischen Trilobiten. V. Asaphiden. Zap. 
imp. Akad. Nauk., Leningrad, 19 (10) : 1-62, 8 pls, 33 figs. 

SHENG, S. F. 1958. The Ordovician trilobites of south-west China. Acta palaeont. sin., 
Peking, 6 : 183-204, pls. I-7. 

Sun, Y. C. 1931. Ordovician trilobites of Central and Southern China. Palaeont. sin., 
Peking, (B) 7 : 1-47, 3 pls. 

THORAL, M. 1935. Contribution a V’étude paléontologique de l’Ordovicien de la Montagne Noire 
et révision sommaire de la faune Cambrienne de la Montagne Noire. 362 pp., 35 pls. Mont- 
pellier. 

TJERNVIK, T. E. 1956. On the early Ordovician of Sweden, stratigraphy and fauna. Bull. 
geol. Instn. Univ. Upsala, 36 : 107-284, 11 pls., 45 figs. 

WHITTARD, W. F. 1960. The Ordovician Trilobites of the Shelve Inlier, West Shropshire, 
4. Palaeontogr. Soc. [Monogr.] London, pp. 117-162, pls. 16-21. 

WuitTiIncTon, H. B. 1963. Middle Ordovician trilobites from Lower Head, western New- 

foundland. Bull. Mus. Comp. Zool. Harv., 129 : 1-118, 36 pls. 

1965. Trilobites of the Ordovician Table Head Formation, western Newfoundland. 

Ibid., 132: 275-442, pls 1-68. 

— 1966. Trilobites of the Henllan Ash, Arenig Series, Merioneth. Bull. Br. Mus. nat. Hist., 

Geol., 11 : 489-505, 5 pls. 

1966a. Phylogeny and distribution of Ordovician trilobites. J. Paleont., Menasha, 40 : 
696-737, 16 figs. 


W. T. Dean, D.Sc., Ph.D. 
GEOLOGICAL SURVEY OF CANADA 
601 BootH STREET 

OTTAWA, 4, CANADA 


EXPLANATION OF PLATES 


All the material illustrated was sprayed lightly with ammonium chloride before 
photographing. Specimens preserved as internal moulds were painted with a black 
opaque before spraying ; casts of black latex were made from external moulds. The 
specimens carry numbers with the prefix It. and are housed in the British Museum 
(Natural History), London. Photographs by the writer. 


PLATE 1 


Geragnostus lycaonicus sp. nov. 
Seydisehir Formation, Seydisehir Shales, locality B.650, Sobova Valley. 
Fic. 1. Plan of internal mould of incomplete cranidium. Paratype. It.7991. x 8. 
Fics. 3, 4, 8. Posterior, left lateral and plan views of internal mould of pygidium. Note 
median tubercle on tip of ill-defined axis. Holotype. It.7992. x Io. 
Fic. 7. Latex cast of incomplete cranidium. Paratype. It.7993. ™ Io. 


Colpocoryphe sp. 
Seydisehir Formation, Seydisehir Shales, locality B.650, Sobova Valley. 
Fic. 2. Plan view of internal mould of cranidium. It.7994. x 7. 
Fics. 9, 10. Left anterolateral and plan views of internal mould of incomplete cranidium. 


Iite79950 xe 


Ampyx ? sp. 
Seydisehir Formation, Seydisehir Shales, locality C.543, 4:5 kms south of Kizilca. 
Fic. 5. Plan view of damaged cranidium with centre of glabella missing. It.8658. x 5. 


Neseuretus sexangulus sp. nov. 
Seydisehir Formation, Seydisehir Shales, locality C.216, 8 kms north-west of Seydisehir. 
Fics. 6, 11, 12. Right lateral, anterior and plan views of internal mould of crandium. 
Holotype. It.7996. x 5. 


PLATE 1 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 1 


PLATE 2 


Symphysurus blumenthali sp. nov. 
Seydisehir Formation, Seydisehir Shales, locality B.650, Sobova Valley. 
Fics. 1, 7,10. Plan, anterior and right lateral views of partially exfoliated cranidium. 
Holotype. It.7997. xX 3:5. 
Fic. 3. Partly exfoliated pygidium. Note the axial furrows, which are strongly developed 
only on the internal mould. Paratype. It.7998. x 3:5. 
Fics. 4, 6, 8. Left lateral, plan and posterior views of pygidium. Paratype. It.7999. x 2. 


Cheirurid ? gen. et sp. indet. 
Seydisehir Formation, Seydisehir Shales, locality C.160, 6 kms west of Seydisehir. 
Fics. 2,5. Anterior and right lateral views of internal mould of incomplete cranidium. 
It.8000. xX 3:5. 


Neseuretus ? sp. 
Seydisehir Formation, Seydisehir Shales, locality B.650, Sobova Valley. 
Fic. 9. Internal mould of incomplete, small pygidium. It.8001. x 5. 


PLATE 2 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 1 


PLATE 3 


Asaphid gen. et sp. undet. 
Seydisehir Formation, Seydisehir Shales, locality C.312a, 6 kms west of Seydisehir. 
Fics. I, 9,11. Plan, anterior and left lateral views of internal mould of left librigena BM. 
it8OO2= sm oxwrAr 


Seydisehir Formation, Seydisehir Shales, locality B.650, Sobova Valley. 
Fics. 2, 4, 7. Left lateral, plan and anterior views of slightly distorted internal mould of 
cranidium. BM. It.8003. X 2:5. 


Taihungshania sp. 
Seydisehir Formation, Seydisehir Shales, locality C.543, 4:5 kms south of Kuizilca. 
Fic. 3. Plan view of incomplete pygidium. BM. It.8004. x 3. 


Symphysurus sp. 
Seydisehir Formation, Seydisehir Shales, locality B.650, Sobova Valley. 
Fics. 5, 10. Posterior and plan views of damaged pygidium showing impression of ventral 
surface of doublure. BM. It.8005. x 3. 
Fic. 6. Plan view of small pygidium. BM. It.8006. x 3. 


Megistaspis ? sp. 
Seydisehir Formation, Seydisehir Shales, locality C.310, 6 kms west of Seydisehir. 
Fic. 8. Plan view of largely exfoliated right librigena. Note genal spine and inner margin 
of doublure. BM. It.8007. x 2. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 1 PLATE 3 


PLATE 4 


Asaphid gen. et sp. undet. 
Seydisehir Formation, Seydisehir Shales, locality B.650, Sobova Valley. 


Fics. 1, 3, 4. Plan, left lateral and anterior views of internal mould of cephalon and first six 
thoracic segments. BM. It.8008. x 2:5. 


Seydisehir Formation, Seydisehir Shales, locality C.310, 6 kms west of Seydisehir. 


Fics. 6,9. Plan and left anterolateral views of incomplete left librigena with part of doublure 
exposed. BM. It.8010. x 4. 


Symphysurus sp. 
Seydisehir Formation, Seydisehir Shales, locality C.312, 6 kms west of Seydisehir. 


Fic. 2. Ventral side of incomplete pygidium showing doublure ornamented with terrace- 
lines. BM. It.8009. X 1°5. 


Mesgistaspis sp. 
Seydisehir Formation, Seydisehir Shales, locality C.312, 6 kms west of Seydisehir. 


Fic. 5. Partly exfoliated small pygidium. Note lack of furrows on external surface. BM. 
It.8013. x 4. 


Ptychopyge sp. 
Seydisehir Formation, Seydisehir Shales, locality C.310, 6 kms west of Seydisehir. 
Fic. 7. Internal mould of hypostoma. BM. It.801r. x 6. 


Ptychopyge ? sp. 
Seydisehir Formation, Seydisehir Shales, locality C.312a, 6 kms west of Seydisehir. 
Fic. 8. Plan view of small pygidium. BM. It.8012. x 4. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 1 


PLATE 5 


Megistaspis sp. 
Seydisehir Formation, Seydi¢ehir Shales, locality B.650, Sobova Valley. 
Fic. 1. Internal mould of incomplete pygidium. BM. It.8014. 2:5. 


Seydisehir Formation, Seydisehir Shales, locality C.314, 8 kms north-west of Seydisehir. 
Fics. 3, 4, 6. Internal mould of pygidium. BM. It.8015. x 2. 
Fic. to. Internal mould of large pygidium. BM. It.8017. x 1°5. 


Asaphid gen. et sp. indet. 
Seydisehir Formation, Seydisehir Shales, locality C.314, 8 kms north-west of Seydisehir. 
Fics. 2, 7. Partly exfoliated fragment of large right librigena. BM. It.8018. x 2. 


Paramegalaspis sp. 
Seydisehir Formation, Seydisehir Shales, locality B.650, Sobova Valley. 
Fic. 5. Internal mould of pygidium showing doublure. BM. It.8020. 3. 
Fic. 8. Internal mould of left librigena. BM. It.8016. x 2. 
Fic. 11. Internal mould of hypostoma. BM. It.8019. x 6. 


Seydisehir Formation, Seydisehir Shales, locality C.314, 8 kms north-west of Seydisehir. 
Ftc. 9. Internal mould of almost complete cranidium. BM. It.8021. x 5. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 1 


r% 


> 


\ 


3 


A/LIST SOR SUPPLEMENTS 
TO THE GEOLOGICAL SERIES 
OF THE BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 


1. Cox, L. E. Jurassic Bivalvia and Gastropoda from Tanganyika and Kenya. 
Pp. 213; 30 Plates; 2 Text-figures. 1965. {6. 

2. EL-NAGGAR, Z. R. Stratigraphy and Planktonic Foraminifera of the Upper 
Cretaceous—Lower Tertiary Succession in the Esna-Idfu Region, Nile Valley, 
Egypt, U.A.R. Pp. 291; 23 Plates; 18 Text-figures. 1966. {r10. 

3. DAvEyY, R. J., Downie, C., SARGEANT, W. A. S. & WiiL1AMs, G. L. Studies on 
Mesozoic and Cainozoic Dinoflagellate Cysts. Pp. 248; 28 Plates, 64 Text- 
figures. 1966. £7. 2 

3. APPENDIX. DAVEY, R. J., DowniE, C., SARGEANT, W. A. S. & WILLiams, G. L. 
Appendix to Studies on Mesozoic and Cainozoic Dinoflagellate Cysts. Pp. 24. 
1969. 16s. 

4. Evtiott, G. F. Permian to Palaeocene Calcareous Algae (Dasycladaceae) of the 
Middle East. Pp. 111; 24 Plates, 17 Text-figures. 1968. {£5 2s. 6d. 

5. RHopES, F.H.T., Austin, R.L.& Druce,E.C. British Avonian (Carboniferous) 
Conodont faunas, and their value in local and continental correlation. Pp. 315; 
31 Plates, 92 Text-figures. 1969. 11. 

6. Cuitps, A. Upper Jurassic Rhynchonellid Brachiopods from Northwestern 
Europe. Pp. 119; 12 Plates, 40 Text-figures. 1969. £4 15s. 

7. Goody, P.C. Therelationships of certain Upper Cretaceous Teleosts with special 
reference to the Myctophoids Pp. 255; 102 Text-figures. 1969. {£6 Ios. 


hee 1 ee ee ee, eae Ay eee ee 


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PRINTEDIN GREAT BRITAINBYALDEN & MOWBRAYLTD AT THE ALDEN PRESS, OXFORD 


LOWER CRETACEOUS AMMONITES FROM 
NORTH-EAST ENGLAND: THE HAUTERIVIAN 
GENUS SIMBIRSKITES 


BY 


PETER FRANKLIN RAWSON 


(Queen Mary College, London) 


Pp. 25-86; 12 Plates; 10 Text-figures 


BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 
GEOLOGY Vol. 20 No. 2 
LONDON: 1971 


THE BULLETIN OF THE BRITISH MUSEUM 
(NATURAL HISTORY), instituted in 1949, 1s 
issued in five series corresponding to the Departments 
of the Museum, and an Historical sertes. 

Parts will appear at irregular intervals as they become 
ready. Volumes will contain about three or four 
hundred pages, and will not necessarily be completed 
within one calendar year. 

In 1965 a separate supplementary series of longer 
papers was instituted, numbered serially for each 
Department. 

This paper is Vol. 20, No. 2 of the Geological 
(Palaeontological) series. The abbreviated titles of 
periodicals cited follow those of the World List of 
Scientific Periodicals. 


World List abbreviation 
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© Trustees of the British Museum (Natural History), 1971 


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THE BRITISH MUSEUM (NATURAL HISTORY) 


Issued 23 April, 1971 Price £4:30 


LOWER CRETACEOUS AMMONITES FROM 
NORTH-EAST ENGLAND: 
THE HAUTERIVIAN GENUS SIMBIRSKITES 


By P. F. RAWSON 


CONTENTS 

Page 
I. INTRODUCTION . ; : : a : : : 0 28 
II. STRATIGRAPHY 5 : ‘ : : ‘ j 29 
(a) The Speeton Clay 3 ‘ : ¢ 0 d ; 29 
(b) The Tealby Beds : : : : : A 34 
1 The Lower Tealby Clay : c 6 5 : 34 
2 The Tealby Limestone . : ¢ : : . 35 
III. THE ASSOCIATED AMMONITE FAUNA . : : ‘ : ‘ 36 
IV. SYSTEMATIC DESCRIPTIONS : - : 5 A A a 36 
Subfamily Simbirskitinae Spath . : : 6 ; : 37 
Genus Simbirskites Pavlow : ‘ : : e : 38 
Subgenus Speetoniceras Spath : ; 42 
Simbirskites (Speetoniceras) Subei piciiovmne. (Spath) C 43 
Simbirskites (Speetoniceras) inversum (M. Pavlow) - 43 
Simbirskites (Speetoniceras) cf. versicolor (Trautschold) 46 
Simbirskites (Speetoniceras) sp 47 
Subgenus Milanowskia Chernova 5 ° 47 
Simbirskites (Milanowskia) concinnus $ (Phillips) : . 48 
Simbirskites (Milanowshkia) speetonensis (Young & eye 50 
Simbirskites (Milanowskia) sp 52 
Simbirshites (Milanowskia) See Wedekind ; : 53 
Simbirskites (Milanowskia) lippiacus (Weerth) . : 54 
Simbirskites (Milanowskia) cf. lippiacus ran 2 55 
Subgenus Craspedodiscus Spath . 5 . 55 
Simbirskites (Craspedodiscus) gottschet (Keenen)). A 56 

Simbirskites (Craspedodiscus) cf. kayseri abe & 
Uhlig) ; ; j : c 57 
Simbirskites (Craspedodiscus) caabils sp. nov. 4 57 
Simbirskites (Craspedodiscus) discofalcatus (ieiees) : 59 
Simbirskites (Craspedodiscus) phillipsit (Roemer) : 61 
Simbirskites (Craspedodiscus) sp. (phillipsi group) 5 62 
Simbirskites (Craspedodiscus) judd sp. nov. 6 : 62 
Simbirskites (?Craspedodiscus) sp.a . : , . 63 
Simbirskites (?Craspedodiscus) sp. b . : : : 64 
Subgenus Simbirskites Pavlow é : : : : 64 
Simbirskites (Simbirskites) umbonatus (Lahusen) : 65 
Simbirskites (Simbirshites) marginatus (Phillips) . 4 65 


Simbirskites (Simbirskites) yorkshivensis Chernova 5 66 


28 HAUTERIVIAN AMMONITE SIMBIRSKITES 


The Simbirskites (Simbirskites) dechent (Roemer) group 67 

Simbirskites (Simbirskites) cf. virgifer (Neumayr & 
Uhlig) ¢ , : : : ' 68 
Simbirskites spp. : c : : 6 : 69 
V. ZONATION OF THE Simbirskites BEDS OF THE SPEETON CLAY : 69 
VI. CORRELATION WITH OTHER AREAS . : : : 5 : 74 
(a) North Germany é : : : c 4 : 74 
(b) Russia. : ‘ : : : : : ¢ ae, 
VII. THE HAUTERIVIAN-BARREMIAN BOUNDARY IN NORTH-WEST EUROPE 80 
VIII. ZusSAMMENFASSUNG , , e Z ‘ ; 3 : 81 
IX. REFERENCES. : : s : . : é , ; 82 

SYNOPSIS 


Simbirskites (with four subgenera, Simbirskites s.s., Speetonicervas, Milanowskia and Cras- 
pedodiscus) occurs in Beds C7—LBs5 of the Speeton Clay of Filey Bay, Yorkshire, and in the 
Lower Tealby Clay and Tealby Limestone of Lincolnshire. The stratigraphy of these beds is 
outlined and 21 species of Simbirskites occurring therein are described. 2 species, S. (C.) juddi 
and S. (C.) vaviabilis, are new, 14 are referred to or compared with previously described species, 
and 5 are left under open nomenclature. The occurrence of the ammonite genera Aegocrio- 
cevas, Criocevatites, Pavacriocevas, Pyotaconeceras, Spitidiscus, Hypophyllocevas and Lytocevas in 
the Simbirskites beds is reviewed. Asa result of careful bed-by-bed collecting of the ammonite 
fauna the Simbirskites beds of the Speeton Clay have been divided into five zones, all defined by 
species of Simbirskites. This new zonation replaces earlier schemes proposed by Spath (1924) 
and Chernova (1951). The faunal succession now established allows a detailed comparison to 
be made with the equivalent beds in Russia and north Germany. The problem of correlating 
the Hauterivian-Barremian boundary of the standard Tethyan sequence with the north 
European succession is briefly discussed with reference to the well-known occurrence in the 
northern Caucasus and Crimea of a mixed Boreal (Simbirskites)—Tethyan fauna. 


I. INTRODUCTION 


Simbirskites occurs in the Hauterivian beds of the Boreal Province and is a useful 
zonal form in Russia, north Germany and north-east England. The ammonite 
fauna of the Russian Simbirskitid Beds consists almost exclusively of species of this 
genus, whereas the corresponding beds in Germany and England yield a more 
varied fauna with crioceratitid ammonites common at some horizons. Hence 
different zonal schemes have evolved, the German (Koenen 1902, Stolley 1925) and 
north-west European (Spath 1924) zonations utilizing a combination of Simbirskites 
and crioceratitid and holcodiscid ammonites as zonal forms while the Russian 
scheme (Pavlow 1901, Chernova 1951) relies exclusively on Simbirskites. The 
differences between the various zonations obscure the close similarity that exists 
between the Simbirskites faunas of the three areas. 

The first species of Simbirskites to be described were the Speeton Clay ““Ammon- 
ites’ speetonensis (Young and Bird 1828) and “A.” concinnus, “‘A.” marginatus and 
“A.” venustus (Phillips 1829), but most of the early descriptive work was published 
in Germany (e.g. Roemer 1841, Neumayr and Uhlig 1881, Weerth 1884) and Russia 
(e.g. Trautschold 1865, Lahusen 1874, M. Pavlow 1886, A. P. Pavlow 1go1). Many 
of the German type and figured specimens have subsequently been lost or destroyed. 


FROM NORTH-EAST ENGLAND 29 


The English fauna has never been described in detail, though Simbirskites is quite 
common in the Speeton Clay (beds C7-LB5) of Yorkshire and also occurs in the 
Lower Tealby Clay and Tealby Limestone of Lincolnshire. A few species have been 
figured by Pavlow (1889), Pavlow in Pavlow and Lamplugh (1892) and Danford 
(1906), and individual records have been discussed by Judd (1867, 1868, 1870) and 
Lamplugh (1889, 1896). The standard reference on the Speeton ammonite sequence 
is Spath’s (1924) exhaustive faunal list which recorded over 20 Simbirskites species. 

The present review of the English fauna is based on material collected bed by bed 
by the author, supplemented where necessary by museum material. Most of the 
museum specimens are poorly localized and reference is made therefore only to 
particularly important specimens. The author’s collection has been divided 
between the British Museum (Natural History) and the Department of Geology, 
University of Hull. 

This paper forms part of a study commenced during the tenure of an N.E.R.C. 
Research Studentship in the University of Hull (1963-66) and continued during the 
tenure of an N.E.R.C. Post-Doctoral Fellowship at Queen Mary College, University 
of London (1966-67). Field work in Germany was assisted by a grant from the 
British Council under the Younger Research Workers Interchange Scheme (1965) 
and an award from the Daniel Pidgeon Fund of the Geological Society of London 
(1969). I gratefully acknowledge an award from the Central Research Fund of the 
University of London. 

Among many colleagues who have assisted me are Dr. R. Casey (I.G.S.), Professor 
D. T. Donovan (University College, London), Professor V. V. Drushchitz (Moscow), 
Dr. B. N. Fletcher (I.G.S.), Dr. C. Forbes (Sedgwick Museum, Cambridge), Dr. M. K. 
Howarth (British Museum), Dr. E. Kemper (Hannover), Professor J. F. Kirkaldy 
(Queen Mary College), Dr. J. W. Neale (Hull), Mr. E. F. Owen and Mr. D. Phillips 
(British Museum), Dr. J. Remane and Dr. S. Ritzkowski (Gottingen), Dr. Fr. Schmid 
(Hannover), Mr. G. F. Wilmot (York Museum), Mr. C. J. Wood (I.G.S.) and Mr. 
C. W. Wright (London). Dr. F. A. Middlemiss (Queen Mary College) kindly read 
the initial manuscript. 


TT Sai REAGT HG aRCANE EIAs 


(a) The Speeton Clay 


The type-locality of the Speeton Clay is a 1-2 kilometre (3 mile) coastal section 
along the southern part of Filey Bay, Yorkshire (Text-fig. 1). Here the clay crops 
out in low cliffs, where the succession is frequently obscured by slipped or rain- 
washed material. Hence the section often appears as “a wild and tumbled slope 
of clay in which at first sight it is hopeless to make out any order’ (Blake 18o1 : 
138). Occasionally, however, the sea reaches the cliff face and cleans parts of the 
section, or sand may be removed from the beach in the intertidal zone to give 
continuous exposures of the underlying clays. Such transient exposures allow one 
to build up a composite picture of the Speeton succession, though some parts are 
still poorly known. 


30 HAUTERIVIAN AMMONITE SIMBIRSKITES 


Leckenby (1859) and Judd (1868) made the first serious attempts to subdivide the 
Speeton Clay, but the classic description, and the one upon which all subsequent 
work has been based, is that of Lamplugh (1889). On the basis of the belemnite 
sequence Lamplugh recognized four major divisions, labelled A—D from the top 


HUNMANBY FAULT 


\ 


a a 7 
West North Speeton® 


Heslerton Fordon 


MARKET@® 
WEIGHTON 


6 
miles 


GM Pre-Albian Lower Cretaceous 


Caistore 
Nettletone 


Normanb %5 
aca. 


Tealby.®& 


e 
Willingham 


Donnington-on-Baine 


Fic. 1. Map showing the distribution of pre-Albian Lower Cretaceous rocks in East York- 
shire and North Lincolnshire, and the localities mentioned in the text. 


FROM NORTH-EAST ENGLAND 31 


downward (the reverse of the normal stratigraphical procedure). A fifth division, 
bed E, is a 100 mm (4 inch) thick seam of phosphatic nodules, the ‘“‘Coprolite Bed’, 
which rests on Upper Kimmeridge Clay. 

Lamplugh further divided each of his major divisions; thus the B Beds were 
divided into Upper B, the Cement Beds and Lower B, and the C Beds into Cr to Crr. 
These subdivisions provided the framework for a more detailed subdivision (based on 
lithological changes) of the Lower B Beds by Kaye (1964) and of the C Beds by 
Fletcher (1969). Szmbirskites first appears in C7H (the lowest subdivision of bed C7) 
and the last known specimens are from LB5E, only 0-61 metres (2’) above the 
base of Lower B. All the author’s specimens have been localized according to 
Fletcher’s and Kaye’s bed numbers. The succession below is essentially that of 
Fletcher and Kaye, with only minor amendments, and their bed numbers are 
followed throughout. 


SUCCESSION: metres ft. in. 


LB5D Dark, often shaly, pyritic clay with 75 mm (3”) 
mottled band (light mottles in dark clay) at 
top . ; : 0-91 3 0 
LB5E Dark, highly ‘plauconitic mottled clay : ; 0:46 r.6 
LB6 ~—~Pale blue clay, weathering brown, with occa- 

sional “‘potato stone” nodules. Top 75 mm 


(3”) mottled (dark mottles in light clay) : O'51 1G) 
Cr1A Dark, glauconitic clay with conspicuous pale 

mottling . ‘ 0°13 5 
Cr1B__—sC—w Pale grey clay mottled by fares, dark, placa: 

nitic streaks. 0-10 4 
C2A Dark grey glauconitic abe with eee Pyrite 

crystals. : 0:30 i (0) 


C2B swale grey clay, darker in lowest 75-100 mm 
(3-4”). Band of small (25-50 mm), brown- 


weathering calcareous nodules at base . : 0°30 18 
C2C Medium grey clay becoming paler downwards . 0-76 Zan0 
C2D Dark, gritty, glauconitic clay with pale streaks. 

Stands out as a thin but prominent dark band 

among the lighter clays above and below. 0-10 4 
C2E Pale grey clay; brown-weathering streak with 

occasional calcareous nodules in upper part . 0:46 I 6 
C2F Medium grey clay. Boundary between this and 

C3 is gradational 5 0-61 2 0 


C3 (The “Echinospatangus Bed” of Lamplugh) Pale 
grey clay with a conspicuous layer of sparsely 
scattered, brown-weathering calcareous nod- 
ules (up to 150 mm diameter) 0-9 m (3’) above 
the base . : 3 , , ; 4 2°44 8 oO 


32 


metres ft. in. 


HAUTERIVIAN AMMONITE SIMBIRSKITES 
SUCCESSION: 
C4A Thin limestone band, pale grey-green when fresh 
but weathering a pale reddish-purple; forms a 
good marker horizon for the top of C4 . 0:07 
C4B Dark, glauconitic clay ; 0-76 
Pale clay with small phosphatic nodules ; : 0-61 
Cuc Mottled bed; light mottles in dark glauconitic 
ai clay . 5 : : : O-15 
Pale clay : : O15 
C4D__— Thin, greenish-yellow impure Jimestone. "Very 
similar to bed C4A 0:07 
C4E Dark grey glauconitic clay 0:30 
C4F ‘Pale grey clay ; 0:46 
C4G Dark grey clay, mottled at top (large pale ppreaks 
in dark clay) : 0-46 
C4H Brown weathering silty clay with occasional 
round calcareous nodules (up to 150 mm in 
diameter) . : 0:23 
C4I Dark, shaly clays . 3°05 
C4J Brown-weathering silty clay with small, slightly 
flattened brown calcareous nodules at base 0:23 
C4K Dark grey clays, glauconitic in middle 2°70 
C4L Brown weathering silty band, without nodules 
but patchily indurated. Large Simbirskites 
(Craspedodiscus) gottschet and Aegocrioceras cf. 
seeleyi : 0°23 
C5A Dark grey clays with thin mottled band at top 1°52 
C5B Olive grey clay with large, light coloured 
mottles at base . 0-46 
C5C Dark grey clay with occasional small brown 
nodules. 0-91 
C5D ___—siDark grey clay with pyrite; facts, mottled bed 
near top 0:76 
C5E _—s— Pale green, slightly glauconitic clay with occa- 
sional nodules : 0:23 
C5F Dark grey clays with large pale mottles near ar top: ; 
bed of small nodules in middle . 0-91 
C5G  Brown-weathering silty clay, partially indurated, 
and with widely scattered, large calcareous 
nodules 0:23 
C5H Medium grey clay . 0-76 
CsI Pale grey clay F O15 
C5J Olive grey clay, mottled i in part ight mottles i in 
darker clay) : ; ‘ 0-46 


Io 


Dw 


loonie) 


FROM NORTH-EAST ENGLAND 33 


SUCCESSION: metres ft. in. 
C5K Dark grey clay with some pyrite; occasional 
small brown nodules . : 70 5 6 
C5L _Brown-weathering silty clay, partially indurated 
and with widely scattered calcareous nodules 0:23 9 


C6 Dark grey shaly clays with 75 mm (3”) mottled 

bed at top (large and small pale grey mottles 

in dark clay). Occasional brown nodules in 

upper portion. Small Simbirskites (Milanow- 

skia) concinnus common in lowest 0-61 m (2’) 4°55 15 0 
C7A _Brown-weathering, silty indurated clays with 

large calcareous nodules. Large Crioceratites 


common . : ‘ ; : ; 0:30 1G) 
C7B__—C—Pale grey clay : 0:30 iG A 
C7C Dark grey clay with large mottling (alle mottles 

in dark clay) at top . : : 0:38 TS 
C7D __—sCPPale grey clay with a little glauconite : 0°30 i © 


C7E Black clay; large pale grey mottles at top. 
Glauconite abundant in upper part of clay, 


decreasing downward and absent at base. 0°38 Fi 
Pale grey clay with abundant flattened impres- 
sions of Simbirskites (Speetoniceras) sp.. : 0-15 6 
Pale grey silty clay, weathering brown and 
C7F locally indurated. Contains rounded phos- 


phatized nodules (up to 150 mm diameter) and 
larger, more irregular calcareous concretions. 


Body chambers of Aegocrioceras common. 0:23 9 
C7G__—C=iPale grey clay, mottled in part. ecaasaa 
bicarinatum common . : 0°53 Ta} 


C7H Dark grey clay with abundant glauconite. 
Small Simbirskites (Speetoniceras) inversum 


and crushed Thracia phillips: common. , 0°30 x 0) 
( Pale grey clay with large (up to 100 mm dia- 
meter) nodules . ‘ : : 0:23 9 


C8 Dark grey clay with bed of small (20 mm), 
brown-weathering nodules in middle. Ende- 
moceras regale . ; ‘ : i ‘ 1-80 6 oO 


Beds C8, C7 and the base of C6 are well exposed in the southern part of Middle 
Cliff, while the high C Beds (C4B to Cr) and Lower B are seen in the cliff and adjacent 
parts of the foreshore at Black Cliff slip (opposite a breakwater at TA 151763) and 
also along a low cliff immediately north of Speeton Beck (for all localities on this 
section see map in Kaye 1964, figs 5 and 6). C4, C5 and most of C6 are seen only on 


34 HAUTERIVIAN AMMONITE SIMBIRSKITES 


temporary beach exposures; C4 and C5 in particular are rarely clearly exposed, but 
from occasional observation and from published records both appear to be sparsely 
fossiliferous. 

Although the succession is essentially argillaceous it is by no means monotonous; 
well-marked nodule bands, alternating pale and dark clays, gritty glauconitic beds, 
and bioturbated horizons (the “‘mottled beds’’) provide a series of useful marker 
horizons. In particular the brown-weathering, silty clays of C4H, C4J, C4L, C5G, 
C5L, and C7A are more resistant to erosion than the surrounding clays and stand 
out as slight but noticeable scars on beach exposures. 

The Speeton Clay crops out inland along the southern edge of the Vale of Pickering, 
at the foot of the wold scarp, finally disappearing in the vicinity of Knapton (Text- 
fig. 1). The C and Lower B beds have never been exposed but have been proved in 
boreholes at North Fordon (Neale 1960 : 203) and West Heslerton (Neale and 
Sarjeant 1962 : 439). 


(b) The Tealby Beds 


The Lower Cretaceous deposits of the Lincolnshire—North Norfolk basin consist of 
a series of shallow-water ironstones, sandstones, limestones and clays. They thin 
southward towards the London Platform and northward towards the Market 
Weighton Upwarp, both of which were landmasses in pre-Albian Lower Cretaceous 
times. 

The Tealby Beds, which form the middle part of the Lincolnshire succession, are 
subdivided into the Lower Tealby Clay, the Tealby Limestone and the Upper Tealby 
Clay. Ammonites are rare, but Simbirskites occurs in the Lower Tealby Clay and 
the Tealby Limestone. At present, the only good exposures of these beds occur at 
Nettleton, in north Lincolnshire, where they have been exposed during the quarrying 
of the underlying Claxby Ironstone. The correlation between the Lower Cretaceous 
succession here and the Speeton Clay has been summarized in Penny and Rawson 
(1969 : 212, table 1). The Lower Tealby Clay was formerly well exposed in the 
brick-yard next to Donnington-on-Bain station and the Tealby Limestone in 
numerous shallow pits around Tealby, Normanby and North Willingham. 


1. The Lower Tealby Clay 


The Lower Tealby Clay is generally a fairly uniform, stiff blue-grey clay with 
phosphatic nodules and prominent glauconitic streaks. Hzibolites jaculoides, index 
belemnite of the C Beds of the Speeton Clay, occurs throughout, and this and rare 
ammonites together indicate a correlation with beds Cr to C7. There appears to 
have been a break in deposition between the Claxby Ironstone and the Lower 
Tealby Clay, for the former yields ammonites and belemnites typical of the upper 
D Beds of the Speeton Clay. The vegale zone (C8—C11r) is unrepresented in Lincoln- 
shire, a faunal break first commented on by Lamplugh (1896 : 203). 


FROM NORTH-EAST ENGLAND 35 


Above the ironstone quarries in Nettleton Valley (TF 118985) the Lower Tealby 
Clay is about 12 metres (about 40 feet) thick. Partially phosphatized nodules in 
the basal 0-61 metres (2 feet) have yielded fragments of Aegocrioceras cf. bicarinatum 
(Young and Bird), a species common just above the base of C7 (C7G) at Speeton. 
The only Simbirskites from this locality have been found loose on tip heaps; they 
include a specimen close to S. (M.) polivnensis (p. 69), a crushed specimen of the 
S. (M.) concinnus group, and a whorl fragment of S. (S.) cf. virgifer, though the last 
may have come from the Tealby Limestone. 

Elsewhere, Simbirskites has only been recorded from the old brick-pit at 
Donnington-on-Bain, where the record of “Ammonites” speetonensis (including 
“vars.”’ venustus and concinnus) (Ussher, Jukes-Brown and Strahan 1888 : 97) 
suggests the speetonensis zone. ‘“‘Crioceras duvali”’ (probably a Crioceratites of the 
wermbtert group) indicates a similar or slightly earlier (top 7mversum zone) horizon, 
while Lamplugh’s (1896 : 207) record of “‘Olcostephanus (Simbirskites) umbonatus”’ 
(figured by Pavlow (1892), and discussed below under S. (S.) yorkshirensis) from the 
same pit suggests that a higher horizon (early variabilis zone) is also represented. 


2. The Tealby Limestone 


The Tealby Limestone consists of a series of thin, impure arenaceous limestones 
interbedded with oolitic clays. It reaches its maximum thickness of 6 metres 
(20’) in Nettleton Valley, and forms a prominent scarp feature from Caistor to 
Donnington-on-Bain. Further south the individual limestones become thinner and 
softer and no longer form a noticeable ridge, until in south-east Lincolnshire the 
Tealby Limestone is virtually indistinguishable from the Lower and Upper Tealby 
Clays. 

Belemnites (Oxyteuthis pugio and allies) indicate a correlation with the B Beds 
of the Speeton Clay, and the rare ammonites suggest a correlation with the lower 
part of Lower B; the only ammonite common to both beds is Simbirskites (Craspedo- 
discus) discofalcatus which occurs in Bed LB6 at Speeton. The ammonites described 
below (S. (C.) juddi, S. (C.) discofalcatus and S. (?C.) sp. b) were collected in the last 
century at a time when the numerous shallow pits between Normanby and North 
Willingham and around Tealby were being worked by hand. Details of some of the 
exposures have been given in Judd (1867: 244) and Lamplugh (1806 : 209). 
Although the present exposures in Nettleton Valley are good the limestone is now 
removed mechanically and the workmen very rarely collect ammonites. A single, 
poorly preserved, indeterminate S. (Craspedodiscus) has been collected by the author. 

Spath’s (1924 : 79, 82) anomalous record of S. aff. toensbergensis (Weerth) and S. 
aff. fasciatofalcatus (Lahusen) from the Claxby Ironstone of Claxby led him to 
tentatively correlate the upper part of the ironstone with C4 of the Speeton Clay. 
The two specimens are in the Sedgwick Museum, numbers Bri1122 and Br1123 
respectively; their preservation shows that the former (an indeterminate species) 
came from the Tealby Limestone or Lower Tealby Clay and the latter (discussed 
below as S. (C.) discofalcatus) from the Tealby Limestone. 


30 HAUTERIVIAN AMMONITE SIMBIRSKITES 
Ill. THE ASSOCIATED AMMONITE FAUNA 


Representatives of five other ammonite families, the Crioceratitidae, Holco- 
discidae, Oppeliidae, Phylloceratidae and Lytoceratidae are associated with Simbir- 
skites in beds C7—LB5 of the Speeton Clay; only the Crioceratitidae are common. 
The rare oppeliid genus Protaconeceras is represented by an undescribed species from 
C4 (Casey 1954 : 270) and the holcodiscid Spitidiscus rotula (Sowerby) occurs in the 
lower part of C5 (C5L). A related form, S. znflatiformis Spath, occurs in the nodule 
bed at the top of C8. A whorl fragment (author’s colln., BM. C.75852) of the 
phylloceratid Hypophylloceras cf. perlobatum (Sayn), previously known from Speeton 
by a single specimen from C8 (Rawson 1966 : 455), has been found about 0-60 metres 
(approximately 2 feet) above the base of C6. From slightly higher in C6 (about 
1-8 metres above the base )Whitehouse and Brighton (1924 : 360) recorded Lytoceras 
cf. subfimbriatum (d’Orb.). 

The Crioceratitidae first appear in bed C7G, just above the base of C7, and occur 
through the overlying Upper Hauterivian and Barremian beds of the Speeton 
section. Numerous species of Aegocrioceras occur in bed C7 (Spath 1924, Rawson 
1970) and Crioceratites is common in C7A and lower C6. Higher in the C Beds 
section crioceratitids are rare; large body chamber fragments of Aegocrioceras cf. 
seeleyt (Neumayr and Uhlig) occur in C4L and two small, septate whorl fragments of 
Paracrioceras statheri Spath have been collected in bed C2C. 

In Lincolnshire, Aegocrioceras and Crioceratites occur in the Lower Tealby Clay 
(p. 35) and poorly preserved crioceratitids in the] Tealby Limestone. A single 
Lytoceras aff. vogdtt Karakasch is recorded from the latter bed (Spath 1924 : 79). 


IV. SYSTEMATIC DESCRIPTIONS 


Morphological terms used in the systematic descriptions are defined in the 
ammonoid volume of the “Treatise on Invertebrate Paleontology” (1957: R. C. 
Moore, editor). Detailed ontogenetic studies of sutural development are beyond 
the scope of this paper, and for the purposes of general morphological description of 
representative suture lines the relatively simple terminology used in the “Treatise” 
(Moore 1957 : Lo6, fig. 141) has been followed. 

Dimensions are given in millimetres, as follows: diameter; oblique whorl height, 
whorl thickness, width of umbilicus. 

The oblique whorl height is measured from the mid-line of the venter to the 
umbilical seam, and the whorl thickness has been measured on the ribs and not 
between. 

The specific descriptions are based on 227 specimens from Speeton and Lincoln- 
shire, together with a limited number of foreign specimens (12 German and 5 
Russian) which are referred to for comparative purposes. The 244 specimens are 
distributed among 23 discrete taxa, as follows: 


Speeton Lincolnshire Germany Russia 
S. (Sp.) subbipliciforme 7 — - ~ 
S. (Sp.) inversum 29 - - 2 


FROM NORTH-EAST ENGLAND 37 


Speeton Lincolnshire Germany Russia 


S. (Sp.) cf. versicolor 2 as s if 
S. (S#.) sp. i = if a 
S. (M.) concinnus 66 - it es 
S. (M.) speetonensis 22 = 2 I 
S. (M.) sp. 3 — I a 
S. (M.) staffi 2 as 2 es 
S. (M.) lippiacus and 
S. (M.) cf. ippiacus 4 = 2 - 
S. (C.) gottsches 8 - 2 - 
S. (C.) cf. Raysert 3 - I — 
S. (C.) variabilis 12 = as ze 
S. (C.) discofalcatus and 
S. (C.) cf. discofalcatus 6 7 = I 
S. (C.) phillipss = = 2 ss 
S. (C.) sp. (phillipsi group) 3 a ps = 
S. (C.) juddt = 2 es = 
S. (?C.) sp. a 14 a a ae 
Se.) Sp» b. — I = = 
S. (S.) umbonatus = = = I 
S. (S.) marginatus 13 = s ss 
S. (S.) yorkshirensis and 
S. (S.) cf. yorkshirensis 5 iT = = 
S. (S.) dechemt group 15 - xe = 
S. (S.) cf. virgifer - I = = 
215 12 12 5 


In addition, reference is made at the end of this section to a number of specimens 
which are too inadequately preserved for accurate determination. 

Abbreviations: BM. = British Museum (Natural History); GSM. = Geological 
Survey Museum; Gottingen = Geologisches-Palaeontologisches Institut, Georg- 
August-Universitat, Gottingen; NLfB = Niedersachsisches Landesamt fiir Boden- 
forschung, Hannover; HU. Rn. = Rawson collection, University of Hull; SM. = 
Sedgwick Museum, Cambridge; YM. = Yorkshire Museum, York. 


Suborder AMMONITINA Hyatt, 1889 
Superfamily PERISPHINCTACEAE Steinmann, 1890 
Family OLGOSTEPHANIDAE Haug, 1910 
Subfamily SIMBIRSKITINAE Spath, 1924 


Three genera, Speetoniceras, Simbirskites and Craspedodiscus were included in the 
subfamily by Wright (1957 : L349). Speetoniceras, Craspedodiscus and Milanowskia 


38 HAUTERIVIAN AMMONITE SIMBIRSKITES 


(Chernova 1952) are here regarded as subgenera of Simbirskites, so that the sub- 
family now consists of Simbirskites, divided into four subgenera, and the provincial 
north American genera Hertleimites Imlay 1958 and Hollisites Imlay 1957. 

The Simbirskitinae are a widespread and important group in the later Hauterivian 
beds of the Boreal Province, and are the last surviving members of the Middle 
Jurassic to Lower Cretaceous superfamily Perisphinctaceae, dying out at the end 
of the Hauterivian. 


Genus SIMBIRSKITES Pavlow 1892 


TYPE SPECIES: Ammonites dechent Roemer 1841, by original designation. 


DiaGnosis: Ornament consists of short, sharp primary ribs branching into a 
varying number of secondary ribs; in most species there is a prominent tubercle at 
the point of branching in at least the earlier growth-stages. Other secondary ribs 
may branch from earlier ones higher on the whorl-flank, or may be intercalated. 
The ribs curve forwards on crossing the venter. 

The external suture consists of five trifid lobes, a ventral, a lateral, and three 
auxilliaries, separated by bifid saddles; none of the incisions within these major 
elements is deep. The suture is inverse (ascendent) i.e. if a radial line is drawn 
from venter to umbilical edge, the saddles are seen to ascend towards the aperture 
on approaching the umbilicus. 


Discussion: Simbirskites is a very variable genus, embracing evolute, coronate 
forms to involute, compressed forms. Within individual species there are often 
considerable changes in whorl proportions, rib pattern and rib density with growth. 
The genus was first proposed for “‘olcostephanids” of the O. decheni group, and 
subsequently (Pavlow IgoI : 67) divided into three groups, the Perisphinctoidea 
(group of S. versicolor), the Umbonati (group of S. wmbonatus and S. dechent) and the 
Discofalcati (group of S. discofalcatus). Spath later divided Simbirskites into three 
genera, Simbirskites s.s. “restricted to the original coronate forms of the dechemi 
group” (Spath 1924 : 87), Speetoniceras, proposed for the perisphinctoid early forms 
and therefore equivalent to Pavlow’s Perisphinctoidea, and Craspedodiscus, proposed 
for the discoidal forms. The last genus included many of Pavlow’s Discofalcati, 
though Spath included some of these in Simbirskites. In fact, Spath was inconsistent 
(Chernova 1952 : 46) in restricting Szmbirskites to the coronate forms and then 
including in it S. speetonensis and S. progredicus which are moderately compressed 
species of Pavlow’s Discofalcati group. 

Wright (1957 : L350) followed Spath in regarding Speetoniceras, Simbirskites and 
Craspedodiscus as separate genera, placing two other genera, Thysanotoceras 
Whitehouse 1927 and Stoicoceras Whitehouse 1927, in synonomy with Simbirskites. 
Thysanotoceras was proposed for Weerth’s (1884 : 12, pl. 2, fig. 5-6) A. picteti, and 
“includes the group with prominent bundling of costae in groups of four at the 
tubercle’ (Whitehouse 1927 : 109). The genus is here regarded as a junior sub- 
jective synonym of Simbirskites s.s. Stoicoceras was not defined, but was proposed 


FROM NORTH-EAST ENGLAND 39 


for A. teutoburgensis Weerth (1884 : 20, pl. 5, fig. 1). This species is difficult to 
interpret, but appears to be a neocomitid. 

Roman (1938 : 393) regarded Speetoniceras and Craspedodiscus as subgenera of 
Simbirskites, as did Bahr (unpublished dissertation)!. 

Chernova’s (1952) major work on Simbirskites included detailed ontogenetic 
studies, from which she concluded that Speetoniceras and Simbirskites are separate 
genera. In the former genus Chernova included Pavlow’s Perisphinctoidea and 
Discofalcati, and in the latter his Umbonati plus S. coronatiformis (M. Pavlow) and 
S. pavlovae Chernova (nomen novum for S. elatus M. Pavlow non Trautschold), which 
were originally included in the Perisphinctoidea. Chernova divided Speetoniceras 
into three subgenera, Speetoniceras sensu stricto, Craspedodiscus and a new subgenus, 
Milanowskia. Simbirskites remained undivided. 

According to Chernova (1952 : 53) Simbirskites is more inflated than Speetoniceras 
sensu Chernova, though the earliest Simbirskites and contemporary Speetoniceras s.s. 
are very similar in the adult stage. In addition, she suggested that the sculpture in 
the two genera developed differently ; in Simbirskites the tubercles normally appear 
first, followed by the primary ribs and lastly the secondaries, whereas in Speetoniceras 
the primary ribs appear first and are followed by the secondary ribs and then the 
tubercles. However, Chernova shows that in the two earliest (versicolor zone) 
species of Simbirskites (S. coronatiformis and S. pavlovae) the primary ribs appear 
before the tubercles (as in contemporary Speetoniceras). There thus seems no merit 
in placing any major phylogenetic significance on the order of appearance of each of 
these features. Furthermore, in practice it can be very difficult to decide which 
feature does appear first. 

Chernova (1952 : 54) further assumed an independent origin for the two genera, 
deriving Simbirskites sensu Chernova from Polyptychites of the gravesiformis group 
(i.e. the forms separated by Pavlow (1913) as Euryptychites) and Speetoniceras sensu 
Chernova from another (undescribed) group of Polyptychites or from Tollia. On the 
available evidence it is more reasonable to derive Simbirskites sensu Chernova (the 
group here included in the restricted subgenus Simbirskites) from S. (Speetoniceras) 
versicolor, with S. (S.) pavlovae and S. (S.) coronatiformis, the two earliest Russian 
Simbirskites s.s., as connecting links (see page 64). 

It is impossible to draw sharp boundaries between Cvaspedodiscus, Milanowskia, 
Simbirskites s.s. and Speetoniceras, and all four are here regarded as subgenera of 
Simbirskites. In certain species the inner whorls have previously been placed in 
one genus and the outer whorls in another. Although the evolutionary relationship 
between some species appears clear, the complex Simbirskites lineages have by no 
means been unravelled completely and Chernova’s (1951 : figs 1 and 2) detailed 
lineages are of doubtful value. At present, therefore, the division of Simbirskites 
into four subgenera is based as far as possible on phylogenetic studies, but as our 
knowledge of the interrelationships between various species increases the boundaries 


1Bahr, H. H., 1964. “‘Die Gattung Simbirskites (Ammonoidea) im Ober-Hauterive Nordwest- 
deutschlands’. Unpublished dissertation, Technischen-Hohschule, Braunschweig. Referred to 
throughout this paper as ‘‘Bahr, unpublished dissertation’. 


HAUTERIVIAN AMMONITE SIMBIRSKITES 


40 


bx3 

hx 2-5 
ex 2.5 

1x6 


f x1 j k x1 


Fic. 2. Suture lines of Simbirskites. a-f sutures with relatively broad elements, g—k 
sutures with narrower, deeperelements. a. S.(S.) cf. decheni var. a, at 21 mm diameter 
(BM. C.75887). b. S. (M.) concinnus, at 20 mm diameter (HU. Rn.397). c. S. (M.) 
staffi, at 34 mm. diameter (NL{B Kp.37). d. S. (Sp.) inversum, at 85 mm. diameter 
(BM. C.4). e. S. (S.) kowalewsku. f. S. (S.) umbonatiformis. g. S. (S.) dechent. 
h. S. (S.) yorkshivensis, at 17 mm. diameter (BM. C.75885). i. S. (S.) marginatus, at 
9°5 mm diameter (holotype, YM. tablet 414). j. S. (M.) progvedicus. k. S. (S.) 


umbonatus. 
figures a—d, h, i, original; figures e-g, j, k, redrawn from Pavlow (1901). 


FROM NORTH-EAST ENGLAND 41 


between the subgenera, and possibly the number of subgenera recognized, will 
doubtless require adjustment. 

An outstanding problem, which can only be resolved after a detailed study of 
sutural ontogeny of the Russian, German and English forms, is the significance of 
the relative length and breadth of the elements of the suture. Both Pavlow (1901) 
and Chernova (1952) recognized that in some species of Simbirskites the saddles are 
broad and only slightly subdivided at all growth stages, while in other species they 
are narrow and longer and become more strongly subdivided with growth (Text-fig. 
2). Pavlow (1901) regarded these sutural differences as the main feature distinguish- 
ing S. (S.) wmbonatiformis from S. (S.) wumbonatus and S. (S.) kowalewsku from S. (S.) 
dechem. ‘This variation has not been observed in Speetoniceras (with broad saddles) 
and Craspedodiscus (with narrow saddles) but is recorded in Milanowskia and 
Simbirskites s.s. Observation of the limited amount of suitable Speeton material 
suggests that there may be a time significance, the earlier species having the broader 
saddles and later species the narrower saddles. 

Simbirskites probably evolved in the Boreal Ocean from one of the late Valanginian 
polyptychitids; the time break between these and the earliest Simbirskites (Speetont- 
cevas) is represented in the Russian successions by a stratigraphical break and in 
north-west Europe by beds with Endemoceras, an endemic boreal neocomitid genus 
derived from a tethyan ancestral stock. 

Numerous species of Szmbirskites have been described from the Russian Platform, 
north Germany, Heligoland and Speeton. Unfortunately, it is a particularly difficult 
genus to study; Pavlow (1901 : 66) has discussed the taxonomic difficulties caused 
by the considerable morphological changes which often occurred during growth. 
Failure to recognize these changes, or inadequate type material, has resulted in a 
proliferation of specific names and there are probably far more names available than 
there are species of Simbirskites. 

Comparisons between the Szmbirskites species of the various parts of the Boreal 
Province are further complicated by differences in size of the preserved specimens. 
At Speeton, most specimens are septate inner whorls rarely more than 25 mm in 
diameter, whereas many of the Russian species described by Lahusen (1874), M. 
Pavlow (1886) and A. P. Pavlow (1901) and the north German species of Neumayr 
and Uhlig (1881) were described from much larger specimens. The numerous 
species described by Weerth (1884) from the Teutoburger Wald and by Koenen 
(1904) from Heligoland were based upon small and medium-sized specimens directly 
comparable with the Speeton forms. 

Outside the Anglo-German and Russian Platform regions, Simbirskites is rare. 
It has recently been recorded from Spitzbergen (see Parker 1967 : 502). From the 
Northern Richardson Mountains in the North-West Territories of Canada, Jeletzky 
(1964 : 58, pl. 15, fig. 2) has figured a poorly preserved, apparently simbirskitid, 
ammonite as S. cf. kleini (Neumayr and Uhlig). More definite records of Simbir- 
skites are the species figured by Imlay (1960) from California and Oregon. 

The description of an Australian species, Simbirskites morvenae (Whitehouse 
I927 : III), was based on material in an old collection in Queensland Museum 


42 HAUTERIVIAN AMMONITE SIMBIRSKITES 


labelled “Victoria Downs, Morven”. The record has not been substantiated by 
further collecting and Whitehouse (1946) subsequently questioned the provenance 
of the specimens as they closely resemble comparable German individuals in preserva- 
tion. There is no other evidence for marine Hauterivian strata in the area. 

Spath (1924: 82, 87) included the Mexican and Himalayan ‘“‘Simbirskites”’ 
described by Burckhardt (1912) and Uhlig (1910) respectively in the Upper Jurassic 
genus Grayiceras. Leanza’s (1958) Argentinian Simbirskites have been misidentified 
generically. In lateral view S. auracanus Leanza is similar to S. decheni and S. 
quadripartitus Leanza resembles S. kleint, but all four of Leanza’s species differ from 
Simbirskites in that the ribs extend straight across the venter instead of curving 
forwards. Leanza’s species appear closer to Rogersites; the recorded stratigraphical 
horizon (late Valanginian) would agree with this. 

Simbirskites occurs, very rarely, in the south of France; unfortunately the specimen 
from Barréme in the Astier collection (BM. 73463) referred to as “comparable to 
forms of C6” (Spath 1924 : 82) is too poorly preserved to be identified. 


Subgenus SPEETONICERAS Spath 1924 
TYPE SPECIES: Sp. subbipliciforme Spath 1924, by original designation. 


DiacGnosis: A perisphinctoid subgenus of Szmbirskites with a moderately evolute 
to evolute shell, rounded to coronate whorl section, and strongly biplicate ribbing. 
The suture has relatively broad, only slightly subdivided saddles and lobes at all 
growth stages. 


Discussion: Following Spath (1924 : 87), the subgenus Speetoniceras is here 
retained for the early perisphinctoid species of Simbirskites, i.e. Pavlow’s (1901 : 67) 
“Perisphinctoidea, ou groupe de Simbirskites versicolor’. Chernova (1952 : 50) also 
included within the subgenus the German group of S. inverselobatus (Neumayr and 
Uhlig). 

Chernova (1952: 50) states that all Speetoniceras species reach maturity at 
about 90 mm diameter and grow to as much as 500-600 mm diameter; within this 
growth-range the general form and sculpture of each species remains constant. 
Most of the large Russian specimens were originally included in Sp. versicolor 
(Trautschold), but after studying the ontogeny of the various forms M. Pavlow (1886) 
distinguished three species, Sp. inversum, Sp. subinversum and Sp. versicolor. There 
is a gradation between the three, Sp. versicolor having the most inflated inner whorls 
with strong tubercles and coarse ribbing, while at the other extreme Sp. inversum 
has the least inflated inner whorls with feeble tubercules and finer ribbing. With 
growth these differences diminish so that the outer whorls of the three species are 
virtually identical and can best be separated by sutural differences. The sutures of 
Sp. inversum were described as strongly inverse, those of Sp. subinversum less so, 
and those of Sp. versicolor only slightly inverse. The stratigraphical ranges of these 
three species in the Volga section reflect the morphological gradation; Sp. versicolor 


FROM NORTH-EAST ENGLAND 43 


appears first, followed by Sp. subinversum and then by Sp. inversum (Chernova 
I95I : 52-53. Text-fig. 10 here). 

Although large specimens of Speetoniceras are common in Russia, the Speeton 
material consists almost entirely of septate inner whorls of less than 30 mm diameter, 
so that it is difficult to compare specimens from the two areas. 

Speetoniceras is not known from north Germany, but has been recorded from 
Spitzbergen (Parker 1967 : 502) and from Oregon (Imlay 1960 : 213). 


Simbirskites (Speetoniceras) subbipliciforme (Spath) 
(Pl. 1, figs 2, 5) 


1906 Olcostephanus (Simbirskites) ?sp. Danford: pl. 12, fig. 3. 
1924 Speetoniceras subbipliciforme (= ‘‘?sp.’’ Danford, pl. 12, fig. 3) Spath: 76. 

Type: The holotype, refigured here, pl. 1, fig. 2; GSM. 17930, Danford collection, 
from “‘C7—-8”’ of the Speeton Clay. 


MATERIAL: Six septate nuclei; author’s collection BM. C.75620-21; HU. Rn. 26, 
Rn. 230, Rn. 1102; GSM. 17913. Speeton Clay, bed C7H (BM. C.75620-21 and 
Rn. 1102; horizon of others unrecorded). 


DESCRIPTION: Known only from septate inner whorls, the largest being 28-7 mm 
in diameter. Shell evolute, whorl section rounded. Ribs strong, gently prorsi- 
radiate; rib pattern regular, the short primary ribs normally bifurcating at a subdued 
swelling about a third of the distance over the whorl flank. Rarely, a primary rib 
remains unbranched. The secondary ribs curve forwards on crossing the rounded 
venter. 


DIMENSIONS OF FIGURED SPECIMENS: 
GSM. 17930 (holotype). 28-0; 10-2, 10:6, 11-2. 18 pr., approx. 34 sec. ribs. 
BM. C.75620. 21:4: at 20-7; 7°5, 8-0, 8-0. Ig pr., approx. 36 sec. ribs. 


Discussion: S. (Sp.) subbipliciforme has not previously been described; the 
specific name was introduced by Spath (1924) as a nomen novum for Danford’s 
(1906) figured “‘Olcostephanus (Simbirskites) ?sp.”. The species differs from the 
inner whorls of other Speetoniceras in being more evolute, less inflated, and more 
coarsely ribbed; the secondary ribs curve forwards more strongly over the venter 
than in other species. It is approached only by the more coarsely ribbed varieties 
of S. (Sp.) inversum, which differ in being less evolute and a little more inflated. 


DISTRIBUTION: Speeton Clay, inversum zone, Speeton. 


Simbirskites (Speetoniceras) inversum (M. Pavlow) 
(Pl. 1, figs 1, 3, 4, 6, 7, 9; Pl. 2, fig. 1; Text-figs 2d, 3-5) 
?1865 Ammonites versicolor Trautschold: pl. 2, fig. 3 (non fig. 4). 


1886 Ammonites (Olcostephanus) inversus M. Pavlow: 36, pl. I, figs 4, 5; pl. 2, fig. I. 
1892 Olcostephanus (Simbirskites) inversus (M. Pavlow) Pavlow: 508, pl. 18, fig. 14. 


44 HAUTERIVIAN AMMONITE SIMBIRSKITES 


21892 Olcostephanus (Simbirskites) aff. inversus (M. Pavlow); Pavlow: pl. 15, fig. 3. 

1892 Olcostephanus (Simbirskites) subinversus M. Pavlow; Pavlow: 507, pl. 18, fig. 12 (?fig. 13). 
1906 Olcostephanus (Simbirskites) subinversus (M. Pavlow); Danford: 110, pl. 12, fig. 4. 
?1907 Simbirskites inversus (M. Pavlow) Karakasch: 129, pl. 13, fig. 4a, 4b (interior). 

1924 Speetoniceras inversum (M. Pavlow) Spath: 76. 

1924 Speetoniceras subinversum (M. Pavlow) Spath: 76. 

1960 Speetoniceras inversum (M. Pavlow); Drushchitz and Kudryavtseva: 273, pl. 17, fig. 2. 


Type: M. Pavlow’s figured syntypes are in the Geological Reconnaissance 
Institute, Moscow; the original of Pavlow’s plate 1 figure 5, is here selected as 
lectotype. 


MATERIAL: 29 septate inner whorls from bed C7H (common) and C7G (rare) of 
the Speeton Clay. Author’s collection, BM. C.75622-46 (25 specimens) and HU. 
Rn. 147, Rn. 690, Rn. 708, and Rn. 937 (4 specimens). 2 specimens from Simbirsk, 
Russia, BM. C.4 (Damon collection) and Kabanov collection, number 1364. There 
is additional material from Speeton in all the collections examined. 


DESCRIPTION (of specimens up to 30 mm diameter): Shell moderately evolute, 
flanks and venter rounded, whorl section sub-circular. Primary ribs extend almost 
half-way over the whorl-flank, where they bifurcate at a subdued tubercle; very 
rarely a primary rib either remains single or trifurcates. The secondary ribs curve 
gently forwards over the venter. There are 20-28 (usually 21-25) primary ribs and 
40-55 secondary ribs per whorl at 16-32 mm diameter (Text-fig. 4). 

The shell is smooth to 7-8 mm diameter, when primary and secondary ribs appear 
practically simultaneously ; one individual (BM. C.75643) remains smooth for another 
half-whorl, to about 12 mm diameter. 

The suture-line (Text-fig. 2d, 3) is inverse with broad, only slightly subdivided 
saddles. 


DIMENSIONS OF FIGURED SPECIMENS: 


BM. C.75626. 20:5; 8-7, 8:0, 7:0. 23 pr., 46 sec. ribs. 

BM. C.75624. 24-8; 10-3) 10°0, 8-5. 27 pr., 49/sec. ribs. 

BM. C.75623. 27:2; 11:6, 12°8, 8:4. 25 pr., 50 Sec. ribs. 

BM. €:75625. 20-O)11-4, Ti°2, TI-0. (23) pr 740 sec. tus. 

BM? C:75627. 31:2; 12-0, 13-0, 11-2. 270 pis, 50 Sec. Hibs. 

BM. C.75622. 35°4; 13°7, 14°, 13-4. 21 pr., 4% sec. ribs. 
Kabanov colln. 1359. 78-5; 27°5, 27:2, 33:0. 32 pr., 64 sec. ribs. 


Discussion: This species is represented at Speeton by small, septate specimens up 
to 32 mm diameter; they are slightly less inflated than the smallest of Pavlow’s 
syntypes (1886 : pl. 1, fig. 5), a plaster cast of which has been made available by 
Professor Drushchitz. However, Chernova (1952: fig. 3) illustrated the whorl 
section of a Russian individual of 30 mm diameter, and this compares closely with 
whorl sections of Speeton specimens of similar diameter. M. Pavlow described the 
inner whorls of S. (Sp.) inversum as rounded, with feeble tubercles at the point of 
bifurcation of the ribs; at a later growth-stage the tubercles disappear and the 


FROM NORTH-EAST ENGLAND 45 


whorl flanks flatten. Large specimens, comparable in size to the typical Russian 
forms, are virtually unknown at Speeton, but the two large whorl fragments from 
Speeton figured by Pavlow (1892) as S. (Sp.) aff. enversum and S. (Sp.) subinversum 
may belong to S. (Sp.) inversum. A large Russian specimen is figured here (PI. 1, 
fig. 4) for comparison. 

The small Speeton specimens of S. (Sp.) inversum exhibit variation in general 
whorl proportions (Text-fig. 5), rib density (Text-fig. 4) and degree of inversion of 
the suture-line (Text-fig. 3). A. P. Pavlow (1892 : pl. 18, figs 12 and 14) figured 
two Speeton specimens as two different species, S. (Sp.) inversum and S. (Sp.) sub- 
inversum, separating them mainly according to the degree of inversion of the suture. 


ena 


\ 


e 


Fic. 3. Simbirskites (Speetoniceras) imversum: variation in degree of inversion of suture 
lines of 5 specimens from Bed C7H, Speeton. a. BM. C.75640 at 20:5 mm diameter; 
b. HU. Rn.937 at 18:2 mm diameter. c. BM. C.75645 at 25:0 mm diameter; 
d. BM. C.75625 at 28-6 mm diameter. e. BM. C.75627 at 30:2 mm diameter. 
All x 2. 


+ yn un Ww w 
o (e) ity + Cc 


Primary ribs/whorl 
secondary ribs/whorl 
> 
o 


TOM Gee -2Ol i222) 240 we2oy 9 28m SO) 1512 16 18 200 22,524) 2On 28 SOM Si2: 
diameter diameter 


Fic. 4. Variation in density of primary and secondary ribs per whorl in 18 specimens of 
Simbirskites (Speetoniceras) inversum from Bed C7H, Speeton. 


46 HAUTERIVIAN AMMONITE SIMBIRSKITES 


The difference between them is small and both fit into the range of variation of 
S. (Sp.) inversum. Danford’s (1906) and Spath’s (1924) records of S. (Sp.) sub- 
inversum from the Speeton Clay are apparently based on A. P. Pavlow’s inter- 
pretation of the species. 

S. (Sp.) agnessense Imlay differs from S. (Sp.) inversum in having more involute 
and more finely-ribbed inner whorls. 


DISTRIBUTION: Speeton Clay, imversum zone, Speeton; inversum and pavlovae 
subzones of the versicolor zone, Russia. 


ie} = i) 
= 1 


whorl thickness 
oO 
4 


64 
54 
T T T | = =| TD ERR 
12 14 16 18; 207 22) 245-26 28 30 32 12 14 16 18 "20 22) 24 26) 2830) 32 
diameter diameter 


Fic. 5. Variation in whorl-proportions of 21 specimens of Simbirskites (Speetoniceras) 
inversum from Bed C7H, Speeton. 


Simbirskites (Speetoniceras) cf. versicolor (Trautschold) 
(PI. 1, fig. 8) 


cf. 1865 Ammonites versicoloy Trautschold: pl. 2, figs 3, 4. 
cf. 1886 Ammonites (Olcostephanus) versicoloy Trautschold; M. Pavlow: 30, pl. 1, figs 1-3. 


MATERIAL: One septate specimen (author’s collection, BM. C.75647) and one 
whorl fragment (HU. Rn. 84) from the C Beds of the Speeton Clay (exact horizon 
unknown). 


DESCRIPTION: Shell moderately evolute, inflated, whorl section almost coronate. 
Coarsely ribbed, the short, sharp primary ribs branching into two, rarely three, 
secondary ribs at a prominent tubercle about a third of the way over the whorl 
flank. The secondary ribs curve gently forwards over the broadly rounded venter. 


DIMENSIONS OF FIGURED SPECIMEN: 
BM. C.75647. 30:4; 11-5, 14:6, 12°5. 20 pr., 44 sec. ribs. 


FROM NORTH-EAST ENGLAND 47 


Discussion: The inner whorls of S. (Sp.) versicolor figured by M. Pavlow (1886) 
are similar to the Speeton specimens in degree of inflation, but the tubercle is higher 
on the flanks. However, Chernova’s (1952 : fig. 3) diagrammatic cross-section at 
30 mm diameter is very close to that of the Speeton example; the Speeton specimens 
are therefore provisionally referred to S. (Sp.) versicolor. They are considerably 
more inflated than the inner whorls of S. (Sp.) anversum. 

The Speeton specimen(s) on which Spath’s (1924 : 76) record of S. (Sp.) versicolor 
was based has not been traced. 


DISTRIBUTION: Speeton Clay; exact horizon not known. Versicoloy zone, Russia. 


Simbirskites (Speetoniceras) sp. 
(Plt x, figs 10) 


Discussion: A small, partly crushed specimen (author’s collection, BM. C.75648), 
20:3 mm in diameter, appears close to S. (Sp.) inmversum in general features but is 
more finely ribbed, having 30 primary and approximately 60 secondary ribs on the 
last whorl. The specimen came from the pale blue clay just above the hard stone 
band of C7F, the highest horizon from which Speetoniceras has so far been recorded 
at Speeton. A number of similar but completely crushed forms were found in the 
same bed but disintegrated on exposure. 


Subgenus MILANOWSKIA Chernova, 1952 


TYPE SPECIES: Ammonites speetonensis Young and Bird 1828, by original desig- 
nation. 


Diaenosis: Shell moderately evolute to slightly involute, usually moderately 
compressed though the earliest whorls may be more inflated, resembling those of 
Speetomiceras. Short primary ribs normally branch at a subdued tubercle into 2-5 
secondary ribs; other secondaries may appear higher on the whorl flank. 

Both types of Simbirskites suture occur in Milanowskia. 


Discussion: Species of Milanowskia grew to large diameters, but the two com- 
monest and best-known Speeton species, S. (M.) concinnus and S. (M.) speetonensis, 
are known only from septate inner whorls. S. (M.) concinnus is intermediate in 
form between the earlier S. (Sp.) znversum and the later S. (M.) speetonensis, but the 
relationship between other species is less clear. The origin of S. (M.) staffi and 
related forms from north Germany is particularly problematic, and this group was 
separated from Milanowskia by Bahr (unpublished dissertation) as a new subgenus. 

Among the species of Milanowskia described here the earlier forms (concinnus, 
speetonensis, staffi, and S. (M.) sp.) have a suture with relatively broad, only slightly 
subdivided saddles, while the later S. (M.) lippiacus and S. (M.) cf. lippiacus have 
the narrower, longer, more strongly subdivided saddles typical of Chernova’s 
(1952 : 50) progredicus group of Milanowskia. 


48 HAUTERIVIAN AMMONITE SIMBIRSKITES 


Simbirskites (Milanowskia) concinnus (Phillips) 
(Pl. 2, figs 2-6, 8; Pl. 12, fig. 11; Text-figs 2b, 6) 


1829 Ammonites concinnus Phillips: 123, pl. 2, fig. 47. 

1835 Ammonites concinnus Phillips; Phillips: 94, pl. 2, fig. 47. 

1875 Ammonites concinnus Phillips; Phillips: 264, pl. 2, fig. 47. 

1889 Olcostephanus speetonensis concinnus (Phillips) Pavlow: pl. 3, fig. 7. 

1892 Olcostephanus (Simbirskites) concinnus (Phillips); Pavlow: 501, pl. 18, fig. 16. 
1892 Olcostephanus (Simbirskites) progrediens (Lahusen); Pavlow: 504, pl. 18, fig. 15. 
1906 © Olcostephanus (Simbirskites) concinnus (Phillips); Danford: r10, pl. 12, fig. 2. 
1924 Simbirskites? concinnus (Phillips) Spath: 76. 

1924 Simbirskites progredicus (Pavlow 1892 non auct.) Spath: 77. 

1951 Speetonicevas (Milanowskia) lahuseni Chernova: 63. 

1962 Simbirskites concinnus (Phillips); Howarth: 130, pl. 19, fig. 6. 


Type: The holotype, originally in the Yorkshire Museum, York, has decomposed 
(Melmore 1947 : 235); the specimen figured by Pavlow (1892: pl. 18, fig. 16) was 
designated neotype and refigured by Howarth (1962 : pl. 19, fig. 6). BM. C.465r. 


MATERIAL: 65 septate inner whorls from the Speeton Clay; 62 from 0-3-0-9 metres 
above the base of bed C6 (author’s collection, BM. C.75649-75709, C.75893); BM 
C.34953 (Lamplugh collection), HU. Rn. 397 and GSM. 30582 from C6. One 
specimen (author’s collection, BM. C.75711) from the capricornu zone of Sarstedt, 
near Hannover. There is additional Speeton material in all the examined collec- 
tions. 


DESCRIPTION: Known only from septate inner whorls (up to 33-5 mm diameter). 
Shell moderately evolute with sub-circular whorl section and rounded flanks and 
venter. Sharp primary ribs branch a third of the way over the whorl flank at a 
feeble, radially elongate tubercle, into two or three secondary ribs. There are 
18-25 (usually 19-22) primary ribs and 45-65 (usually 50-60) secondary ribs per 
whorl at diameters of 20-25 mm. The ribs are gently prorsiradiate, curving for- 
wards over the venter. The shell is smooth to about 8 mm diameter when the 
primary and secondary ribs appear practically simultaneously. 

The suture-line (Text-fig. 2b) is inverse, with broad, only slightly subdivided 
saddles. 


DIMENSIONS OF FIGURED SPECIMENS: 
BM. C.75695. 17:5; 8:5, 8-0, 4°3. 
BM. C.75893. 20:4; 8:8, 9:7, 6:0. 20 pr., approx. 48 sec. ribs. 
BM. C.75706. 24:2; 10°5, 10°8, 7:4. 24 pr., 60 sec. ribs. 
BM. C.75708. 25-8; 11:0, 10-7, 7°8. 23 pr., 58 sec. ribs. 
BM. C.75711. 30:6; at 24:3; 10°3, 10-0, 7:1. 18 pr., approx. 46 sec. ribs. 
GSM. 30582. 33:5; 13:6, 12:8, I1°5. 22 pr., 55 sec. ribs. 


Discussion: The variation in the dimensions of this species is shown in Text-fig. 6; 
most of the specimens are less than 20 mm in diameter and the earliest part of the 
last preserved whorl is still smooth, so that few rib counts can be made. The 


FROM NORTH-EAST ENGLAND 


49 


proportion of bifurcating to trifurcating ribs varies; at one extreme only about one 
third of the primary ribs trifurcate while at the other extreme every primary rib 
The neotype is a coarsely ribbed individual; at 27 mm diameter there 


trifurcates. 


height 


whorl 


104 


thickness 


whorl 


12 14 16 (i 20) D7 PE) 2 EN YO) 2 


diameter 


iba T = SSS ahencasiel 


7 
12 14 16 1S rd O22 24 Ay AY SO) 7 


diameter 


34 


Fic. 6. Variation in whorl-proportions of 63 specimens of Simbirskites (Milanowskia) 
concinnus, 62 specimens from Bed C6 (0:3-0-9 metres above base) and 1 specimen 
(GSM.30582, indicated by a X) from the C Beds, Speeton. 


50 HAUTERIVIAN AMMONITE SIMBIRSKITES 


are 18 primary ribs and only about 46 secondary ribs. There is every range of 
variation between this and a finely ribbed, slightly less inflated specimen of S. (M.) 
concinnus figured by Pavlow (1892 : pl. 18, fig. 15) as ““Olcostephanus (Simbirskites) 
progrediens (Lahusen)’’. Pavlow recorded this from C4 but Spath listed “S. 
progrediens (Pavlow, 1892 non auct.)’”’ from C6. Pavlow’s specimen (BM. C.34953) 
has 22 primary ribs and approximately 65 secondary ribs at 23 mm diameter, and 
compares closely with other finely-ribbed specimens of S. (M.) concinnus from low 
C6. Pavlow’s specimen is the holotype of S. (M.) lahuseni Chernova (1951 : 63), 
which was proposed as a nomen novum for S. progrediens (Pavlow 1892 non Lahusen). 
S. (M.) lahusenz is here regarded as a junior subjective synonym of S. (M.) concinnus. 

S. (M.) concinnus is close to Speetoniceras; the more coarsely ribbed specimens 
differ from the small Speeton examples of S. (Sp.) inversum only in the possession of 
trifurcating as well as bifurcating ribs. It has clearly evolved from S. (Sp.) inversum, 
and in turn gives rise to S. (M.) speetonensis. 

S. (M.) concinnus resembles some of the varieties of S. cf. decheni, but is less 
inflated. It is more inflated and more evolute than S. (M.) speetonensis. 

S. (M.) concinnus occurs in north Germany, but from the limited material available 
the German specimens appear to be more coarsely ribbed with fewer secondary ribs 
than the Speeton forms. A German specimen from the upper part of the capricornu 
zone, Sarstedt, is figured here (pl. 2, fig. 5). 


DISTRIBUTION: Speeton Clay speetonensis zone, concinnus subzone; Lower Tealby 
Clay of Donnington-on-Bain, Lincolnshire (p. 35); upper part of capricornu zone, 
north Germany; decheni zone, speetonensis subzone, Russia. 


Simbirskites (Milanowskia) speetonensis (Young and Bird) 
(Pl. 2, figs 7, 9-11, 15; Pl. 11, fig. 4) 


1828 Ammonites spetonensis (sic) Young and Bird: 265, pl. 12, fig. 5. 

1829 Ammonites venustus Phillips: 123, pl. 2, fig. 48. 

1835 Ammonites venustus Phillips; Phillips: 94, pl. 2, fig. 48. 

1874 Ammonites fasciatofalcatus Lahusen: pl. 7, fig. I. 

1875 Ammonites venustus Phillips; Philips: 264, pl. 2, fig. 48. 

1889 Ammonites speetonensis Young and Bird; Lamplugh 613 (pars). 

1889 Olcostephanus speetonensis venustus (Phillips) Pavlow: 59, pl. 3, fig. 6. 

1889 Olcostephanus fasciatofalcatus (Lahusen) Pavlow: 117, pl. 3, fig. 8. 

1892 Olcostephanus (Simbirskites) speetonensis (Young & Bird) Pavlow: 500, pl. 18 (11), fig. 7. 
1901 Simbirskites speetonensis (Young and Bird) Pavlow: 76, pl. 4, fig. 1, pl. 7, fig. 4. 

1906 Olcostephanus (Simbirskites) payert (Toula); Danford: pl. 12, fig. 1. 

1924 Simbirskites venustus (Phillips); Spath; 77. 

1924 Simbirskites speetonensis (Young and Bird); Spath: 77. 

1952 Speetonicevas (Milanowskia) speetonensis (Young and Bird) Chernova: 50. 
?1960 Speetoniceras speetonensis (Young and Bird); Drushchitz and Kudryavtseva: 274, pl. 19, 

fig. I. 
1962 Simbirskites speetonensis (Young and Bird); Howarth: 131, pl. 19, fig. 2. 
1962 Simbirskites venustus (Phillips); Howarth: 131, pl. 19, fig. 3. 


FROM NORTH-EAST ENGLAND 51 


Type: BM. C.34951 (Lamplugh collection), figured by Pavlow (1892: pl. 18, 
fig. 7), was designated neotype and refigured by Howarth (1962 : 131, pl. 109, fig. 2). 
Bed C6, Speeton. 


MATERIAL: 21 septate inner whorls from Speeton; 17 (author’s collection, BM. 
C.75835-51) from the upper part of Bed C6; GSM. 17919 (Danford collection) from 
C6; YM. tablet 419 (holotype of Ammonites venustus Phillips); Neale collection 1701 
from C6; Wrights’ collection 18670. One specimen from Ulyanovsk (Simbirsk) 
(Gottingen, Orig. Nr. 609-1). There is additional material in all the collections 
examined. 


DESCRIPTION: (of specimens up to 25 mm diameter): Shell slightly to moderately 
involute, slightly inflated to moderately compressed. Whorl flanks gently rounded 
in the slightly inflated forms, almost flat in the more compressed varieties. Ribs 
gently prorsiradiate; at first the short primary ribs branch at a subdued tubercle 
about a third of the way over the whorl flank into two or three secondary ribs, then 
above about 20 mm diameter a third or fourth secondary rib is normally intercalated. 
The ribs curve forwards over the rounded venter. There are 20-30 primary ribs 
per whorl at 20-25 mm diameter; in the specimens with fine primary ribbing only 
three secondary ribs are usually associated with each primary. 

The suture has relatively broad elements. 


DIMENSIONS OF FIGURED SPECIMENS: 


BM. C.75847. 18-7; 8:5, 7:5, 5°3. 26 pr., approx. 61 sec. ribs. 
GSM. 17919. 20:8; 9:0, 8-0, 6:2. 26 pr., approx. 66 sec. ribs. 
Wright’s colln. 18670. 21-3; 10-0, 8-I, 5:0. 30 pr., approx. 70 sec. ribs. 
BM. C.75850. 21:7; 9:9, 8:0, 6:2. 22 pr., approx. 64 sec. ribs. 
HU. Neale colln. 1701. 22:5; 10°5, 8:5, 5°7. 25 pr., approx. 64 sec. ribs. 


Discussion: Small, septate specimens of S. (M.) speetonensis are moderately 
common in the upper half of Bed C6 at Speeton; the largest known Speeton example 
(the neotype) is only 34 mm in diameter. They vary in whorl proportions and 
ribbing, and the “typical’”” compressed, moderately involute forms with flattened 
flanks (e.g. the neotype and BM. C.75850) are rare. The commonest forms are less 
involute and slightly inflated, with rounded flanks. In museum collections these 
are often labelled as S. venustus (Phillips), though Howarth (1962) has shown that 
Phillips’ holotype is almost identical at similar diameter to the neotype of S. (M.) 
speetonensis, of which it is a junior subjective synonym. 

Some of the more evolute, slightly inflated varieties of S. (M.) speetonensis have 
moderately coarse ribbing and approach the more finely ribbed varieties of S. (M.) 
concinnus. They are still not as inflated or as coarsely ribbed as the latter species 
but are clearly derived from it. These forms occur in the lower part of the range of 
S. (M.) speetonensis and the more “‘typical’”’ forms near the top. 

The specimen figured by Danford (1906: pl. 12, fig. 1) as S. payert (Toula) is 
refigured here (pl. 2, fig. 15) as a finely ribbed variety of S. (M.) speetonensis. 


52 HAUTERIVIAN AMMONITE SIMBIRSKITES 


A more advanced growth stage of this species was described from Russia 
(Lahusen 1874) as Ammonites fasciatofalcatus. Pavlow (1892, 1901) subsequently 
included Lahusen’s species in synonomy with S. (M.) speetonensis and refigured 
(Pavlow 1gor : pl. 4, fig. 1) Lahusen’s holotype, illustrating the opposite flank to 
that shown in Lahusen’s original figure. Pavlow’s illustration shows the inner 
whorls to be very close to the neotype of S. (M.) speetonensis, and the similarity is 
emphasized by another Russian specimen which Pavlow presented to the Géttingen 
collections (609-1). Both flanks of the Géttingen specimen are figured here. The 
outer whorl (Plate 11, fig. 4b) is identical to Lahusen’s S. fasciatofalcatus while 
the earlier whorls (Plate 11, fig. 4a) are the same as those of S. (M.) speetonensis. 

The Russian examples of S. (M.) speetonensis thus show that above about 40 mm 
diameter the number of secondary ribs usually decreases to three per primary, and 
these branch from a small, mid-lateral tubercle. The whorls are slightly involute 
with flattened flanks. This morphology persists to at least I00 mm diameter 
(Pavlow 1go1: pl. 7, fig. 4). No examples of this morphological stage have yet 
been found at Speeton. 

Septate nuclei of a form close to S. (M.) speetonensis occur in the lower part of 
the German seeleyi zone (p. 76). 


DISTRIBUTION: Speetonensis subzone of the speetonensis zone, Speeton ; speetonensis 
subzone, decheni zone, Russia; seeleyi zone, Germany (S. (M.) ?speetonensis). 


Simbirskites (Milanowskia) sp. (= S. progredicus Danford non Lahusen) 
(Plz, figs 12, 13) 


Non 1874 Ammonites progredicus Lahusen: pl. 6, fig. 3. 
?1902 Simbirskites elatus Trautschold; Koenen: pl. 6, figs 10-12. 
1906 © Olcostephanus (Simbirskites) progrediens (sic) Lahusen; Danford: pl. 12, fig. 5. 


MATERIAL: Three, two septate specimens in the Danford collection, GSM. 21556 
and 17923 (the latter figured by Danford) and part of the body chamber and inner 
whorls of a third specimen in the author’s collection, BM. C.75714. All from the 
Speeton Clay C Beds, exact horizon unknown. 


DEscriPTION: Shell slightly involute, moderately compressed, whorl section oval, 
broadest in the lower third of the whorl and narrowing towards the rounded venter. 
Ribs gently prorsiradiate, curving forwards over the venter; short, sharp primary 
ribs branch at a small, well-developed tubercle about a third of the way over the 
whorl flank into three, or rarely two, secondary ribs. 


DIMENSIONS OF FIGURED SPECIMEN: 
GSM. 17923. 26-9; 11-6, 10-3, 8-4. 20 pr., 59 sec. ribs. 


Discussion: GSM. 17923 was figured by Danford as S. progredicus (Lahusen)e 
although the two species are close in rib pattern the flanks of S. progredicus converg ; 


FROM NORTH-EAST ENGLAND 53 


conspicuously towards the narrowly rounded venter at all growth stages (Pavlow 
1got : pl. 2, figs 4, 5) while those of S. (M.) sp. are flatter. The Speeton ammonite 
which Pavlow (1892 : pl. 18, fig. 15) figured as S. progredicus is more inflated and 
belongs to S. (M.) concinnus (p. 50). A specimen in the Gottingen collection, 
figured by Koenen (1902) as S. elatus (Trautschold), is close to S. (M.) sp. in general 
proportions but has more bifurcating primary ribs. A septate nucleus from Speeton 
in the Neale collection (S1726) is slightly more involute than S. (M.) sp. and the 
tubercles at the points of branching of the ribs are less well developed. 

S. (M.) sp. is more compressed than S. (M.) concinnus and more coarsely ribbed 
than S. (M.) speetonensis. It differs from both in having more clearly developed 
tubercles at the points of branching of the ribs. 

Danford recorded his figured specimen from C6, and his other specimen (GSM. 
21556) from “‘C upper’. 


Simbirskites (Milanowskia) staffi Wedekind 
(Pl. 2, figs 14, 16; Pl. 3, figs 1, 4; Text-fig. 2c) 
1910 Simbirskites staffi Wedekind: 96, pl. 4, fig. 3. 


Type: The holotype, in the Geologisches-Palaontologisches Institut, Gottingen, 
is from the capricornu Zone at Ihme, near Hannover. 


MATERIAL: Two: author’s collection BM. C.75712 from C6, 0-6 metres above the 
base, and BM. C.75713 (loose on cliff face, Speeton). 


DESCRIPTION: The septate inner whorls of one individual and a whorl fragment of 
another are the only known Speeton representatives of this species. Whorls evolute, 
moderately compressed, with almost flat flanks and a narrow, well-rounded venter. 
Umbilicus shallow, broad, occupying almost a third of the diameter. Ribs slightly 
prorsiradiate; the primaries are short, extending about a third of the way over the 
whorl flank where they bifurcate at a small, radially elongated tubercle. A third 
secondary rib frequently appears higher on the flank, branching from the anterior 
side of the posterior rib of the original pair so that a virgatome pattern develops. 
The secondary ribs curve strongly forwards over the venter. 


DIMENSIONS OF FIGURED SPECIMENS: 
BM. C.38369. 42:0; 15:0, 11-7, 16:6. 22 pr., 60 sec. ribs. 
INCE Kp.37. 34°45)12:0, 11-2, 12:90. 22 pr., 58sec. ribs: 
Mer. 75712. (27°2)9%0"0,. 8-7, 0-9: 
BM. C.75713. 27-8: at 26-0; 9-6, 8-3, 9:9. 20 pr., 58 sec. ribs. 


Discussion: Two German specimens of S. (M.) staffi are figured here for com- 
parison with the Speeton specimens. The latter are slightly more evolute than the 
holotype but fit well into the range of variation of a series of specimens in the 


54 HAUTERIVIAN AMMONITE SIMBIRSKITES 


Gottingen collections. The holotype has 18 primary ribs at a diameter of 28 mm. 

S. (M.) staffi differs from species of the S. (M.) speetonensis group in its virgotome 
rib pattern. It is close to two Heligoland species described by Koenen (1904) a 
S. paucilobus and S. triplicatus, but is more evolute. S. virgifer (Neumayr and 
Uhlig) approaches S. (M.) staffi in rib pattern, but the holotype is a large individual 
not directly comparable with the much smaller examples of S. (M.) staffi. Koenen 
(1904 : pl. 21, fig. 2) figured a small specimen which he assigned to S. virgifer but 
which may not be conspecific with Neumayr and Uhlig’s species; it appears close to 
S. (M.) staffi but is more involute. 

Although not previously recorded from Speeton, S. (M.) staffi is one of the com- 
monest German Simbirskites; it is found associated with rare S. (M.) concinnus 
immediately above the beds with abundant Aegocrioceras spp. The only accurately 
localized Speeton specimen (BM. C.75712) was found in the identical stratigraphical 
position associated with numerous S. (M.) concinnus. 


DISTRIBUTION: Speeton Clay, concinnus subzone, Speeton. Upper part of the 
capricornu zone and lower part of the hildesiense zone, north Germany. 


Simbirskites (Milanowskia) lippiacus (Weerth) 
(Pl. 3, figs 2, 5) 


1884 Ammonites (Olcostephanus) ippiacus Weerth: 13, pl. 3, fig. 3, pl. 5, fig. 3. 
1902 Simbirskites lippiacus Weerth; Koenen: 160, 416, pl. 37, fig. 3. 


Types: The syntypes, originally at Detmold, are believed lost. 


MATERIAL: Two specimens from Tonsberg, near Oerlinghausen; Weerth Collection, 
Gottingen, Orig. Nr. 457-125, 609-2. 


DESCRIPTION: Shell slightly evolute, moderately compressed with flattened flanks 
and narrowly rounded venter. Primary ribs strong, gently prorsiradiate, terminat- 
ing a third of the way over the flank at a tubercle, from which arise two or three 
secondary ribs. Some secondaries branch at varying positions higher on the flank 
and other, long secondaries may be intercalated about half-way over the flank. 
5-7 secondaries are associated with each primary. The secondaries curve strongly 
forward over the venter. 


DIMENSIONS OF FIGURED SPECIMENS: 
Gottingen. Orig. Nr. 457-125. 92:8: at 86-0; 35:6, —, 24:9. 
Gottingen. Orig. Nr. 609-2. 44:2: at 40:5; 17:0, 12-2, 10-9. 


Discussion: Weerth’s type specimens are believed lost and the species has not 
been refigured, so that the two Géttingen topotypes are important for the inter- 
pretation of the species. The larger of the two (457-125) was discussed, and its 
suture figured, by Koenen (1902 : 160, pl. 37, fig. 3). It appears slightly more 


FROM NORTH-EAST ENGLAND 55 


evolute than the larger of the two syntypes (Weerth 1884 : pl. 3, fig. 3) but, as 
Koenen noted, the figure is inaccurate in this respect, for Weerth’s description and 
dimensions indicate a slightly more evolute shell than is shown in his figure. 

A neotype for this species will not be selected until the loss of the syntypes is 
definitely established. 

The species is not definitely known from Speeton, but four whorl fragments are 
described below as S. cf. ippiacus. 


Simbirskites (Milanowskia) cf. lippiacus (Weerth) 
(PI. 3, fig. 3) 


MATERIAL: 4 whorl fragments: BM. C.75715-16 (author’s collection) from the 
stone band in Bed C2E, Speeton; BM. C.72643 (Lamplugh collection); GSM. 17542 
(Danford collection) ‘“Upper C’’. 


Discussion: The material is too fragmentary to be definitely referred to S. (M.) 
lippracus ; three of the specimens are similar in general proportions though possibly 
slightly less compressed, and the primary ribs only extend about a quarter of the 
way over the flank. The fourth (BM. C.72643) is more involute and more inflated 
than the Géttingen specimens. 


Subgenus CRASPEDODISCUS Spath 1924 
TYPE SPECIES: Ammonites discofalcatus Lahusen 1874, SD Wright 1957, L350. 


DracGnosis: A subgenus of Simbirskites with compressed, involute, finely ribbed 
whorls in at least one growth-stage. Early Craspedodiscus (gottscher group) become 
more compressed and more evolute with growth, while later Craspedodiscus (disco- 
falcatus group) become more compressed and more involute with growth, becoming 
oxycone in the adult stage. 

The suture has long, narrow saddles and lobes which become strongly subdivided 
during growth. 


Discussion: The boundary between this subgenus and Milanowskia is an arbitrary 
one and is here drawn where the whorls in at least one growth-stage are compressed 
and involute. Cvaspedodiscus includes at least two separate radiations, probably 
from Milanowskia, an earlier kayseri-gottschei group, with rather evolute, almost 
preisphinctoid outer whorls, and a later discofalcatus-juddi group with an oxycone 
adult stage. S. (C.) variabilis probably represents a third offshoot from Milanow- 
skia. Until the ontogeny of some of these species is known in greater detail and 
their relationship to the various species of Milanowskia more clearly understood, it 
is inadvisable to split the group into more subgenera. 


56 HAUTERIVIAN AMMONITE SIMBIRSKITES 


Simbirskites (Craspedodiscus) gottschei (Koenen) 
(Pl. 4, figs 2, 4, 5; Pl. 5, fig. 1) 


1892 Olcostephanus (Simbirskites) discofalcatus Lahusen; Pavlow: 505, pl. 18 (11), fig. 2. 
1904 Craspedites gottschet Koenen: 32, pl. 1, figs. 3, 4. 

1910 Simbirskites extremus Wedekind: 97, pl. 4, fig 4. 

1924 Cvraspedodiscus gottschet (Koenen) Spath: 77. 


Type: The original of Koenen 1904, pl. 1, fig. 3, in the Géttingen collection, is 
designated lectotype. 


MATERIAL: Eight specimens; BM. C.75717—19 (author’s collection) from bed C4L, 
Speeton, BM. C.34958, BM. C.4704, BM. C.27673, and GSM. 21555 (Danford collec- 
tion, ““C4’”’) and Wrights’ collection 24375 (probably C4). 


DEscrIPTION: Inner whorls involute, compressed, with a narrowly arched venter. 
Primary ribs gently prorsiradiate, extending slightly more than half-way over the 
whorl flank. There are 21-26 primary ribs per whorl at 35-45 mm diameter; three 
or four secondaries are associated with each primary, but there is no definite point of 
branching and the ribs are frequently weakened on mid-flank. At first, all the 
secondary ribs either branch from the primary or are intercalated a little more than 
half-way over the flank, but above 25-30 mm diameter very occasional primary ribs 
branch, or a long secondary is intercalated, low on the whorl-flank. These longer 
secondary ribs may branch again later. 

The outer whorls (above 150 mm diameter) are evolute and less compressed; 
whorls of intermediate size (70-150 mm) have not been found. On the outer whorls 
there are four to six broad, shallow, oblique constrictions. Primary ribs branch 
about half-way over the whorl into a bundle of three or four secondary ribs, though 
the point of branching is usually obscure. Some secondaries are intercalated; the 
secondaries curve gently forwards across the rounded venter. Both primary and 
secondary ribs are strongly prorsiradiate. 

The suture-line has moderately narrow, elongate elements. 


DIMENSIONS OF FIGURED SPECIMENS: 
BM. C.75717. 40-3: at 32‘1; 15:9, —, 6-0. 
BM. C.4704. 40-9: at 39:2; 18-9, 14:0, 8-8. 23 pr., approx. 74 sec. ribs. 
Wrights’ colln. 24375. 184: at 165-5; 55, 35°5, 68. 
at 43-7 there are 26 pr. and approx. 93 sec. ribs. 


Discussion: The holotype of S. (C.) extremus Wedekind (Gottingen collection) is 
almost identical in rib pattern and general proportions to the lectotype of S. (C.) 
gottschei, differing only in being more coarsely ribbed; it is here regarded as a junior 
subjective synonym of S. (C.) gottschet. There is some variation in the rib density of 
the inner whorls of the Speeton specimens; hence BM. C.75718 and Wrights’ specimen 
closely resemble the lectotype of S. (C.) gottschei while BM. C.75717 is close to the 
holotype of S. (C.) extremus. Both BM. C.75717 and C.75718 came from bed C4L. 


FROM NORTH-EAST ENGLAND 57 


BM. C.34958 was figured by Pavlow (1892) as S. (C.) discofalcatus and was later 
(Pavlow 1go1 : 79) reidentified as S. (C.) phillipsi; this and a smaller specimen 
(BM. C.4704; pl. 4, fig. 2) are here regarded as inflated varieties of S. (C.) gottschet. 

The outer whorls of S. (C.) gottschet have not been figured before; the excellent 
specimen in the Wrights’ collection has just over three quarters of an evolute outer 
whorl preserved, of which slightly more than half the whorl is body chamber. The 
last sutures are not conspicuously crowded, and in the absence of any noticeable 
uncoiling of the body chamber the specimen cannot definitely be regarded as adult. 
A second, crushed specimen (BM. C.75718) has three quarters of a whorl of incomplete 
body chamber preserved. The outer whorls are close to those of S. (C.) kayseri 
(Neumayr and Uhlig). The inner whorls of the latter differ from those of S. (C.) 
gottschei only in having fewer secondary ribs per primary, and stronger, more clearly 
defined primary ribs (Bahr, unpublished dissertation). 


DISTRIBUTION: gottschei zone, Speeton; seeleyi and possibly tenuis zones, Germany ; 
dechemi zone, speetonensis and discofalcatus subzones, Russia. 


Simbirskites (Craspedodiscus) cf. kayseri (Neumayr and Uhlig) 
ef. 1881 Perisphinctes kaysevi Neumayr and Uhlig: 146, pl. 19, fig. 1. 


MATERIAL: Two septate inner whorls in the Neale collection, S. 1730 and S. 1682, 
and a third specimen in the British Museum, C. 4705. 


Discussion: The three specimens resemble the inner whorls of the more com- 
pressed varieties of S. (C.) gottschei, differing in having only two or three secondary 
ribs associated with each primary; they are identical to a specimen of similar size 
which Bahr (unpublished dissertation) figured as the inner whorls of the large S. (C.) 
kaysert (Neumayr and Uhlig). 

In north Germany this species appears low in the see/eyi zone (Bahr, unpublished 
dissertation) and apparently gave rise to S. (C.) gottschet. 


Simbirskites (Craspedodiscus) variabilis sp. nov. 
(Ply ties 1, 3,6; Pl. 5, figs 3; 4) 


1906 Olcostephanus (Simbirskites) decheni Roemer; Danford: pl. 12, fig. 7. 

1924 Simbirskites aff. toensbergensis (Weerth) (= “‘dechent’’ Danford non Roemer) ; Spath: 77. 
1924 Simbirshites trifurcatus (Bean MS.); Spath: 77. 

21967 ?Simbirskites toensbergensis (Weerth); Kemper: 126, pl. 11, figs 3, 4. 


Diacnosis: Shell compressed; inner whorls involute, with short primary ribs 
ending at a small tubercle. Four to six secondary ribs are associated with each 
primary. Outer whorl slightly evolute, with more regular rib pattern; number of 
secondary ribs reduced to three per primary. 


58 HAUTERIVIAN AMMONITE SIMBIRSKITES 


TYPE SERIES: Holotype: HU. Rn. 700, from Bed LB6 of the Speeton Clay, 
Speeton; Paratypes: II specimens, g in the author’s collection, BM. C.75853-61; 
Neale collection 1901; BM. C.4649. LB6, C2B (base) and C2C, Speeton. 


DESCRIPTION: Shell compressed, inner whorls involute up to 40-50 mm diameter, 
becoming slightly evolute on the outer whorl (body chamber). Earliest whorls 
(Pl. 5, fig. 3), up to 18 mm diameter, slightly inflated with short, widely spaced 
primary ribs which end at a small, sharp tubercle. Four or five secondary ribs are 
associated with each primary; some of these join the tubercle and the others are 
intercalated at about the same level. Above about 18 mm diameter a sixth rib may 
appear and the mode of branching becomes rather irregular (Pl. 4, figs 3c, 6; Pl. 5, 
fig. 4); two or three secondary ribs branch from the tubercle, another rib may be 
intercalated at about the same level, and one of the secondaries may branch again a 
little higher on the flank. 

The number of primary ribs increases with growth, from 9 at 14 mm diameter to 
16 at 35 mm diameter and about 25 at 80 mm diameter. Above about 50 mm 
diameter the number of secondary ribs per primary decreases to three (rarely, two 
or four) (Pl. 4, figs 1, 3a). Of these, two branch from the tubercle and a third branches 
from one of the original pair slightly higher on the whorl. Less commonly, one 
secondary rib is intercalated instead of joining the tubercle. 

In individuals from Cz some secondary ribs branch again close to the venter; 
this may happen in both inner and outer whorls. 


DIMENSIONS OF FIGURED SPECIMENS: 


BM. C.4649. 79:9; 29:2, I9:I, 27:0. 24 pr., 80 sec. ribs (estimated). 
BM. C.75853. 28-7; 14:6, 8-8, 6:0. 14 pr., approx. 60 sec. ribs. 
BM. C.75857. 14:0; 6-8, 6-2, 3:6. 


Discussion: This species has previously been recorded as S. tvifurcatus Bean MS., 
and a specimen in Bean’s collection (BM. C.4649) bearing his label “Am. trifurcatus” 
is the original of Spath’s record of this manuscript name. It consists of one whorl of 
body chamber with trifurcating ribs. Spath recorded the specimen from Cq, 
probably because the matrix invites comparison with some of the siltstone bands on 
this part of the Speeton section; it is much more likely that Bean obtained it from 
LB6, where the holotype and one of the paratypes were collected. The preservation 
of the specimen and its associated matrix supports this view. There are two 
varieties of this species; in specimens from bed C2 some secondary ribs branch 
again near the venter, a feature which has not been noted in the specimens from 
LB6 or in Bean’s specimen. 

The species is known from early whorls and from body chamber fragments with 
associated external moulds of the inner whorls; by placing body chamber against 
mould it has proved possible to make latex casts showing the form of the penultimate 
whorl (Pl. 4, fig. 3c, Pl. 5, fig. 4). There is no definite evidence that any of the 
specimens are adult; the modification of the ribbing and change in tightness of 


FROM NORTH-EAST ENGLAND 59 


coiling of the shell is a recurring feature in Simbirskites and frequently occurs well 
before the adult stage is reached. 

The earliest whorls of this species are similar to those of S. (S.) yorkshirensis but 
are less inflated with less prominent tubercles. Whorls of intermediate size (20-50 
mm diameter) differ from the inner whorls of S. (C.) discofalcatus in being more 
compressed with a less regular rib-pattern. S. (C.) gottschei is less compressed, the 
secondary ribs appear higher on the whorl flank, and there are no tubercles. The 
outer whorl of S. (C.) variabilis is close to Russian examples of S. (M.) speetonensts of 
similar diameter, but the inner whorls are more compressed, and more involute, and 
have a less regular rib pattern with slightly more secondary ribs per primary, than 
Speeton and Russian examples of S. (M.) speetonensis of comparable size. 

Danford’s (1906) figured S. dechent has decomposed, but a plaster cast (GSM. 
17920) shows that it can be referred to S. (C.) variabilis. 

The derived specimens from Alstaétte which Kemper (1967) figured as ?S. toensber- 
gensis may belong to S. (C.) variabilis, though the outer whorl has more numerous 
secondary ribs per primary than in the Speeton species. 


DISTRIBUTION: Speeton Clay, variabilis zone, Speeton. 


Simbirskites (Craspedodiscus) discofalcatus (Lahusen) 
(Ee Oo ieee ble, fies 1.25 Phiri fies 2-350) 


1874 Ammonites discofalcatus Lahusen: 67, pl. 7, figs 2-4. 
1890 Olcostephanus discofalcatus (Lahusen) Pavlow: 2, pl. 6, fig. Tr. 
1901 Simbirskites discofalcatus (Lahusen) Pavlow: 78, pl. 6, fig. 1; pl. 7, fig. 2 (non 3). 
cf. 1906 Olcostephanus (Simbirskites) discofalcatus (Lahusen); Danford: pl. 12, fig. 8. 
1924 Cyraspedodiscus discofalcatus (Lahusen) Spath: 77-79. 
1924 Simbirshkites aff. fasciatofalcatus (Lahusen); Spath 1924 : 79. 
1960 Cvaspedodiscus discofalcatus (Lahusen); Drushchitz and Kudryavtseva: 274, pl. 19, 
fig. 2, ?fig. 3. 


Type: Following Bahr (unpublished dissertation) the original of Lahusen’s pl. 7, 
fig. 2-3, is proposed as lectotype: Mining Museum, Leningrad Mining Institute, 
catalogue number. 12. 


MATERIAL: 2 specimens and 2 whorl fragments from the Speeton Clay: GSM. 
21493 (Danford collection, ‘“‘B. Base’) and York Museum (no number); GSM. 17543 
and 21494 (Danford collection; whorl fragments). 7 specimens from the Tealby 
Limestone: GSM. 30883 (Judd collection) and BM. C.19993 (P. F. Kendall collection) 
from North Willingham, BM. C.73376-78 (J. E. Lee collection) and BM. C.25183 
from Normanby, and SM. Br1123 from Claxby (erroneously recorded from the 
Claxby Ironstone). 

In addition, 2 Speeton specimens (GSM. 17922 (Danford collection) and BM. 
C.72641 (Lamplugh collection)) are figured here as S. (C.) cf. discofalcatus. 


60 HAUTERIVIAN AMMONITE SIMBIRSKITES 


DESCRIPTION (of specimens more than 100 mm in diameter): Shell compressed, 
involute, with narrowly rounded venter. Whorl broadest near the umbilical edge; 
umbilicus moderately shallow, umbilical wall fairly steep. Rib pattern irregular; 
4 or 5 secondary ribs are associated with each primary, but their point of origin is 
usually obscure. Some arise from a primary rib about a third of the way over the 
whorl, others are intercalated either in the middle or on the outer part of the whorl. 
There are 19-23 primary ribs and 100-120 secondary ribs per whorl at about 120 mm 
diameter. 

The strength of the ribs gradually diminishes with growth (Plate 7), until at 
diameters above 150-200 mm the shell becomes almost smooth, ornamented only by 
feeble rib-folds or striae (Plate 8). 


The suture has long, narrow, strongly divided saddles and lobes. 


DIMENSIONS OF FIGURED SPECIMENS: 


BM.C:5. xor: at 86-7; 43:3, 22°2, 17 (apptox.), «Approx. 22) precibparae 
IOI mm diam. 

BM. C.73376. 122°4: at 115-3; 57:8, 30°3, 18-2. 20 pr., approx. 112 sec. at 
122 mm diam. 

BM. C.73377. 212:5; 109°5, 47 (approx.), 26-0. 24 pr. ribs. 

BM. C.19993. 234:0; I19°5, 52°5, 29:0. 


Discussion: Only two specimens (GSM. 21493 and SM. Br1123) show the inner 
whorls, and they are poorly preserved. At small diameters (less than 45 mm) the 
inflation of the whorl is similar to that of some species of Milanowskia, but with 
growth S. (C.) discofalcatus becomes proportionately more compressed; Pavlow 
(1g01 : 79) has discussed in detail the changes in whorl proportions and ornamenta- 
tion with growth. A small, slightly distorted specimen of 25 mm diameter figured 
by Danford (1906 : pl. 12, fig. 8) is refigured here (Pl. 11, fig. 2), together with a 
similar individual in the Lamplugh collection (BM. C.72641), as S. (C.) cf. disco- 
falcatus. Some even smaller, closely related forms which may be the earliest whorls 
of S. (C.) discofalcatus are described below as S. (?C.) sp. a. 

Of the Speeton specimens definitely referred to S. (C.) discofalcatus, one (GSM. 
21493) is recorded as “B. Base” and the horizon of the others is not accurately 
recorded. Lamplugh’s small S. (C.) cf. discofalcatus is from C3. The species is 
more common in the Tealby Limestone of Lincolnshire, where large individuals of 
100-240 mm diameter occur. These closely match the typical Russian forms; a 
Russian specimen from Ulyanovsk (Simbirsk) (Damon collection, BM. C.5) is 
figured here (PI. 11, fig. 5) for comparison. 

The Speeton specimen which Pavlow (1892 : 505, pl. 18, fig. 2) figured as S. (C.) 
discofalcatus belongs to S. (C.) gottsche: (Koenen). 


DISTRIBUTION: varviabilis zone, Speeton and Lincolnshire ; marginatus zone (S. (C.) 
cf. discofalcatus), Speeton; tenuis? and stvombecki zones, north Germany; dechent 
zone, discofalcatus and umbonatus subzones, Russia. 


FROM NORTH-EAST ENGLAND 61 


Simbirskites (Craspedodiscus) phillipsi (Roemer) 
(Pl. 9, fig. 3) 


1841 Ammonites phillipsi1 Roemer: 85. 


Discussion: S. (C.) phillipst, was first described, though not figured, by Roemer 
(1841 : 85), who suggested that Phillips’ (1829 : 123; 1835 : 94) record of Am. 
lamberti? from the Speeton Clay referred to this species. Roemer described Am. 
phillipsi as involute, disc-shaped, with an almost carinate venter, and with ribs 
which bifurcate at a small tubercle near mid-flank, one of the pair bifurcating again 
later on the whorl flank. The primary ribs number 24-30 on the last whorl. The 
size of the specimen was not indicated, though “4-5 whorls’, were recorded which 
suggests that it may have been fairly large. The original is now lost. 

The lack of a figure or a good original definition of the species has led to con- 
siderable variation in its interpretation. Neumayr and Uhlig (1881 : 33, pl. 15, 
fig. 7) were the first to figure the species, their figured specimen probably being 
smaller than Roemer’s original. They state that in their figured, incomplete 
example, there are 24 to 30 primary ribs, which split into 2 or 3 secondaries somewhat 
under half-way over the whorl, occasional ribs bifurcating again later on the whorl. 
The venter is described as narrow and strongly rounded; the figure shows that the 
venter is probably more rounded than in the specimen described by Roemer, but this 
may be a reflection of difference in size rather than of any specific difference. 
Neumayr and Uhlig’s specimen may well belong to Roemer’s species, but unfortun- 
ately this specimen too is lost. 

Weerth (1884 : 17, pl. 4, figs 2, 3) next described and figured a large individual 
(102 mm in diameter) from the Teutoburger Wald. This agrees with Roemer’s 
original description in density of primary ribbing (25 ribs on the last whorl) and in 
having a very narrow, almost keeled venter. Weerth, however, stated that about 
a third of the way over the whorl the primary ribs branch into three or four secondary 
ribs, which in turn frequently bifurcate later, whereas Roemer only recorded two 
secondary ribs, one of which later bifurcates. 

Weerth’s original is believed lost, but in the Weerth collection at Gottingen there 
are two Tonsburg (Teutoburger Wald) specimens (Orig. Nr. 457-124, 457-123) 
referred to by Koenen (1902 : 157), the larger of which (Orig. Nr. 457-124) is almost 
identical in size, general proportions and rib-pattern to Weerth’s figured specimen. 
This specimen is figured here (PI. 9, fig. 3) as S. (C.) phillipsa (Roemer sensu Weerth). 


DIMENSIONS: 

IIo (approx.); 58 (approx.), 25:8, 15:0. 

It is close to S. (C.) discofalcatus in general proportions but has more numerous 
primary and secondary ribs and a slightly narrower umbilicus. 

Pavlow (1901 : 79) included the more inflated Speeton specimen which he had 
previously (1892 : pl. 18, fig. 2) figured as S. (C.) discofalcatus, in S. (C.) phillipsi, 
and suggested that the latter differed from S. (C.) discofalcatus in having more 
numerous primary ribs and a broader venter. In fact, the descriptions reviewed 


62 HAUTERIVIAN AMMONITE SIMBIRSKITES 


above suggest that the German forms described as S. (C.) phillipsi have as sharp a 
venter as that of S. (C.) discofalcatus but are more finely ribbed (25-30 primaries per 
whorl instead of 19-22). The Speeton form figured by Pavlow is here included in 
S. (C.) gottschet (p. 56). 

In view of the difficulty surrounding the interpretation of S. (C.) phillips: it is a 
very unsatisfactory zonal index, though Koenen (1902) and Spath (1924) both 
recognized a phillipsi zone. 


Simbirskites (Craspedodiscus) sp. (phillipsi group) 
(Pl. 5, fig. 2) 
?1904 Simbirskites philliipsi (Roemer); Koenen: pl. 1, fig. 6. 


MATERIAL: Three; one small whorl fragment from the base of C2B (author’s 
collection, BM. C.75881) and latex casts from 2 external moulds on a nodule from 
the base of C2B (author’s collection, BM. C.75882-3). 

The rib-pattern of these three specimens is close to that of the German individuals 
described above as S. (C.) phillips: (Roemer sensu Weerth), but because of their 
much smaller size they cannot definitely be referred to that species. 

The inner whorls of S. (C.) discofalcatus and S. (C.) variabilis have fewer primary 
ribs and a higher number of secondaries per primary. S. (C.) juddi has a similar 
rib-pattern to that of S. (C.) sp. (phillipst group) but has a narrower umbilicus. 

The Heligoland specimen figured by Koenen (1904) as S. phillipsi is probably 
conspecific with the Speeton specimens. 


Simbirskites (Craspedodiscus) juddi sp. nov. 
(Pl. 10,, figs. 1,,2) 


1867 Ammonites clypeiformis d’Orbigny; Judd: 246. 
1924 Cvraspedodiscus clypetformis (Judd non d’Orbigny); Spath: 79, 87. 


DiaGnosis: A compressed, involute, oxycone Craspedodiscus with very narrow 
umbilicus, acute venter and fine, dense, primary and secondary ribs. 


TYPE SERIES: Holotype: GSM. 31059 (Judd collection) from the Tealby Limestone 
of Tealby. Paratype: BM. C.73375 (J. E. Lee collection), Tealby Limestone, 
Normanby. 


DESCRIPTION: Shell compressed, involute, oxycone, umbilicus very narrow. 
Ribs fine, dense, branching irregularly; primary ribs branch about half way over 
the flank into two or three secondaries, and additional secondaries are intercalated 
close to the venter. The ribs curve forwards over the acute venter. 


DIMENSIONS OF FIGURED SPECIMENS: 
GSM. 31059 (holotype). 153: at 145; 78, 29°5, 14. 
BM. C.73375 (paratype). 107°5, 59, 27°5, 9- 


FROM NORTH-EAST ENGLAND 63 


Discussion: The rib pattern can only be seen clearly on part of the holotype, and 
changes of rib-pattern with growth have not been observed. Despite the indifferent 
preservation of the type material, S. (C.) juddi is readily distinguished from S. (C.) 
phillipsi (Roemer sensu Weerth) and S. (C.) discofalcatus (Lahusen) by the greater 
compression of the shell and greater degree of involution with consequently narrower 
umbilicus. It is further distinguished from S. (C.) discofalcatus by its denser primary 
and secondary ribbing. 

S. (C.) juddi was recorded by Judd (1867 : 246) as Ammonites clyperformis d’Orb, 
and the holotype is a specimen from Tealby presented to the Geological Survey by 
Judd in 1867. This is almost certainly the same specimen which Pavlow (1901 : 80, 
footnote) referred to as close to S. (C.) discofalcatus but even more discoidal; Pavlow 
provisionally identified it as “Ammonites discus’’. 

Lamplugh’s (1896 : 210) reference to “Ammonites clypetformis” probably embraces 
both S. (C.) juddi and S. (C.) discofalcatus. 

Stratigraphical information on the relative position within the Tealby Limestone 
of S. (C.) discofalcatus and S. (C.) juddi is lacking, and Spath’s (1924) recognition of 
a clypetformis (Judd non d’Orb.) zone above a discofalcatus zone is presumably 
based on his suggestion (Spath 1924 : 87) that S. (C.) clypeiformis Judd non d’Orb. 
is the final, oxycone stage of the Craspedodiscus group. 


DISTRIBUTION: Upper part of the variabilis zone, Tealby Limestone, Lincolnshire. 


Simbirskites (?Craspedodiscus) sp. a 
(Ved. sepes ails) 


MATERIAL: 14 septate nuclei (10 in author’s collection BM. C.75862-71; 4 in 
Neale collection) from C3, Speeton. 


DESCRIPTION: Known from septate inner whorls only; the largest specimen is only 
about 20 mm in diameter, and in none are details of the ribbing preserved above 
I5 mm diameter. Shell involute, moderately compressed, venter narrowly rounded. 
Primary ribs extend nearly half-way over the whorl, where they swell slightly and 
branch into secondaries. Three or four, sometimes five, secondaries are associated 
with each primary, of which two or three branch from the primary and one or two 
are intercalated close to the point of branching. Ribs prorsiradiate, curving 
strongly forwards near to and over the venter. 


DIMENSIONS OF FIGURED SPECIMEN: 
BM. C.75862. 13:6: 7:0, 6:1, 3:0. 19 pr. ribs. 


Discussion: This species is common in C3 at Speeton, from which bed Lamplugh 
(1889 : 596) recorded it as ‘‘the fine-ribbed variety of Amm. speetonensis’. The 
specimens are too small to be identified with certainty but appear close to the 
earliest whorls of S. (C.) discofalcatus as described by Pavlow (1901 : 79). They 
have more numerous secondary ribs per primary than the early whorls of S. (M.) 
speetonensis. 


64 HAUTERIVIAN AMMONITE SIMBIRSKITES 


Simbirskites (?Craspedodiscus) sp. b 
(Pl. 6, fig. 1) 


1868 Ammonites bipinnatus Williamson MS.; Judd: 246 (pars). 


A large Tealby Limestone ammonite (GSM. 47071, presented by Judd and 

labelled “Ammonites bipinnatus’’) has the following dimensions: 
205: at 198; 76°5, —, 62. 

It is slightly involute with gently curved flanks and narrowly arched venter. 
Primary ribs bifurcate about a third of the way over the whorl flank, and one or 
both secondaries may branch again nearer the venter. Occasionally a secondary is 
intercalated in mid-flank. The suture has long, narrow, strongly divided saddles 
and lobes. 

The specimen is probably an original of Judd’s (1868 : 246) record of A. bipinnatus. 
However, the record of this species from the ‘“‘Ancyloceras beds”’ of the Speeton Clay 
(associated with “Ancyloceras duvalit’”’ in Judd’s fig. 4) probably refers to S. (C.) 
gottschet, the outer whorls of which are close to the present specimen but are more 
evolute with shallow constrictions. The stratigraphical horizon would agree; 
although it is difficult to correlate the ‘“‘Ancyloceras beds” with Lamplugh’s succes- 
sion they may correspond with bed C4, at the base of which S. (C.) gottsche and 
Aegocrioceras cf. seeleyi (the “A. duvalit” of Judd’s record?) occur. 


Subgenus SIMBIRSKITES SENSU STRICTO 


DiaGnosis: Shell inflated to coronate; short primary ribs normally end at 
prominent tubercles, from which arise 2-4 secondary ribs. Both types of suture 
occur. 


Discussion: S. (S.) pavlovae and S. (S.) coronatiformis, the two earliest known 
Simbirskites s.s., occur in the upper part of the Russian versicolor zone and it has 
already been suggested (p. 39) that they may be connecting links between S. 
(Speetoniceras) versicolor and later Simbirskites s.s. The inner whorls of both species 
differ from those of S. (Sp.) versicolor and allies in being more inflated with more 
numerous secondary ribs (3-4) per primary. With growth the number of secondary 
ribs decreases to two per primary and the whorl becomes less coronate, so that adult 
specimens closely resemble contemporaneous Speetoniceras (Chernova 1952 : 53). 
Thus both morphologically and stratigraphically they lie between S. (Sp.) versicolor 
with bifid ribbing and inflated inner whorls, and later Simbirskites s.s. which remain 
inflated or coronate with 3-4 secondary ribs throughout growth. 

Simbirskites s.s. appears to have evolved along a separate line from the Milanow- 
skia—Craspedodiscus groups, though evolutionary relationships are still far from 
clear and there may be connections between these three subgenera. 

Simbirskites s.s. is rare at Speeton, being represented by a few small, septate 
nuclei belonging to three species; large specimens are common in Russia, and the 
most typical form and sculpture is seen in specimens of 50-90 mm diameter 
(Chernova 1952 : 47). Above this diameter the sculpture usually weakens. 


FROM NORTH-EAST ENGLAND 65 


Simbirskites (Simbirskites) umbonatus (Lahusen) 
(Pl. 12, fig. 15; Text-fig. 2k) 


1874 Ammonites umbonatus Lahusen: 33, pl. 5, fig. 2; pl. 6, fig. 1 (non 2). 
1884 Ammonites picteti Weerth: 12, pl. 2, fig. 6 (?nom fig. 5). 
tgor Simbirskites umbonatus (Lahusen) Pavlow: 71, pl. 5, figs 1, 2. 


Discussion: S. (S.) wmbonatus is a coronate species in which strong primary ribs 
branch at a prominent tubercle into three or four secondaries; a Russian specimen 
in which each rib trifurcates is figured here, and has the following dimensions: 

78-7: 28-7, 37°6, 31°7.. 25 primary ribs, approx. 75 secondary ribs. 

The specimen (BM. C.17, Damon collection) is from Ulyanovsk (formerly 
Simbirsk). 

Although S. (S.) wmbonatus is well known in Russia and is a subzonal index in the 
Russian decheni zone, it has not been found at Speeton; the specimens recorded by 
Pavlow (1892 : 503, pl. 18 (11), figs 3, 8) belong to the less inflated S. (S.) yorkshirensis 
Chernova. The small specimens described here as S. (S.) marginatus (Phillips) may 
be the inner whorls of S. (S.) wmbonatus; their relationship is discussed below. 


Simbirskites (Simbirskites) marginatus (Phillips) 
(Pl. 12, figs 13, 14; Text-fig. 21) 
1829 Ammonites marginatus Phillips: 123, pl. 2, fig. 41. 
1835 Ammonites marginatus Phillips; Phillips: 95, pl. 2, fig. 41. 
1868 Ammonites marginatus Phillips; Judd: 247. 
1875 Ammonites marginatus Phillips; Phillips: 264, pl. 2, fig. 41. 
1889 Ammonites marginatus Phillips; Lamplugh; 614. 
1924 Simbirskites marginatus (Phillips) Spath: 77. 
1962 Ammonites marginatus Phillips; Howarth: 132. 


Type: The holotype (from the Speeton Clay of Speeton), formerly believed lost 
(Howarth 1962 : 132), is in the Yorkshire Museum, tablet 414. It is refigured here 
tel 12, fig. 13). 

MATERIAL: 12 specimens: BM. C.75872-79 (author’s collection) from C3 and 
BM. C.75880 from C2F, Speeton. BM. C.34955-6 and YM. tablet 414A from 
Speeton, exact horizon not known. 


DESCRIPTION: Known from early whorls (up to 15 mm diameter) only. Shell 
inflated, whorl-section sub-coronate to coronate. Umbilical wall bears feeble rib- 
folds which terminate just above the umbilical edge in prominent tubercles, 11 or 
12 per whorl. From these arise four or five secondary ribs, of which one is usually 
intercalated. The secondaries curve gently forwards over the broad ventral region. 
The tubercles appear at a very early growth-stage (3:5-4:0 mm diameter) and the 
ribs slightly later (7 mm diameter). 

The external suture (Text-fig. 21) has relatively narrow elements, even at only 
9-5 mm diameter. 


66 HAUTERIVIAN AMMONITE SIMBIRSKITES 


DIMENSIONS OF FIGURED SPECIMENS: 
YM. tablet 414 (holotype). 11-3; 5-1, 7:3, 3°6. 12 tubercles. 
BM. C75874, 12:0; 62,104.37. 12 tubercles: 


Discussion: Although known only from small specimens, this species is sufficiently 
well-marked to have long been recognized as distinctive of part of the Upper C 
Beds, “‘occurring most frequently in the lower part of the Echinospatangus-bed [C3], 
though nowhere abundant”’ (Lamplugh 1889 : 614). It occurs scattered throughout 
C3 and is a useful index fossil for this part of the succession. 

S. (S.) marginatus may be conspecific with the Russian S. (S.) umbonatus (Lahusen), 
for the holotype closely matches a Russian individual of 15 mm diameter figured 
by Pavlow (1901 : pl. 5, fig. 2) as the early whorls of S. (S.) umbonatus. In the 
absence of larger Speeton specimens closer comparison is not possible. The com- 
parison between the two species is further complicated by Chernova’s (1951 : 55) 
view that Pavlow’s figured specimens of S. (S.) umbonatus are not conspecific with 
Lahusen’s originals. Chernova renamed Pavlow’s specimens as S. (S.) pavlovt nom. 
nov., though it is doubtful whether they are really a distinct species. 

S. (S.) marginatus differs from the more inflated varieties of the S. (S.) decheni 
group in having sharper tubercles and finer ribbing. 

Because of the small size of the holotype and Phillips’ sketchy figure, the specific 
name ‘‘marginatus’’ caused confusion for later workers; Roemer (1841 : 86) appar- 
ently applied it to a species of Polyptychites, a practice definitely followed by 
Neumayr and Uhlig (1881 : 157) and Koenen (1902 : 127; 1909 : 25). 


DISTRIBUTION: Speeton Clay, marginatus zone, Speeton. 


Simbirskites (Simbirskites) yorkshirensis Chernova 
(PI. 22, figs.2,.55,7) 


1892 Olcostephanus (Simbirskites) umbonatus (Lahusen); Pavlow: 504, pl. 18 (11), figs 3, 8. 
1924 Simbirskites aff. toensbergensis (Weerth); Spath: 77. 
1951 Simbirskites torkshivensts (sic) Chernova: 63. 


Type: Chernova introduced S. yorkshivensis as a nomen novum for S. (S.) 
umbonatus Pavlow (1892) non Lahusen; of the two syntypes, the original of Pavlow’s 
plate 18 (11) fig. 8, is here selected lectotype. BM. C.34962, from the upper C Beds, 
Speeton. 


MATERIAL: Four small septate specimens from the Speeton Clay; BM. C.75884 
(author’s collection) from bed C2C, BM. C.75885-6 (author’s collection) from the 
upper C Beds, and Wrights’ collection 24284. 


DEscRIPTION: Shell slightly inflated with ellipsoid whorl section, broadest near 
the umbilical edge; venter arched. Short, straight primary ribs extend about a 
third of the distance over the flank, ending in a prominent mid-lateral tubercle. 
There are 10-12 tubercles per whorl at diameters of 14-21 mm. Four, or rarely 
three, secondary ribs are associated with each tubercle, of which one is usually 


FROM NORTH-EAST ENGLAND 67 


intercalated while the others join the tubercle. Ribs nearly straight on the flanks, 
secondaries curving forwards over the venter. 


DIMENSIONS OF FIGURED SPECIMENS: 

Wrights’ colln. 24284. 21-1; 9:6, 9:0, 6-4. 12 pr., 49 sec. ribs. 
BM. C.75885. 18-7; 9-1, 8:6, 5:0. 12 pr., 46 sec. ribs. 

Discussion: Pavlow’s other figured specimen (BM. C.34982) from the Lower 
Tealby Clay of Donnington-on-Bain, Lincolnshire, is considerably larger than the 
Speeton examples and can only provisionally be attached to S. yorkshirensis. 
Pavlow (1892 : 504) regarded his figured S. wmbonatus as intermediate in character 
between S. wmbonatus (Lahusen) and S. toensbergensis (Weerth), and later (Igor : 72) 
referred the Speeton specimens to S. toensbergensis instead. Three specimens of the 
latter species were figured by Weerth (1884 : pl. 4, figs 4-6) of which one (fig. 5) is of 
comparable diameter to the Speeton S. yorkshivensis and differs only in having 
slightly more numerous secondary ribs (four or five to each primary). The two are 
clearly closely related, but Weerth’s species requires modern revision. 

S. (S.) yorkshivensis differs from the inner whorls of S. (S.) cf. dechent in being 
more compressed with stronger tubercles. 


DISTRIBUTION: Speeton Clay variabilis zone, Speeton. Lower Tealby Clay of 
Donnington-on-Bain, Lincolnshire (S. (S.) cf. yorkshirensis). Decheni zone, umbo- 
natus subzone, Russia. 


The Simbirskites (Simbirskites) decheni (Roemer) group 
(Bibi, fisso Pl 128 fieser, 354510) S10) 


Discussion: Although S. (S.) decheni is a difficult species to interpret it is exten- 
sively quoted in the Russian, German and English literature and is the index fossil 
of the Russian decheni zone. The German type-specimen, from the “Quader’’ of 
the Teutoburger Wald, is lost and Roemer’s (1841 : pl. 13, fig. 1) figure is poor; it is 
therefore difficult to decide whether two specimens from the Osning Sandstone of 
Tonsberg (Teutoburger Wald) figured by Weerth (1884 : pl. 1, fig. 3; pl. 2, fig. 1) 
are conspecific with Roemer’s original. Most Russian workers have followed 
Pavlow’s (1g01) interpretation of the species, as did Wedekind (1910: 94) in 
Germany. Pavlow (1901 : 69) had conserved the specific name for those Russian 
forms which (following Lahusen 1874) were commonly referred to S. (S.) dechent, 
whilst showing that Roemer’s original description also corresponded in part to two 
other Russian species, S. elatus and S. pseudobarbott. Pavlow therefore attributed 
authorship of the Russian S. (S.) decheni to Lahusen. 

The species clearly requires stabilization by the erection of a neotype, but this 
cannot be attempted until a satisfactory German specimen becomes available. The 
various English, German and Russian forms which have been figured as S. (S.) 
decheni are closely related and may well be conspecific. At Speeton the S. (S.) 
dechemt group is represented by rare septate inner whorls which exhibit some varia- 
tion in shell proportions and rib density; most can be compared closely with small 
specimens previously figured as S. (S.) dechent. 


68 HAUTERIVIAN AMMONITE SIMBIRSKITES 


Two varieties occur in the lowest 0-61 metres (2 feet) of C6 (concinnus subzone). 
At comparable growth-stages, BM. C.75887-9 (author’s collection) and BM. C.75568 
(collected from the C Beds by Mr. D. Ward) closely match the Speeton specimen 
figured by Pavlow (1892: pl. 18, fig. 5 only; this specimen was later (Pavlow 
Igo : 68) referred to S. elatus (Trautschold)). Four specimens are figured here 
(Pl. 12, figs 1, 3, 4, 10) as S. (S.) cf. dechent (Roemer) var. a. They show only a 
feeble swelling where the primary ribs branch, and differ from S. (M.) concinnus 
only in being slightly more inflated. 

The second variety from low C6 (figured here, Pl. 12, figs 8, 9g as S. (S.) cf. dechemt 
(Roemer) var. b) is more inflated with more clearly developed tubercles; there is a 
small specimen in the author’s collection (BM. C.75890; pl. 12, fig. 9) and a larger 
individual (probably C6) in the Wrights’ collection (17593; pl. 12, fig. 8). 

A larger, strongly tuberculate specimen from Middle C, figured by Pavlow (1892 : 
pl. 18, fig. 4), is close to a German specimen from Ihme figured by Wedekind (1910 : 
pl. 4, fig. 1) and to another Ihme specimen figured here (Pl. 11, fig. 5) as S. (S.) 
dechent (Roemer) sensu Wedekind. It is also close to the Russian individuals 
figured by Pavlow (1901 : pl. 1, figs 4-6). Some partly crushed, coarsely ribbed 
whorl fragments from C4 (author’s collection, BM. C.75891-2 from Bed C4I and 
Wrights’ collection 24578-80, 24697) probably belong to the same variety or to a 
closely related, slightly more compressed form in the Lamplugh collection (BM. 
C.72632) figured here (Pl. 12, fig. 6) as S. (S.) cf. decheni var. c. 


DIMENSIONS OF FIGURED SPECIMENS: 
BM. C.75888. 14:4; 6-8, 8-0, 4:0. 
BM. C.75568. 16:4; 7:5, 9°3, 4°5. 15 pr. ribs. 
BM. C.75889. 16:0; 7-2, 8:6, 4:7. 15 pr. ribs. 
BM. C.75887. 21-9; 10-0, 12-0, 6-7. 18 pr., approx. 50 sec. ribs. 
BM..C:75890;, 14-25/7-0, 9:3, 3:0. 
Wrights’ colln. 17593. 23-1; 9:7, 13:6, 7:9. 16 pr., approx. 52 sec. ribs. 
BM. C.14419. 34:3; 13:4, 17:0, 12:3. 18 pr., approx. 42 sec. ribs. 

Until more material becomes available it will be impossible to make an adequate 
study of the German and English forms or to ascertain the relationship between 
these and the forms figured by Weerth (1884) as S. cf. inverselobatus (Neumayr and 
Uhlig) and S. nodocinctus (Weerth). 


Simbirskites (Simbirskites) cf. virgifer (Neumayr and Uhlig) 
(Pl 12; fig712) 


cf. 1881 Olcostephanus virgifey Neumayr and Uhlig: 160, pl. 33, fig. 1. 


Discussion: A single whorl fragment (HU. Rn. 923, collected by Mr. D. Sowter) 
from the Lower Tealby Clay or Tealby Limestone of Nettleton is close to the holotype 
of S. (S.) virgifer in rib-pattern and general proportions. The primary ribs of the 
Nettleton specimen branch at a slight swelling into two secondary ribs; a third 
usually branches from the anterior side of the posterior rib of the original pair. 


FROM NORTH-EAST ENGLAND 69 
Simbirskites spp. 


In addition to the species described above, there are a number of specimens in the 
author’s collection and in museum collections which are too inadequately preserved 
for description; none of them can be definitely named but they indicate the presence 
of several otherwise unrecorded species. 

A specimen from the Lower Tealby Clay of Nettleton (Wrights’ collection 21711) 
and a similar individual from Speeton (Yorkshire Museum) appear close to S. (M.) 
polivnensis Pavlow (1901 : 77, pl. 7, figs 5-6). Several tuberculate fragments from 
C2C and C2E (author’s collection) belong to the yorkshirensis-toensbergensis group, 
and two other whorl fragments from C2C and C2E (author’s collection) appear close 
to Weerth’s poorly known Simbirskites arminius. 

Some very compressed nuclei from C5? (Wrights’ collection) appear to be an 
undescribed species of Craspedodiscus, and C2E yields large, smooth Craspedodiscus 
fragments. 

A large, indifferently preserved specimen from the Tealby Limestone of Nettleton 
(BM. C.74671, presented by Mr. A. Eborn) has a smooth septate outer whorl and 
sharply ribbed earlier whorls. The whorl section and ribbing of the penultimate 
whorl show that the specimen can be provisionally identified as S. (M.) cf. progredicus 
(Lahusen). 

Spath (1924) recorded several species not described here. His record of S. (S#.) 
subinversum (Pavlow) is believed to be based on A. P. Pavlow’s misidentification of 
that species (p. 46). The originals of S. triplicatus Koenen from C6 and S. 
progredicus (Lahusen) from C3 and Cr have not been traced. The S. (C.) cavinatus 
(Koenen) from B Base is probably a whorl fragment of S. (C.) discofalcatus. The 
records of S. (C.) barbotanus (Lahusen) and S. (C.) phillipsi (Roemer) Weerth sp. 
from the Tealby Limestone have not been confirmed. 


V. ZONATION OF THE Simbirskites BEDS OF THE SPEETON CLAY 


The four belemnite zones which Lamplugh (1889) distinguished in the Speeton 
Clay are large units and are therefore only of limited use in correlation. The 
replacement within the Simbirskites beds of Hibolites jaculoides by Oxyteuthis 
marks the C/B Beds boundary; the same faunal change occurs in Lincolnshire at the 
Lower Tealby Clay/Tealby Limestone junction (p. 35) and in north Germany 
within the varocinctum zone. 

Judd (1867) relied mainly on the ammonite sequence to subdivide the Speeton 
Clay, and was the first author to utilize a Simbirskites (“Am. speetonensis’’) as a 
zonal form. Unfortunately, although some of Judd’s zones are easy to recognize 
others cannot be satisfactorily correlated with Lamplugh’s better known lithological 
subdivisions. Pavlow (1892 : 559) later distinguished two ammonite zones in the 
Speeton Clay Simbirskites beds, a lower S. (Sp.) subinverswm zone (C7—C6) and an 
upper S. (S.) dechem—S. (M.) speetonensis zone (C6—-Cr) ; he equated the former with 
the Russian versicolor zone and the latter with the decheni zone. 


70 HAUTERIVIAN AMMONITE SIMBIRSKITES 


In 1924, Spath published a detailed zonation for the north-west European Lower 
Cretaceous, and for the Speeton succession this appeared to be a great advance on 
previous schemes. Unfortunately Spath’s zonation is based upon a hypothetical 
ammonite succession, the zonal forms being drawn from both Speeton and North 
Germany, and some only occurring in one area or the other (cf. Casey’s (1961 : 494) 
criticism of Spath’s zonation of the Aptian and Lower Albian). 

Spath’s subdivision of the Simbirskites beds is: 


Zone Bed (Speeton) 
Paracrioceras rarocinctum Lower B (pars) 
S. (C.) clypeiforme Not represented (Tealby Limestone 
S. (C.) discofalcatus t at Speeton of Lincolnshire) 
S. (M.) progredicus C1-3 
S. (C.) phillipsi C4 
Spitidiscus rotula C5 
S. (M.) speetonensis C6 
Aegocrioceras capitaner 
Aegocrioceras capricornu C7, 
— — — — (unnamed gap) 


Of the zonal species, Aegocrioceras capricornu and S. (C.) phillips: are difficult to 
interpret, while A. capitanei is an undescribed and indeterminate species known 
from a manuscript name only (Rawson 1970: 591). Spath’s record of S. (M.) 
progredicus has not been confirmed, and the relative position of the discofalcatus and 
clyperforme (=S. (C.) juddt) zones is not known (see p. 63). 

Chernova (1951 : 61) severely criticized Spath’s zonation because his divisions 
were guided by Lamplugh’s lithological divisions rather than by ‘“‘the principle of 
detailed investigation of the group or groups of the most changeable forms (in this 
case the ammonites), which to us seems the basic principle of biostratigraphy”’ 
(translated from the Russian). Because Spath’s zones were not based on the 
appearance of new species Chernova rezoned the Simbirskites beds of the Speeton 
Clay using the species ranges given by Spath, supplemented by reference to earlier 
published information. Her scheme, which utilises simbirskitid ammonites only, is 
as follows: 


Zone Bed 
S. (S.) yorkshirensis and S. (C.) discofalcatus | C2—Base of Lower B 
S. (M.) progredicus Upper part of C4 to C3 
S. (M.) speetonensis Upper part of C6 to lower 
part of C4 
S. (Sp.) versicolor and S. (Sp.) subinversum Upper part of C8 to lower 
part of C6. 


Although this is an improvement on Spath’s scheme, the published information on 
the vertical distribution of the Simbirskites species is inaccurate, as Chernova 
realized, and thus her zonal boundaries are of little value. Again, most of the zonal 
species are extremely rare. The zonation of the equivalent beds in Germany is 
inadequate (p. 75) and is based mainly on crioceratitid ammonites, so that it is 


FROM NORTH-EAST ENGLAND 71 


impracticable to apply the German scheme to the Speeton Clay. The Russian 
zonation is based upon Simbirskites, but some of the zonal forms are not recorded 
from Speeton. 

A new zonation for the Speeton sequence is therefore proposed here (Text-fig. 7) ; 
the only index species used by Spath or Chernova which has been retained in the 
new scheme is S. (M.) speetonensis. It must be stressed that in the beds above C6 
ammonites are rare, and the proposed zonation for this part of the succession is 
tentative. In C6 and C7 ammonites are relatively common, so that here the zona- 
tion is more firmly established. 

Although it is not apparent from Spath’s (1924 : 76) faunal list, detailed collecting 
has shown a major change in the generic composition of the fauna at the C8/C7 
boundary, i.e. at the base of the Simbirskites beds. The neocomitids (Endemoceras? 
and Acanthodiscus) and Olcostephanus die out at the top of C8 while the first Simbir- 
skites and crioceratitids appear low in C7. Only the rare Tethyan forms Spitidiscus 
and Hypophylloceras cross the boundary. 


SPATH 1924 CHERNOVA 


1951 


ZONATION 4 


PROPOSED HERE 


| 80 | PAVLOW 1892 


LOWER 
B 


Paracrioceras 
rarocinctum 


Paracrioceras 
rarocinctum 7 


S.yorkshirensis 


and 


(pars) 


C.variabilis 


M.progredicus C.discofalcatus 


: 
C3 S.decheni S.marginatus C3 
and M.progredicus 
= —$— 
M.speetonensis C.phillipsi C.gottschei C4 
ao eee 
cs Spitidiscus rotula M.speetonensis iis peclon-d 
M.speeton- 
|= ensis| Subzone 
cé6é 5 cé6 
| opens 
Aegocrioceras capitane/ Sp. versicolor ave 
Sp. subinversum goer P : 
C7 Aegocrioceras capricornu and Sp. inversum C7 
pa Sp.subinversum i Engen oceras T ——=—| 
cB ndemoceras regale| cupastieria sulcosa regale cs 
(C8- C11) 
| = (C8 - CN) =) 


Fic. 7. Zonal schemes proposed for the Simbirskites beds of the Speeton Clay. 


2The genus Endemocervas (type species Hoplites amblygonius Neumayr & Uhlig) was proposed by 
Thiermann (1963) for a group of boreal neocomitids previously included in Lyticocevas Hyatt. Lytico- 
cevas (type species Am. cryptocevas d’Orb.) is regarded as a junior subjective synonym of Leopoldia. 


72 HAUTERIVIAN AMMONITE SIMBIRSKITES 


The rvegale zone 

INDEX SPECIES: Endemoceras regale (Pavlow) 

The index species occurs throughout C1o, Cg and C8; other species include Acan- 
thodiscus spp. (Cg and C8), Olcostephanus subfilosus Spath (C8), Subastieria sulcosa 
(Pavlow) (CoA), Parastieria peltoceroides (Pavlow) (CgA, CoC) and Spitidiscus 
inflatiformis Spath (top nodule band of C8). 


The inversum zone 

INDEX SPECIES: Simbirskites (Speetoniceras) inversum (M. Pavlow) 

The zone spans the whole of C7 and is 2:9 metres (9-5 feet) thick. The index 
species appears at the base of the zone, being common in bed C7H and rare in C7G. 
Rare S. (Sp.) subbipliciforme (Spath) occur in C7H and large, indeterminate S. 
(Speetoniceras) fragments in the nodule band of C7F. Small, flattened S. (Sp.) s 
(p. 47) occur in the pale blue clay of C7F just above the nodule band. 

The heteromorph genus Aegocrioceras appears in abundance in C7G and from here 
to the top of the znverswm zone is the dominant element of the fauna. Crioceratites 
first appears at the top of the zone, in bed C7A. 


The speetonensis zone 
INDEX SPECIES: Simbirskites (Milanowskia) speetonensis (Young and Bird). 


INVERSUM 


SPEETON- 
Pvsis|  GOTTSCHE! MARGINATUS VARIABIL'S 
“ T ae 
le. C78 ICS carlcaxjcasicar Cah! c3|caF|c2e|c20|cac lem C1B|CIA ae 
lower AL | | | 
| 


SPECIES 
Sp.subbi- 
ee pliciforme 
Sp. inversum x 
— 

Sp. sp. 


Sp.indet. 


M.concinnus 


M.staffi 


M speetonensis 
M.cf. lippiacus 


C. gottschei 
= 


C.sp.a 


C.variabilis 


— 


| C.sp. = 


\(phillipsi group) 


C. discofalcatus 


S. decheni group 
+ 


S.marginatus 


S.yorkshirensis 
——Jt 


Fic. 8. Distribution of species of Simbirskites in the Speeton Clay. 


FROM NORTH-EAST ENGLAND 73 


Includes beds C6 and C5, and is approximately 12-9 metres (42-2 feet) thick. 

Both Spath (1924) and Chernova (1951) recognized a speetonensis zone, though 
with different upper and lower limits (Text-fig. 7). 

The base of the zone is drawn at the base of C6, where there is an important 
change in the ammonite fauna. The abundant Aegocrioceras of the inversum zone 
die out, and there is a change in the subgeneric composition of the Simbirskites 
fauna, species of Milanowskia and Simbirshites s.s. replacing Speetoniceras. From 
this level upward Simbirskites becomes the dominant ammonite of the C Beds 
fauna. Two subzones are recognized, a concinnus subzone below and a speetonensis 
subzone above, S. (M.) concinnus being limited to the lower part of C6 and S. (M.) 
speetonensis to the upper. C5 has not yielded identifiable Simbirskites and can only 
provisionally be included in the speetonensis subzone. 

Fragments of septate inner whorls of the Cvioceratites beant group occur in the 
concinnus subzone and S. (M.) staffi and S. (S.) cf. decheni in the basal part of the 
subzone. Rare Spitidiscus rotula (Sowerby) occur in bed C5L (speetonensis sub- 
zone). 


The gottschei zone 

INDEX SPECIES: Simbirskites (Craspedodiscus) gottschet (Koenen). 

Includes all the subdivisions of bed C4, and is approximately 9-5 metres (31-2 
feet) thick. The index species occurs in the basal bed, C4L, and from this level 
upward Simbirskites occurs spasmodically through the rest of the C Beds and 
extends into the base of Lower B. Large Aegocrioceras cf. seeleyi (Neumayr and 
Uhlig) are associated with S. (C.) gottschei in C4L. Although Simbirskites is rare 
higher in C4, crushed S. cf. decheni occur in C4I (p. 68) and large, flattened Simbir- 
skites of the kleini group have been seen high in C4. 


The marginatus zone 

INDEX SPECIES: Simbirskites (Simbirskites) marginatus (Phillips). 

The zone includes bed C3 and beds C2F—C2D, and is 3-6 metres (11-8 feet) thick. 
The index species occurs throughout C3, appearing at the very base of this bed, and 
a single specimen is known from C2F. Associated with it in C3 are the small speci- 
mens described above (p. 63) as S. (C?) sp.a. Beds C2D and C2E are provisionally 
included in this zone: C2E yields S. (M.) cf. lippiacus (Weerth) and indeterminate 
fragments of the yorkshirensis-toensbergensis group (p. 69), together with poorly 
preserved fragments of a large, indeterminate Simbirskites with smooth outer 
whorls (p. 60). 


The variabilis zone 

INDEX SPECIES: Simbirskites (Craspedodiscus) variabilis sp. nov. 

The base of the zone is drawn at the base of C2C where the index species first 
appears. S. (C.) variabilis is the commonest ammonite of the zone, occurring in 
C2C, the nodules at the base of C2B, and in LB6. Rare S. (S.) yorkshirensis 
Chernova and Paracrioceras statheri Spath occur in C2C and S. (C.) sp. (phillipsi 
group) (p. 62) in the nodules at the base of C2B. Some larger whorl fragments of 


74 HAUTERIVIAN AMMONITE SIMBIRSKITES 


the yorkshirensis-toensbergensis group occur in C2C. A single S. (C.) discofalcatus is 
recorded from LB6 and two indeterminate Simbirskites nuclei have been found in 
LB5E. S. (C.) discofalcatus, S. (C.) guddi and S. (?C.) sp. b occur in the Tealby 
Limestone of Lincolnshire, which is correlated with the upper part of the variabilis 
zone. 


The varocinctum and fissicostatum zones 

Ammonites are rare above Bed LB6 and the only common forms are large, crushed 
and indeterminate crioceratitids which usually decompose on exposure. The few 
determinable specimens are conspecific with German forms and the German zonal 
divisions can provisionally be adopted for this part of the Speeton succession. Kaye 
(1964 : 349) recorded Paracrioceras strombecki from Bed LB3 and considered it likely 
that beds LB4-6 were also of strombecki zone age. Kaye's record is doubtful; the 
occurrence of S. (C.) discofalcatus in the German stvombecki zone (p. 76) suggests 
that this zone should be equated with part of the Simbirskites beds (Text-fig. 9). My 
own collecting has yielded several fragmentary Hoplocrioceras fissicostatum (Roemer 
sensu Neumayr and Uhlig) in Bed LB3, thus equating this part of the succession 
with the German /fissicostatum zone. Beds LB4-LBs5D are provisionally included 
in the rarocinctum zone, though identifiable ammonites have not yet been found here. 


VI. CORRELATION WITH OTHER AREAS 


(a) North Germany 

The marine Lower Cretaceous strata of the Lower Saxony Basin overly non- 
marine Wealden Beds; invasion of the sea commenced early in the Lower Valan- 
ginian (German “‘Mittel Valendis’’). From then to the upper Cretaceous there was 
continuous deposition of sediments, dark grey, often shaley clays with bands of 
ferruginous concretions being laid down in the central part of the basin while 
shallower-water, marginal facies beds were deposited along the extremities (Thier- 
mann and Arnold 1964 : 692). Sandstones, usually interdigitating with clays, occur 
around the south-western margin (Bentheim embayment: Kemper 1963) and along 
the Teutoburger Wald and Eggegebirge. Further east, fringing the northern foot- 
hills of the Hartz, occur the important iron ores of the Saltzgitter region. 

Simbirskites is well represented in German museum collections though there are 
few localities from which it can still be collected. The large specimens figured by 
Neumayr and Uhlig (1881) came from the ironstones of Saltzgitter while the fauna 
described by Weerth (1884) was collected from the sparsely fossiliferous Osning 
Sandstone of the Detmold region (Teutoburger Wald). The most prolific collecting 
locality was the brick-pit at Ihme, 8 kilometres south-west of Hannover (Wedekind 
1910). The best modern section is the Moorberg brick-pit at Sarstedt, 17 kilometres 
south-south-east of Hannover, where the Hauterivian and Barremian are well 
exposed. Here the clays were deposited in relatively shallow water in the region of 
a salt stock. They are lighter in colour and less shaley than their equivalents in the 
central region of the Lower Saxony Basin, but are lithologically very similar to the 
equivalent horizons at Speeton. 


FROM NORTH-EAST ENGLAND 75 


The Simbirskites described by Neumayr and Uhlig (1881) and Weerth (1884) have 
remained difficult to interpret, and few species were figured in Koenen’s (1902) 
monograph on the north German Lower Cretaceous ammonites. The latter author 
did, however, describe numerous crioceratitid species from the later Hauterivian and 
early Barremian strata, and the zonal schemes for this part of the German Lower 
Cretaceous have consequently relied largely on crioceratitids (e.g. Koenen 1902; 
Stolley 1925). The zonation currently in general use (e.g. Bartenstein and’ Betten- 
staedt 1962; Bahr, unpublished dissertation) is summarized in Text-fig. 9. This 
zonation is inadequate, for many of the zonal species are extremely rare and difficult 
to interpret. 

The pattern of ammonite distribution in the later Hauterivian strata is similar to 
that at Speeton, in that crioceratitids become rare above the beds with abundant 
Aegocrioceras while Simbirskites decreases in numbers upwards but usually dominates 
the fauna. From Bahr’s unpublished work and from my detailed collecting in the 
lower part of the Simbirskites beds at Sarstedt it is apparent that the Szmbirskites 
zones proposed here for the Speeton succession could usefully be adopted, with 
modification to allow for local variation, for the north German succession. Many of 
the species ranges discussed below have been obtained from Bahr’s unpublished 
dissertation. 


The capricornu zone 


INDEX SPECIES: Aegocrioceras capricornu (Roemer). 

The capricornu zone overlies the Endemoceras noricum zone, the fauna of the 
vegale zone of Speeton and the Speetoniceras fauna of the base of the inmverswm zone 
being unrepresented in north Germany. This is believed to be due to a failure in 
preservation rather than to a stratigraphical break. 

Aegocrioceras is abundant in the lower part of the capricornu zone, and rare body 
chamber fragments of large Crioceratites of the wermbteri group appear in the middle 
of the zone (author’s collection, from Sarstedt). Abundant Simbirskites appear a 
few centimetres above this level and almost completely replace Aegocrioceras. 
Exactly the same faunal sequence is seen at Speeton, where A egocrioceras is abundant 
through most of the zmverswm zone (C7), is joined by Crioceratites cf. wermbtert 
(Koenen) in the top bed of the zone (C7A) and is replaced by abundant Simbirskites 
a few centimetres higher in the succession, at the base of the speetonensis zone 
(base C6). The same species, S. (M.) concinnus, S. (M.) staffi and S. (S.) cf. dechent, 
appear in both areas, replacing identical Aegocrioceras assemblages, but there is a 
significant difference in the relative abundance of the Simbirskites species; at 
Speeton S. (M.) concinnus is common and S. (M.) staffi extremely rare, while the 
inverse relationship holds in Germany. 


The hildestense zone 


INDEX SPECIES: Crioceratites lildesiense (Koenen). 
The index species is rare; its first appearance defines the base of the zone. S. (M.) 
staffi extends into the lower part of the zone and S. (S.) of the decheni group occur 


76 HAUTERIVIAN AMMONITE SIMBIRSKITES 


throughout. The zone can be correlated with some part of the speetonensis zone of 
Speeton. 


The seeleyz zone 


INDEX SPECIES: Aegocrioceras seeleyi (Neumayr and Uhlig) 

A. seeleyi is common at the base of the zone (Bahr, unpublished dissertation) ; 
about 2 metres above the base in the southern part of the Moorberg pit, Sarstedt, 
there is a rich Simbirskites horizon, from which I have collected numerous septate 
inner whorls of an undescribed species (=S. sp. nov. of Wedekind (1910: pl. 4, 
fig. 2) and S. ihmensis Bahr MS.), a form close to S. speetonensis (=S. speetonensis 
venustus of Bahr) and S. dechent (Roemer) sensu Wedekind. None of the species 
can be matched exactly with any well-localized Speeton forms (a single S. decheni 
sensu Wedekind is known from ‘“‘Middle C” (p. 68)) but the assemblage probably 
correlates with the higher part of the speetonensis zone. 

S. (C.) gottschet appears higher in the seeleyi zone; this is found associated with 
A. cf. seeleyi at the base of the gottsche zone at Speeton. 

Bahr also recorded S. virgifer (Neumayr and Uhlig) and S. paucilobus Koenen 
from the seeleyi zone; neither species is recorded from Speeton though S. cf. virgifer 
occurs at Nettleton. 


The tenuis zone 

INDEX SPECIES: Simbirskites (Craspedodiscus) tenuis Koenen. 

The only German zone defined by a simbirskitid is based on a very rare species 
originally described from about 6 specimens; Bahr did not find a single specimen and 
was unable to separate the tenuis from the underlying seeleyi zone. S. (C.) disco- 
falcatus first appears at about this level. 


The strombecki zone 

INDEX SPECIES: Paracrioceras strombecki (Koenen). 

The index species is not common, and according to Bahr it extends up into the 
lower part of the fissicostatum zone. Simbirskites is rare, but S. (C.) discofalcatus 
occurs. 


The varocinctum zone 

INDEX SPECIES: Paracrioceras rarocinctum (Koenen). 

The zonal species is very rare and Simbirskites was not recorded by Bahr. The 
belemnite Oxyteuthis, typical of the Speeton B Beds, is first recorded from this 
zone. 


The fissicostatum zone 

INDEX SPECIES: Hoplocnioceras fissicostatum (Roemer). 

The index species is difficult to interpret (compare the considerably different 
figures in Neumayr and Uhlig 1881 : pl. 56, fig. 1, and Koenen 1902 : pl. 22, figs 1, 


FROM NORTH-EAST ENGLAND 77 


2) but is recorded from Sarstedt by Bahr; H. fisstcostatum (Roemer sensu Neumayr 
and Uhlig) occurs in LB3 at Speeton. 

The correlation between Speeton and north Germany suggested by these records 
is summarized in Text-fig. 9; much of the correlation can only be regarded as 
tentative, pending further detailed collecting in both areas. 

Lower Cretaceous clays with Simbirskites occur off the coast of Heligoland, and 
specimens picked up off the beach were described by Koenen (1904). 


(b) Russia 

Thick, sandy clays of Hauterivian and Barremian age are widespread through 
the middle Volga region and the Moscow synclise. They have been divided into 
the Simbirskitid Beds below and the Belemnite Series above, the former yielding an 
extensive Simbirskites fauna and the latter a belemnite-lamellibranch fauna. Early 
work on the Simbirskitid Beds culminated in Pavlow’s (1901) extensive review of 
the stratigraphy and Simbirskites fauna. The Simbirskitid Beds were divided into 
a versicolor zone below and a decheni zone above, each of which has subsequently 
(Chernova 1951) been divided into three subzones. Chernova reviewed earlier 


TETHYS 


SPEETON GERMANY RUSSIA 
J 


LB3 | fissicostatum | fissicostatum 


SUBZONE ZONE 


BELEMNITE SERIES 


=>~=FMDD>D 


with 
LB4- | rarocinctum rarocinctum 
(aolaranonites Oxyteuthis brunsvicensis 
LB5D recorded) (pars) 


2 


variabilis 
strombecki angulicostata 


umbonatus 
marginatus ? 
tenuis 2 
discofaicatus seeen! 
gottschei ? Y 


seeleyi 
? 


hildesiense 
? 


speetonensis 


speetonensis 


capricornu paviovae 


? 
inversum versicolor 


C7 inversum 


duvali/ 


U 
3 =e~zsr~amnee®'s 
= 


versicolor 
? 


? 
radiatus 
(pars) 


FAU NAL 
BREAK 


? 


c8- 
Cait 


le k ‘ 
EK NO DEPOSITS 


Fic. 9. Comparison between the Speeton zones and their German, Russian and Tethyan 
equivalents. ? indicates that the correlation with the Speeton zones is only approximate. 


78 HAUTERIVIAN AMMONITE SIMBIRSKITES 


evidence showing that the Endemoceras fauna of the earliest Hauterivian beds of 
western Europe is absent over most of Russia, the Simbirskitid Beds resting on an 
eroded Valanginian surface in the Middle Volga region and transgressing over 
various horizons of the Valanginian or late Jurassic in the Moscow synclise. 

The classic sequence in the Simbirskitid Beds and Belemnite Series is a 7 km 
section along the right bank of the Volga, from the village of Polivny to Ulyanovsk 
(formerly Simbirsk). Here, Chernova (1951 : 52-55) recognized the following 
faunal sequence in the Simbirskitid Beds: 


The versicolor zone 

The zone is typified by species of the subgenus Speetoniceras, which dies out at the 
top of the zone. 
a. versicolor subzone 


S. (Sp.) versicolor occurs sporadically in the lower part of the subzone and becomes 
abundant higher up, where S. (Sp.) subinversum and S. (S.) coronatiformis appear. 


b. «inversum subzone 
The species of the versicolor subzone are joined by S. (Sp.) inversum. 


c. pavlovae subzone 


In the lower part of the subzone the species of the imverswm subzone still occur, 
together with S. pavlovae Chernova (nomen novum for S. elatus M. Pavlow non 
Trautschold). In the upper part of the subzone S. (S.) coronatiformis disappears 
and S. (Sp.) versicolor and S. (Sp.) tnversum are rare. 


The decheni zone 
a. speetonensis subzone 


The base of the subzone is marked by a major faunal break; all the species of the 
versicolor zone disappear and are replaced by species of the subgenera Simbirskites s.s., 
Milanowskia and Craspedodiscus. 


b. discofalcatus subzone 


Most species of the speetonensis subzone disappear but the subzone is charac- 
terized by large numbers of S. (C.) discofalcatus, S. (M.) progredicus, S. (M.) polivnen- 
sis, S. (S.) umbonatiformis and S. (S.) pseudobarboti. 


c. wumbonatus subzone 


Characterized by S. (S.) wmbonatus and S. (S.) pavlovt Chernova (nomen novum for 
S. umbonatus Pavlow 1901 non Lahusen). Ammonites are restricted to the lower 
part of the subzone. 

The distribution of Simbirskites in the Ulyanovsk section is summarized in Text- 
fig. 10, compiled from Chernova’s (1951 : table 5; pp. 52-55) published work. 

The boundary between the versicolor and decheni zones correlates with the 
inversum|speetonensis zonal boundary at Speeton. The Russian inversum subzone 
is represented in the lower part of the Speeton Clay inversum zone while the pavlovae 


FROM NORTH-EAST ENGLAND 79 


subzone probably correlates with the upper part of the zone. The relative position 
of the Russian versicolor subzone is more difficult to decide; there is either a faunal 
break at this level at Speeton (i.e. between the vegale and inversum zones) or the 
versicolor subzone is represented by part of the vegale zone. The latter is regarded 
as more likely (Text-fig. 9); Speetoniceras probably arose in the northern seas and 
migrated into the Speeton seas at a later date, replacing the neocomitid fauna. 
The Russian decheni zone is equated with the speetonensis to variabilis zones, but 


VERSICOLOR DECHENI 


PAVL- ||\SPEET- 
OVAE|| ONENSIS| ALCATUS 


Sp. versicolor 

Sp. subinversum 
Sp.coronatiformis 
Sp. inversum 

S. paviovae 
C.phillipsi 
C.gottschei 
C.barboti 
M.speetonensis 


M.concinnus 


M.lahuseni 
S.elatus 


S.decheni 


S.kowalewskii 


C.discofalcatus 


M. progredicus 


M. polivnensis 
S.umbonatiformis 
S. pseudobarboti 
S.umbonatus 


S.yorkshirensis 


S.paviovi 


Fic. 10. Distribution of species of Simbiyskites in the Ulyanovsk (= Simbirsk) section 
(after Chernova 1951). 


80 HAUTERIVIAN AMMONITE SIMBIRSKITES 


the relative position of the higher two subzones of the decheni zone is more difficult 
to establish. At this horizon there are few species in common between the two 
areas, though this difference may be more apparent than real, the probable 
similarity between the two faunas being obscured by taxonomic separation due to 
size differences between the large Russian forms and the small, rare Speeton 
individuals. 

The umbonatus subzone is equated with the marginatus and variabilis zones at 
Speeton; S. (S.) yorkshirensits and S. (C.) discofalcatus are common to both areas, 
while the Speeton S. (S.) marginatus is close to (and possibly conspecific with) S. (S.) 
umbonatus and S. (S.) pavlowr. 

This implies that the Russian discofalcatus subzone should be correlated with the 
upper part of the gottschei zone, i.e. with upper C4. However, S. (C.) discofalcatus 
occurs only at a much higher horizon in England—at the base of Lower B and in the 
Tealby Limestone of north Lincolnshire. A single, crushed S. (C.) cf. discofalcatus 
(Pl. 11, fig. 3) is known from C3 at Speeton, and this earlier record will be strength- 
ened if the nuclei described here as S. (?C.) sp. a do eventually prove to be the 
earliest whorls of S. (C.) discofalcatus. On the other hand, S. (C.) gottschet occurs in 
the discofalcatus subzone in Russia. In Germany, S. (C.) discofalcatus probably 
occurs in both the tenuis and strombecki zones, and thus has a similar range to the 
Russian forms. If the correlations outlined above are correct, then S. (C.) disco- 
falcatus should also occur in upper C4 at Speeton. 


VII. THE HAUTERIVIAN-BARREMIAN BOUNDARY IN 
NORTH-WEST EUROPE 


Faunal separation in the European Lower Cretaceous reached its peak in Hauter- 
ivian and Barremian times, the ammonite faunas of the Boreal and Tethyan 
Provinces being almost mutually exclusive. Simbirskites and, in Germany and 
England, crioceratitids dominated the Boreal seas during late Lower Hauterivian 
and Upper Hauterivian times; Simbiyskites is represented in southern Europe by 
only a few stray specimens, and the Tethyan crioceratitids are specifically distinct 
from northern forms. 

Hence direct correlation between the two provinces can only be attempted on 
evidence from the northern Caucasus and Crimea, where elements of the two faunas 
intermingle. Chernova (1951), after discussing evidence from earlier Russian works 
(especially Karakasch 1907), concluded that the two Simbirskites zones recognized 
in the Simbirskitid Beds of the Volga Region can be traced over the Crimea and 
Northern Caucasus. She equated the lower, versicolor zone with the Cvioceratites 
duvali zone of Tethys, and the upper, dechent zone with the Tethyan Subsaynella 
saymi and Pseudothurmannia angulicostata zones. Subsequent work by Drushchitz 
and Kudryavtseva (1960) supports this correlation. 

Chernova followed Haug (1910) in drawing the Hauterivian/Barremian boundary 
at the base of the sayz zone of the standard Tethyan sequence, and hence included 


FROM NORTH-EAST ENGLAND 81 


the Russian dechemi zone in the Barremian, a practice independently followed by 
other Russian workers. It is this which accounts for the records in Russian literature 
of Simbirskites in the Barremian. The Lyons Colloquium (Rat 1963 : Debelmas 
and Thieuloy 1965: Busnardo 1965) recommends that Kilian’s (1910) interpretation 
be followed, in which the sayni and angulicostata zones are included in the Hauteri- 
vian, and the base of the Barremian is drawn at the base of the overlying Nicklesia 
pulchella zone. In Russia, Drushchitz (1962, 1964) now follows Kilian’s scheme, and 
therefore includes the decheni zone in the Hauterivian. Following this correlation, 
the Speeton equivalents of the decheni zone, i.e. the speetonensis-variabilis zones 
(beds C6-LB5E) should be included in the Hauterivian, and the Hauterivian/ 
Barremian boundary is provisionally drawn between the variabilis and rarocinctum 
zones. Chernova (1951 : 66) equated the top of the decheni zone with the raro- 
cinctum or possible fissicostatum zone of north Germany, and Bahr provisionally 
drew the Hauterivian/Barremian boundary through the German rarocinctum zone. 
The same boundary is adopted here (Text-fig. 9) though German workers have 
customarily drawn it lower, at the base of the strombecki zone. 

At present, the base of the Barremian in England and Germany cannot be more 
accurately defined; the Barremian ammonite faunas of north-west Europe consist 
almost exclusively of crioceratitids, specifically distinct from the rich crioceratitid 
faunas of the Tethyan Barremian (Sarkar 1955: Thomel 1964). In the Caucasus 
and Crimea the Lower Barremian faunas are essentially Tethyan, though in the 
Nalchik sequence of the Caucasus Paracrioceras denckmanni (Koenen) is recorded in 
association with Costidiscus recticostatus and other Lower Barremian Tethyan 
ammonites, overlying beds with Pseudothurmannia angulicostata and Simbirskites 
(Craspedodiscus) spp. (Chernova 1951: 74). If the identification is correct it 
provides a useful cross-check, for P. denckmannz is the index fossil for the zone above 
the fissicostatum zone in north Germany. 

Thus all the available evidence shows that Szmbirskites, the last representative of 
the Perisphinctaceae, is a useful zonal form in the north European Hauterivian and 
dies out at the end of the Hauterivian. 


VIII ZUSAMMENFASSUNG 


Die Ammonitengattung Simbirskites charakterisiert Schichten des Hauteriviums 
der borealen Provinz und stellt brauchbare Zonen-Leitfossilien in RuBland, Nord- 
deutschland und NE-England. Sie tritt in England in der C7—-LB5-Folge des 
Speeton Tons (Yorkshire) sowie im Unteren Tealby Ton und im Tealby Kalkstein 
(Lincolnshire) auf. Die Stratigraphie dieser Schichtenfolge wird hier erlautert. 
Dabei werden 21 Simbirskites-Arten beschrieben. Zwei davon sind neu: S. (C.) 
quddi und S. (C.) variabilis. Vierzehn werden bekannten Arten zugeordnet oder 
mit ihnen verglichen und fiinf in offener Nomenklatur behandelt. Einige der 
Arten wurden zuerst aus RuSland oder Norddeutschland beschrieben. Von den 
deutschen Arten werden Topotypen des nur wenig bekannten S. (M.) lippiacus 


82 HAUTERIVIAN AMMONITE SIMBIRSKITES 


(Weerth) aus dem Osningsandstein vom Tonsberg abgebildet. Ferner wird die 
problematische Interpretation von S. (C.) phillips: (Roemer) und S. (S.) decheni 
(Roemer) ausftihrlich diskutiert. 

Als Ergebnis einer sorgfaltigen, horizontierten Absammlung der Speeton-Folge 
ist eine Unterteilung der Simbirskiten-Schichten in Yorkshire nach Simbirskites- 
Arten in fiinf Zonen moglich. Weiterhin erlaubt die bei Speeton ermittelte Faunen- 
folge einen detaillierten Vergleich dieser Schichten mit den entsprechenden 
Ablagerungen in Norddeutschland und Rufland. Der in Norddeutschland zur 
Zeit tblichen Zonengliederung, die auf Arbeiten von Koenen und Stolley zuriickgeht, 
liegen in erster Linie crioceratitische Ammoniten zu Grunde. Die meisten dieser 
vermeintlichen Zonenleitfossilien sind aber sehr selten. Vertreter der Gattung 
Simbirskites sind dagegen haufiger, so daB es empfehlenswert erscheint, Simbirskites- 
Arten als Leitfossilien auch in Norddeutschland heranzuziehen. Vermutlich kann 
die bei Speeton ermittelte Gliederung mit geringen Einschrankungen auch in Nord- 
deutschland verwendet werden. Die russischen Simbirskiten-Schichten sind in 
eine Serie von Zonen und Subzonen gegliedert worden (Pavlow Igor, Chernova 
1951), die enge Vergleiche mit der Schichtenfolge Yorkshires gestatten. 

Das Auftreten von gemischten Faunen aus borealen und Tethys-Elementen im 
Nordkaukasus und auf der Krim erlaubt die Ankntipfung der borealen Zonenfolge 
an die Standard-Gliederung des Hauteriviums im Tethys-Raum (Text-fig. 9). 
Dabei ergibt sich, da die Grenze Hauterivium/Barremium innerhalb der raro- 
cinctum-Zone Norddeutschlands (Bahr, unverdffentlichte Dissertation) und an der 
Basis der varocinctum-Zone von Speeton verlauft. 

I thank Dr. E. Kemper for this translation. 


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1967. Die alteste Ammoniten-Fauna im Aptium Nordwest-Deutschlands. Paldont. 
Z. Stuttgart, 41 : 119-131, pls. 11-14. 

Kirtan, W. t910. Unterkreide (Palaeocretacicum), im Frech. Lethaea Geognostica. 2, Meso- 
zoic. Vol. 3, Kreide. Lief. 1, 169-287. 

KoENEN, A. 1902. Die Ammonitiden des Norddeutschen Neocom. Abh. pyreuss. geol. 
Landesanst., Berlin, N. F. 24 : 1-451, atlas with 55 pls. 

Kornen, A. 1904. Uber die untere Kreide Helgolands und ihre Ammonitiden. Abh. K. Ges. 

Wiss. Gdttingen, Math-physik. Kl., N. F. 3 : 1-63, pls. 1-4. 

1909. Die Polyptychites-Arten des Unteren Valanginien. Abh. preuss. geol. Landesanst., 
Berlin, N. F. 59 : 1-89, atlas with 33 plates. 

Lauusen, I. 1874. Fossiles de l’argile de Simbirsk. Bull. Soc. Minéy. St. Pétersbourg, 
SP 33-77- 

3Translations of these papers are available from the National Lending Library, Boston Spa, numbers 

RTS 3310 and 3311 respectively. 


84 HAUTERIVIAN AMMONITE SIMBIRSKITES 


LampLuGH, G. W. 1889. On the subdivisions of the Speeton Clay. Q. Jl geol. Soc. Lond., 


45 : 575-6018. 
1896. On the Speeton Series in Yorkshire and Lincolnshire. Q. Jl geol. Soc. Lond., 
52 : 179-220. 


Leanza, A. F. 1958. Acerca de la existencia de Simbirskites en el Neocomiano argentino. 
Revta Asoc. geol. argent., Buenos Aires, 12 : 5-17, pls. 1-3. 

LECKENBY, J. 1859. Note on the Speeton Clay of Yorkshire. Geologist, London, 2 : 9-11. 

Moorg, R. C. (editor). 1957. Tveatise on Invertebrate Paleontology Part L Mollusca 4. 490 pp. 
University of Kansas Press, Lawrence, Kansas. 

NEALE, J. W. 1960. Marine Lower Cretaceous Ostracoda from Yorkshire, England. Micro- 
paleontology, New York, 6 : 203-224, pls. 1-4. 

NEALE, J. W. & SarjJEANT, W. A. S. 1962. Microplankton from the Speeton Clay of York- 
shire. Geol. Mag., London, 99 : 439-458. 

Neumayer, M. & Uutic, V. 1881. Ueber Ammonitiden aus den Hilsbildungen Norddeutsch- 
lands. Palaeontographica, Stuttgart, 27 : 129-203, pls. 15-57. 

PaRKER, J. R. 1967. The Jurassic and Cretaceous Sequence in Spitsbergen. Geol. Mag., 
London, 104 : 487-505. 

Paviow, A. P. 1889. Etudes sur les Couches Jurassiques et Crétacées de la Russie. I. 

Jurassique supérieur et Crétacé inférieur de la Russie et de l’Angleterre. Byull. mosk. 

Obshch. Ispyt. Priy., Moskva, N. S. 3 : 61-127, pls. 2-4. 

1890. Le Néocomien des montagnes de Worobiewo. Byull. mosk. Obshch. Ispyt. Prir., 
Moskva, N.S. 4 : 173-186, pl. 6. 

1892. Ammonites de Speeton. In Pavlow, A. P. and Lamplugh, G. W. (see below). 
1go1. Le Crétacé inférieur de la Russie et sa faune. Nouv. Mém. Soc. (imp.) Nat. Mosc., 
Moskva, N.S. 16 : 1-87, 8 pl. 

1913. Les céphalopodes du Jura et du crétacé inférieur de la Siberie septentrionale. 

Zap. imp. Akad. Nauk. St. Petersburg, Cl. Phys.-Math., 21 : 1-68, pls. 1-18. 

Paviow, A. P. & Lamptucu, G. W. 1892. Argiles de Speeton et leurs équivalents. Byull. 
mosk. Obshch. Ispyt. Priv., Moskva, N.S. 5 : 181-276; 455-570, pls. 4-8, 13-18. 

Pavitow, M. 1886. Les ammonites du groupe Olcostephanus versicolor. Byull. mosk. Obshch. 
Ispyt. Priv., Moskva, 3 : 1-18, pls. 1, 2. 

Penny, L. F. and Rawson, P. F. 1969. Field meeting in East Yorkshire and North Lincoln- 
shire. Pvoc. Geol. Ass., London, 80 : 193-218. 

PHILLIPS, J. 1829. Idlustvations of the Geology of Yorkshire; ov, a description of the stvata and 

organic vemains of the Yorkshive Coast: 1-129, pls. 1-14, York. 

1835. Ibid. Second edition, London. 

1875. Ibid. Third edition, edited by R. Etheridge. London. 

Rat, P. 1963. Conclusions du colloque de Stratigraphie sur le Crétacé inférieur en France, 

Lyon, septembre 1963. C. 7. somm. Seanc. Soc. geol. Fr., Paris, 8 : 292-296, 4 Nov. 1963. 
Rawson, P. F. 1966. A phylloceratid ammonite from the Speeton Clay (Lower Cretaceous) 
of Yorkshire. Palaeontology, London, 9 : 455—457, pl. 72. 

1970. The interpretation of some English species of Aegocrioceras (Cephalopoda: 
Ammonoidea) from the Speeton Clay (Lower Cretaceous). J. nat. Hist., London, 4: 
585-591. 

Rormer, F. A. 1841. Die Versteinerungen des novddeutschen Kveidegebirges. Hannover. 
145 pp., 16 pls. 

Roman, F. 1938. Les ammonites juvassiques et crétacées. Paris. 554 pp., 53 pls. 

SaRKAR, S. S. 1955. Révision des ammonites déroulées du Crétacé inférieur du Sud-est de 
la France. Mém. Soc. géol. Fy., Paris, no. 72 : 1-176, 11 pls. 

SpaTtH, L. F. 1924. On the ammonites of the Speeton Clay and the subdivisions of the 
Neocomian. Geol. Mag., London, 61 : 73-89. 

STOLLEY, E. 1925. Die leitenden Belemniten des norddeutschen Neokoms. Jber. nieder- 
sachs. geol. Vey., Hannover, 17 : 112-126. 


FROM NORTH-EAST ENGLAND 85 


THIERMANN, A. 1963. Die Ammonitengattung Endemoceras n.g. aus dem Unter-Hauterive 
von Nordwest-Europa. Geol. Jb., Hannover, 81 : 345-412, pls. 20-25. 

THIERMANN, A. & ARNOLD, H. 1964. Die Kreide im Miinsterland und in Nordwestfalen. 
Fortschr. Geol. Rheinld Westf., Krefeld, 7: 691-724. 

THOMEL, G. 1964. Contribution a la connaissance des Céphalopodes Crétacés du Sud-Est de 
la France. Note sur les ammonites déroulées du Crétacé inférieur Vocontien. Mem. 
Soc. geol. Fr., Paris, no. 101 : 1-80, 12 pls. 

TRAUTSCHOLD, H. 1865. Der Inoceramenthon von Simbirsk. Byull. mosk. Obshch. Ispyt. 
Prir., Moskva, 38 : 1-24, pls. 1-3. 

UnLic, V. 1903-10. The fauna of the Spiti Shales. Mem. geol. Survey India Palaeont. 
indica, Calcutta, 15 : 1-511, 94 pls. 

UssHER, W. A. E., JukEs-Browne, A. J., and Srrawan, A. 1888. The geology of the 
country around Lincoln (explanation of sheet 83). Mem. geol. Suvv. U.K., London, 
x + 218 pp., 1 pl. 

WEDEKIND, R. 1910. Ueber die Lobentwicklung der Simbirskiten. Sbev. Ges. naturf. 
Freunde Berl., Berlin, nr. 3 : 93-105, pl. 4. 

WEERTH, O. 1884. Die fauna des Neocomsandsteins im Teutoburger Walde. Paldont. Abh. 
Berl., 2 : 1-77, pls. 1-11. 

WHITEHOUSE, F.W. 1927. Additions to the Cretaceous ammonite fauna of Eastern Australia. 

Part 1 (Simbirskitidae, Aconeceratidae and Parahoplitidae). Mem. Qd. Mus., 9 : 109-120, 

pls. 16-17. 

1946. A marine early Cretaceous fauna from Stanwell (Rockhampton District). Proc. 

Royal Soc. Qd., 57 : 1-15. 

WHITEHOUSE, F. W. & BricHton, A.G. 1924. Notes on some Neocomian Cephalopoda from 
Speeton. Naturalist, 359-360. 

Wricut, C. W. 1957. See R. C. Moore (editor) 1957. 

Youne, G. M. and Birp, J. 1828. A Geological Survey of the Yorkshire Coast: describing the 
stvata and fossils occurring between the Humber and the Tees, from the Geyman Ocean to the 
Plain of York. (Second edition), iv + 368, 17 pls. Whitby. 


ADDENDUM 


Since this paper was written, two points have been drawn to my attention. In 
June 1970 Dr. Kemper informed me that renewed search at Detmold, by members of 
the Geologisches Landesamt Nordrhein-Westfalen, has successfully resulted in the 
discovery of Weerth’s collection, hitherto believed lost. Dr. Kemper has sub- 
sequently (on 10 November 1970) seen the collection and recognized several type 
specimens of Simbirskites, though the majority appear to be lost. The collection 
does, however, include other specimens which were apparently collected after 
Weerth’s paper was published in 1884. 

In a recent paper by Hiltermann and Kemper (1969) the occurrence of Simbirskites 
in the Heligoland Hauterivian is reviewed. Four species are figured: Simbirskites 
(Speetoniceras) versicolor (Trautschold), S. (Sp.) cf. enversum (M. Pavlow), S. (Cras- 


86 HAUTERIVIAN AMMONITE SIMBIRSKITES 


pedodiscus) juv. sp., and S. (C.) carinatus Koenen. The two figured Speetoniceras 
closely resemble Speeton examples of the same species. The figured S. (C.) cavinatus 
are similar in lateral view to the Speeton form which I figure (Pl. 5, fig. 2) as S. (C.) 
sp. (phillipst group). Hiltermann and Kemper (p. 22, footnote) consider it possible 
that S. (C.) carinatus could be the juvenile stage of S. (C.) phillipsi (Roemer). 


P. F. Rawson, B.Sc., Ph.D., F.G.S. 
Dept. of Geology 

QUEEN Mary COLLEGE 

Lonpbon, E.1 


PLATES 


The photographs are by Mr. B. Samuels, of Queen Mary College, except Plate 1 
figure 4 by the author. 

All specimens have been coated with ammonium chloride. 

The figures are natural size, unless otherwise stated. 


PLATE 1 


Fic.1. Simbirskites (Speetoniceras) inversum (M. Pavlow). Bed C7, Speeton, collected 
by Mr. R. G. Clements. BM. C.75622. 

Fic. 2. Simbirskites (Speetoniceras) subbipliciforme (Spath). Holotype. “‘Bed C7 or 
C8,” Speeton. Danford collection, GSM. 17930. 

Fic. 3. Simbirskites (Speetoniceras) inversum (M. Pavlow). Bed C7H, Speeton. 
BM. C.75625. 

Fic. 4. Simbirskites (Speetoniceras) inversum (M. Pavlow). Versicoloy zone, Ulyanovsk 
(Simbirsk), Russia. Kabanov collection, 1364. 

Fic. 5. Simbirskites (Speetoniceras) subbipliciforme (Spath). Bed C7H, Speeton. 
BM. C.75620. 

Fics 6, 7. Simbirskites (Speetoniceras) inversum (M. Pavlow). Fig. 6. Bed C7H, 
Speeton. BM. C.75626. Fig. 7. Bed C7G, Speeton. BM. C.75623. 

Fic. 8. Simbirskites (Speetoniceras) cf. versicolor (Trautschold). Lower C Beds, 
Speeton. BM. C.75647. 

Fic. 9. Simbirskites (Speetoniceras) inversum (M. Pavlow). Bed C7H, Speeton. 
BM. C.75627. 

Fic. 10. Simbirskites (Speetoniceras) sp. Bed C7F, pale blue clay just above the 
Aegocrioceras nodule band. BM. C.75648. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 2 PiPAvir an 


PLATE 2 


Fic. 1. Simbirskites (Speetoniceras) inversum (M. Pavlow). Bed C7H, Speeton. 
BM. C.75624. 


Fics 2-6. Simbirskites (Milanowskia) concinnus (Phillips). Figs 2, 3. Bed C6, 
Speeton, approx. 0:76 metres above base, BM. C.75708 and C.75706. Fig. 4. Bed C6 Speeton, 
GSM.30582. Fig. 5. Upper part of the capricoynu zone, Sarstedt, north Germany. BM. 
C.75711. Fig. 6. Partly crushed specimen from Bed C6, Speeton, BM. C.75852. 


Fic. 7. Simbirskites (Milanowskia) speetonensis (Young & Bird). Bed C6, Speeton, 
approx. 1:5 metres below top. BM. C.75847. 


Fic. 8. Simbirskites (Milanowskia) concinnus (Phillips). Bed C6, Speeton, approx. 
0-6 metres above base. BM. C.75695. 


Fics 9—11. Simbirskites (Milanowskia) speetonensis (Young & Bird). Fig. 9. Mid 
C, Speeton, Wrights’ colln. 18670. Fig. 10. C6 Speeton, 5 cm below top, BM. C.75850. 
Fig. 11. C6, Speeton, HU. Neale colln. 1701. 

Fics 12, 13. Simbirskites (Milanowskia) sp. Fig. 12. ‘Co’, Speeton, Danford collec- 
tion, GSM. 17923 (figd Danford 1906 as S. progredicus). Fig. 13. C Beds, Speeton, BM. 
C.75714. 

Fic. 14. Simbirskites (Milanowskia) staffi Wedekind. Upper part of capricoynu zone, 
Fiimmelse, near Wolfenbiittel, north Germany. BM. C.38369. 

Fic. 15. Simbirskites (Milanowskia) speetonensis (Young & Bird). C Beds, Speeton. 
Danford colln., GSM. 17919 (figd Danford 1906 as S. payer). 


Fic. 16. Simbirskites (Milanowskia) staffi Wedekind. C Beds, Speeton (found loose on 
cliff face). BM. C.75713, collected by Mr. R. Hinton. 


PLATE 2 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 2 


U/, 


PLATE 3 


Fic. 1. Simbirskites (Milanowskia) staffi Wedekind. Upper capricovnu zone? Stdcken, 
near Hannover. NLfB. Orig. Nr. Kp.37. 


Fic. 2. Simbirskites (Milanowskia) lippiacus (Weerth). Topotype, Osning Sandstone, 
To6nsberg, near Oerlinghausen, north Germany. Géttingen, (Weerth collection). Orig. 
nr. 609-2. 


Fic. 3. Simbirskites (Milanowskia) cf. lippiacus (Weerth). Upper C Beds, Speeton. 
Danford colln., GSM. 17542. 


Fic. 4. Simbirskites (Milanowskia) staffi Wedekind. Bed C6, Speeton, 0-6 metres 
above base. BM. C.75712. 


Fic. 5. Simbirskites (Milanowskia) lippiacus (Weerth). Topotype, Osning Sandstone, 
Ténsberg, near Oerlinghausen, north Germany. G6ttingen, (Weerth colln.). Orig. nr. 457-125. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 2 


5a 5b 


PLATE 4 


Fic. 1. Simbirskites (Craspedodiscus) variabilis sp. nov. Paratype. Speeton Clay, 
Bean colln., BM. C.4649. 

Fic. 2. Simbirskites (Craspedodiscus) gottschei (Koenen). C Beds, Speeton. BM. 
C.4704. 

Fic. 3. Simbirskites (Craspedodiscus) variabilis sp. nov. Holotype. Bed LB6, 
Speeton. a, b natural mould of body chamber, c latex cast of earlier whorls of same specimen. 
HU. Rn.7oo. 

Fic. 4. Simbirskites (Craspedodiscus) gottschei (Koenen). C4 (?), Speeton. Inner 
whorls ( 1) of specimen figured on Plate 5, fig. 1. Wrights’ colln. 24375. 

Fic. 5. Simbirskites (Craspedodiscus) gottschei (Koenen). Bed C4L, Speeton. BM. 
C.75717.- 

Fic. 6. Simbirskites (Craspedodiscus) variabilis sp. nov. Paratype. Bed C2C, 
Speeton. BM. C.75853. 


PiVAe i, 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 2 


PLATE 5 


Fic. 1. Simbirskites (Craspedodiscus) gottschei (Koenen). Bed C4 (?), Speeton. 
Body chamber and septate inner whorls (see plate 4, fig. 4). Wrights’ colln. 24375, X0-75. 


Fic. 2. Simbirskites (Craspedodiscus) sp. (phillipsi group). Bed C2B (base), Speeton. 
Latex cast from external mould. BM. C.75882. 


Fic. 3. Simbirskites (Craspedodiscus) variabilis sp. nov. Paratype. Bed C2C, 
Speeton. BM. C.75857. x 2. 


Fic. 4. Simbirskites (Craspedodiscus) variabilis sp. nov. Paratype. Bed LBé6, 


Speeton. Latex cast of penultimate whorl of a specimen in the Neale collection (Hull Univer- 
sity), no. IgoT. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 2 PLATE 5 


PLATE 6 


Simbirskites (?}Craspedodiscus) sp. b. Tealby Limestone, North Lincolnshire (Tealby?). 
GSM.47071, presented by J. W. Judd, 1867. x 0-7. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 2 PLATE 6 


PLATE 7 


Simbirskites (Craspedodiscus) discofalcatus (Lahusen). Tealby Limestone, Normanby. 
BM. C.73377, presented by J. E. Lee, 1885. x 0-64. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 2 ee 


BSS Y, 


PLATE 8 


Simbirskites (Craspedodiscus) discofalcatus (Lahusen). Tealby Limestone, North 
Willingham. BM. C. 19993, presented by P. F. Kendall, 1919. x 0-62. 


PLATE 8 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 2 


PLATE 9 


Fic. 1. Simbirskites (Craspedodiscus) discofalcatus (Lahusen). Tealby Limestone, 
Normanby. BM. C.73376, presented by J. E. Lee, 1885. x 0-72. 

Fic. 2. Simbirskites (Craspedodiscus) discofalcatus (Lahusen). Speeton Clay, Speeton. 
York Museum, labelled ““Ammonites yo? Kimmeridge Clay, Speeton”. x 0-72. 

Fic. 3. Simbirskites (Craspedodiscus) phillipsi (Roemer sensu Weerth). Osning 
Sandstone, Ténsberg, near Oerlinghausen, north Germany. Gottingen, Orig. mr. 457-124 
presented by O. Weerth, 1897. xX 0°72. 


PLATE 9 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 2 


PLATE to 


Fic. 1. Simbirskites (Craspedodiscus) juddi sp. nov. Holotype. 


Tealby. GSM. 31059, presented by J. W. Judd, 1867. x 0°75. 


Fic. 2. Simbirskites (Craspedodiscus) juddi sp. nov. Paratype. 


Normanby. BM. C.73375, presented by J. E. Lee, 1885. x 0°75. 


Tealby Limestone, 


Tealby Limestone, 


PLATE 10 


Bull. By. Mus. nat. Hist. (Geol.) 20, 2 


PPA Ey snr 


Fic. 1. Simbirskites (?}Craspedodiscus) sp.a. Bed C3, Speeton, BM. C. 75862 x 2. 


Fic. 2. Simbirskites (Craspedodiscus) cf. discofalcatus (Lahusen). Speeton, originally 
figd. by Danford (1906). GSM. 17922. 


Fic. 3. Simbirskites (Craspedodiscus) cf. discofalcatus (Lahusen). Bed C3, Speeton. 
BM. C.72641 (Lamplugh colln.). 

Fic. 4. Simbirskites (Milanowskia) speetonensis (Young & Bird). Decheni zone, 
Ulyanovsk (formerly Simbirsk), Russia. G6ttingen, Orig. nr. 609-1, presented by A. P. Pavlow, 
1902. 

Fic. 5. Simbirskites (Craspedodiscus) discofalcatus (Lahusen). Decheni zone, Ulyan- 
ovsk (formerly Simbirsk), Russia. BM. C.5 (Damon colln.). 


Fic. 6. Simbirskites (Simbirskites) decheni (Roemer) sensu Wedekind. “Simbirskites 
zone’’ (upper capricornu zone?), Ihme, near Hannover, north Germany. BM. C.14419. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 2 PEATE xr 


a iG 


\ 


IBID NADIE 9099 


Fic. 1. Simbirskites (Simbirskites) cf. decheni (Roemer) var. a. Bed C6, Speeton, 
approx. 0-76 metres above base. BM. C.75887. 


Fic. 2. Simbirskites (Simbirskites) yorkshirensis Chernova. Upper C Beds, Speeton, 
collected by Mr. M. Thompson. BM. C.75885. 


Fic. 3. Simbirskites (Simbirskites) cf. decheni (Roemer) var. a. C Beds, Speeton, 
collected by Mr. D. Ward. BM. C.75568. 


Fic. 4. Simbirskites (Simbirskites) cf. decheni (Roemer) var. a. Bed C6, Speeton, 
approx. 0-76 metres above base. BM. C.75889. 


Fic. 5. Simbirskites (Simbirskites) yorkshirensis Chernova. Upper C Beds (C4 ?), 
Speeton. Wrights’ colln., 24284. 


Fic. 6. Simbirskites (Simbirskites) cf. decheni (Roemer) var. c. C Beds, Speeton. 
BM. C.72632 (Lamplugh colln.). 


Fic. 7. Simbirskites (Simbirskites) yorkshirensis Chernova. Bed C2C, Speeton. BM. 
C.75884. 

Fics 8,9. Simbirskites (Simbirskites) cf. decheni (Roemer) var.b. Fig.8. probably C6, 
Speeton, Wrights’ colln. 17593. Fig. 9. C6, Speeton, 0-76 metres above base, BM. C.75890. 
xX 2. 


Fic. 10. Simbirskites (Simbirskites) cf. decheni (Roemer) var. a. Bed C6, Speeton, 
0:76 metres above base. BM. C.75888. x 2. 


Fic. 11. Simbirskites (Milanowskia) concinnus (Phillips). Bed C6, Speeton, 0-76 
metres above base. BM. C. 75893. 

Fic. 12. Simbirskites (Simbirskites) cf. virgifer (Neumayr & Uhlig). Lower Tealby 
Clay or Tealby Limestone, Nettleton. HU. Rn.g23, collected by Mr. D. Sowter. 

Fics 13, 14. Simbirskites (Simbirskites) marginatus (Phillips). Fig. 13. Holotype, 
Speeton Clay Speeton, YM. tablet 414. Fig. 14. Bed C3 (upper part), Speeton. BM. 
C.75874. Both figs x 2. 


Fic. 15. Simbirskites (Simbirskites) umbonatus (Lahusen). Decheni zone, Ulyanovsk 
(formerly Simbirsk), Russia. BM. C.17 (Damon colln.). 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 2 PLATE 12 


ys 


 % 
A 


THE BRITISH MUSEUM 1 (ATU AL 1 


Mesozoic and Cainozoic Dinofagellate Cysts 
- figures. os the 


Pp. aa 31 Piste 7 92. gg tea feos 
6. Cuitps, A. Upper Jurassic Rhynchonellid Brack 
Europe. Pp. 119; 12 Plates; 40 Text-figures. 1 
Goopy, sled, C. ane arene ue Psa i 


esl OF PERAMUS 


. CLEMENS - ees 
‘E MILLS | ee. . 


REVIEW OF PERAMUS TENUIROSTRIS OWEN 
(EUPANTOTHERIA, MAMMALIA) 


BY 
WILLIAM ALVIN CLEMENS 


Department of Paleontology, University of California, Berkeley 
AND } 


JAMES RICHARD EWART MILLS 


Institute of Dental Surgery, University of London 


Pp. 87-113; 4 Plates; 3 Text-figures 


BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 
GEOLOGY Vol. 20 No. 3 
LONDON : 1971 


THE BULLETIN OF THE BRITISH MUSEUM 
(NATURAL HISTORY), instituted im 1949, 1s 
issued in five series corresponding to the Departments 
of the Museum, and an Historical series. 

Parts will appear at irregular intervals as they become 
ready. Volumes will contain about three or four 
hundred pages, and will not necessarily be completed 
within one calendar year. 

In 1965 a separate supplementary series of longer 
papers was instituted, numbered serially for each 
Department. 

This paper is Vol. 20, No. 3 of the Geological 
(Palaeontological) series. The abbreviated titles of 
periodicals cited follow those of the World List of 
Scientific Periodicals. 


World List abbreviation 
Bull. Br. Mus. nat. Hist. (Geol.) 


© Trustees of the British Museum (Natural History) 1971 


TRUS ES) OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 


Issued 28 April, 1971 Price £1°30 


REVIEW OF PERAMUS TENUIROSTRIS OWEN 
(EUPANTOTHERIA, MAMMALIA) 


By W. A. CLEMENS & J. R. E. MILLS 


CONTENTS 
Page 
I. INTRODUCTION AND ACKNOWLEDGMENTS . ‘ : 3 ‘ 89 
Il. TAXONOMY AND MATERIAL : : : : : 90 
III. D&EscrRIPTIONS AND INTRAGENERIC COMPARISONS . : : < on 
(a) Maxilla, B.M.(N.H. i M21887 : : : ‘ : QI 
(b) Mandible, B.M.(N.H.) 47739 2 6 : 94 
(c) Other mandibles, excepting B.M. (N. lel. 47799 and 48404 98 
(d) Mandibles, B.M.(N.H.) 47799 and es : 6 d 99 
(e) Intrageneric variation : : : : 100 
IV. OcCLUSION AND FUNCTIONAL RELATIONSHIPS : ¢ ; é IOI 
V. PHYLOGENETIC RELATIONSHIPS . : : é : : : 106 
(a) Comparison with Amphitherium . . : : . 106 
(b) Comparison with Late Jurassicmammals . ¢ : 109 
(c) Ancestry of Pevamus, summary . ; : 5 : IIo 
(d) Possible descendants of Pevamus . > : : . 110 
VI. SUMMARY AND CONCLUSIONS . 5 : : : ¢ A 112 
VII. REFERENCES . , : : 4 . ' : 5 j 113 
SYNOPSIS 


Review of Pevamus tenuivostyis Owen (Eupantotheria, Peramuridae) was occasioned by the 
discovery of a fragmentary maxilla, B.M.(N.H.) M21887, containing part of the hitherto 
undescribed upper dentition. M2 and M3 of this fossil have large paracones and metacones, 
small stylocones, and lingual cingula but lack distinct protocones. M1! lacks a stylocone and 
the metacone does not have the typical tribosphenic functions. A lingual cingulum is not 
developed. The four premolars are two-rooted and have trenchant crowns. M4, the terminal 
molar, was destroyed during fossilization. G. G. Simpson’s (1928) catalogue and description 
of the mandible of Pevamus are revised. 

Pevamus probably is a descendant of the Rhaetic mammal Kuehneotherium, but Amphi- 
theyium is not one of the members of this lineage. Aegialodon from the English Wealden could 
be a descendant of Peramus. Pappotherium and Holoclemensia from the Albian, Trinity Sands 
of North America probably include a peramurid other than Pevamus in their late Jurassic 
ancestry. 


I. INTRODUCTION AND ACKNOWLEDGMENTS 


The entire sample of Peramus tenuirostris Owen, family Peramuridae, is now pre- 
served in the collections of the Department of Palaeontology, British Museum 
(Natural History). All these fossils are part of the S. H. Beckles collection from 
Purbeckian strata exposed at Durlston Bay, Dorset. Since publication of G. G. 
Simpson’s catalogue (1928) the sample has been significantly augmented in both 


90 REVIEW OF PERAMUS TENUIROSTRIS OWEN 


size and scientific value. In this paper his catalogue is brought up to date, two 
specimens of Peramus tenuirostris that recently have been thoroughly prepared are 
described, and some interpretations of dental function and phylogenetic relation- 
ships of the genus are presented. 

Several years ago while studying the collections of Purbeckian reptiles in the 
British Museum (Natural History), Dr. Robert Hoffstetter (1967) found four partially 
prepared fossils from the Mammal Bed that he suspected to be mammalian remains. 
Additional preparation verified his suspicions. One of these is a mandible, M21885, 
containing an incisor, a larger tooth of caniniform morphology, and fragments of 
postcanine teeth. This fossil, which was formerly catalogued under number 48255, 
is certainly part of the lower jaw of a mammal, but a more specific identification 
cannot be made. Three mammalian fossils were found in a group of specimens 
numbered 48407. One, M21886, is a fragment of mandible containing two molars 
that is now identified as Amblother1wm sp. The second, M21887, is the fragment of 
maxilla of Peramus tenwirostris described subsequently. The third, M21888, is a 
fragmentary mandible of P. tenuirostvis that has been described elsewhere (Mills 
1964). 

The research reported here reflects the encouragement and help of a large number 
of colleagues. Dr. Errol I. White, former Keeper of the Department of Palaeon- 
tology, and Dr. A. J. Sutcliffe initially suggested that the sample of Peramus tenui- 
vostyis be restudied and made the material available. They and Dr. H. W. Ball, 
Keeper of Palaeontology, have supported this study in a variety of significant ways. 
Their contributions are gratefully acknowledged. 

As the specimens of Pevamus were prepared and became available for study, they 
have been seen by many palaeontologists. A paper including a description of 
Mz21888 has been published (Mills 1964). Drs. K. A. Kermack and J. R. E. Mills 
started to prepare a report on the maxilla, M21887, but the press of other respon- 
sibilities kept it from completion. When a Natural Science Foundation Post- 
doctoral Fellowship made it possible for W. A. Clemens to return to England, he 
was invited to take part in the study. Dr. Kermack withdrew, however he not 
only made his preliminary notes and photographs available, but also Prof. M. 
Abercrombie and he provided research facilities in the Department of Zoology, 
University College, London. 

The conclusions presented here embody the results of interchanges of ideas with 
many other palaeontologists. Although not committing them to the interpretations 
given subsequently, we wish to acknowledge the valuable, long discussions with 
Prof. P. M. Butler, Prof. A. W. Crompton, Dr. K. A. Kermack, Dr. B. Krebs, Prof. 
A. W. Kihne and Mrs. Frances Mussett that have played an important part in their 
formation. 

The fossils described here were skilfully released from the rock by Mr. Arthur 
Rixon whose deft preparation has added greatly to the value of the collections of 
Peyamus and other British Mesozoic mammals. Text-fig. 1 and the plates are the 
work of Mr. A. J. Lee. The cost of preparation of these illustrations was met 
through a grant from the Museum of Paleontology, University of California, 
Berkeley. 


REVIEW OF PERAMUS TENUIROSTRIS OWEN Ql 


Il. TAXONOMY AND MATERIAL 


The synonymies of Peramus tenuirostvis Owen given by Simpson (1928, p. 121) 
have not been modified. The following additions are made to his catalogue of 
material (7bid., pp. 121-122): 

47742. None [Holotype]. 

47739. Removed from rock and cleaned by A. Rixon in 1968; redescribed here. 

47744. Removed from rock and cleaned by A. Rixon in 1962; described by 
J. R. E. Mills (1964). 


47751. None. 
47754. None. 
47799. None. 


48404. Removed from rock and cleaned by A. Rixon in 1962; described by 
J. R. E. Mills (1964). 

M21887. Left maxilla with eight fragmentary postcanine teeth. Removed from 

rock and cleaned by A. Rixon in 1961; described here. 

M21888. Right mandible with Ms, trigonid of M, and fragments of Ps through 

Me. Removed from rock and cleaned by A. Rixon in 1962; 
described by J. R. E. Mills (1964). 

As far as can be determined from the records all these fossils came from the 
Mammal Bed, one of the units of the Purbeck beds exposed in the cliffs at Durlston 
(=Durdlestone) Bay. The Mammal Bed is stratigraphically below the Cinder Bed 
and part of the Lulworth Beds (Casey, 1963). Problems of determination of the 
age of the Lulworth Beds have been reviewed by Dodson et al. (1964). Because the 
Purbeckian mammals have long been described as being of late Jurassic age and a 
change in terminology to reflect the disparity of standards has no apparent value in 
the context of this paper, the Boreal standard for the Jurassic-Cretaceous boundary 
and a late Jurassic age for the Purbeckian mammals are employed. Purbeckian 
is used in the sense suggested in the report by Ager (1963), “. . . not a stage but a 


” 


facies, predominantly fresh-water and continental . . .”. 


Ill. DESCRIPTIONS AND INTRAGENERIC COMPARISONS 


a. Maxilla, B.M.(N.H.) M21887 

In addition to lateral displacement, the fossil (Pls 1 and 2) was distorted by pres- 
sure from a posterior direction that crushed or severely damaged the distal three 
molars. A groove along its dorsal edge above these molars (PI. 1, fig. 1) might mark 
the course of a maxilla-jugal suture. Otherwise no clear evidence of bones other 
than the maxilla was found in M21887. An anteroposteriorly elongated trench 
dorsal to P4 and M! probably marks the course of a collapsed infraorbital canal 
with its foramen dorsal to P? and P4. 

Eight teeth in various states of preservation are present. Part of the root of a 
tooth immediately mesial to the first preserved premolar (Pl. 1, fig. 1) shows these 
teeth were not separated by a long diastem. The lingual and distal sides of the 
alveolus of this more mesial tooth and the fragment of its root suggest the tooth 
was large, single-rooted, and caniniform. Curvature of the maxilla and absence of 


92 REVIEW OF PERAMUS TENUIROSTRIS OWEN 


evidence of alveoli suggests the dentition lacked additional distal elements. Thus 
the fossil probably contains the remains of the entire postcanine dentition. The 
postcanine dental formula proposed by Simpson (1928) for the lower dentition of 
Peramus, four premolars and four molars, is adopted here. 

All premolars are two rooted and their crowns have a basic trenchant morphology. 
The crown of P! is broken from its roots and displaced buccally. Its apex is slightly 
in advance of the center of the crown. No evidence of basal accessory cusps or 
cingula was found. 

The crown of P2 is displaced buccally and slightly mesially to overlap the distal 
end of P!. Unlike P!, the fracture is closer to the apex of the crown and cuts across 
the region where basal cusps or cingula would be expected. Probably a small 
posterior basal cusp was present and its remains are not now clearly distinguishable 
among the fragments along the zone of fracture. However, the step on the distal 
margin of P2 might only be an artifact of mesial displacement of the crown. Other- 
wise no evidence signals the presence of basal cusps or cingula. P? has the appear- 
ance of being slightly smaller than P1! but damage at the crown’s base prevents 
accurate measurement of comparable dimensions. 

The position of their roots suggests P1-2 were not separated by a diastem. A 
major fracture zone crosses the fossil posterior to P?. Movement associated with 
this fracturing displaced the anterior part of the maxilla posteroventrally with a 
slight rotation and depression of its anterior end. Before distortion P? and P3 were 
separated by a small diastem of about the same length as that separating P3 and P4. 

Although the mode of preservation has muted textural and colour differences 
between enamel and dentine, the absence of a vitreous surface layer, discernable on 
other teeth, indicates that enamel has been lost from large parts of the dorsal two- 
thirds of the crown of P3. At least a small, posterior basal cusp was present. The 
roots of P38, which form an angle of approximately 45 degrees, appear to be much 
more widely divergent than those of the other premolars. Perhaps the tooth here 
designated P3 is a deciduous premolar. 

The bone forming the surface of the diastem between P? and P4 is deeply pocketed 
(Pl. 1, fig. 2). The palatal process of the maxilla is broken and distorted in this 
region. The pit might be an artifact, but this appears unlikely. 

In length and height of crown P# is distinctly larger than the other premolars. 
A nearly horizontal fracture cuts the mesial half of the crown near its base. Loss of 
enamel along this fracture accentuates the anterior basal cingulum (Pls 1 and 2). 
The apex of the main cusp is slightly in advance of the midpoint of the crown. Its 
mesial surface lacks a vertical ridge. Distally a prominent ridge extends from the 
apex toward the disto-lingual basal cusp. They are separated by only a small 
notch. Buccal to this ridge the surface of the main cusp is either flat or slightly 
depressed. A second distal basal cusp of slightly smaller size and more mesial 
position is situated buccal to the first. A small cingulum extends forward a short 
distance mesially from the disto-lingual basal cusp. Otherwise the tooth lacks 
lingual or labial basal cingula. 

M1 is two rooted, the distal root is larger and slightly wider transversely. A high 
paracone, which is now fractured and displaced at two levels, dominates the crown. 


REVIEW OF PERAMUS TENUIROSTRIS OWEN 93 


Low on its distal surface is a second major cusp. Identification of this cusp is dis- 
cussed subsequently (p. 103). M1 has been moved lingually and mesially, and its 
mesio-buccal corner damaged. What remains indicates only one small cusp was 
present. Certainly this part of the crown did not overlap the buccal side of the distal 
end of P4. The crest along the mesial edge of the paracone might not have reached 
the mesio-buccal cusp. Irregularities of the crown’s damaged surface suggest the 
crest was deflected disto-buccally. If it was, this disposition of the crest suggests 
the mesiobuccal cusp is a parastyle and not a stylocone. 

On the lingual surface of M1, just ventral to the alveolar margin, are vestiges of a 
narrow cingulum. Mesio-lingually it is represented by a relatively broad shelf 
carrying two distinct cusps of which the more lingual is also the more dorsally placed. 
Distally, across the middle of the crown, the cingulum is virtually obsolete being 
represented only by a line marking an abrupt change in the slope of the lingual 
surface. On this line are two isolated cusplike expansions. On the most distal 
quarter of the crown the cingulum again becomes distinct. In this region it curves 
ventrally to reach a small cusp which lies adjacent to the large cusp at the distal end 
of the crown. Mesio-bucally from the latter are two stylar cusps. The stylar shelf 
is continued mesially by a narrow cingulum. 

Most of the parastylar region of M2 is missing, however enough remains to show it 
was large and overlapped the distal end of M1. Several approximately horizontal 
fractures pass through the crown of M2 but little displacement occurred along most of 
them. The crown of M3, acting as a wedge, was driven dorsal to that of M? pushing 
it ventrally and rotating its base distally. Distal displacement appears to be minor 
and the angle of the embrasure between M1! and M2 not greatly distorted. In 
contrast, the distal lobe of the stylar shelf of M? was crushed against the crown of M3. 

From the high paracone of M2 a ridge sweeps mesio-buccally to a small cusp, the 
stylocone, immediately adjacent to the missing parastylar region (Pl. 1, fig. 2, and 
Pl. 2, fig. 2). Two small cuspules are present on what remains of the buccal edge of 
the anterior lobe of the stylar shelf. The small stylocone is undamaged by post 
mortem fracturing and can only have been slightly blunted by wear. A short ridge 
extends mesially from its base. Directly mesial to the ridge linking the stylocone 
and paracone the crown is gently rounded, not a vertical wall. 

Dorsally, near the lingual base of the crown, three cuspules are imperfectly linked 
to form a cingulum-like ledge (Pl. 2). The metacone of M2? is high on the side of the 
paracone. Their common base is separated from the distal lobe of the stylar shelf 
by a diagonal linear depression, now the locus of a major fracture. Mesial to the 
paracone of M3 the crown of M2 is heavily crushed. The shards remaining are 
sufficient to be the residue of a cusp the size of that in the comparable position on 
M%. Buccal to this crushed area part of the crown of M2 remains intact but dis- 
placed. From a small cusp near the disto-buccal corner a ridge extends toward the 
crushed area. A groove mesio-buccal to this cusp separates it from what appears to 
be the remains of one or two smaller cusps. M2? is supported by three roots of 
approximately equal size. 

Part of the parastylar region of M? is also missing but, in comparison to M2, the 
fracture is more vertically oriented and situated farther buccally. It cuts through 


94 REVIEW OF PERAMUS TENUIROSTRIS OWEN 


a cusp, possibly the parastyle, on the buccal side of the crown. A ridge from the 
stylocone extends disto-buccally toward the edge of the crown but reaches neither 
the parastylar cusp nor the more distal, small marginal stylar cusps. Relative to 
this section of the crown the paracone and metacone are displaced mesially. These 
cusps do not differ in size or position from those of M2. Although now offset, a low 
ridge, paracrista, connected the paracone and stylocone. 

On the lingual surface of the crown a short, narrow cingulum shows no evidence of 
subdivision into cusps (Pl. 2). This part of the tooth suffered some damage and is 
partly obscured by the remains of M4. Clearly both mesially and lingually no pieces 
of the crown of M® are missing and, except for possible slight distortion or post 
mortem abrasion, the original shape of the crown and its lingual cingulum is 
preserved. Distolingually some enamel is missing. Loss of these chips carried 
away that part of the distal limb of the cingulum not covered by M4. The curvature 
of adjacent enamel surfaces does not suggest, but cannot rule out, greater transverse 
width of the distal part of the lingual cingulum. Probably three roots are present, 
but they are not clearly visible. 

Like M2, a fracture follows the depression between the common base of paracone 
and metacone of M3 and the distal lobe of the stylar shelf, but the latter area is not 
as heavily damaged. Three cusps are present on this lobe. The most lingual is the 
highest and largest. Although its apex is higher than the buccal cusp, the middle 
cusp in the row has the smallest volume. 

M‘ bore the brunt of the distorting pressure and its crown is now crushed against 
M3. Remains of alveoli prove that at least part of the material is derived from an 
upper molar. No evidence suggests the presence of parts of a lower molar, but the 
possibility cannot be ruled out. 

The mass of dental material now covering part of the disto-lingual surface of M3 
could be the remains of the major lingual cusp of M4. The buccal mass of M#is not 
as crushed but was rotated clockwise through approximately go degrees. It 
includes part of the parastylar region carrying the bases of two cusps of subequal 
size followed distally by two smaller cusps. M4 was supported by at least a buccal 
root under the parastylar region and a second lingual root. No indication of a third 
root was found. 

At the time of its death the animal from which M21887 is derived had not lived 
long enough to heavily wear its dentition. Only one or two surfaces that are clearly 
the result of wear could be found, for example flat areas on the crests of the ridges 
radiating from the stylocone of M2. Planar areas on the disto-lingual surface of the 
paracones and mesio-lingual surface of the metacones of M2? and M3 might be wear 
facets, but the evidence is not conclusive. Admittedly evidence of wear may now 
be obscured by a combination of the small size of the fossil, imperfections in preser- 
vation of the surfaces of the teeth, and the necessary coat of preservative. 


b. Mandible, B.M.(N.H.) 47739 

The two distal, single-rooted incisors are represented by the broken root of the 
more mesial and the alveolus of the distal (Text-fig. 1). Dimensions of both alveoli 
are approximately: length = 0-4 mm., width = 0-3 mm. Although the tip of the 


REVIEW OF PERAMUS TENUIROSTRIS OWEN 95 


dentary is missing, the curvature of what remains suggests the presence of an addi- 
tional one or two, if not more incisors in the complete dentition. Before burial the 
canine was lost. The oval aperture of its alveolus has a length of I-o mm. and a 
maximum width of 0:3 mm. Although its alveolus is slightly constricted medially, 
the canine was probably supported by a single root. 

The distal margin of the crown of P, is slightly concave and slopes down to the 
single posterior basal cusp. Probably Pi, like Pz and P3, lacked an anterior basal 
cusp, but this area of the crown is damaged. There is no indication of a lingual or 
buccal basal cingulum. All premolars are two rooted (Pls 3 and 4). 

Other than its slightly larger overall size and relatively larger posterior accessory 
cusp, Pz is very similar to P}. On the buccal side of the dentary a mental foramen 
is present below and slightly in advance of the anterior root of Pe. Ps illustrates 
the mesio-distal trends for gradual increase in premolar size and increase in relative 
size of the posterior basal cusp. 

P, is distinctly larger and higher than Ps. It also differs in the presence of a small 
anterior basal cusp just lingual to the midline of the crown. From the apex of the 
main cusp a crest on its lingual side curves buccally onto the damaged dorsal surface 
of the talonid-like posterior basal cusp. What remains suggests this crest extended 
directly to the apex of a single cusp. There is no evidence of a metaconid or distinct 
talonid basin on either side of the crest. 

Mj is neither as long nor as high as Py. Its largest cusp, the protoconid, has a flat 
lingual and convex buccal surface. Two small cusps are present on the mesial end 
of the crown. The smaller is situated just in front of and in line with the lingual 
side of the protoconid. A larger cusp (anterior cusp of Mills 1964), its apex now 
missing, was present directly lingual to it. Possibly a third cusp was present buccal 
to the first at a point where a small, oval scar indicates a flake of enamel was chipped 
away (Pl. 4, fig. 1). My lacks a large, projecting metaconid of the kind found on the 
following molars. However, the distal slope of its protoconid is drawn out into a 
blade. Buccal and lingual grooves on the crown vaguely demark the bodies of the 
protoconid and metaconid. The tip of the metaconid is now broken away but the 
fracture surface indicates that it had a small, separate apex. The crest along the 
distal edge of the metaconid is separated by a notch from the crest of the talonid 
cusp. Apparently there was only one talonid cusp set slightly lingual to the midline, 
but its apex is missing and the possibility of the presence of two, very closely approx- 
imated cusps cannot be excluded. Lingually and buccally from this crest the crown 
falls away gradually toward the nearly vertical sides of the talonid. An entoconid 
is lacking. Slight bevelling of the buccal side of the talonid is probably the first 
stage in development of a wear facet resulting from contact with the paracone. No 
evidence of wear was found on the lingual side of the talonid. A mental foramen is 
present beneath and between the adjacent roots of P4 and Mj. 

Unlike Mi, Me has a high, three-cusped trigonid. Its protoconid is distinctly 
higher than the paraconid. The latter is closer to the midline than the larger and 
more lingually situated metaconid. The edge of the crown extends mesially to 
contact the back of M;. Enamel is missing from both the lingual and buccal sides 
of the mesial end of the trigonid. Basal cusps serially homologous to those of Ms 


96 REVIEW OF PERAMUS TENUIROSTRIS OWEN 


and M4 might have been present. A prominent crista sweeps down from the meta- 
conid to a low point at the base of the hypoconid distal to the embrasure that 
received the paracone. This crest forms a prominent vertical “‘lip’’ on the back 
of the trigonid (Mills 1964). The surface of the embrasure between protoconid and 
hypoconid was scarred during early preparation and, if any existed, clear traces of 
wear cannot now be recognized. At the end of the crown, distal and lingual to the 
hypoconid, is a much smaller and lower hypoconulid. A very shallow trough 
starting between these cusps and paralleling the crista obliqua, descends linguo- 
mesially across the lingual face of the talonid. A small cusp is present in the position 
of an entoconid. 

M2 and Mz were probably very similar in size and morphology, the major differ- 
ences now distinguishing them appear to be the result of post mortem damage. 
M3 has two prominent anterior basal cusps; the lingual is awl-like and directed 
mesiodorsally. The buccal anterior basal cusp, now slightly blunted, is in a more 
ventral position and merges with an expansion extending toward the buccal base of 
the protoconid. The hypoconulid of M3, which is situated between the anterior 
basal cusps of M,, is slightly larger and extends farther distally than that of Me. 

The trigonid of M, does not exhibit any significant differences from that of M3. 
Its buccal anterior basal cusp is better preserved and clearly illustrates union with 
the expansion across the base of the protoconid. In contrast, the talonid of M4 
most closely resembles that of Mj in its narrower, ridge-like morphology and presence 
of only one major cusp. Unlike Mj, a small entoconid is present and the talonid 
crest is directed posterobuccally. 

Mesially (Text-fig. 1) the masseteric fossa terminates in a distinct pocket. Ventro- 
laterally the concave floor of this fossa continues onto the convex side of the hori- 
zontal ramus without interruption by a pocket or a ridge. On the lingual side of the 
dentary the slope of the dorsal surface of the symphysis is continued posteriorly along 
the horizontal ramus to the level of Mi by a line reflecting a change in curvature of 
the ramus. Slightly posterior to the level of M4 a well defined groove begins and 
extends to the posterior end of the specimen. This groove first les beneath the 
anterior part of the pterygoid fossa and then merges withit. The fragments of bone 
preserved in 47739 give no evidence of a dental foramen. Also there is no evidence 
clearly suggesting the presence of a coronoid. 


TABLE I 
Measurements, B.M.(N.H.) 47739, in millimetres 
Length Width 
Py “52 24 
Pe -66 “27 
P3 CaF — 
12 -96 -36 
Mi "93 “40 
Me 1-0 “51 
M3 Io “47 


Ma "gt ‘47 


97 


OF PERAMUS TENUIROSTRIS OWEN 


REVIEW 


«( 


H(i 


i 


ne 


oar Pr 


Mandible, B.M.(N.H.) 47739, with fragment 


S< 13). 


occlusal view, and C, labial view. 


’ 


ie 


aint 


Pevamus tenuirvostvis Owen. 
of root of an incisor (I3?), alveoli of distal incisor and canine, P14 and Mj_4 (teeth out- 


lined, see pls 3 and 4) in A, lingual view, B 


RIGs i. 


98 REVIEW OF PERAMUS TENUIROSTRIS OWEN 


c. Other Mandtbles, Excepting B.M.(N.H.) 47799 and 48404 

The presence of at least four lower incisors is demonstrated by 47744 in which 
three incisors are represented by alveoli and a fourth (probably Iz), a procumbent 
peg-shaped tooth, is preserved (note Mills 1964, p. 118). Probably only four lower 
incisors were present but none of the available mandibles clearly rules out the 
presence of additional teeth anteriorly. 

Although slightly constricted medially the canine alveolus of 47739 (Text-fig. 1) 
is clearly one that housed a single-rooted tooth. Mills (1964, p. 118), on the basis of 
the morphology of M21888 and 47744 thought the canine of Peramus was two rooted. 
The canine region of 47744 is crushed and fragments of bone are missing from one 
side of the ramus. The parts preserved suggest the tooth was either two-rooted or 
had a single root with a deep vertical medial constriction. 

Reinterpretation of M21888 in light of comparisons with 47739 results in identifica- 
tions of the teeth preserved differing from those published earlier (Mills 1964). The 
most distal preserved molar, only its trigonid remains, is probably M4. Ms is the 
most complete molar preserved in the jaw. Me and M; are represented by the bases 
of their crowns and talonid regions. P4 is similarly damaged but more of the crown 
of Ps, which is the most mesial tooth in M21888, is preserved. By this interpretation 
the posterior mental foramen of M21888, like 47739, lies beneath and slightly 
anterior to the mesial half of Mj. 

None of the anterior premolars, P; through P3, preserved in these mandibles have 
a distinct anterior basal cusp. Some show a slight swelling on their mesio-buccal 
slope, the region of the “‘antero-buccal ledge’’ in the terminology of Butler (1939). 
The Ps of M21888 was mistakenly thought to be a geminated tooth (Mills 1964, 
p. 119). Comparisons with the subsequently cleaned 47739 indicate abnormal 
development did not take place. 

P4 of M21888 has lost its main cusp but the posterior basal cusp remains. The 
curvature of the fracture surface indicates a small cusp might have been present 
lingual and mesial to the posterior basal cusp. P,’s of both 47744 and 47754 are 
damaged. What remains of their crowns does not differ from that of 47739. 

M; of the holotype, 47742, closely resembles the first molar of 47739. It differs in 
lacking the pronounced flattening of the lingual side of the protoconid. Also only 
one prominent anterior basal cusp is present slightly lingual to the midline of the 
crown, but a basal mesial cingulum continues across the crown to the buccal side. 
The talonid is broad and dominated by a single cusp. Because of a covering of 
matrix, presence or absence of an entoconid cannot be determined. 

In comparison to the adjacent teeth, Mi of 47744 is relatively small. The area 
mesial to its protoconid is broken and distortion may be masked by a thick layer of 
preservative. Its talonid is short (mesio-distally), narrow and unicuspid. The 
metaconid is not well defined. Like the M; of 47742 the protoconid lacks the 
flattening of its lingual surface found in 47739. 

The first molars of 47751 and M21888 are damaged. As far as can be determined 
M, of 47751 does not differ significantly from that of 47739 except in the presence of 
a minute entoconid. My, of M21888 is larger, relative to the adjacent teeth, than 
that of 47739. The lingual anterior basal cusp and the buccally directed cingulum 


REVIEW OF PERAMUS TENUIROSTRIS OWEN 99 


of M21888 resemble those of 47742. The distal face of the protoconid is broad and 
expanded buccally, thus resembling the posterior molars more than is the case in 
47739. A-small cusp on the distal face of the trigonid might be the metaconid but 
it could be a posterior accessory cusp comparable to those found on the molars of 
47799 and 48404. 

Recognizing the points of difference, probably reflecting individual variation, the 
M1’s of 47739, 47742, 47744, 47751, and M21888 conform to a morphological pattern 
that clearly distinguishes them from the more distal molars. If present, the meta- 
conid is only a small projection on the distal slope of the protoconid. None of the 
My’s have a paraconid, although one of the anterior basal cusps might be its remnant 
or precursor. Excepting the minute entoconids present on some My’s, their talonids 
are unicuspid. The crest of the talonid is directed distally or distolingually and 
lacks a prominent buccal expansion. 

The mesial end of Mz of 47739 is damaged and presence of anterior basal cusps 
cannot be verified. Morphology of Me’s of 47742, 47744, 47751, and Mz21888 
indicates that two anterior basal cusps can be present. These are situated on either 
side of the midline; the intervening depression received the distal end of Mi. The 
lingual basal cusp (anterior cusp, Mills 1964) is larger and in a more dorsal position 
than the buccal (antero-buccal ledge, zbzd.). Mills (zbzd.) has described the variation 
in structure of the trigonid of Mz and the “lipping”’ produced by the high ridge 
extending down the distal face of the trigonid. 

The talonid of Mz of M21888 is damaged but certainly its hypoconid did not 
project as far buccally as that of 47739. A wear facet on the anterior buccal basal 
cusp of Ms of M21888 is aligned with the wear facet produced by the paracone of M2 
on the talonid of Mz. Perhaps in this animal a re-entrant to receive a metacone was 
not present. To the extent that they are preserved and prepared the talonids of the 
Mo’s of 47742, 47744, and 47751 do not differ significantly from that of 47739. The 
crest along the distal face of their trigonids extends posterobuccally to a hypoconid 
and then turns posterolingually to reach a smaller hypoconulid thus producing a 
small but distinct buccal salient. A minute entoconid is present on at least some 
Mo’s. 

Myg’s preserved in 47742, 47751 and M21888 do not differ significantly from that of 
47739. On all the talonid is dominated by the hypoconulid and slightly higher, 
buccally salient hypoconid. Mills (1964, p. 120) has described the few differences 
between Mz and M3. The talonid of M, of 47742 is relatively shorter (mesiodistally) 
than that of M4, of 47739. Although partly obscured by rock, it also appears to be 
dominated by a single cusp. 

Krebs (1969) called attention to the presence of a rudimentary coronoid on the 
lower jaws of certain dryolestid and paurodont eupantotheres. Traces of a coronoid 
or a coronoid-dentary suture are not apparent on 47739. However, small triangular, 
rugose areas near the anteroventral corners of the pterygoid fossae of 47751 and 
47754 might indicate the presence of coronoids in these individuals of Peramus. 


d. Mandibles, B.M.(N.H.) 47799 and 48404 
These two mandibles are described separately for they consistently differ from the 


100 REVIEW OF PERAMUS TENUIROSTRIS OWEN 


others in one character of molar morphology. On all the molars preserved in 47799 
and 48404 a small cusp is present near the base of the trigonid on the crest linking 
the metaconid and a talonid cusp. This cusp is always mesial to the lowest point on 
the crest and either at the head or just distal to the base of the groove that received 
the paracone. It is designated the posterior accessory cusp (Mills 1964). None of 
the molars in the other mandibles of Peramus, with the possible exception of the My 
of M21888, have a posterior accessory cusp. 

In comparison to the last premolar of 47739, Pa of 48404 has a shorter (mesio- 
distally) posterior basal cusp that is not enlarged into a talonid-like spur, and a larger 
conical, mesially projecting anterior basal cusp. The protoconid of M, exhibits the 
same lingual flattening found in 47739. Its posterior accessory cusp is low on the 
slope of the protoconid and set off by a distinct notch from the major distal talonid 
cusp. A small entoconid is present. Thus, like the first molars of the other group 
of jaws, the talonid lacks a prominent buccal projection. 

The major differences between Mz and Mz of 48404 and 47739 are associated with 
the presence of the posterior accessory cusp on the molars of 48404. On Mg the cusp 
is situated low at the base of the trigonid; breakage and distortion of the crown make 
it appear to bea talonid cusp. Hypoconid and hypoconulid are not so well separated 
as in 47739 but form a prominent buccal projection mesial and dorsal to the anterior 
basal cusp of M3. An entoconid might have been present, but this area is damaged 
and now covered with preservative. Msg of 48404 is closely comparable to the Me. 
The differences have been described by Mills (zbzd.). 

As now preserved and illustrated by Mills (1964, fig. 1) the talonid of M4 of 48404 
appears to differ significantly from that of 47739, which is essentially unicuspid. 
On 48404 the distal is the highest talonid cusp. A ridge projecting buccally links 
it with the posterior accessory cusp, but this ridge is always lower than the apices of 
these two cusps and might be the result of breakage. A hypoconid could have been 
present and lost after death. If it was not present the talonid of M4 would have a 
structure more closely comparable to the talonid of M, than those of Mz and Ms. 
M3 and M,gare preserved in 47799 and clearly show the presence of posterior accessory 
cusps on both molars. Although in need of further preparation what is now exposed 
shows the talonid of M4 had only one major cusp distal to and separated by a notch 
from the posterior accessory cusp. 

47799 is the only mandible of Peramus in which the posteriorly placed dental 
foramen, the angular process and the base of the condylar process are now preserved. 
The angle was preserved in the type specimen 47742 and figured by Owen (1871). 
A small rugose area at the anterior end of the pterygoid fossa might mark the 
position of a coronoid bone. 


e. Intrageneric Variation 

Noting what appeared to be a relatively wide range in variation in size of the teeth 
in the mandibles referred to Pervamus tenuirostris, Simpson (1928, p. 124) concluded 
two species might be represented. If this proved correct, he suggested 47742 and 
48404 would be members of the species with a dentition of larger size. Another 
suggestion based on considerations of size and various other morphological charac- 


REVIEW OF PERAMUS TENUIROSTRIS OWEN IO 


ters, was that 47742 and M21888 represented a species distinct from Pevamus 
tenuirostris but no formal changes in nomenclature were proposed (Mills 1964). 
Further preparation of the fossils and additional material has given a slightly better 
appreciation of variation in size within the sample that in itself does not indicate the 
presence of two species. 

Most other aspects of dental morphology do not clearly indicate heterogeneity of 
the sample. The exception is the presence or absence of a posterior accessory cusp. 
It is present on the molars of 48404 (Mi—4) and 47799 (M3-4). A posterior accessory 
cusp might be present on the M; of M21888 but the cusp in question is minute and 
could be the metaconid or a curious individual variation. The talonids of Mz and 
M3 of M21888 are damaged, but if present and as large as those of 48404, some 
indication of the posterior accessory cusp should be preserved. It is not. Thus 
the sample can be clearly subdivided on the basis of presence or absence of a posterior 
accessory cusp, which might indicate taxonomic heterogeneity. Considering the 
small number of available fossils, we choose to note and describe the variation but 
not suggest changes in nomenclature. 


IV. OCCLUSION AND FUNCTIONAL INTERPRETATIONS 


Through the introductory and descriptive sections it has been assumed that 
M21887 is a maxilla of Peramus tenuirostris, a species typified on a mandible. This 
assumption is justified on the following evidence: M21887, the type, and all other 
specimens of P. tenwirostris came from the Purbeckian Mammal Bed at Durlston 
Bay. The maxilla is of the proper size to be referable to P. tenwivostris and, like the 
mandible, carries eight postcanine teeth. The upper and lower postcanine teeth 
exhibit the same pattern of differentiation. The mesial three are clearly pre- 
molariform. M2, M3, and probably M4, like Me through My, are molariform. In 
both upper and lower dentitions the last premolar is larger than the immediately 
adjacent premolar and molar and has basal cusps not found on the other premolars. 
Although molariform, the first molars differ from the others primarily in the absence 
or small size of primary cusps of the trigon and trigonid. Finally, it will be shown 
here that when restored the dentition of M21887 is a functional counterpart of the 
kind of lower dentition on which P. tenuirostris was typified. 

Because of the lack of extensive wear on the molars of M21887, small size of the 
fossil, and need to maintain a coat of preservative over fractured areas, wear facets 
cannot be clearly delimited. This attempt to deduce the functional pattern of the 
dentition depends primarily on considerations of molar morphology and comparisons 
with other mammals rather than facets and other direct evidence of wear. 

When considered in the context of the work by Crompton and Hiiemée (1969) on 
Didelphis and studies of various primitive mammals, the morphology of the dentition 
of Peramus suggeststhat mastication was affected almost entirely by orthal movement 
of the mandible. A lingual component was introduced during the final stage of jaw 
closure when the protoconid and parastylar region and/or paracone and buccal wall 
of the talonid came into contact. The mandibular symphysis of Peramus was not 
fused. The dentition probably was anisognathic and during mastication the animal 
can be assumed to have alternately employed the right or left side of the dentition. 


102 REVIEW OF PERAMUS TENUIROSTRIS OWEN 


Fic. 2. Pevamus tenuivostyvis Owen. Restorations of dentition. P4 and M!~-4 in A, 
occlusal view, and B, labial view. Occlusal relationships of distal premolars and molars 
near completion of jaw closure in C. (sty stylocone; pa paracone; me metacone.) 


REVIEW OF PERAMUS TENUIROSTRIS OWEN 103 


No evidence suggests the occlusal pattern of the antemolar dentition differed 
significantly from the basic therian pattern. The lower canine no doubt occluded 
just mesial to the upper and the mesial lower premolars lay between the uppers 
making only limited, marginal contact during mastication. 

Although now slightly shifted in position, M! having been driven mesially and 
lingually relative to P4, clearly these teeth of M21887 were not separated by a deep 
triangular embrasure like those between adjacent molars (Text-fig. 2). Correlated 
with the lack of an embrasure is the basically single-cusp morphology of the trigonid 
of M;. During the early phase of closure its protoconid was probably received in 
the valley between the paracone and mesio-lingual cusps of M!, which in M21887 
appears to show traces of wear. When the dentition was fully occluded the proto- 
conid of M; appears to have lain distolingual to the point of contact of P4 and M1}. 

The distal crest of the protoconid of M; and the crest of its talonid usually form an 
almost straight line. A buccal salient has not been observed. The paracone of M1 
was received in the groove on the buccal side of M, that delimits the talonid and the 
anterior unit of the crown. A wear facet on the mesial side of this groove is evident 
on one fossil (facet B, Mills 1964). Apparently the distal crest of the protoconid of 
Mj, including the metaconid where present, and the mesial crest of the paracone of 
M! formed a functional unit. 

The apex of the metacone of a tribosphenic molar is at the junction of two shearing 
crests. The mesial crest, extending to the base of the paracone, occludes with the 
crest on the distal slope of the hypoconid. The distal crest forms part of the meta- 
stylar blade that occludes with the blade formed by the crest linking the paraconid 
and protoconid of the distal lower molar. 

On M1! of M21887, between the paracone and the cusp at the disto-buccal corner of 
its crown, is a large cusp. Its apex is higher than that of the disto-buccal cusp but 
lower than that of the paracone. In comparison with the paracone the disparity in 
height is much greater than that of the closely approximated paracone and metacone 
of M?or M3. The lingual surface of the crown of M! just distal to the paracone is not 
recessed nor are there any traces of wear. The crest linking the distal cusp in 
question and the disto-buccal cusp of M! is blunted and appears to have functioned 
as a shearing blade acting in conjunction with the crest linking paraconid and 
protoconid of Mz. The narrow disto-lingual cingulum on M! served to deflect food 
that otherwise would have been driven directly into the gingiva. 

Determination of the homologies of the cusp distal to the paracone of M! is open to 
question. The unicuspid talonid of M, lacks a hypoconid or other buccal projection. 
Thus the typical tribosphenic pattern of shear between the distal crest of the hypo- 
conid and mesial crest of the metacone is lacking in the M! of Peramus. This hypo- 
conid-metacone shear pattern is also lacking in Kuehneotherium. In this Rhaetic 
mammal the paraconid, which towered over the talonid of the preceding lower molar, 
moved upwards to lie between the paracone and “‘c-cusp” or “‘metacone” of the 
upper molar. The talonid of Kuehneotherium lower molars is small and usually 
lacks a buccal salient. Two hypotheses can be offered for the pattern of evolution 
of tribosphenic molars from those of Kuehneotherium. One proposes that in the 
descendants of Kuehneothertum the origin and enlargement of the hypoconid was 


104 REVIEW OF PERAMUS TENUIROSTRIS OWEN 


coupled with elongation of the talonid, and enlargement and lingual shift of the 
“c-cusp’’. Shearing between trigonid and “‘c-cusp” was limited to the distal face of 
the latter. The mesial face of the “c-cusp”’ supported a crest which came to shear 
against the distal crest of the hypoconid. It follows that the ‘“‘c-cusp” of Kuenheo- 
therium is the precursor of the metacone of tribosphenic molars. Crompton (pers. 
comm.) has informed us that some lower molars of Kuehneotherium have a short 
buccal salient and on a few upper molars he has observed a small wear facet high on 
the distal crest of the paracone well removed from the “‘c-cusp”. These observations 
suggest a second working hypothesis. Origin of the hypoconid and metacone were 
correlated, the latter arising as the high point of an angulation of the distal crest of 
the paracone mesial to the “‘c-cusp’’. Thus the metacone of tribosphenic molars 
would be a new cusp and the “‘c-cusp”’ might be homologous to the cusp found on 
the metastylar blade of some primitive tribosphenic molars, the penultimate molar 
of Pappotherium for example. 

Because of the inadequacies of the fossil record a decision on the homologies of the 
cusps distal to the paracone of M1 of Peramus will also reflect a choice between the 
following alternatives: M} of Pevamus are phylogenetically derived from molars that 
had a hypoconid-metacone shear like that of M3. Or, the ancestors of Pevamus 
lacked Mj with a hypoconid-metacone shear and in Pervamus these teeth are some- 
what modified molars of the Kuehneotheriwm functional pattern. 

The cusp of M! of Peramus situated between the paracone and disto-buccal cusp 
performed a function akin to that of the metacone of a tribosphenic molar in that it 
was at one end of a buccally directed shearing blade. However, it did not support a 
mesial crest that sheared against a crest of the hypoconid. Because it did not tully 
perform the functions of a primitive tribosphenic metacone we prefer not to apply 
this name. Also the authors cannot agree on whether the “‘c-cusp” of Kuehneo- 
thertum can or should be considered the phylogenetic precursor of the distal cusp of 
the M! of Peramus or the metacone of tribosphenic molars. We conclude, however, 
that most probably the ancestors of Peramus lacked M} with a hypoconid-metacone 
shear (p. 108). 

If common features of the occlusal patterns of mammals with tribosphenic 
dentitions and Kuehneotherium can be used to interpret the occlusion of Peramus, 
the stylocone of M2 and the ridge extending mesially from it should be just buccal to 
the point where the protoconid of Mz first contacted the upper molar during closure 
of the jaws. Because of the curvature of the side of M? further closure of the jaws 
would have required a transverse movement in order to allow the protoconid to slide 
up the lingual side of the parastylar region. The small size of the stylocone and the 
ridges radiating mesially and lingually (buccal end of the paracrista) from it and the 
convexity of the mesial side of the crown of M2? in this region suggest little shearing 
occurred here until the protoconid started to slide lingually and dorsally. This 
moved the crest linking the apex of the protoconid and the base of the metaconid 
transversely across the nearly vertical segment of the mesial crest (lingual end of the 
paracrista) of the paracone. The existence of a transverse component of movement 
is also indicated by the orientation of wear scratches on the M, of 47744 (Mills 1964, 
103 20720)). 


REVIEW OF PERAMUS TENUIROSTRIS OWEN 105 


The metacone of M? is situated high on the slope of the paracone. On the lingual 
surface of the crown a pronounced groove separating the two is directed toward the 
distal end of the lingual cingulum. This groove received the hypoconid of Me. 
Wear facets (facet D) on several Mo’s of Peramus (Mills 1964, p. 121) demonstrate 
that shearing occurred between the distal crest of the hypoconid and mesial crest of 
the metacone. The “‘lipping”’ (Mills zb¢d.) produced by the crest on the distal side of 
the metaconid helped form a long, well-defined groove on the lower molar that 
received the paracone. As the lower molars were moved dorsally, shearing occurred 
between the distal crest of the paracone and mesial crest of the hypoconid (note 
facet C, Mills zbcd.), Thus, unlike M!, M2 exhibits the occlusal pattern of the 
paracone, metacone, and hypoconid found in tribosphenic molars. 

Indications of wear have been found on the lingual surfaces of the talonid and on 
the crest linking metaconid and hypoconid of several molars of Peramus (Mills 1964). 
None are clearly the result of tooth on tooth contact. If M21887 is a maxilla of 
Peramus and there was not gross individual variation, the molars of Peramus lack 
protocones or other projections that could have produced wear on the lingual surface 
of the talonid. The top of the talonid crest might have been worn by contact with 
the lingual cingulum of the opposing molar, possibly acting as a stop to prevent 
overclosure. The evidence of wear on the lingual side of the talonid is probably 
the result of abrasion by food. 

Because of crushing and distortion, the relative positions of M2 and M3 cannot be 
accurately determined. The distal margin of M2 has been restored using M3 as a 
model. As the relative position of these molars is reconstructed here, the two most 
disto-buccal cusps are treated as parts of the stylar shelf not directly involved in 
providing shearing surfaces. The large unnamed cusp between the disto-buccal 
cusps and the metacone of M? was situated mesio-lingual to the point where the 
protoconid of M3 contacted the parastylar region of M. Shearing might have 
occurred between the buccal margin of this unnamed cusp of M2? and the lingual 
margin of the protoconid of M3 as the latter was moved lingually and dorsally. The 
existence of this shearing mechanism is highly speculative. 

During closure of the jaws once the trigonids moved lingually and were in position 
to slip deep into the embrasures between the upper molars, the crest between the 
paraconid and protoconid of M3 was positioned to move across the crest between 
the unnamed cusp and metacone of M2. This is the typical occlusal relationship 
found between the metastylar blade and trigonid of tribosphenic molars. 

M3 of Peramus appears to have had the same occlusal pattern as M?: 

1. In Kuehneotherium an important shearing mechanism involves the entire 
crest of the ridge linking stylocone and paracone (paracrista) and all of the proto- 
conid-metaconid crest on the distal edge of the talonid. Because of the small size 
of the stylocone, low buccal end of the paracrista, and convexity of the mesial 
margin of the crown adjacent to the parastylar region, shearing in this part of the 
crown of Peramus was limited to action between the bucco-mesial margin of the 
paracone and disto-lingual margin of the protoconid. Although the shearing 
mechanism was restricted to employ only parts of the crests utilized in Kuehneo- 
therium, it does not appear to have been diminished in importance. 


106 REVIEW OF PERAMUS TENUIROSTRIS OWEN 


2. Functions of the distal crest of the paracone, mesial crest of the metacone, 
and crests of the hypoconid are those typical of tribosphenic molars. 

3. The basal lingual cingulum on the upper molars acted to deflect food away 
from the gingiva. It might have made contact with the crest of the talonid and 
served as a stop to prevent overclosure. Evidence of wear on the lingual side of the 
talonid of the opposing molar is probably the result of abrasion by food, not tooth 
on tooth contact. 

4. A metastylar blade, which functioned with the paraconid-protoconid crest, 
was formed between the metacone and the unnamed cusp on the distal margin of 
the crown. The buccal margin of the latter cusp might have been a continuation 
of the metastylar blade and acted with the lingual edge of the protoconid to produce 
a shear. 

Only the parastylar region of M4 of M21887 is preserved. It suggests the para- 
stylar regions of M2 and M$ could have been large buccal extensions of their crowns 
each carrying several cusps. On all M,a’s of Pevamus the talonids are essentially 
unicuspid, but unlike M,, their crests are directed disto-buccally and form distinct 
salients. This hypoconid-like projection suggests both a paracone and a much 
smaller metacone were present on M4. 

The occlusal pattern of Peramus exhibits several important differences from those 
found in mammals with tribosphenic molars. M? and M3 differ in absence of the 
shearing surfaces associated with the protocone. The small size of the stylocone 
and paracrista suggest little shearing was effected in this area. Additionally, M1 
and M, lacked the interaction of the shearing crests of the paracone, metacone and 
hypoconid. 


V. PHYLOGENETIC REEATIONSHIPS 


a. Comparison with AmpMtherium 

Amphitherium prevostii is known from four mandibles discovered in the Stones- 
field Slate, a Bathonian (middle Jurassic) unit within the Great Oolite. Maxillae 
or isolated upper teeth of the species have not yet been found. In most recent 
studies of Mesozoic mammals Amphitherium is classified with the therian mammals 
and treated as a member or representative of the stock ancestral to Peramus, 
dryolestids, paurodonts*, and mammals with tribosphenic dentitions. 

Making use of the morphology and pattern of wear of the lower molars an attempt 
to reconstruct the upper molars of Amphitherium has been made (Text-fig 3, from 
Mills 1964, p. 125-7). The lower molariform teeth have a basically triangular 
occlusal outline. The uppers must have had a similar outline but of opposite 
orientation. When a dentition of this reversed triangular pattern is brought into 
occlusion the margins of the gingiva at the apices of the embrasures could be damaged 
by food impacted by the opposing molars. On the lower molars the projecting spur 


*The recent study by W. G. Kiihne (1968) clearly shows that the concept and content of the Pauro- 
dontidae needs thorough review in light of new material from the Jurassic of Portugal. Without 
attempting to revise the family, for the sake of convenience we choose to employ the Paurodontidae 
for Paurodon, several genera from the Kimmeridgian of Portugal yet to be formally named, Archaeotrigon, 
Tathiodon, Avaeodon, Pelicopsis, Mathacolestes, and, possibly Brancatherulum. 


REVIEW OF PERAMUS TENUIROSTRIS OWEN 107 


of the talonid protects this part of the gingival margin. No doubt a salient para- 
stylar region with a similar function is present on the upper molars of Amphitherium. 

The pattern of wear of the trigonids of Amphitherium (facets A and B, Mills Ibid.) 
resembles that found on Mz through M, of Peramus. A large wear facet (facet C, 
which is not clearly delimited from facet B on the distal slope of the trigonid) was 
developed on the bucco-mesial side of the single-cusped talonid. The crest of the 
talonid is directed disto-buccally and slightly overlaps the trigonid of the following 
molar. One of the authors (Mills) has re-examined the specimens of Ampiitherium 
with improved equipment and finds that the talonid was situated against and largely 
under the trigonid of the succeeding molar. Where it appears otherwise, this is due 
to post-mortem displacement. A wear facet along the oblique crest of the talonid 
(facet F) was interpreted (Mills zbzd.) to be the result of contact with a lingual 
cingulum on the upper molar. Evidence from Peramus, and other mammals, now 
indicates contact with a lingual cingulum might have contributed to the wear, but 
probably facet F is the product of abrasion by food. 

As reconstructed (Mills 77d.) the upper molars of Amp/itherium are shown with a 
prominent lingual cingulum and the metacone situated very near the disto-buccal 
corner of the crown. These two features of the reconstruction can be modified on 
the basis of information derived from Peramus. Wear on the crest of the talonid 
(facet F) of Amphitherium can be primarily or entirely accounted for through 
abrasion by food. Probably a lingual cingulum protecting the gingiva is present on 
the upper molars of Amphitherium but it need not be larger than those of Peramus 
or Kuehneotherium. 

If the apex of the metacone on an Amp/itherium molar is lower than that of the 
paracone, and the magnitude of transverse movement slightly greater than pre- 
viously estimated, the metacone could have been in a much more lingual position 
than shown in the earlier reconstruction and still produced the facet on the distal end 
of the talonid (facet D). The wear facet on the distal face of the trigonid (facet B) is 
larger than that on the mesial (facet A), a relationship similar to that in Peramus. 
This suggests the stylocone and paracrista of Amphitheriwm molars are as small as 
those of Peramus. Thus, within the limits of the available evidence, the upper 
molars of Amphitherium can be reconstructed in a form not greatly different from 
that of M2 or M3 of Peramus. 


Fic. 3. Amphitherium prevosti (H. v. Meyer). Earlier restoration of upper molars 
(redrawn from Mills 1964, fig. 4B) in occlusal view. 


108 REVIEW OF PERAMUS TENUIROSTRIS OWEN 


In spite of the possibility of these similarities in upper molar structure and resem- 
blances in the morphology of the lower molars, several features of the dentition of 
Amphtherium suggest it is not directly ancestral to Peramus. Like Amphitherium, 
the first molars of paurodonts, dryolestids, and the late Jurassic and younger 
symmetrodonts do not differ greatly from the second. Usually there are some 
differences in size—the first molar being smaller—and proportions; but these are not 
of the magnitude of the differences found between the first and second molars of 
Peramus. We assume that Kuehneotherium from the Rhaetic is either a member or 
representative of the therian radical (Mills 1964; K. A. Kermack et al. 1965; D. M. 
Kermack e¢ al. 1968). Information on the morphological differences of its first two 
molars is not yet available. However, the uniqueness of the degree of morphological 
difference between the first and second molars of Peramus among the probable 
descendants of Kuehneotherium warrants a working hypothesis that this magnitude 
of difference is not a primitive trait of therians. 

M! of Peramus, except for the small size or absence of the stylocone, closely 
resembles upper molars of Kuehneotherium (note Kermack ef al., 1968, Fig. 1). The 
trigonid of M, of Peramus does not resemble those of any of the described molars of 
Kuehneotherium but is derivable from them through near or complete loss of the 
paraconid and metaconid. These changes could reflect a reduction of fully molari- 
form teeth through a pattern of change akin to that involved in the evolution of 
carnassials in Cenozoic carnivores (Mills zbzd., p. 127). In the absence of a hypoconid 
or buccal salient the M, talonid of Peramus resembles those of most lower molars of 
Kuehneotherium, not Amphitherium. Thus the first molars of Peramus are most easily 
derived from those of a Kuehneothertum-type without involving the acquisition and 
subsequent reduction of the talonid structure found in all molars of Amphitherium. 

Relative sizes of the distal premolar and mesial molar of Kuehneotherium are not 
certainly known, however, judging from the isolated teeth described by Kermack 
et al. (1968, Fig. 7), the distal premolar could have had a higher crown. The last 
premolar of the English, late Jurassic symmetrodont Spalacotherium is higher than 
the mesial molar but in at least the lower dentition of T7nodon from North America 
they are of equal height. Among American, late Jurassic dryolestids (Simpson 
1929, p. 62) and paurodonts greater crown height of the distal lower and possibly 
upper premolars appears universal. Of the English representatives of these families 
Amblotherium pusillum contradicts the pattern. Its last lower premolar is higher 
than the first lower molar, but the inverse proportion characterizes the upper den- 
tition. This evidence suggests another hypothesis: probably greater crown height 
of the distal premolar relative to the first molar is a primitive therian trait. If so, 
Amphlitherium in which the crown of the first molar slightly overtops that of the 
distal premolar, can be regarded as having diverged from the primitive condition 
while the lineage leading to Peramus did not. 

Thus, the simplest interpretation of phylogenetic relationships taking morphology 
of the distal premolars and mesial molars into account, is that Amphitherium and 
Peramus are representatives of disparate lineages. In order to reflect this inter- 
pretation we now follow Kermack et al. 1968, and others, in removing Peramus from 
the Amphitheriidae and allocating it to a separate family, Peramuridae Kretzoi. 


REVIEW OF PERAMUS TENUIROSTRIS OWEN 109 


b. Comparisons with Late Jurassic mammals 

The work of W. G. Kihne and his associates has produced samples of at least two 
major Kimmeridgian local faunas from Portugal, here referred to by the names of the 
principal localities, Guimarota and Porto Pinheiro. Descriptions of these local 
faunas are just beginning to be published (note Ktihne 1968 and refs.; and Krusat 
1969), but already several specimens giving evidence pertinent to the ancestry of 
Peramus have been described. 

Kiihne (1968, p. 121) briefly commented on a mandible containing only P2 from 
Guimarota that he identified ‘“‘cf. Peramus’’. In addition from Guimarota he 
recovered two isolated lower molars of the size expected for teeth of cf. Peramus. 
Kihne (:j:d.) comments on the “‘striking similarity’”’ of these teeth to Kwuehneo- 
therium and points out several close similarities to Amphitherium. 

One of us (Clemens) had the opportunity to study these fossils. With a more 
extensive knowledge of the morphology of Peramus it now appears less probable 
that cf. Peramus is part of its ancestry. The gross structure of their dentaries is 
similar, especially in the size and salient nature of the angular process. However, 
P2 of cf. Peramus has two small cusps distal to the main cusp while only one is 
present in Peramus and Amphlutherium. The trigonids of the isolated molars from 
Guimarota allocated to cf. Peramus do not differ significantly from those of M2 to 
M, of Peramus. However, the talonid is unicuspid and “‘not provided with ridges’. 
Thus it is more closely comparable to the talonids of Kuehneotherium and Amplu- 
therium than thethree or two-cusped, slightly basined talonids of Mz to Ma of Peramus. 

Another fossil pertinent to consideration of the ancestry of Peyamus is a molar of 
an as yet unnamed mammal from Porto Pinheiro described by Krusat (1969). The 
trigonid of this tooth resembles the trigonids of Mz to M4 of Peramus as well as those 
of the molars of Amphitherium and Kuehneotherium. In contrast, the talonid is 
quite unlike those of any of these mammals. It is large and deeply indented on the 
labial side. A J-shaped ridge carrying three cusps, originates from the distal slope 
of the metaconid and forms the lingual and distal margins of this indentation. 

Krusat (zb7d.) rightly points out the uniqueness of the talonid structure of the 
Porto Pinheiro tooth among molars of Jurassic therians. Only in Peramus do some 
molars also have a three-cusped talonid, but they are incipiently basined and have 
a distinct crista obliqua. The cusp in the position of a hypoconid at the end of the 
J-shaped crest on the Porto Pinheiro tooth is by far the lowest of the talonid cusps. 
Probably this mammal lacked the hypoconid-metacone shear found in some molars 
of Peramus and those of the full tribosphenic type. 

It can be hypothesized that in the Porto Pinheiro mammal the paracone supported 
two long shearing surfaces meeting at a slightly obtuse angle at its apex. Enlarge- 
ment of the talonid could reflect selection for increase in the size of the paracone and 
emphasis on this shearing mechanism. The proliferation of talonid cusps might be 
associated with elaboration of the mechanisms for interlocking adjacent teeth and 
protection of the gingiva. In any event, if the described tooth is typical of the lower 
molars of this Porto Pinheiro mammal, it seems unlikely that it is part of the ancestry 
of Peramus in which the evolution of a crista obliqua and lingual basin must have 
occurred concomitant with enlargement of the talonid. 


110 REVIEW OF PERAMUS TENUIROSTRIS OWEN 


Brancatherulum tendagurense is based on an endentulous mandible found in the 
Tendaguru area of Tanzania in the late Jurassic, Upper Saurian Bed. Simpson 
(1929) suggested Brancatherulum is closely allied to Peramus. Kihne (1968) noted 
these two genera are members of a group of eupantotheres including Amphitherium, 
Archaeotrigon, and the Kimmeridgian cf. Peramus that have a docodontlike angular 
process of the mandible. Unfortunately the dentition of Brancatherulum is unknown 
and the phylogenetic relationships of the genus remain obscure. 


c. Ancestry of Peramus, summary 

Kuehneotheriwm from the Rhaetic is considered to be ancestral to or representative 
of the radical of therian mammals. 

Amplitherium from the Bathonian exhibits a grade in evolution of the lower and, 
we infer, upper molars that probably characterized ancestors of Peramus. However, 
comparison of their distal premolars and mesial molars suggests Peramus was not 
derived from Ampiitherium. Recently Henkel and Krebs (1969) have adduced 
evidence suggesting that dryolestids also are not direct descendants of Amphi- 
therium. These interpretations suggest, not unexpectedly, that the available 
collection of Bathonian mammals is a poor sample of eupantotherian diversity at 
that time. 

None of the Kimmeridgian mammals so far described provides compelling evidence 
for inclusion in the ancestry of Peramus. The molars allocated to cf. Peramus by 
Kiihne (1968) are more closely comparable to those of Amphitheriwm or Kuehneo- 
therium, particularly in structure of the talonid. Cf. Peramus could be ancestral to 
Peramus but we feel this conclusion should be treated as one of several working 
hypotheses until more material becomes available. 

Although passing through the evolutionary grade of dental evolution represented 
by Amphitherium, apparently the lineage linking Kuehneotherium or a closely related 
Rhaetic mammal and Peramus has yet to be found. 


d. Possible descendants of Peramus 
Most early Cretaceous therians are members of the Spalacotheriidae or Dryo- 
lestidae, families established in or before the late Jurassic and certainly not descen- 
dants of Peramus. The few early Cretaceous mammals that might be derived from 
Peramus are: Aegialodon from the English Wealden, the therians of eutherian- 
metatherian grade from the Trinity Sands including Pappotherium and Holo- 
clemensia, and Endotherium, a poorly known Asian mammal. 
Aegialodon is based on an isolated tribosphenic molar from the Cliff End bone bed, 
a unit of the Wealden, Hastings Beds. In many characters it closely resembles Mz 
and M3 of Peramus but there are some distinguishing features. The relative 
difference in height of trigonid and talonid appears to be less in Aegialodon. In 
both the paraconid is higher than the metaconid but the latter cusp has a slightly 
more mesial position, relative to the protoconid, in Aegialodon. Like at least M3 
and M, of Peramus, lingual and labial anterior basal cusps (mesial cuspule and mesial 
ridge respectively of Kermack e¢ al. 1965) are present on the molar of Aegialodon. 
The talonid of Aegialodon carries a relatively larger and better delimited basin 


REVIEW OF PERAMUS TENUIROSTRIS OWEN wien 


than that of Peramus. We do not agree with Kermack e¢ al. (p. 542, 1965) and 
Krusat’s (1969) suggestions that the crista obliqua of Aegialodon is a product of 
abrasion and Krusat’s (ibid.) further contention that the structure is not homologous 
with the ridge linking metaconid and hypoconid found on the molars of various 
Trinity Sands’ therians. Although it was probably accentuated by development of 
adjacent wear facets, the crista obliqua of Aegialodon rises slightly above the lingual 
talonid facet in a fashion suggesting its eminence is not solely the product of wear. 

In Pervamus the hypoconids of Mz and Ms are situated at the apices of distinct 
buccal salients and are as large or larger than the hypoconulids. A hypoconid- 
metacone shear was functional. A buccal salient is present on the talonid of 
Aegialodon but two, closely approximated cusps smaller than the hypoconulid are 
present in the position of the hypoconid. The entoconid of Aegzalodon is larger and 
in a more mesial position than that of Peramus. Also the talonid basin of Aegialodon 
is larger and is worn in a manner that Kermack et al. (1965) thought to be indicative 
of the presence of a small protocone on the occluding upper molar. 

If a lineage derived from Peramus was characterized by selection favouring evolu- 
tion of a protocone, then Aegialodon could be its Wealden descendant. Small size 
and subdivision of the hypoconid is unexpected but the wear facets demonstrate a 
hypoconid-metacone shear was functional. Although permissive, the evidence 
supporting the hypothesis that Aegialodon is derived from Peramus is not compelling. 

The Albian therians Pappotherium and Holoclemensia probably are not descendants 
of Peramus if the hypothesis that Kuehneotheriwm is representative of the therian 
radical is correct. Upper molars of Pappotheriwm have a large stylocone linked to 
the paracone by a high ridge, the paracrista. A similar pattern pertains in Kuehneo- 
therrum. In Peramus, however, the labial end of the paracrista is very low and the 
stylocone minute. An evolutionary pattern involving reduction of paracrista and 
stylocone and then, subsequently, their enlargement seems unlikely. Although 
smaller than that of Pappotheriwm, the stylocone of Holoclemensia is much larger 
than that of Peramus. 

On upper molars of both Pappotherium and Holoclemensia the protocone and 
parastyle are linked by a cingulum across the mesial face of the paracone. This 
cingulum, and the protocone, are probably homologous to part of the mesially 
continuous lingual cingulum of upper molars of Kuehneotheriwm. In Peramus this 
cingulum is reduced to a short ledge lingual to the paracone and metacone and not 
continuous across the mesial face of the paracone. Thus, both the small size of the 
stylocone and lingual cingulum of Peramus suggest it is not ancestral to either 
Pappotherium or Holoclemensia. 

Little can be said about the possibility of direct phylogenetic relationships between 
the enigmatic Asian Endotherium and Peramus. In grade of evolution the lower 
molars of Endotheriwm more closely resemble those of Pappotherium than those of 
Peramus. No features of Endotherium rule out its descent from Pevamus, but no 
evidence strongly suggests this was the case. 

In summary, we hypothesize that in the late Jurassic probably there were several 
peramurid genera. Bvancatherulum from Africa and cf. Peramus from Guimarota 
could be members of this family. Aegialodon, and possibly Endotherium, might be 


112 REVIEW OF PERAMUS TENUIROSTRIS OWEN 


descendants of Peramus. Although Peramus probably is not their direct ancestor, 
possibly Pappothertum and Holoclemensia are descendants of a peramurid having a 
large stylocone and mesially complete lingual cingulum. 


VI. SUMMARY AND CONCLUSIONS 


Peramus tenuirostvis Owen is represented in the fossil record by only a few frag- 
mentary mandibles and a maxilla. All are from the Purbeckian Mammal Bed, part 
of the Late Jurassic (Boreal standard) Lulworth Beds of England, and are now in 
the collection of the British Museum (Natural History). 

The dental formula of Pevamus is Ij, Cj}, P{, Mj. Presence of more than four 
incisors cannot be excluded. In some individuals the large lower canines are 
supported by deeply scored but probably undivided roots. Of the four premolari- 
form teeth the last, most distal, is distinctly the largest. Neither P4 nor Pa is 
molariform. 

Mi, although molariform, is distinguishable from the following molars through 
absence of a distinct paraconid, small size or absence of a metaconid, and absence of 
a hypoconid or other buccal projection on the talonid. Likewise M! differs from 
M2-3 in its lesser width of crown, relative to length; absence of a cusp with all the 
functions of a tribosphenic metacone; and lack of a prominent anterior lobe of the 
stylar shelf. 

Mz-3 are fully molariform tribosphenic molars with three-cusped, imperfectly 
basined talonids. M2-3 have a broad stylar shelf; small stylocone; high, closely 
approximated paracone and metacone; and narrow lingual cingulum. Unless great 
individual variation occurred, the upper molars probably lacked a distinct protocone. 
The morphology of M4is unknown. The trigonid of M4 resembles that of M3 but the 
talonid of the last molar is essentially a buccally deflected blade carrying a small 
entoconid. 

All specimens of Pevamus are allocated to P. tenuivostris. The only character 
suggesting the presence of two species is the regular development of a small cusp, the 
posterior accessory cusp, on the crista obliqua of the molars of some individuals. 

The morphology of its dentition, especially the tribosphenic-like molars, and 
mandible demonstrate the therian affinities of Peramus. We assume that Kuehneo- 
therium from the Rhaetic is a member or representative of the therian radical. 
Also Pappotherium and Holoclemensia from the Albian are assumed to be representa- 
tive of therians of eutherian-metatherian grade. 

Ampmtherium from the Bathonian (Middle Jurassic) has been suggested to be 
phylogenetically intermediate between Kuehneotherium and Peramus. The morpho- 
logic differences of their distal premolars and mesial molars are interpreted as 
indicating Amphitheriwm is not directly ancestral to Peramus. 

Of the Kimmeridgian mammals described by Ktihne (1968) ‘‘cf. Peramus’’ might 
be ancestral to Peramus, but the evidence is not compelling. If the isolated tooth 
from Porto Pinheiro described by Krusat (1969) is a typical lower molar of a Kim- 
meridgian mammal, it is unlikely this mammal is part of the ancestry of Peramus in 
which evolution of the crista obliqua, lingual talonid basin, and encircling cusps 
must have occurred concomitant with enlargement of the talonid. 


REVIEW OF PERAMUS TENUIROSTRIS OWEN 113 


Kuehneotherium, Pappotherium, and Holoclemensia have upper molars with a large 
stylocone linked to the paracone by a high paracrista and a continuous basal cingu- 
lum across the mesial face of the crown. In Pevamus the stylocone is greatly reduced 
and the cingulum interrupted. Although Cretaceous eutherians and metatherians 
probably had a peramurid ancestor, Peramus is not a member of this lineage. 


VII. REFERENCES 


AGER, D. V. 1963. Jurassic Stages. Nature, Lond., 198 : 1045-1046. 

BuTLer, P. M. 1939. Studies of the mammalian dentition. Differentiation of the post- 
canine dentition. Pyvoc. zool. Soc. Lond., 109 : 1-36, 28 figs. 

CasrEy, R. 1963. The dawn of the Cretaceous Period in Britain. Bull. S.-E. Un. sci. Socs., 
67 : I-15, 3 figs. 

Crompton, A. W., & HilEMAzE, K. 1969. Functional occlusion in tribosphenic molars. 
Nature, Lond., 222 : 678-679. 

Dopson, M. H., Rex, D. C., Casry, R., & ALLEN, P. 1964. Glauconite dates from the Upper 
Jurassic and Lower Cretaceous. Jm: Harland, W. B., et al. eds. The Fossil Record, London 
(Geological Society), pp. 145-158. 

HENKEL, S., & Kress, B. 1969. Zwei Saugetier-Unterkiefer aus der Unteren Kreide von 
Una (Prov. Cuenca, Spanien). Neues Jb. Geol. Paléont., Monatshefte, Stuttgart, 8 : 449- 
463, 2 figs. 

HOFFSTETTER, R. 1967. Coup d’oeil sur les sauriens (=Lacertiliens) des couches de Purbeck 
(Jurassique superieur d’Angleterre). In: Problems Actuels de Paléontologie (Evolution 
des Vertébrés), Colloques int. Cent. natn. Rech. scient., 163 : 349-371, 13 figs. 

Kermack, D. M., Kermack, K. A., & Mussett, F. 1968. The Welsh pantothere Kuehneo- 
thevitum praecursovis. J. Linn. Soc. London, (Zool.), 47 : 407-423, 11 figs., 3 pls. 

Kermack, K. A., Lees, P. M., & Mussett, F. 1965. Aegialodon dawsoni, a new trituberculo- 
sectorial tooth from the Lower Wealden. Proc. voy. Soc., Lond., 162B : 535-554, 6 figs., 
pls 55-58 

Kress, B., 1969. Nachweis eines rudimentaren Coronoids im Unterkiefer der Pantotheria 
(Mammalia). Paldont. Z., Berlin., 43 : 57-63, 4 figs., pl. 4. 

Krusat, G. 1969. Ein Pantotheria-Molar mit dreispitzigem Talonid aus dem Kimmeridge 
von Portugal. Palaont. Z., Berlin, 43 : 52-56, 1 fig. 

Ktune, W. G. 1968. Kimeridge mammals and their bearing on the phylogeny of the 
Mammalia. Jn: Drake, E. T., ed., Evolution and Envivonment, pp. 109-123, 8 figs., Yale, 
New Haven. 

Mitts, J. R. E. 1964. The dentitions of Pevamus and Amphitherium. Proc. Linn. Soc. 
Lond., 175 : 117-133, 6 figs., 2 pls. 

OweEN, R. 1871. Monograph of the Fossil Mammalia of the Mesozoic Formations. Palae- 
ontogy. Soc. (Monogy.), London, 115 pp., 26 figs., 4 pls. 

Stmpson, G. G. 1928. A catalogue of the Mesozoic Mammalia in the British Museum., x + 

215 pp., 55 figs., 12 pls., London. 

1929. American Mesozoic Mammalia. Mem. Peabody Mus. Yale, New Haven, 3 : i-xv 


+ 171 pp., 63 figs., 32 pls. 


W. A. CLEMENS, Ph.D., 
Dept. of Paleontology, 
UNIVERSITY OF CALIFORNIA, 
BERKELY, CAL., 

U.S.A. 


eke 2. Mires, D:D:.S., M:Sc., 
Institute of Dental Surgery, 
EASTMAN DENTAL HosPITAL, 
Lonpon, W.C.1. 


PEA Es 


Peramus tenuirostris Owen 
B.M.(N.H.) M21887 


Fic. 1. Labial view, left maxilla with P!-4and M!~-4. x25. 


Fic. 2. Occlusal view. Heavily damaged lingual section of M4 outlined but not shaded. 


X25. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 3 PLATE ¢ 


Fic. 1 
Fic. 
Fic. 


Fic. 


PLATE 2 
Peramus tenuirostris Owen 
B.M.(N.H.) M21887 


Lingual view, left maxilla with P!~4 and M14. x25. 
Oblique view across labial fragment of M4, and crowns of M% and M?. x25. 
Cross-section through base of crown of M2 to show development of lingual cingulum. 


x25. 
Cross-section through base of crown of M3 to show development of lingual cingulum. 


X25. 


PIL ININE 2 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 3 


PLATE 3 
Peramus tenuirostris Owen 
B.M.(N.H.) 47739 


Fic. 1. Occlusal view of canine alveolus, Py_4 and My-4. x25. 
Fic. 2. Lingual view with outline of mandibular ramus. X25. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 3 


oe 


> ia 
als 


PLATE 3 


PLATE 4 
Peramus tenuirostris Owen 


B.M.(N.H.) 47739 


Fic. 1. Labial view of a section of mandibular ramus containing canine alveolus, Pj~4 and 
My= 47 X25. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 3 PLATE 4 


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“A LIST OF SUPPLEMENTS 
TO THE GEOLOGICAL SERIES” Pee 
OF THE BULLETIN OF aS ee 
THE BRITISH MUSEUM a (NATURAL HISTORY) eae 


. Cox, L. R. Jurassic Bivalvia and cadena from Tanganyika anc 
Pp. 213; 30 Plates; 2 Text-figures. 1965. /6. Pa ee 
. Ex-Naccar, Z. R. Stratigraphy and Planktonic eee : 
Cretaceous—Lower Tertiary Succession in the Esna-Idfu Region, ile 

Egypt, U.A.R. Pp. 291; 23 Plates; 18 Text-figures. : 
. Davey, R. J., Downie, C., SARGEANT, W. A. S. & WItiams, TG Ste 
Mesozoic and Cainozoic Dinofiagellate Cysts. pax cee 28 oe. 


figures. 1966. £7. 


Appendix to Studies 0 on 1 Mesozoic and Cainozoic 
1969. Sop. ‘ 
. Erziotr,G. F. Permian to Palaascate Calcareous Algae (Dasycladaceae 
Middle East. Pp. 111; 24 Plates; 17 Text-figures 
» Ruoves, F. H. T., Austin, R. L. & Druce, De: 
ferous) Conodont faunas, and their value in local and c 
Pp. 315; 31 Plates; 92 Text-figures. 1969. £11. 
. Cuitps, A. Upper Jurassic Rhynchonellid Brachiopoc | from 


Europe. HE x19) 12 Plates; 40 geo, 00 3 SATS: fp-2 


special refeconce to the Myctophoids. Pp. 255; 102 ens ee 
. OWEN, H. G. Middle Albian mesa yer in the Aa ‘Basin 
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RDOVICIAN TRILOBITE 
feta FAUNAS OF THE 

_ BUILTH-LLANDRINDOD INLIER 
CENTRAL WALES. PART IL 


») 


C. P. HUGHES 


~ 


BULLETIN OF” ee 
ITISH MUSEUM (NATURAL HISTORY) 
ie Saat Vol. 20 No. 4 
LONDON: 1971 © 


THE ORDOVICIAN TRILOBITE FAUNAS OF 
THE BUILTH-LLANDRINDOD INLIER, 
CENTRAL WALES. PART II. 


24 uy 


N197] 


BS 


ip 
Al WIS 


BY 


CHRISTOPHER PAUL HUGHES | 


Pp. 115-182, 16 Plates, 13 Text-figures 


BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 
GEOLOGY Vol. 20 No. 4 
LONDON: 1971 


THE BULLETIN OF THE BRITISH MUSEUM 
(NATURAL HISTORY), instituted in 1949, 1s 
issued in five series corresponding to the Departments 
of the Museum, and an Historical series. 

Parts will appear at irregular intervals as they become 
veady. Volumes will contain about three or four 
hundred pages, and will not necessarily be completed 
within one calendar year. 

In 1965 a separate supplementary series of longer 
papers was instituted, numbered serially for each 
Depariment. 

This paper is Vol. 20, No. 4 of the Geological 
(Palaeontological) series. The abbreviated titles of 
periodicals cited follow those of the World List of 
Scientific Periodicals. 


World List abbreviation 
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© Trustees of the British Museum (Natural History), 1971 


TRUSTEES OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 


Issued 22 June, 1971 Price £4°15 


THE ORDOVICIAN TRILOBITE FAUNAS OF 
THE BUILTH-LLANDRINDOD INLIER, 
CENTRALE WALES: "PART It 


By CHRISTOPHER PAUL HUGHES 


CONTENTS 

Page 

I. TERMINOLOGY : . : : : 3 : : 117 

II. DEFINITION OF MEASUREMENTS . : c . : : 5 118 

III. SySTEMATIC DESCRIPTIONS F ‘ : ‘ : I19 

Family Trinucleidae Hawle) & Corda : . : : : 119 

Subfamily Trinucleinae Hawle & Corda : 6 : 121 

Trinucleus fumbriatus Murchison . ‘ ¢ : 122 

Trinucleus abyuptus sp. nov. . ; : . 9 132 

Trinucleus cf. acutofinalis Whittard. 5 : : D7 

Anebolithus sp... é : 5 é c : 139 

Bergamia prima (Elles) . : : : : : 140 

Bergamia whittavdi sp.nov. . : ; c : 146 

Trinucleinid gen. et sp. indet. 2 5 : 6 I51 

Subfamily Cryptolithinae Angelin : é : : 152 

Cryptolithus instabilis sp. nov. : : : : 152 

Cryptolithus sp. A. é : : . : : 157 

?Cryptolithus sp. B. : 6 : F $ : 157 

?Cryptolithus sp. C. : . 3 5 : : 158 

Bettonia chamberlaini (Elles) . : é : : 159 

Bettonia aff. superstes Whittard : : : : 167 

Subfamily Marrolithinae subfam. nov. i ¢ 5 167 

Marrolithus sp. . : 2 . 0 168 

Protolloydolithus jeticulatas (Elles) . . 5 - 169 

Telaeomarrolithus intermedius sp.nov. . 5 6 174 

Telaeomarrolithus vadiatus (Murchison) . a c 178 

IV. ACKNOWLEDGEMENTS 6 . 3 , : j : ; 179 

V. REFERENCES . 2 0 r 3 : : 5 179 
SYNOPSIS 


This paper is the second in a series of four dealing with the Ordovician trilobite faunas of the 
Builth-Llandrindod Inlier. Those described belong to eight genera and seventeen species, of 
which four are new. They comprise three subfamilies of the family Trinucleidae. The 
Marrolithinae is a new subfamily. 


I. TERMINOLOGY 


THE terminology adopted here is that in standard use for trinucleids, with the 
addition of the following two terms. The term ‘arc’ is used instead of ‘concentric 
row’ as previously proposed (Hughes 1970), and the term ‘inter-radial ridge’ is used 
for the ridges separating adjacent rows of pits on the fringe. 


118 


ORDOVICIAN TRILOBITE FAUNAS 


Il. DEFINITION OF MEASUREMENTS 


As in part I of this study (Hughes 1969), the single orientation method of measure- 
ment proposed by Shaw (1957) has been followed. In those measurements involving 
distances between, or to, furrows, the measurements have been taken from the 
deepest (dorsoventrally) point in the furrow. All measurements are taken from 
internal moulds except where specifically stated to the contrary. 

Measurements taken on trinucleids (see Text-fig. 1). 


A 


Ay 


By 


Bo 


preoccipital cephalic length—measured in the sagittal line from the occipital 
furrow to the anterior margin of the cephalon. 

cephalic length—measured in the sagittal line from the posterior margin 
of the occipital ring to the anterior margin of the cephalon. If an occipital 
spine is present, then the measurement is taken from the posterior tip of the 
spine. 

glabellar length—measured in the sagittal line from the occipital furrow 
to the anterior of the glabella. 

the distance between the posterior lateral glabellar furrows and the anterior 
of the glabella, as projected onto the sagittal line. 

the distance between the median lateral glabellar furrows and the anterior 
of the glabella, as projected onto the sagittal line. 


Fic. 1. Diagram showing the measurements taken on trinucleids. 


FROM CENTRAL WALES 119 


B3 the distance between the anterior lateral glabellar furrows and the anterior 
of the glabella, as projected onto the sagittal line. 

Ba the distance between the median glabellar node and the anterior of the 
glabella, measured in the sagittal line. 

I cephalic width—measured in a transverse direction along the posterior margin 
of the cephalon. 

I; maximum cephalic width excluding fringe—measured in a transverse direction. 

K maximum glabellar width—measured in a transverse direction between the 
axial furrows. 

K, posterior glabellar width—measured in a transverse direction across the 
occiput. 

R,; maximum thoracic width—measured in a transverse direction. 

Rg anterior thoracic axial width—measured in a transverse direction along the 
anterior thoracic margin between the axial furrows. 

Q thoracic length—measured in the sagittal line. 

Q; anterior thoracic segment length—measured in the sagittal line. 

W maximum pygidial width—measured in a transverse direction. 

X anterior pygidial axial width—measured in a transverse direction. 

Z pygidial length—measured in the sagittal line between the articulating 
furrow and the inner margin of the posterior border. 


Die SNS EVA Ce DES CRP ll ONS 
Family TRINUCLEIDAE Hawle & Corda, 1847 


In this study the need for the revision of the subfamilial classification of the 
trinucleids became apparent and this question is to be dealt with fully elsewhere. 
For convenience of reference and comparison diagnoses of the subfamilies and genera 
described in this paper are given below. The subfamily Marrolithinae nov. is here 
erected for those genera thought to be closely related to Marrolithus, but placed 
in the Cryptolithinae by Whittington (77 Moore 1959), i.e. Marrolithus, Crypto- 
lithoides, Marrolithoides, Protolloydolithus, Reuscholithus, Telaeomarrolithus together 
with Costonia. 


Subfamily TRINUCLEINAE Hawle & Corda, 1847 


Diacnosis. Cephalon semi-circular; glabella with three pairs of lateral glabellar 
furrows; pseudofrontal lobe generally prominent; alae may be developed; occipital 
spine absent; eye tubercles and ridges absent. Fringe with pits of upper lamella 
sunk into radial sulci; variable number of arcs present external to the girder. 


Genus TRINUCLEUS Murchison, 1839 


Diacnosis. Trinucleinids having one E arc and variable number of I arcs; 
glabella clavate with prominent pseudofrontal lobe. Pygidium much broader than 
long, generally with furrowed pleural fields. 


120 ORDOVICIAN TRILOBITE FAUNAS 


Genus ANEBOLITHUS Hughes & Wright, 1970 


Diacnosis. Trinucleinids with no E arcs, I; and Ig complete I3 variably de- 
veloped. Glabella pyriform with pseudofrontal lobe; median glabellar node 
present. Pygidium much wider than long, anterior part of pleural fields faintly 
furrowed. 


Genus BERGAMIA Whittard, 1955 


DiaGnosis. Trinucleinids having E; fully and E» variably developed; up to 
six I arcs present laterally; glabella clavate with prominent pseudofrontal lobe; 
median glabellar node present. Pygidium short, pleural fields furrowed. 


Subfamily CRYPTOLITHINAE Angelin, 1854 


Diacnosis. Cephalon generally semi-circular; glabella clavate to carinate; 
up to three weakly developed lateral glabellar furrows; occipital node generally 
present though may be small, absent in Eirelithus; alae, eye tubercles and ridges 
generally absent in adult form. Fringe with one arc external to girder in early 
genera, more arcs present in later forms; except in early genera, pits generally 
arranged radially; concentric ridges between arcs on upper lamella common. 


Genus CRYPTOLITRAUS Green, 1832 


Diacnosis. Cryptolithinid with E; and up to three I arcs continuous medially, 
variable number of further I arcs developed laterally; pits of upper lamella arranged 
radially medially but may be irregular laterally due to adventitious pits; E; and 
I, pits generally larger than the remainder; concentric ridges between arcs on upper 
lamella common. Glabella clavate with three pairs of weak lateral glabellar 
furrows. Pygidium wider than long; pleural fields generally furrowed. 


Genus BETTONIA Whittard, 1956 


Diacnosis. As for Cryptolithus except that a variable number of adventitious 
pits may be developed medially and posterolaterally external to Ej. 


Subfamily MARROLITHINAE subfam. nov. 


Diacnosis. Cephalon generally with angulate margin anterolaterally; glabella 
pyriform, rarely with swollen pseudofrontal lobe; occipital spine may or may not 
be developed. Fringe typically swollen anterolaterally except in early genera; 
one arc developed external to the girder except in later genera in which two are 
developed; pits may or may not be radially arranged, if so may be set in sulci. 


FROM CENTRAL WALES 121 


Genus MARROLITAHUS Bancroft, 1929 


Diacnosis. Marrolithinid with one E and a variable number of I arcs; fringe 
sharply angulated anterolaterally with variable inflation and pit enlargement. 
Glabella pyriform with one to three pairs of generally weakly developed lateral 
glabellar furrows. Pygidium wider than long, pleural fields usually weakly fur- 
rowed or smooth. 


Genus PROTOLLOYDOLITHUS Williams, 1948 


Diacnosis. Marrolithinid with regular FE; and I, arcs and numerous smaller 
irregularly arranged pits internal to I,; E; and I; separated by a sharp ridge on upper 
lamella; anterolateral corners rounded; no swelling or inflation of pits. Glabella 
elongate with three pairs of weak lateral glabellar furrows; short preglabellar 
field developed. Pygidium wider than long, pleural fields generally strongly 
furrowed. 


Genus TELAEOMARROLITAHUS Williams, 1948 


Dracnosis. Marrolithinid with only one complete E arc but up to eleven I 
arcs present anterolaterally; occasional pits of Ez may be developed anterolaterally ; 
anterolateral corner angulate; lower lamella may be inflated anterolaterally with 
pits of E; enlarged; upper lamella with pits in sulci except in inner regions laterally. 
Glabella pyriform with weakly developed pseudofrontal lobe; three pairs of lateral 
glabellar furrows developed. 


Subfamily TRINUCLEINAE Hawle and Corda, 1847 
Genus TRINUCLEUS Murchison, 1839 


1927 Botriodes Stetson. 
1950 Edgellia Shaw in Shaw and Stubblefield. 


DiaGnosis. See above (page 119). 
Type Species. Tvinucleus fimbriatus Murchison 1839. 


DistripuTion. Arenig to basal Caradoc of the British Isles, Norway and 
Sweden; Middle Ordovician of Russia. Type species from the basal Caradoc of 
Wales. 


Discussion. There has been considerable debate, both in the early part of the 
century and again in the 1950’s, over the validity of the generic name Tvinucleus 
Murchison 1839 and its type species. The early discussion, conducted chiefly 
by Foerste (1910: 10) and Raymond (1913: 4; 1913@: 26-30) centred around whether 
Cryptolithus Green 1832 should have priority over Tvinucleus. Subsequent work 
however, has shown the two genera to be distinct. Shaw im Shaw and Stubblefield 
(1950: 624), like Raymond (1913: 4), considered ‘Tvinucleus’ cavactaci Murchison 


122 ORDOVICIAN TRILOBITE FAUNAS 


to be the type-species of Tvimucleus and erected Edgellia for what became, as a 
result of his selection, the generically unplaced fimbriatus. However they had 
overlooked the selection by Vogdes (1890: 84) of T. fimbriatus as the type-species 
of Trvinucleus. In March 1958 the ICZN opinion 505 was published validating 
Trinucleus Murchison 1839 non Link 1807, with Tvinucleus fimbriatus Murchison 
1839 as type species. 

Stgrmer (1930: 13) showed the genus Botvioides Stetson, 1927 to be synonymous 
with Tvimucleus Murchison. 


Trinucleus fimbriatus Murchison, 1839 


(Pl. 1, figs 1-9; Pl. 2, figs 1-14; Pl. 3, fig. 1; Text-figs 2, 3) 


1839 Tvinucleus fimbriatus Murchison: 660, pl. 23, figs 2a, b. 

1851 Tvetaspis fimbriatus (Murchison) ; Sedgwick and M’Coy: pars, 146, non pl. 1E, figs 16, 16a. 

1853 Ivetaspis fimbriatus (Murchison); Salter: 3, 5, 8. 

1890 Tvinucleus fimbriatus Murchison; Vogdes: 84. 

1912 Tvinucleus fimbriatus Murchison; Reed: 349, 351-352, 385, 390, pl. 18, fig. 10, pl. 19, 
figs 2, 2a. 

1913 Tvinucleus fimbriatus Murchison; Raymond: 4. 

1913a Trinucleus fimbriatus Murchison; Raymond: 28-30. 

1914 Tvinucleus fimbriatus Murchison; Reed: pars, 350-352, 354, pl. 28, fig. 2, non figs 1, 3. 

1925 Tvinucleus fimbriatus Murchison; Raymond: 19-21. 

1927 Trinucleus fimbriatus Murchison; Stetson: 87-88, 96, fig. 5. 

1930 Tvinucleus fimbriatus Murchison; Stormer: 14, 30, 36, 75. 

1940 Tyvinucleus fimbriatus Murchison; Elles: pars, 415-419, 421, 424, 432, pl. 30, fig. 6. 

1940 Trinucleus fimbriatus mut. ultimus Elles: 416-419, 421, 424-425, 432, pl. 30, figs 7, 8. 

1940 Tvinucleoides salteri Elles: 428, pl. 30, fig. 9. 

1941 Trinucleus fimbriatus Murchison; Whittington: 22, 23, 26. 

1941 Tvinucleoides salteri Elles; Lamont: 443-444. 

1948 Trvinucleus fimbriatus Murchison; Williams: 85. 

1948 Tvinucleus fimbriatus Murchison; Lamont: 376-379, fig. A. 

1950 Edgellia fimbriatus (Murchison); Shaw in Shaw and Stubblefield: 624-625. 

1956 Tvinucleus fimbriatus Murchison; Stubblefield and Whittington: 49-54. 

1956 Tvinucleus fimbriatus Murchison; Whittard: 45, 46, 48, 65, pl. 6, fig. 4. 


DiaGnosis. Tvinucleus with arcs I,-5 generally developed; E; and I, pits larger 
than remainder; I; rarely present medially; inter-radial ridges angulate. Pygidium 
triangular with between six and nine axial rings; pleural fields generally with six ribs. 
It should be noted that the figure of the species given in Moore (1959: fig. 323.5) is 
incorrect both in the distribution of the pits on the fringe and in the characters of 
the pygidium. 

LectotyPeE. GSM Geol. Soc. Coll. 6836a. (Pl. 2, fig. 2). External mould of 
cranidium. 

Dimensions. Although the lectotype is poorly preserved the following approxi- 
mate measurements give some indication of its dimensions. 

A I 
8-0 20:0 


FROM CENTRAL WALES 123 


Both measurements in mm. For explanation of symbols see Text-fig. 1. 


TYPE LOCALITY AND HORIZON. Dark shales in the Gwern-yfed-fach quarry half 
a mile south-east of Builth Road station of basal Caradoc age (gracilis Zone). 


OTHER FIGURED MATERIAL. It. 2719 (Pl. 2, fig. 4); It. 2720 (Pl. 2, fig. 13); It. 
Petal: 220); it. 27227(Pl ox, fig. 6); It. 2723 (Pl. 2, fieia4); Tte2724 (Pl. 2, 
eile 2725 (Pl. 2, fig. 8); It. 2726 (Pl. x, fig. 3); It. 2727 (Pl. 1 fie. 9); It. 2728 
fees. 5) lt. 2720 (Pl. x, fig. 8): It.-2730 (Pl. x, fig. 7, Pl. 2, fis. 12); It. 273% 
meee. t) it. 2732 (Pl. x, fig 5): It. 2733 (Plot, fig. 2); It. 2734 (PL. 2, fig: 11); 
It. 2735 (PI. 1, fig. 4); It. 8798 (Pl. 2, figs 9, 10); BM 59499 (PI. 2, fig. 7); GSM 35356 
(Pl. 3, fig. 1); Wattison Collection, H.12 (PI. 1, fig. 1). 


DISTRIBUTION. Known with certainty only from the basal Caradoc of the 
Builth-Llandrindod region. It may also be present in South Wales but none of the 
records of the species in the Geological Survey Memoirs for South Wales has been 
confirmed to date. 


Description. The complete individual is roundly rectangular being slightly 
wider than long, excluding the genal spines. 


The cephalon is semi-elliptical and approximately twice as wide as long; large 
individuals are relatively wider; small ones relatively narrower. Discounting the 
fringe, the maximum width measured across the genal regions is always slightly 
over twice the glabellar length, with the larger individuals relatively narrower. 

The glabella is clavate, strongly convex and elevated above the genal regions, 
consisting of a swollen pseudofrontal lobe occupying the anterior two-thirds of the 
glabella, with a narrow stalk-like posterior portion. In profile it is convex in front 
and on top, sloping uniformly down to the posterior. Three pairs of lateral glabellar 
furrows are present. The anterior pair occur as small pit-like depressions on the 
side of the glabella, slightly posterior to the mid-point of the pseudofrontal lobe 
(Pl. x, fig. 3). The median pair, marking the rear of the pseudofrontal lobe, consists 
of elongated (tv.) pits. The posterior furrows are again elongate (tv.) pits directed 
anteromedially. Both the median and posterior pairs of glabellar furrows are placed 
on the side of the glabella some distance inside the axial furrows (Pl. 1, fig. 4). 
Lateral and slightly posterior to the posterior lateral glabellar furrows there is 
commonly a small pit-like depression of uncertain significance, which may represent 
the outer end of the posterior lateral glabellar furrow (PI. 1, fig. 3). The base of the 
glabella (Pl. 1, fig. 7), behind the posterior lateral glabellar furrows, is slightly 
swollen to form an occiput which is a little less than half the width of the pseudo- 
frontal lobe, and is bounded posteriorly by the occipital furrow. A small median 
glabellar node is usually present on the external surface of the glabella approximately 
opposite the anterior pair of lateral glabellar furrows. Medially the dorsal surface 
of the glabella bears a coarse reticulation, which may also be present, though much 
finer, on the frontal slope and sides of the glabella (PI. 1, fig. 7). 

The occipital ring is short (sag.), convex posteriorly and with no occipital spine. 
Deep elongate pits are developed at the lateral ends of the occipital furrow, which is 
relatively shallow medially. The posterior margin is rounded. 


124 ORDOVICIAN TRILOBITE FAUNAS 


Anteriorly the axial furrows are deep and narrow with prominent fossulae near 
their anterior extremities (Pl. 1, fig. 4). Posteriorly the furrows closely follow the 
margin of the glabella to about the position of the anterior pair of lateral glabellar 
furrows; posterior to this the furrows converge slightly and become much wider 
and shallower (PI. 1, fig. 4). 

The genal regions are roundly triangular, the outer margin is strongly convex, 
the inner margin slightly concave, and the posterior margin more or less straight. 
The genae are moderately convex, the outer margin being very steep and the inner 
regions sloping more gently posteromedially. Externally they are covered with a 
strong reticulate pattern of raised ridges, which is most coarsely developed along a 
broad band lying between the genal angles and the anterior fossulae (PI. I, fig. 7). 
At the genal angles the raised ridges tend to coalesce to form a ridge which cuts 
across the posterior border furrow to the posterior margin, thus isolating the posterior 
border furrow from the fringe. No eye tubercle or eye ridges are developed. The 
posterior border furrow is straight, wide and shallow, terminating in a shallow lateral 
pit slightly lateral to the fulcrum (Pl. 1, fig. 7). The posterior margin is 
rounded. 

The internal surface of the glabella and the genal regions may show a faint im- 
pression of the external reticulate pattern. The lateral pits, and lateral glabellar 
furrows form raised platforms internally, those of the anterior lateral glabellar 
furrows commonly being poorly developed; the fossulae form small apodemes. 
The median glabellar node is rarely discernable on the inside of the glabella. Small 
apodemes are present ventrally, immediately posterior to the lateral extremities of 
the occipital ring. 

The hypostoma is not known. 

In most specimens the fringe has almost certainly undergone some degree of 
flattening, but it seems most likely that the fringe possessed a gently convex genal 
roll becoming concave towards the brim. The fringe is of almost uniform width, 
expanding only slightly towards the genal angles. Six arcs of pits are generally 
developed, namely E; and Ij-; (Pl. 1, fig. 4); pits of Ig present occasionally. The 
pits are arranged in deep radial sulci separated by angulate ridges, the pits of Ey and 
I, being larger than the remainder. The radial arrangement of the pits is remark- 
ably persistent, breaking down only at the genal angles. 

As has already been shown (Hughes, 1970) half-fringe statistics may safely be 
used in trinucleid studies without reference to the size of individuals, providing that 
no early meraspides or protaspides are included. The number of pits in the E; and 
I, arcs is generally the same on account of the good radial arrangement and ranges 
from 18—24 (half-fringe) with a mode of about 21 (see Tables 1, 4 for full details). 
The number of radial rows developed varies between 12 and 20 (half-fringe) with a 
mode of 17 (see Table 6). Generally arcs I; 4 are present frontally with I; commencing 
by row 3 or 4 (see Tables 2, 5). 

Slight deformities in the radial pattern of pits are not uncommon. These are 
usually due to the fusing or bifurcation of an inter-radial ridge giving rise to an 
incomplete row of pits. Rarely two rows, partial or complete, occur within a single 


FROM CENTRAL WALES 125 


sulcus, and a further type of irregularity is occasionally seen in the development of 
an oversize pit in Iz or Ig. 

Contrary to Reed’s belief (1912: 385) the pits of the lower lamella do correspond 
to those of the upper lamella. On the lower lamella shallow sulci are developed 
however only along the anterior part of the fringe, internal to the girder. The 
inner part of the lower lamella is convex dorsally and the outer part more or less 
flat, but directed upwards and outwards from the girder. Commonly the girder is 
found flattened, obscuring the inner part of the lower lamella and giving a false 
picture of the pit distribution and shape of the lower lamella. The girder is strong, 
smooth and merges at the genal angles with the genal spines. These spines are 
nearly straight, diverge slightly to the rear, have a slight keel on the dorsal side and 
probably extend for a short distance posterior of the pygidium. 

The precise course of the facial suture has not been traced, but by analogy with 
other trinucleids it is almost certainly marginal, becoming dorsal only at the genal 
angles, thus leaving the genal spines attached to the lower lamella. Lamont 
(1948: 376) states that on a specimen from the Llanfawr Quarries ‘a semi-circular 
anterior facial suture appears to be present and to run just outside the anterior 
pits and forward into the fringe so as to enclose a number of pits in the innermost 
concentric row’. However of the three hundred and fifty cranidia examined from 
this locality none shows any sign of such a suture. Many do however possess cracks 
in roughly this position and it is thought that Lamont’s ‘suture’ may well be one 
of these. 

The thorax consists of six segments and is rectangular, being about two and a half 
times wider than long. The axis, which occupies about one-fifth of the total width, 
tapers very slightly and is moderately convex. Dorsally the axial furrows are 


Fic. 2. Reconstruction of the cephalon of Tvinucleus fimbriatus Murchison in dorsal view. 
CAKEG 


126 ORDOVICIAN TRILOBITE FAUNAS 


poorly developed, being identified essentially as the line of junction between the 
convex surface of the axis and the flat surface of the pleurae. Ventrally the furrow 
is represented by a ridge which appears as a slight depression on internal moulds. 
The swollen posterior portion of the axis of each segment is separated from the 
articulating half ring by a wide, shallow articulating furrow, which is deepened 
laterally into elongate (év.) pits which correspond with strong apodemes on the 
ventral surface. The anterior segment, however, has no articulating half ring 
developed, but anterior to the normal pair of apodemes a second pair of weakly 
developed apodemes is present. Small articulatory sockets and processes are 
developed in the axial furrows, anteriorly and posteriorly respectively, of each thoracic 
segment, except for the anterior segment which only has the posterior processes. 
The pleural regions are flat, bluntly terminated, and deflected ventrally and slightly 
posteriorly at the fulcrum. They are divided into two roughly equal parts by a 
transversely directed pleural furrow, which is deflected to the posterior at its distal 
end. The pleurae of the anterior segment are obliquely truncated; the facets being 
relatively large. 

The triangular pygidium is between three and four and a half times wider than 
long. In general the smaller individuals are relatively wider than the larger. The 
anterior margin, excluding the articulating half ring, is straight except for the 
lateral extremities which are deflected slightly to the posterior at a point correspond- 
ing to the fulcrum of the posterior thoracic segment. The posterior margin is 
defined by a slightly raised marginal rim marking the upper limit of the steeply 
declined posterior border which has, on the external surface, faint, closely spaced 
terrace lines. The axis is convex, clearly differentiated, and segmented. There 
may be from six to nine axial rings present, plus a small terminal piece, there being 
a slight positive correlation between the size of the pygidium and the number of 
axial rings developed (see Table 9). Anteriorly the axis occupies between about 
one-fifth and one-seventh of the width of the pygidium and tapers to about one-half 
this width. The axial furrows are slightly more prominent on the internal moulds 
than on external moulds, indicating some slight thickening of the exoskeleton along 
the line of the furrow. Only the anterior axial ring bears apodemes. The pleural 
fields are gently undulate and are crossed by straight furrows which become pro- 
gressively more and more posteriorly directed. Each field possesses an anterior 
border, usually five or six ribs (rarely four or seven, see Table 10), and a small tri- 
angular terminal area. Occasional specimens show differing numbers of ribs on 
the two pleural fields. 


The species shows the usual discoidal enrollment characteristic in the trinucleids, 
with the posterior margin of the pygidium in contact with the inner margin of the 
lower lamella. Since no articulating half ring is developed on the anterior thoracic 
segment it 1s possible that the flexure of the thorax was accommodated between 
the first and second, and second and third segments to avoid the production of an 
unprotected lenticular area between the occipital ring and the axis of the anterior 
thoracic segment (see Whittington, 1941a: 510). Enrolled specimens tend to be 
too flattened to indicate the relative amounts of flexure between the various segments. 


FROM CENTRAL WALES 127 


However the first segment generally retains the same orientation as the cephalon, 
while segments two-six are folded underneath. This suggests that slightly more 
than half the flexure at least was accommodated by the first two segments; thus on 
compaction the second segment became inverted with the more posterior thoracic 
segments and the pygidium (PI. 2, fig. 6). 

ONTOGENY. Only one complete meraspis is known, of degree five, but it is 
reasonable to suppose that isolated cranidia and pygidia smaller than this are also 
likely to be meraspides. As Barrande (1852: 265) and Whittington (1940: 254; 
1959: 447) have recorded, the later meraspides of trinucleids are very similar to the 
holaspis form; the meraspides of 7. fimbriatus follow this pattern. Even the 
smallest specimen (pre-occipital length, A = 2-2 mm, genal width, I, = 4-6 mm) 
shows, as far as can be determined, very little difference from holaspides (PI. 2, fig. 14). 

The cephalon in the degree five meraspis (A = 5:3 mm, Ij = 13:5 mm) (PI. 2, 
fig. 8) differs from mature individuals in that the fringe barely reaches posterior 
of the posterior margin of the cephalon, the posterior margin of the fringe being 
directed only slightly to the posterior from the genal angle. This is also seen in a 
slightly larger specimen (A = 5-7 mm) but a further specimen of the same size 
shows the typical holaspis form. Thus a pre-occipital length of 5-7 mm may mark 
the approximate upper size limit of meraspides. 

Two specimens (A = 3:5 mm, 5:0 mm) have the posterior margin of the fringe 
directed transversely and in the smallest specimen known (A = 2:2 mm, ]y = 
4‘6 mm) the posterior margin is directed forwards from the genal angles (Text-fig. 3). 
Further, in these tiny specimens, the anterior lateral glabellar furrows are poorly 
developed. 

All the pygidia which are thought to be of meraspides are very like those of 
holaspides. Following the general growth pattern found in the holaspides they 
tend to be relatively wider than the larger individuals. Counts of axial rings and 
ribs are difficult to make due to their poor definition towards the posterior, but 
there appears to be six or seven axial rings and about five ribs. 

BIOMETRICAL DATA. The following fringe data and bivariate analyses indicate 
the characteristics of the major features of the dorsal exoskeleton. They also show 
that there are no significant differences between the sample from the middle quarry, 
Llanfawr, and the sample from the type locality. 


Fic. 3. Diagram illustrating the change in the posterolateral outline of the fringe in 
meraspides of Tvinucleus fimbriatus Murchison with increase in size. c. X 4. A based 
on It. 2723 (PI. 2, fig. 14); B on It. 2732 (Pl. 1, fig. 5); C on It. 2725 (PI. 2, fig. 8). 


128 ORDOVICIAN TRILOBITE FAUNAS 


Although ideally it is considered that the best measurements of size (length, 
width) of the cephalon would be the cephalic length (A;) and the cephalic width (I), 
it is found, due to slight flattening of the fringe that the glabellar length (B) and the 
maximum genal width (I,) give a more useful indication of size. A general quali- 
tative study of the thorax, combined with the small amount of quantitative data 
available, indicates that it shows little variation, as is believed the case in most 
trinucleids. Insufficient data, however, are available to determine if the ratio 
length to width varies with the overall size of the individual. The sample of pygidia 
from the middle quarry Llanfawr may include a few specimens of Telaeomarrolithus 
intermedius sp. nov. (see page 174) or even Marrolithus sp. (see page 168). The 
effect of any such specimens will, however, be very small since it has proved im- 
possible on qualitative and quantitative grounds to separate differing types of 
trinucleid pygidia at this locality. Also 7. zntermedius is very much rarer than 
T. fimbriatus, and Marrolithus sp. is extremely rare indeed. 

Although it is demonstrated below that the sample from Gwern-yfed-fach does 
not differ significantly from the much larger sample from Llanfawr, the data from the 
two samples are not combined, so that further samples may be compared directly 
with that from the type locality if required. 

Fringe Data (half-fringe). 

Sample from type locality (Gwern-yfed-fach). 


TABLE I 
Number of pits 21 22 23 24 
FE; arc: Number of specimens 2 — _- I 
I; arc: Number of specimens if — os I 


Table giving the frequency distribution of the number of pits in the E; and J, arcs (half-fringe) 
for Tvinucleus fimbriatus Murchison from the type locality. 


TABLE 2 
TOW Number of 
I 2 3 4 Specimens 
Iq 100% == = oan 5 
I5 335% - TOE% 33570  LOE% 6 
Ig a= — — 100% a 


Table showing the percentage of specimens in which a particular inner I arc commences in a 
given row for Tyinucleus fimbriatus Murchison from the type locality. 


TABLE 3 
Number of rows 16 17 18 19 
Number of specimens i I 4 I 


Table giving the frequency distribution of the number of rows developed (half-fringe) for 
Trinucleus fimbriatus Murchison from the type locality. 


Sample from Middle quarry, Llanfawr, Llandrindod. 


FROM CENTRAL WALES 129 


TABLE 4 


FE, arc 
Number of pits nOeNIOs LO TOs 20 205" 21 214" 22 
No. of specimens 4 3 ae Ee OL 2b 7 5 
mean — 20-00. Var, — 1-7650; 1 — 86 


I, are 
Number of pits EO 1655 LO) 105°) 20°20, 2m "25" 22 "224 23° 23k 24 
No. of specimens 3 2 5B tO, | 5 8 120" *8 Be Py: it 


mean = 20:64; var. = 1°5856; n = 85 


Table giving the frequency distributions of the number of pits in the E, and J], arcs (half- 
fringe) for Tvinucleus fimbriatus Murchison from the Middle quarry, Llanfawr. Pits occurring 
on the sagittal line are counted as half pits. 


TABLE 5 
row Number of 
I 2 3 4 Specimens 
Iq 96% 4% a) a 26 


Is 25% 25% 08% 333% 12 


Table showing the percentage of specimens in which a particular inner I arc commences in a 
given row for Tyinucleus fimbriatus Murchison from the Middle quarry, Llanfawr. 


TABLE 6 
No. of rows 124 13 134 14 144 15 154 16 1634 17 174 18 184 19 I94 20 204 
No. of specimensI —— — I 3 7 14 6 15 3 9 4-— 3 2 2 


Mean O-O5 aval. — 2-076. M170 


Table giving the frequency distribution of the number of rows developed (half-fringe) for 
Trinucleus fimbriatus Murchison from the Middle quarry, Llanfawr. Rows situated along the 
sagittal line are counted as a half row. 


Comparison of the number of pits in the E; and I, arcs and also the number of 
radial rows present for the two samples show no significant differences. The data 
for the commencement of the inner arcs is also very similar in the two samples; in 
both virtually all specimens have the I arc continuous medially, and 50% of speci- 
mens in both cases show I; developed at or before radial row 2 and only rare cases of 
Ig commencing before row 5. It is thus seen that regarding the major charac- 
teristics, the fringe pit distribution is essentially the same in both samples. 


Table 7 gives the bivariate statistics for various parameters for both samples. 
Comparison where possible shows there to be no significant differences between the 
two samples. 


130 ORDOVICIAN TRILOBITE FAUNAS 


TABLE 7 
x6 2 5Y x Svan XaY! var. y r Te a var. a var. a n 
ity, & JAN 10°95 31:3967 5°85 10:8633 0-999 1:000 1:09 0-0001 — — 4 
iti 8 183 10°95 31:3967 4:42 5:4892 0-997 0-998 1:03 0:0025 0-42 0-:00048 4 


153.3 IES 4°74 4°6130 3°50 3:1900 0:989 0-991 I-‘II 0:0075 0:83 0-:00491 5 


WZ 11-48 4:6670 3:90 1:2600 0:979 0:982 I-51 00270 — 5 
XZ 1:80 0°4089 3:81 2°8188 0:°977 0-980 1:22 0:0074 — — ste) 
3 ANH 19:27 88740, 9:18 1:3069 0:933 0:°934 0-81 0:0076 — — 13 
ih) Bus 13°55 5:9093 7°84 2:4620 0:955 0956 III 00022 — — 51 
ity, 3-18) 13°81 5°8768 6:02 1:°3653 0:938 0-939 I:10 oO-0019g — — 77 
IN BS) 7°83 2:2087 5:90 1:2516 0-983 0:984 0:99 0:0003 0°74 0-00015 122 
18} 3 18%) 6-08 I'2710 4:88 07859 0:977. 0:978 0:98 0:0002 0:79 0-:00017 168 
B: Be 6:05 1:2872 3:91 0:5840 0:967 0-967 1:04 00004 — — 176 
B: Bs 6:09 I‘O41O 2°75 0:2487 0:923 0:924 1:08 oO-001I2 — oe 140 
BEES 6:03 I'2344 4:46 07819 0:926 0:927 1:08 000090 — — 77, 
KEG 4°46 078236 1:87 O-1194 0°879 0-881 OO 0:0013 — — 144 
Wi Z 11°37 3°1960 3:37 0:4882 0-949 0:950 1:31 O-0016 — — 104 
Ween 18 3:2768 2:09 0°1903 0-916 0-918 1:31 00028 — — 98 
XZ, 2:10 0'1606 3:48 0:4381 0-860 0:862 1:00 00-0017 1:65 0:00487 148 


Bivariate statistics for Tvinucleus fimbriatus Murchison. Upper part of Table for sample 
from the type locality (Gwern-yfed-fach); lower part for the sample from the middle quarry 
Lianfawr. All measurements in mm. For explanation of symbols see Text-fig. 1. 


TABLE 8 
Ry Re Q Qi 
It. 2725 (meraspis 5) Q°4.* “FO — 3-0 — 
H 22 14:0 — 58 10 
NMW. 68.376. G186 16:8 — 69 12 
NMW. 68.376. G187 12°8 — — o9 
NMW. 68.376. G188 Tees 4:6 1-0 


Thoracic measurements for Tyvinucleus fimbyiatus Murchison from the middle quarry, Llan- 
fawr. No data available for the type locality. All measurements in mm. For explanation 
of symbols see Text-fig. I. 


TABLE 9 
maximum pygidial width in mm 7-0-11:0 II-I-17-0 
Number of 6-7 — — 
axial rings 8-9 4 us 
maximum pygidial width in mm 7-0-11-0 II-I-17-0 
Number of 6-7 10 4 
axial rings 8-9 1, 35 


2 X 2 tables showing relationship between pygidial size (as measured by width) and number 
of axial rings, for Tvinucleus fimbriatus Murchison. Upper part of table for type locality 
(Gwern-yfed-fach) ; lower part for the middle quarry, Llanfawr sample. 


FROM CENTRAL WALES 131 


TABLE I0 
Number of ribs on pleural fields 4 5 6 i 8 
Number of specimens — 2 it 3 >— 
Number of ribs on pleural fields 4 5 6 7 8 
Number of specimens 4 13 109 5 — 


Mean = 5°88; var. = 0:2465; n = 131 


Frequency distribution for the number of pleural ribs developed on the pygidium of Tvinucleus 
fimbriatus Murchison. Upper part of table for type locality sample (Gwern-yfed-fach) ; lower 
part for the middle quarry Llanfawr sample. 


It may be seen from the above Tables that quantitatively there are no significant 
differences between the two samples and thus the data from the larger, though 
non-topotypic sample may be reasonably taken as characterising the species, until 
such time as more complete data becomes available from the type locality. 


Discussion. A difficulty encountered in redescribing this species is the generally 
poor preservation, particularly of the fringe pits at the type locality, Gwern-yfed- 
fach. However it has been shown above that the form found at the middle quarry, 
Llanfawr appears not to differ significantly from that found at the type locality, 
and the redescription above has been based mainly on the more satisfactory Llanfawr 
sample. 

Elles (1940: 424-425) in describing two new mutations of T. fimbriatus, though 
on pp. 416, 417 recording T. fimbriatus from Gwern-y-fed Quarry and not from 
Pencerrig Lake, considered (p. 425) Pencerrig Lake to be the type locality of T. 
jimbriatus Murchison. There is, however, no doubt that the lectotype came from 
Gwern-yfed-fach. Although her descriptions were brief she did infer that the 
fringe of 7. fimbriatus mut. ultimus is wider than in the typical form and also that 
the pits show better radial arrangements at the genal angle. Although she records 
both the typical form and the wltimus mutation as occurring at Llanfawr, no con- 
firmation has been found for the existence of two varieties at this locality, and all 
would appear to belong to her witimus form. However, it has been shown above 
that the Llanfawr form does not differ from the form occurring at the type locality 
of T. fimbriatus (Gwern-yfed-fach); thus Elles’s mutation ultimus must be con- 
sidered as a synonym of T. fimbriatus s.s. The present study has also shown that 
Elles’s T. fimbriatus s.s. and mutation primus from Pen-cerig Lake quarry, although 
dorsally bearing some similarity to T. fimbriatus, possess a lower lamella which clearly 
shows that two E arcs are present and both are here assigned to the genus Bergamia 
Whittard, 1955. 

T. acutofinalis Whittard, 1956 is readily distinguished by having only three arcs 
developed internal to the girder; it also differs in that all the pits are of equal size, 
and the inter-radial ridges are rounded. T. foveolatus (Angelin, 1854) and T. 
foveolatus var. intermedius Stormer, 1930 differ from T. fimbriatus in being much 
smaller and in having a median ridge developed on the glabella posterior of the 


132 ORDOVICIAN TRILOBITE FAUNAS 


median glabellar node, and also lateral eye tubercles; further the fringe in T. 
foveolatus does not extend behind the posterior margin of the cephalon. T. bronni 
Sars and Boeck im Boeck, 1838, is distinguished by its short stubby pygidium with 
few axial rings and pleural ribs. This last species is very similar to Bergamia, 
particularly in the characters of the pygidium, although Stgrmer’s figures (1930, 
Pl. 2, figs 2, 5, 6, 7) show only one E arc and so, for the present at least, it seems 
better to retain this species in the genus Tvinucleus. Tvrinucleus abruptus sp. nov. 
(see below) may be easily distinguished by the anterior deflection of the posterior 
border of the cephalon at the fulcrum, the smaller number of pits in each arc on the 
fringe and its relatively narrower pygidium with fewer ribs. 

Trinucleoides salteri Elles, 1940 is here considered as a junior synonym of T7- 
nucleus fimbriatus Murchison. The single known specimen in the Wyatt-Edgell 
Collection (GSM 35356, Pl. 3, fig. 1) is almost certainly from the basal Caradoc at 
Gwern-yfed-fach and is associated with Trinucleus fimbriatus and Cnemidopyge 
bisecta (Elles) and not with Lloydolithus as claimed by Lamont (1941: 441). Owing 
to the lower lamella being slightly displaced and pushed up through the upper 
lamella in places, Elles was misled into believing that the arcs of pits were separated 
into two series and that tubercles were present laterally. The surface of the glabella 
and genae is poorly preserved and no trace of any caecae or other surface markings 
exists. The elongate alae and prominent occipital ring are thought to be accentu- 
ated due to distortion on preservation, and the groove between the fringe and left 
gena to be due to a pygidium folded back beneath the cephalon. 


Trinucleus abruptus sp. nov. 
(Pl. 3, figs 2-4, 6, 7; Text-fig. 4) 


1940 Tyvinucleus chamberlaim Elles: pars, pl. 29, fig. 13. 
1940 Tyinucleus cf. foveolatus Angelin; Elles: 425, pl. 31, figs 1-2a. 


Diacnosis. Tvinucleus with six arcs of pits developed, most probably being 
Ej, I,-5; fringe of approximately uniform width with posterior border bent for- 
wards external to fulcrum; inter-radial ridges rounded; small median glabellar 
node; no eye tubercles. Pygidium triangular with segmented axis and faintly 
ribbed pleural fields. 


TYPE MATERIAL. Holotype. BM~ In 36920 (PI. 3, fig. 7). Internal mould 
of nearly complete specimen. 

Paratypes. BM. In 36921 (Pl. 3, fig. 2) Internal mould of complete specimen. 
BM 59200 External mould of nearly complete specimen. It. 2736 (Pl. 3, fig. 3) 
Internal mould of nearly complete specimen. It. 2737 Internal mould of pygidium. 
It. 2738 (Pl. 3, fig. 6) External mould of cephalon. OUM B179 (PI. 3, fig. 4) Internal 
mould of nearly complete specimen. 


FROM CENTRAL WALES 133 


DIMENSIONS. 
A B Br Be Bs I Iy BS 1G 
Holotype Pop IO2Oy 95620, VAS2's 3:0) | 18:8) S14 Ze 5°20 2:0 
In 36921 SZ On aS 7m eA Sain 20iSe 1505 :0 kos 
BM 59200 63 55 45 36 25 153 25 48 18 
It. 2736 578i 450 35) S22 CAO 5:0" 1-9 
It. 2738 — O42 — — —C6.135¢.IrI — — 
OUM B179 c.8:0c.66 — — — 188 146 5°5¢. 2:5 
No. of No. of ribs 
Ry Q W Xx Z  axialrings Left Right 

Holotype 1378 — 125 — — — — — 
In 36921 15-2) 0-0 TAT 2:00 ACA 6+ 3 2+ 
BM 59200 Oy AS | 10-62-32) 1 3°8 8+ 3+ 3+ 
It. 2736 c.150 — — €.2:5¢. 4'I 6+ 4+ 4+ 
It. 2737 Degg ES ai 3+ = 

OUM B179 NO-0 95°20 12-On 2-5-0 9 3 2 


All measurements in mm. For explanation of symbols see Text-fig. 1. Measure- 
ments on BM 59200 were taken from a latex impression. 


TYPE LOCALITY AND HORIZON. The original label affixed to the holotype (figured 
Elles, 1940, pl. 31, figs 1, 1a as T. cf. foveolatus Angelin) states “Trinucleus ornatus 
Sternb. Llandeilo Flags Gwernyfydd. Griffith Davies Coll.’ The lithology is, 
however, completely different from that found at Gwern-yfed-fach, Nr. Builth, 
but is very like that found at the small quarries 600 yds east of Upper Gilwern, 
and the presence of similar specimens at this locality suggests it to be the true locality 
for the holotype, and also paratypes In. 36921, BM 59200. The evidence of the hand 
specimen is supported by thin sections taken from the holotype slab and Upper 
Gilwern material. Of the other paratypes, It. 2736 is from the small quarries 
600 yds east of Upper Gilwern and OUM B179 is almost certainly from this locality 
also; It. 2737, It. 2738 are from the cliff section on the left bank of the Howey 
Brook half a mile east-south-east of Carregwiber. 


DisTRIBUTION. Apart from the two localities from which the type material is 
drawn, the species is also known from the exposures in the left bank of the track 
from Bwlch Llwyn to Hendy Bank, 100 yds south-east of Bwlch Ilwyn. All these 
localities are confined to the upper part of the Lower Llanvirn. At present the 
species is known only from the Builth inlier. 


Description. Excluding the genal spines, the complete exoskeleton is oval 
in outline, but with the maximum cephalic width approximately equal to the total 
sagittal length. 

The elliptical cephalon is about two and a half times as wide as long. The 
glabella is clavate in plan, strongly convex, extending slightly onto the fringe; 
three pairs of lateral glabellar furrows developed, the median pair marking the 
posterior of the prominent pseudofrontal lobe. In profile the glabella is strongly 


134 ORDOVICIAN TRILOBITE FAUNAS 


convex anteriorly, levelling off medially and sloping gently down to the posterior. 
The anterior pair of lateral glabellar furrows, situated just anterior of the mid-point 
of the glabella, consist of small, weakly developed pit-like depressions in the side 
of the glabella. The median furrows are more strongly developed and are situated 
at about two-thirds the distance along the glabella from the anterior. The posterior 
furrows are well developed, slightly elongate sagittally and mark the front of the 
weakly developed occiput, near the rear of the glabella. Small crescentic alae are 
present, though poorly developed. A small median glabellar node is present on 
the external surface of the glabella situated approximately level with the median 
pair of lateral glabellar furrows. Medially the external surface of the glabella is 
covered with small closely spaced pits which may also be present on the sides of the 
glabella (PI. 3, fig. 6). 

The occipital ring is short (sag.), posteriorly convex, transversely arched and 
overlaps the anterior part of the axis of the first thoracic segment. The occipital 
furrow is wide and shallow with occipital pits being only weakly developed at the 
lateral extremities. No occipital spine is present. 

Anteriorly the axial furrows are deep and narrow, becoming somewhat wider 
to the posterior. No anterior fossulae have been observed, but by analogy with 
other trinucleids it seems likely that they are developed. 

The genal regions are transversely semi-oval, the outer margin being strongly 
convex, the inner margin strongly concave and the posterior margin more or less 
straight medially, curving forwards at the lateral extremities. The genae are 
moderately elevated with the outer parts sloping steeply down to the fringe. 
Externally they are, like the glabella, covered with small pits. Specimen It. 2738 
(Pl. 3, fig. 6) shows, on the external surface, a single, unbranched genal caeca extend- 
ing obliquely from the anterior lateral glabellar furrows to just outside the lateral 
pits. No eye tubercles or ridges are developed. 

The posterior border furrow is moderately deep and narrow axially, becoming 
wider laterally and terminating in a shallow lateral pit. The posterior margin is 
straight medially, but is deflected forwards through about 40° at the fulcral processes 
(BL 3; ties7) 

Internally the lateral glabellar furrows and lateral pits form variably raised 
platforms. The small median glabellar node is not evident on the inside of the 
glabella. 

The hypostoma is not known. 

The fringe is about I-5 mm in width narrowing to about 1-0 mm in front of the 
glabella. The upper lamella is gently convex, turning abruptly upwards at the edge 
to form a prominent rim. The marginal band is declined steeply downwards. 
Six arcs of pits are developed, the pits of the outer arc being larger than the re- 
mainder. The arcs present are probably Ej, I;-5 but as the lower lamella is not 
known there is no way of being certain of this at present. The pits are arranged 
in shallow radial sulci separated by low, rounded ridges. The radial pattern is 
persistent, breaking down only at the genal angles. The holotype is the only 
specimen known showing the individual pits at all clearly; there being nineteen 


FROM CENTRAL WALES 135 


pits in FE on the left half-fringe and about eighteen on the right half. The number 
of pits in the anteromedian rows cannot be determined but five I arcs are present 
by row 9g on either side of the fringe and continue to the genal angles. Irregularities 
in the pit distribution occur, the holotype showing two ridges fusing between row 13 
and row 14 on the left half of the fringe, and between row 8 and row g on the right 
side (Pl. 3, fig. 7). The paratype OUM Br79 (PI. 3, fig. 4) possesses about 43 pits 
in the FE, arc, of which about 21 are situated on the left half-fringe. The preserva- 
tion of the inner portion of the fringe however does not allow determination of the 
number of arcs developed. 

The facial suture is marginal, being near the bottom of the marginal band anteri- 
orly and tending obliquely across it laterally to be just below the marginal rim at the 
posterolateral corners, whence it follows the posterior border of the fringe inwards 
towards the fulcral processes (Pl. 3, fig. 7). The genal spines are known on a single 
specimen, It. 2736, in which the left spine extends behind the pygidium for about 
six mm, 

The thorax is rectangular in shape, being about two and a half times wider than 
long. The six segments conform to the usual trinucleid pattern and require no 
further detailed account. The axial furrows are however better developed dorsally 
than in the type species. 

The triangular pygidium is about three times as wide as long. The posterior 
margin is defined by a very small raised rim marking the upper limit of the steeply 
declined posterior border. The convex, clearly differentiated axis may have at 
least nine rings present, although they are only well developed anteriorly. Up 
to three faint ribs may be present on the pleural fields in addition to the anterior 
border (PI. 3, fig. 4). 


BIOMETRICAL DATA. Although relatively few specimens of this species are 
available, some bivariate analyses have been possible, as detailed below. No 


Fic. 4. Reconstruction of the cephalon of Tvinucleus abyuptus sp, nov. in dorsal view. 
Cr Xa: 


136 


ORDOVICIAN TRILOBITE FAUNAS 


data apart from the few mentioned above in the description are available for the 
pit distribution or for the pygidial segmentation. 
or inferred to be from, the small quarries 600 yds east of Upper Gilwern, unless other- 
wise stated. 


XS BY Ks var. x 


Ty 


es & 


men BU 273 from the cliff section in the Howey Brook. 


TA I4‘I5 1:9367 
Ky 5:18 O-1217 
gz 10°74 5°3780 
Z 2:20 0-1500 


y 
7°30 
2:00 
3°58 
3°58 


var. y 
0:6067 
0:0280 
0°4920 
0:4920 


TABLE II 
ip Te 
0:993  9°993 
0:959 0-960 
0:967 0-968 
0-985 0:985 


a 
1:08 
I-24 
O:9g1 
I°Il 


var. a 
0:0078 
0:0305 
0-0173 
0-0122 


a 
0:56 
0°48 
0-30 
1-81 


All data refer to specimens from, 


var. a 
0:00209 
000457 
0:00196 
0°03324 


An at B 


Bivariate statistics for Tvinucleus abyuptus sp. nov. from the small quarries 600 yds east of 


Upper Gilwern. All measurementsinmm. For explanation of symbols see Text-fig. 1. 


It. 2736 
In. 36920 
In. 36921 


BM 59200 


It. 8603 
BU 273 


TABLE I2 
B By 
oe) a6 
6-0 5:2 
7:0 Sh 
6:2 5:0 
5r5 45 
64 54 


B3 
22% 
370 
3°4 
2°5 


Data for the position of the lateral glabellar furrows for Tyvinucleus abyuptus sp. nov. Speci- 


explanation of symbols see Text-fig. 1. 


with the larger pits, represents an Ey, arc. 


In. 36921 
BM 59200 
It. 8603 
It. 8801 


TABLE 13 
Ry QO 
15:2 6:0 
17 4:8 
116 48 
9°7 41 


Thoracic measurements for Tvinucleus abruptus sp. nov. 
ments for It. 8801 taken from external mould. For explanation of symbols see Text-fig. 1. 


R/Q 
2°5 
2:6 
2:4 
2°4 


All measurements in mm. For 


Allmeasurementsinmm. Measure- 


Discussion. Although the position of the girder is not known, this species is 
placed in the genus Tvimucleus Murchison on the assumption that the outer arc, 
This generic placing is supported by 
the general Tvinucleus-like glabella and also by the close similarity between this 
species and Tvinucleus acutofinalis Whittard, 1956. 


FROM CENTRAL WALES 137 


Elles (1940: 425) compared this trilobite with Tvinucleus foveolatus Angelin, 1854. 
Apart from the difference in size noted by Elles, the present species differs in fringe 
shape, lack of eye tubercles, and also in the external surface ‘ornament’. In 
addition the small median glabellar node is more pronounced on the external surface 
of T. abruptus, whereas in T. foveolatus it is apparently more prominent on the internal 
moulds. TJ. abruptus may be distinguished from the somewhat younger, but closely 
related T. acutofinalis by the presence of at least six arcs of pits, and also by the 
lateral continuation of the sharp upper external rim of the upper lamella. The 
pygidia of the two species may be separated on the higher number of axial rings and 
pleural ribs in T. acutofinalis. T. fimbriatus is readily distinguished by the presence 
of genal prolongations to the fringe, and a relatively wider pygidium with more ribs. 
Trinucleus bronnt Sars and Boeck im Boeck, 1838 is distinguished by having only 
two to four arcs of pits developed and also in possessing lateral eye tubercles. 

Although very little information is available, it would appear from the holotype 
that the same kind of irregularities in the pit distribution as found in T. fimbriatus 
are also present in T. abruptus. 

A single lower lamella, here described as Anebolithus sp. (p. 139, Pl. 4, figs. 3, 5) 
having no E arcs developed, is known from the type locality of T. abruptus, but it 
differs in outline, particularly at the genal angles. However until such time as a 
lower lamella is discovered in place in T. abruptus there remains the possibility that 
this species may be better placed in Anebolithus Hughes and Wright, 1970. 


Trinucleus cf. acutofinalis Whittard 
(PI. 3, fig. 5; Pl. 4, figs 4, 7, 8) 


FIGURED MATERIAL. It. 2739 (PI. 3, fig. 5) Internal and external moulds of 
anterior thoracic segment. It. 2741 (Pl. 4, fig. 4) Internal mould of pygidium and 
part of thorax. It. 2742 (Pl. 4, fig. 8) Internal and external moulds of damaged 
cranidium. It. 2743 (Pl. 4, fig. 7) Internal and external moulds of nearly complete 
specimen. 


LOCALITY AND HORIZON. All the figured specimens are from the ashy mudstones 
and sandstones at the top of the Cwm-Amliw Ash (Didymograptus murchisom 
Zone) exposed in the stream section about 200 yds south-west of Wern Ddu Barn. 
Specimens It. 2739-2742 being from the left bank, and specimen It. 2743 from the 
right bank. These are the only two localities from which the species is known. 


DeEscripTion. The cephalon is slightly over two and a half times as wide as 
long. Anteriorly the margin is only slightly curved, but becomes more strongly 
so laterally. The posterior margin is straight axially but is deflected forwards at 
the fulcrum. The glabella is typically trinucleinid with a swollen anterior portion; 
details of the lateral glabellar furrows are not known. No indication of any median 
glabellar node is preserved. The external surface of the genal regions is covered 


138 ORDOVICIAN TRILOBITE FAUNAS 


with numerous small pits (Pl. 4, fig. 7). A single genal caeca is developed commenc- 
ing opposite the mid-point of the glabella and directed obliquely to the genal angle. 
No eye tubercles or ridges appear to be present. The fringe is narrow and has a 
prominent marginal rim anteriorly and laterally. Details of the pit distribution 
are poorly known but it seems probable that four arcs of pits are developed, the 
inner one or two arcs being absent anteromedially due to the slight encroachment 
of the glabella onto the fringe. The pits are sunk into radial sulci, there being 
between seventeen and twenty rows on each half-fringe. Posterolaterally, inter- 
radial rows with pits of the inner two arcs may be developed (Pl. 4, fig. 8). The 
position of the girder is not indicated on the upper lamella, though it is possible that 
the outer arc is external to the girder due to the slightly larger size of the pits. 

The thorax appears to conform to the usual trinucleid pattern. As in T. acuto- 
finalis and T. abruptus sp. nov., the pleural termination of the anterior thoracic 
segment is markedly oblique (PI. 3, fig. 5). 

The triangular pygidium is nearly three times as wide as long. At least four axial 
rings and two pleural ribs are developed. Posteriorly the preservation deteriorates, 
and it is impossible to ascertain if these are the total number of rings and ribs 
developed. 


Discussion. This species is important, for apart from a few incomplete specimens 
occurring near the base of the Lower Didymograptus murchisoni shales, this is the 
only trinucleid known from the Upper Llanvirn of Builth. Obvious similarities 
exist between this form and 7. acutofinalis Whittard from the Betton beds of the 
Shelve region (Upper part of D. murchisoni Zone) with regard to the general outline 
and fringe details. The marginal rim however, does not diminish laterally and the 
pygidium has fewer axial rings and pleural ribs than 7. acutofinalis. In these latter 
features T. cf. acutofinalis is more like T. abruptus from the upper part of the Lower 
Llanvirn. However, owing to the probable development of only three I arcs it is 
thought that these Builth specimens are most closely related to T. acutofinalis. 

The attitude of the exoskeleton of specimen It. 2743 (Pl. 4, fig. 7) is of interest 
as the thorax and pygidium are sagittally concave dorsally in a manner akin to, 
though more pronounced than, the specimen of Tvetaspis seticornis (Hisinger, 1840) 
figured by Stormer (1930, fig. 47). 


Genus ANEBOLITHUS Hughes and Wright, 1970 


DIAGNOSIS. See page 120. 
TYPE SPECIES. Incaia simplicior Whittard, 1966. 
DISTRIBUTION. Lower Arenig and Lower Llanvirn of the Welsh Borderland. 


Discussion. The genus has recently been discussed together with Incaia in 
Hughes and Wright, 1970, and no further discussion is necessary. 


FROM CENTRAL WALES 139 
Anebolithus sp. 


(PI. 4, figs 3, 5) 

FIGURED SPECIMEN. It. 2744 Internal and external moulds of lower lamella. 

HorIzoN AND LOCALITY. Uppermost part of the Lower Llanvirn (Subzone 
D. speciosus) from the small quarries 600 yds east of Upper Gilwern. 

DescripTion. A single specimen is known of a lower lamella apparently having 
no pits developed external to the girder. It is 14 mm in width at the posterolateral 
extremities; the estimated cephalic length being about 6-5 mm. The seemingly 
smooth girder is well developed and nearly semicircular in outline. Traces of two 
or three arcs of pits internal of the girder are visible with radially arranged pits on 
most of the convex genal roll. Long outwardly curved genal spines are present 
extending about 12:5 mm from the posterolateral extremities of the girder, their 
maximum separation being 16-5 mm which occurs at approximately one-third of 
their total length as measured from the anterior. 

Discussion. Unless the absence of pits external to the girder is due to imperfect 
preservation it seems that this single specimen is best placed in Anebolithus Hughes 
and Wright, 1970. Its outline, particularly near the genal angles appears to preclude 
it from being the lower lamella of T. abruptus. With only the lower lamella, no 
adequate comparison can be made with the only other known species of the genus. 
However it is noteworthy that the Builth specimen is larger and is more smoothly 
rounded anteriorly than is the case in A. semplicior (Whittard, 1966) from the Lower 
Arenig at Shelve. 


Genus BERGAMIA Whittard, 1955 


1966 Cochliovvhoe Whittard. 

DIAGNOSIS. See page 120. 

TYPE SPECIES. Bergamia rhodesi Whittard, 1955. 

DIsTRIBUTION. The genus is known from the British Isles where it is recorded 
from beds ranging from the Arenig to basal Caradoc, and from the Llandeilo (Dob- 
rotiva Formation) of Czechoslovakia. The genus may also be present in the Upper 
Llanvirn (4a«) of Norway (Bruton, pers. comm.). 

Discussion. In erecting Bergamia in 1955 Whittard defined his genus as typically 
bearing E;, Ez and J, arcs, fully developed. In 1966, following the discovery of 
forms apparently lacking between three and five pits of the Ey, arc anteromedially, 
he erected the genus Cochliorrhoe to accommodate forms with Eg only partially 
developed. However, the type species of Bergamia, B. rhodes Whittard, has an 
Ez pit lacking posterolaterally and might therefore be placed within Cochliorrhoe if 
his diagnosis were strictly followed. It is now known that Bergamia whittardi sp. 
nov. (see p. 146), in common with other trinucleids shows some variation in the 
total number of pits developed in each arc and in particular in the Eg arc which is 
only well developed anterolaterally. In both Bergamia and Cochliorrhoe the Eg arc 
may first appear as twin-pits within the E) arc, and from the fringe formulae listed 


140 ORDOVICIAN TRILOBITE FAUNAS 


by Whittard (1966: 279-280) it appears that the essential difference between his 
two genera was that in Cochliorrhoe two separate arcs cannot be distinguished, 
possessing either twinned or distinctly separate pits, until between rows three and 
five. Although it has been the practice in recent years to base the trinucleid genera 
on the particular arcs developed, it is thought that the partial development of the 
FE» arc does not warrant generic status and it is proposed to consider Cochliorrhoe 
Whittard, 1966 as a junior synonym of Bergamia Whittard, 1955. 

Bergamia is closely related to Lordshillia Whittard, 1966, Stapeleyella Whittard, 
1955 and Anebolithus Hughes and Wright, 1970, but it may be readily distinguished 
by the presence of the Eg arc partially or fully developed. Bergamia also shows 
some similarities to Tvetaspis M’Coy, 1849, but differs in that it has no lists developed 
between the I arcs of the upper lamella, or eye ridges or tubercles on the genal 
regions as are typical of Tvetaspis. 

The occurrence of Bergamia prima (Elles) and Bergamia whittardi sp. nov. is of 
interest as it is the first record of the genus from the Llandeilo of Britain, it being 
known previously only from the Llandeilo (Dobrotiva Formation) of Czechoslovakia 
(Pribyl and Vanék, 1969). (It is considered by the present author that ‘Tvetaspis’ 
praecedens Klouéek, 1916 was correctly placed in the genus Bergamia by Piibyl 
and Vanék.) Other previous British occurrences are from the Arenig of South 
Wales and Shropshire, Lower Llanvirn of Anglesey and from the basal Caradoc of 
south-east Ireland. 


Bergamia prima (Elles) 
(Pl. 4, figs 1, 2, 6; Pl. 5, figs 1-6; Pl. 6, figs 1-6, 8; Text-fig. 5) 
1940 Trinucleus fimbriatus mut. primus Elles: pars, 410-412, 421, 424, pl. 30, figs 1-3 non 4, 5 
which are B. whittardt. 

Diacnosis. Bergamia with about twenty to twenty-three pits developed in E, 
and FE arcs on each half-fringe; pits of E arcs very close together particularly antero- 
laterally. Pygidium short, with five or six axial rings and three or four pleural 
ribs. 


TYPE MATERIAL. Holotype. BU 257 (PI. 4, fig. 6; Pl. 5, figs 1, 2) (Chamberlain 
Collection) Internal and external moulds of nearly complete specimen. 

Paratypes. BU 258 (Chamberlain Collection) Internal mould of incomplete 
specimen. BU 259 (Chamberlain Collection) External mould of cephalon. 


DIMENSIONS. 

A B By Be Bs Ba ly K Ky 
Holotype == 16, 54 CA 6.33 aoe Cn 2" 66. 122. <A Aa eee 
BU 258 67:0 — — — —_— 
BU 259 — ¢66 — — — — ¢.125 6.50 — 

No. of No. of ribs 
Ry @) Qi WwW xX Z axial rings Left Right 

Holotype. 22:8555-0 (i OmNO S22 5 4 4 


All measurements in mm. For explanation of symbols see Text-fig. 1. 


FROM CENTRAL WALES 141 


TYPE LOCALITY AND HORIZON. The type specimens are all from the shales as- 
signed to the Zone of G. teretiwsculus exposed in the old quarry 350 yds west of 
Maesgwynne. 

OTHER FIGURED MATERIAL. It. 2745 (PI. 4, figs 1, 2); It. 2746 (Pl. 5, figs 3, 4); 
02747 (Pl. 6, figs2, 3); It. 2748 (Pl. 6, fig. 5); It. 2749 (Pl. 5, fig. 6); It. 2750 (Pl. 6 
mest, 4); [t. 2751 (Pl. 6, fig. 6); It. 2752 (Pl. 6; fig. 8); It. 2753) (Pl. 55 fig. 5). 

DIsTRIBUTION. The species is known only from the Builth region, being recorded 
with certainty only at the type locality and the stream section 15 yds south-west 
of the type locality. 

DESCRIPTION. Excluding the genal spines, complete specimens are approximately 
circular in outline. 

The semicircular cephalon varies between two and two and a half times as wide 
as long, excluding the steeply declined fringe. The strongly convex, clavate glabella 
is elevated well above the genae, overhanging and obscuring the fringe anteriorly. 
The swollen pseudofrontal lobe is just over one-half of the glabellar length and 
bears a median node, generally discernible on both internal and external moulds, 
situated somewhat variably, but generally immediately behind the anterior of the 
three pairs of lateral glabellar furrows. These furrows occur at about two-fifths 
of the distance along the glabella from the anterior, and consist of small pit-like 
depressions in the side of the glabella. The median furrows, marking the posterior 
of the pseudofrontal lobe, are elongate (tv.) pits which extend about half the distance 
to the sagittal line. The posterior furrows are also elongate (tv.) pit-like structures 
directed anteromedially. Both the median and posterior pairs of lateral glabellar 
furrows are situated well inside the axial furrows and alae are developed (PI. 5, 
figs. 5, 6). A similar depression to that described in Tvinucleus fimbriatus occurs 
laterally and slightly posteriorly to the posterior pair of lateral glabellar furrows 
(Pl. 5, fig. 2). The occiput is generally slightly less than half as wide as the pseudo- 
frontal lobe. A coarse reticulate pattern is developed over the entire external 
surface of the glabella. 

The occipital ring is very short (sag.), transversely convex and has no occipital 
spine. The occipital furrow is shallow medially deepening laterally forming elongate 
(tv.) occipital pits. 

Anteriorly the axial furrows are deep and narrow. Posteriorly they converge 
slightly and become wider and shallower; the alae being situated between the 
furrows and the glabella. Anterior fossulae are usually poorly preserved. 

The genal regions are quadrant-shaped, moderately tumid, with the outer margin 
declined steeply, and possess a reticulate pattern which becomes less pronounced 
peripherally on the steep outer margins and posteromedian portions of the genae. 
No eye ridges or tubercles occur. The posterior border furrow is straight, wide and 
rather shallow; lateral pits well developed though rarely well preserved (Pl. 6, fig. 4). 

The internal surface of the glabella and genae is smooth. The lateral glabellar 
furrows form raised platforms internally, and small apodemes, corresponding to the 
anterior fossulae, are present. 

The hypostoma is not known. 


142 ORDOVICIAN TRILOBITE FAUNAS 


Although commonly distorted, the fringe probably possessed a steep, nearly 
vertical genal roll, which flattened out towards the brim. The narrow fringe widens 
somewhat at the genal angles. Owing to poor preservation, there is very little 
information concerning the distribution of pits on the fringe. All pits are small 
and appear to be of approximately equal size. They are arranged in shallow radial 
sulci separated by low rounded ridges (Pl. 5, fig. 6). The FE; and Eg arcs are con- 
tinuous medially and contain between twenty and twenty-three pits on each half- 
fringe; at the posterolateral extremity only the Ey arc is developed. The number of 
arcs present internal to the girder is uncertain, but probably does not exceed two 
anteromedially, with up to four present posterolaterally (Pl. 5, fig. 4; Pl. 6, figs 1, 2). 

The lower lamella is nearly flat medially, but laterally the girder forms a strong 
ridge separating an almost flat outer part from a steeply inclined inner region. 
The E, and Eg are sunken into short sulci and are very close together; at the antero- 
lateral corners they merge into little more than a single arc of twin pits (PI. 4, fig. 1; 
Pl. 5, fig. 3; Pl. 6, fig. 3). The girder is apparently smooth and well formed except 
anteromedially. Posterolaterally it merges with the base of the genal spine. Medi- 
ally some irregularities may occur with pits of the E2 arc being absent (PI. 6, figs 2, 3). 

The genal spines are approximately straight, diverging slightly to the rear and with 
a low dorsal keel; they extend well behind the pygidium (PI. 4, fig. 6). The entire 
course of the facial suture has not been traced, but laterally it is marginal, situated 
high on the marginal band, and becomes dorsal at the genal angle. 

The thorax consists of six segments and conforms to the general trinucleid type. 
It is not more than about two and a half times as wide as long, and narrows slightly 
to the rear. The distal extremities of the pleurae are deflected posteriorly and 
ventrally, the amount of deflection becoming progressively greater posteriorly. A 
strong pleural ridge divides the pleurae into a small posterior and a larger anterior 
band. A small median node is present on the anterior portion of the axis of each 
segment (Pl. 4, fig. 6). 


Fic. 5. Reconstruction of the cephalon of Bergamia prima (Elles) in dorsal view. c. 
SS Ge 


FROM CENTRAL WALES 143 


The triangular pygidium is slightly less than four times as wide aslong. Excluding 
the articulating half ring, the anterior margin is straight except for the posteriorly 
directed lateral extremities. The posterior and lateral margins are marked by a 
low ridge at the upper limits of the steeply declined border region, with closely 
spaced terrace lines developed on the external surface. The axis is convex, clearly 
differentiated and segmented, with between three and six axial rings plus a small 
terminal piece. The axis continues posteriorly as a convex protuberance on the 
border region (PI. 5, fig. 5). Anteriorly the axis occupies about one-fifth of the width 
of the pygidium, tapering posteriorly to about half this width. As is usual in the 
trinucleids the axial furrows are slightly more prominent on internal than external 
moulds. The pleural fields are flat and each has an anterior border, usually three 
or four ribs (rarely two), and a small triangular terminal area. The furrows separat- 
ing the ribs are straight, sub-parallel and directed slightly to the posterior. 

The species exhibits discoidal enrollment as is normal in the trinucleids (Pl. 6, 
fig. 8). 

OnTOGENY. Of the two small specimens known from the stream section 15 yds 
south-west of the type locality, the larger has a maximum genal width of 4-6 mm and 
is assocated with four slightly disarticulated thoracic segments and a pygidium, 
and may thus represent a meraspid degree four. Apart from their size, the specimens 
are similar to larger individuals, except that the glabella and genal regions are more 
highly convex (PI. 6, fig. 5). 

DIMENSIONS. 

A Ay B Bie Be Bg Ba ih K Ki 
It. 2748 2) Ome 2 Ane? Cah Om Ae eT Ti | AL Ong TA O-7 

All measurements in mm. For explanation of symbols see Text-fig. 1. 

BIOMETRICAL DATA. Various analyses were undertaken on the major features of 
the dorsal exoskeleton. Since data for the type locality sample is rather scant, data 
is also given for the total sample from the inlier. 


TABLE I4 
xy se var. xX y var. y r Te 4 var. « a var. a n 
IBE B 1S€ 5°14 0'90730 4:10 0:5850 0-974 0:975 0:97 0:0158 0:78 0-01020 5 


Ti, Gey 9°38 7:4444 4:17 1:°5625 0-976 0:977 1:03 0:0069 0:46 0-0014I 9 
iN 5 1B) 4°70 2:0850 4:26 2-1630 0-997 0-998 1:12 0:0020 — — 5 
B: Bi 4:29 1:°8958 3:33 I:1106 0-984 0:985 0:99 0:0026 0:77 0:00164 13 
B: Be 4°49 11-7961 2:84 0:7334 0:985 0-986 1:01 0:0024 0:64 0-:00102 14 
B: Bg 3°66 1:4330 1:50 01650 0:997 0:998 0:83 0:0008 0:34 0:00020 5 
B:K 4°23. 1'4450 3°35 I°1507 0-978 0-979 I-12 0:0037. — — 16 
lke BSG 3°42 14976 1:50 0:2560 0-983 0-984 0:°95 0:003I 0-41 0:00062 II 


W:X 6-40 3:°9950 1:24 0:2480 0-974 0:977 1:27 0:0238 0:25 0:00104 5 
x 2 Z I-46 01776 1:79 01774 0:°824 0:°830 0:82 O-O19I 1:00 0:02909 13 

Bivariate statistics for bergamia prima (Elles). Upper part of table for the type locality 
sample; lower part for the total sample from the inlier. All measurements in mm. For 
explanation of symbols see Text-fig. 1. 


144 ORDOVICIAN TRILOBITE FAUNAS 


TABLE I5 
B By Be 
It. 2750 FYE ee CES 6 GO 
It. 2753 5 Se 2 
It. 8805 50 — a2 
It. 8803 62°) 47" 328 
It. 8804 Com Eg e356 


Data for the position of the lateral glabellar furrows for Bergamia prima (Elles) from the type 
locality. Data are insufficient to give meaningful bivariate statistics. All measurements in 
mm. Measurements for It. 8805 taken from external mould. For explanations of symbols 
see Text-fig. 1. 


TABLE 16 
Ry Q 
BU 257 128 5:0 
It. 2753 Irs 5-1 
NMW 68.376.G189 7 Omak 
NMW 68.376.G190 9:8 ~~ 4:0 


Thoracic measurements for Bergamia prima (Elles). First two specimens from the type 
locality. All measurements in mm. For explanation of symbols see Text-fig. 1. 


TABLE 17 
Ww x Z 
BU 257 98 23 25 
It. 2753 8:5 17 2°3 
NMW 68.376.G191 a I°9 2°2 
It. 8802 i I°I I5 
NMW 68.376.G192 — 1-9 2°4 


Pygidial measurements for Bergamia prima (Elles), from the type locality. All measurements 


inmm. For explanation of symbols see Text-fig. 1. 


TABLE 18 
Number of axial rings 3 4 5 
Number of specimens — — 3 I 
n= 4 
Number of axial rings 3 4 5 
Number of specimens ai 7 12 I 
ae 


Frequency distributions for the number of pygidial axial rings developed in Bergamia prima 
(Elles). Upper part of table for the type locality sample; lower part for the total sample from 
the inlier. 


FROM CENTRAL WALES 145 


TABLE 19 
Number of pleural ribs 2 3 4 
Number of specimens _- 6 2 
a0) 
Number of pleural ribs 2 3 4 
Number of specimens I 13 14 
rm +28 


Frequency distributions for the number of pygidial pleural ribs developed in Bergamia 
prima (Elles). Upper part of table for the type locality sample; lower part for the total sample 
from the inlier. 


Discussion. Owing to the poor preservation of the fringe on much of the 
material available, Elles (1940: 424) erroneously believed this species to occur at 
Pencerrig Quarry, and to be conspecific with a form from Pencerrig Lake quarry 
which she considered as a mutuational form of Tvinucleus fimbriatus Murchison, 
1839. The presence of the two arcs of pits external to the girder clearly separates 
this species from 7. fimbriatus and indicates its relationship to the genus Bergamia 
Whittard, 1955. The superficially similar form occurring at Pen-cerig Lake quarry 
is here referred to Bergamia wiittardi sp. nov., and may be distinguished from 
Bergamia prima by the Eg arc being present only anteriorly. 

Bergamia rhodesi Whittard, 1955 is similar to B. prima, but with apparently 
slightly fewer pits in each arc. However, the data at present available are insuf- 
ficient to determine the amount of variation of the number of pits in each arc for 
either of these two forms. Subsequent collecting may well show them to be 
synonymous, in which case B. prima (Elles) would take priority. B. prima is easily 
distinguished from B. praecedens, (Kloucéek) by the smaller number of pits along the 
posterior margin of the fringe, the closeness of the E; and Eg arcs and the differing 
surface sculpture on the glabella. B. prima is distinguished from B. inquiliwm 
(Whittard, 1966) and B. matura Whittard, 1966, which are thought to represent but 
a single species, by its greater number of pits in the E arcs and the median develop- 
ment of the Ig arc. ‘Tvinucleus’ gibbsi Murchison, 1859, ‘Trinucleus’ sedgwicki 
Salter, 1866 and ‘Tvinucleus’ etheridge: Hicks, 1875 were provisionally placed by 
Whittard in Bergamia. B. gibbsi may be distinguished by its apparent lack of pits 
internal to the girder lateral to row 8. B.? sedgwicki appears to be similar to B. 
prima in general shape and in the presence laterally of three arcs internal to the 
girder, but differs in having fewer pits in the Ej and I; arcs. B.? etheridgei is here 
considered as a nomen dubium (see Whittard, 1955: 35), on account of the poor 
preservation of the type specimens. Preliminary studies on ‘Tvinucleus’ libernicus 
Reed, 1895 from the Tramore Limestone Series support Whittard’s (1955: 31) view 
that the species is best placed in Bergamia, as E2 arc is fully developed, excepting for 
two or three pits at the posterolateral extremities of the arc, while one arc occurs 
internal to the girder. It is easily distinguished from B. prima by this single I arc, 
further, the separation of the two E arcs is greater in B. hibernicus. The specimens 
referred to Bergamua (?) sp. by Bates (1968: 184-185, pl. 13, figs 3, 4, 9, 13) from the 


146 ORDOVICIAN TRILOBITE FAUNAS 


Lower Llanvirn of Anglesey are clearly referable to this genus though insufficient 
detail is known to allow proper comparisons with other known species. 


Bergamia whittardi sp. nov. 
(Pl. 6, fig. 7; Pl. 7; figs 1-12; Pl. 8, figs 1-9) 1; Plo) figs 2, 25 Vext-fiesig. 7) 


1851 Tvetaspis fimbriatus (Murchison); Sedgwick and M’Coy: pars, 146, pl. IE, figs 16, 16a. 
1914 Tvinucleus fimbriatus Murchison; Reed: pars, 350-352, 354, pl. 28, figs I, 3, nom fig. 2. 
1940 Trinucleus fimbriatus mut. primus Elles: pars, 410-412, 421, 424, pl. 30, figs 4, 5. 


Dracnosis. Bergamia with up to fourteen pits present anteromedially in Eg arc 
(full-fringe), Ey arc fully developed with about twenty-six to thirty pits (half-fringe) ; 
I,-5 arcs developed laterally. 


TYPE MATERIAL. Holotype. BU 260a (Chamberlain Collection) (Pl. 7, fig. 6) 
(figured as Tvinucleus fimbriatus mut. primus by Elles, 1940, pl. 30, fig. 5) Mould 
of dorsal surface of incomplete lower lamella. 

Paratypes. It. 2754 (Pl. 7, fig. 12) Internal mould of nearly complete specimen. 
It. 2755 (Pl. 8, fig. 3) External mould of nearly complete specimen. It. 2756 (Pl. 7, 
fig. 7) Fragment of mould of dorsal surface of lower lamella. It. 2757 (Pl. 8, fig. 7) 
Internal mould of cephalon. It. 2758 (Pl. 7, fig. 10) Internal mould of nearly com- 
plete specimen. It. 2759 (PI. 7, fig. 3) Fragment of mould of dorsal surface of lower 
lamella. It.2760 (P1.8, fig. 1) Internal mould of nearly complete specimen. Wattison 
Collection H14 (Pl. 8, fig. 9) Internal mould of damaged cephalon. 


DIMENSIONS. 

Ak” “BS Bye Bee be ar KG. 
It. 2754 a= 57 AS gS 2:6) = Osama 
It. 2755 — 26 20 16 r2 — r0 — r5 — 
It. 2758 —- — 23 319 %I'4 OQ — 57 (an 1:6 
Wattison Coll. H14 c.8:0 —.  — 5:11 4:0 2:9 3:°0¢.15:°0 4:8 — 

No. of No. of ribs 

Ry QO WwW Z W = axialrings Left Right 

It. 2755 A5UTLOy) 3080768 3 3 3 

lis2757; i == ielo39 Siar 6 4 4 

Lt. 2758 waa 557). 25a OO 2 4+? 3 3 


All measurements in mm. For explanation of symbols see Text-fig. 1. 

Fringe data for holotype. Left half-fringe: E; 1-c. 27; Ee 1-c. 7; lh I-c. 21; Ie I-c. 19; 
I3 1-c. 19; I4 11-c. 19; I5 17-c. 19. Auxiliary pit: xvi, xvii, xviii present in I3_5. Number of 
radial rows ¢. 19. 


TYPE LOCALITY AND HORIZON. The holotype and all the paratypes are from the 
small quarry at the south-western end of Pen-cerig Lake in shales of the uppermost 


FROM CENTRAL WALES 147 


Llandeilo, with the exception of paratype It. 2760 which is from shales of Llandeilo 
age from the stream section 120 yds south-east of Tre coed. 

OTHER FIGURED MATERIAL. It. 2761 (PI. 7, fig. 9); It. 2762 (Pl. 7, fig. 1); It. 2763 
feo ie. Tx) It. 2765 (Pl. o, fie. 1); It..2766 (Pl. 7, fig. 8); It. 2767 (PL. 9, fig. 2); 
Meme oou(b ls (8;"fie.4))3 It. 2769 (Pl. 8; fig. 8); lt. 2770 (Pl..8, fig. 5)5 It. 277 (Pl. 7, 
aes) lt. 2772 (Pl. 7, fig. 2); 1t.2773 (Pl.6, fig.. 7); It. 2774) (Pl: 8, fig.16); It. 2775 
een 8, fie. .2); It. 2776 (Pl. 7, fig: 4);-1t. 2778 (Pl. 7, fig. 11). 

DISTRIBUTION. The species has only been recorded from the Llandeilo of the 
Builth region. It is extremely abundant in the Pen-cerig Lake quarry and is also 
known from the Dulas Brook as well as the other locality from which the type material 
is drawn. 

DescriPTION. Excluding the genal spines, complete specimens are generally 
subcircular to oval in outline (PI. 7, fig. 10; Pl. 8, fig. 2). 

The cephalon is semicircular and, excluding the fringe, varies between two, and 
two and a half times as wide as long. The clavate glabella, its furrows and the 
occipital ring are similar to those of Bergamia prima. The median glabellar node 
is typically not well developed on internal moulds, while axial furrows and alae 
are again very similar in the two species. 

The genal regions are quadrant-shaped, less tumid than in B. prima and have a 
strong reticulate pattern which is most coarsely developed along a diagonal band 
from the genal angles to the antero-median corner of each genae. No eye ridges 
or tubercles are present. The posterior border furrows are wide, shallow and more 
or less straight, terminating in clearly developed lateral pits. Rarely, traces of the 


Fic. 6. Reconstruction of the cephalon of Bergamia whittardi sp. nov. in dorsal view. 
Ca LO: 


148 ORDOVICIAN TRILOBITE FAUNAS 


reticulate pattern are present in internal moulds (PI. 8, fig. 9). Internal platforms 
reflecting the lateral glabellar furrows are present as in B. prima. 

The hypostoma is not known. 

The preservation of the fringe varies considerably. In the majority of specimens 
the fringe is fairly flat, commonly showing signs of cracking around its inner margin 
(Pl. 8, fig. 9). In a few specimens, however, the genal roll is steeply inclined as in 
B. prima. Although much of the flattening of the fringe may be attributed to 
preservation in shale, it is considered that the initial inclination of the fringe of 
B. whittardi may not have been so great as in b. prima. The pits are arranged in 
shallow radial sulci which are separated by low rounded ridges. The pits of the Ey 
and J, arcs are larger than the rest, which are small and subequal in size. Dorsally 
the pits of the anteromedially developed Eg2 arc are very close to those of the Ej arc 
and give the impression of twin-pits; ventrally the pits, although closely spaced, 
are separated and represent two distinct arcs (Pl. 7, figs 3, 6, 7). 

Insufficient data are available to allow a full statistical description of the pit 
distribution on the fringe, but the following observations may be made. The 
number of pits in the E; and J, arcs varies between about twenty-four and thirty. 
The development of the Ez arc anteromedially appears to vary, but at least seven 
pits are present on the half-fringe of the holotype. Specimen It. 2754 suggests, 
however, that the pits of the Eg arc are not always present in all the anteromedian 
rows. Only a single specimen, It. 2754, shows the arc internal to the girder at all 
clearly (Pl. 7, fig. 12). On the left half-fringe of this specimen arcs I; and Ig are 
present medially with I3 appearing at row four, I, at row nine and I; at row twelve. 
The genal flanges are large and consist of an outer fimbriate zone incorporating the 
pits of the Ej, I; and Ig arcs, and an inner fimbriate zone with four or five pits in 
each row developed along the margin of the genae and along the posterior border. 
Up to about twelve rows of pits may be present in this inner zone. The central 
triangular area between the two fimbriate zones has its pits irregularly positioned 
(Pl. 7, fig. 12). The genal flange has up to seven or eight E; pits on its posterior 
extension from the cephalon. 

The facial suture is marginal medially where it is situated very high on the marginal 
band becoming dorsal at the genal angles. The girder merges posterolaterally 
with the base of the genal spines. Only the anterior portions of the genal spines are 
known and are gently curved in a smooth arc continuous with the lateral cephalic 
margins. 

The thorax is typically trinucleid and is very similar to that of B. prima. The 
extremities of the pleurae are however slightly less strongly deflected posteriorly 
(PL eos sties 1), 

The triangular pygidium is about four times as wide as long, with the anterolateral 
corners deflected slightly posteriorly as noted in the thoracic segments. The 
number of axial rings ranges from five to seven, with two to four pleural ribs. In 
all other features the pygidium is very similar to that of B. prima. 

ONTOGENY. The only certain meraspis is of degree four and has the posterior 
margin of the fringe directed anterolaterally from the genal angle in a similar manner 


FROM CENTRAL WALES 149 


to that found in the meraspis of Tvinucleus fimbriatus. On the other hand, the 
smallest certain holaspis has well-developed genal flanges extending posterior to the 
cephalon (PI. 7, fig. 11; Pl. 9, fig. 1). It seems reasonable to assume that other small 
isolated cephala with the posterior border of the fringe directed either anterolaterally 
or transversely are also late meraspides. The degree four meraspis is about 4 mm 
in length and is very like the holaspid form apart from the number of segments and 
the anterolaterally directed posterior margin of the fringe. The genae rise fairly 
steeply from the axial furrows, leaving the posterior part of the axial furrows and 
the alae rather sunken. Collections also include a single isolated cranidium which is 
slightly smaller, but otherwise similar; this is also presumed to be of degree 4. An 
impression of an enrolled individual of similar size, is too poorly preserved to reveal 
its stage of development (PI. 6, fig. 7). Four slightly larger isolated cephala have a 
posterior margin to the fringe which becomes directed progressively less antero- 
laterally, until in the largest individual it is directed transversely (Text-fig. 7). 
This last form may be a degree five meraspis, but until more specimens showing 
the number of thoracic segments are available no definite assignment can be made. 

A single tiny isolated pygidium (maximum width approximately 2-4 mm), though 
poorly preserved, shows a segmented axis and ribbed pleural fields (Pl. 7, fig. 2). 
This pygidium is slightly smaller than that of the degree four meraspis and may 
thus represent an earlier meraspis degree. 


Fic. 7. Diagram illustrating the change in the posterolateral outline of the fringe in 
meraspides of Bevgamia whittarvdi sp. nov. with increase in size. c. 7. A based 
on It. 2763 (Pl. 8, fig. 11); B on It. 2765 (Pl. 9, fig. 1); C on It. 2768 (PI. 8, fig. 4); D on 
It. 2775 (Pl. 8, fig. 2). 


150 


lhe, AG 
It. 2763 
T2776. 
It. 2765 
It. 2768 
It. 2775 


It. 2774 
It. 2778 


ORDOVICIAN TRILOBITE FAUNAS 


TABLE 20 
Ay B lh K 
— ¢12 30 08 
— ¢12 ¢28 — 
¢.2°0 ¢.16 — — 
18 15 37 1-0 
I-86, 1°5  =3"0 0-8 
1 OQ) eZ 0:6 
ae) One eS 


holaspis 


Dimensions of meraspides and the smallest known holaspis of Bergamia whittardi sp. nov. 
All measurements in mm. For explanation of symbols see Text-fig. 1. 


BIOMETRICAL DATA. 


XY; x 
ih 3 Jk 6-42 
ity) 9183 6-48 
A:B 3°38 
B: Bi 4°13 
B:Bzo 4:35 
B: Bg 4°30 
B: Ba, 4°22 
158) 5 JE 3:20 
WY 8 ZZ 6:56 
W:X 6:56 
BZ 1°39 


var. x 
5:2870 
5°9209 
Ona 7 
29090 
24918 
2°3720 
351379 
2°1153 


6-9538 
6-9538 
0°3341 


A number of bivariate analyses were undertaken and the 
results given below. As the majority of data available are from the type locality 
sample (Pen-cerig Lake quarry), the data given are restricted to this sample. 


y 
3°42 
2:89 
2:82 
3°27 
2°75 
1:82 
2:14 
2:22 


1-63 
1:28 
1-79 


var. y 
1:2620 
1-4622 
0-7017 
1°8140 
I-o118 
0°3737 
0:6280 


1:2703 


05246 
0°3173 
0°5974 


TABLE 21 
r he 

0:990 0-991 
O'971T = =9°974 
9:997  0°997 
0°994 9°995 
0:990 0-901 
0:988 0-989 
0:968 0-971 
0-973 0976 
0:979 0-981 
0:985 0:987 
0:981 0-982 


a 
0:92 
I‘Il 
I-00 
I-00 
I-O1 
0:94 
0:89 
I-Il 


I-10 
I-09 
1-04 


var. a 
0:0053 
0:0032 
0-0015 
0-0009 
0-0019 
0:0050 
0-0152 
0:0022 


0:0056 
0:0039 
0:0034 


a 
O49 
0:83 
Pe) 
0:64 
0-40 
O45 


0:27 
0-21 
1°34 


var. a 
0-00160 
O-OOIIO 
0:00063 
0:00082 
000095 
0:00417 


0:00039 
0-00017 
000613 


10 
13 


Bivariate statistics for Bergamia whittardi sp. nov. from the type locality. All measurements 


inmm. For explanation of symbols see Text-fig. 1. 


It. 2755 
It. 2762 


It. 2758 


TABLE 22 


Q 

I'9Q 
2°5 
2°5 


Details of thoracic measurements for Bergamia whittardi sp. nov. from the type locality. 
All measurements in mm. For explanation of symbols see Text-fig. 1. 


FROM CENTRAL WALES 151 


TABLE 23 
Number of pleural ribs 3 4 
Number of specimens 2 12 
ie 4 


Frequency distribution for the number of pleural ribs developed in Bergamia whittardi sp. 
nov., from the type locality. 


TABLE 24 
Number of axial rings 5 6 or 7 
Length of o-Ig-1-g mm 5 2 
pygidial axis 20-27 mm 5 4 


Details of the number of axial rings developed in Bergamia whittardi sp. nov. from the type 
locality sample. 


The figures in Table 24 above suggest that for the type locality sample there is 
possibly a correlation between the size and the number of axial rings developed 
(P = 0-06). This is confirmed by the data for the total known sample of the species 
where P < 0:05. 

Discussion. Bergamia whittardt, although closely related to B. prima (Elles) 
may be readily distinguished from that and all other species assigned to Bergamia by 
the incomplete Ez arc being developed only anteromedially. It also differs from 
B. prima in having a slightly higher number of axial rings developed on the pygidium. 
B. inquilium (Whittard, 1966) is similar in having an incomplete Eg arc, but in this 
species it is only developed in the posterolateral regions. B. praecedens may also 
be distinguished by the greater separation of E; and E2 and by the surface sculpture. 


Trinucleinid gen. et sp. indet. 
(Pl. 8; fig. 10; Pl. 9, figs:3, 7) 


FIGURED MATERIAL. It. 2779 (Pl. 8, fig. 10) Internal and external moulds of 
pygidium and posterior part of thorax. It. 2780 (PI. 9, figs 3, 7) Internal and ex- 
ternal moulds of nearly entire specimen. 


LOCALITY AND HORIZON. Both specimens occur in the Lower Didymograptus 
murchisont shales. Specimen It. 2779 being from the pale ashy shales in the track 
exposures about sixty yards south-west of Bwlch-y-cefn and It. 2780 from the 
darker shales of the main tributary to the Howey Brook. 


DEscRIPTION. The complete specimen is about 14 mm long, and excluding the 
fringe, is approximately 12 mm wide (PI. 9, figs 3, 7). Very little detail is preserved 


152 ORDOVICIAN TRILOBITE FAUNAS 


of the cephalon. The glabella however appears to expand anteriorly as is typical 
of the trinucleinae. Long curved genal spines extend posteriorly of the pygidium. 
The thorax appears to be typically trinucleid. 
The pygidium is triangular in outline, just under four times as wide as long. 
Faint traces of segmentation are visible on the axis and one very weakly developed 
rib may be present on the pleural fields. 


Discussion. These two specimens are worthy of note owing to the extreme 
rarity of trinucleid remains in the Lower Didymograptus murchisoni shales of the 
Builth region. The only others known are three fragments of a cryptolithinid. 
The two specimens described above are here considered as belonging to the same 
form owing to the similarity of the pygidia and their similar stratigraphical age. 
Until more complete and better preserved material is available no real comparisons 
can be made with other forms, though it is noted that T. cf. acutofinalis occurs at 
Builth only a little higher in the succession at the top of the Cwm-Amliw Ash. 


Subfamily CRYPTOLITHINAE Angelin, 1854 
Genus CRYPTOLITAUS Green, 1832 


DIAGNOSIS. See page 120. 
TYPE SPECIES. Cryptolithus tessellatus Green. 


DISTRIBUTION. The genus is recorded with certainty in the British Isles from the 
uppermost Llanvirn to Upper Caradoc. In N. America the genus does not appear 
until the Upper Caradoc (Barnveld of Fisher, 1962). The genus is present in the 
Caradoc and Ashgill of Czechoslovakia (Pribyl and Vanék, 1969) and may also be 
present in the Caradoc of South-eastern Turkey (Dean, 1967). 


Discussion. With the inclusion of all the cryptolithinids of the Lower Llanvirn 
of the Builth district in Bettonia, the earliest known representative of Cryptolithus is 
from the passage beds at the top of the Betton Beds (top of D. murchisoni Zone) 
in the Shelve region. There is thus a possibility that Cryptolithus may have 
developed from Bettonia by the loss of the frontal adventitious pits. The N. 
American species possess a smaller number of arcs internal to the girder than is 
typical of the British species and it is thought that further studies may reveal the 
existence of two or more genera at present placed within Cryptolithus. 


Cryptolithus instabilis sp. nov. 
(Pl. 9, figs 4-6, 8; Pl. ro, figs 1-8; Pl. 11, figs 5, 12; Text-fig. 8) 


DiaGnosis. Cryptolithus with about thirty pits in the E; and I, arcs on each 
half-fringe; I,-3 continuous medially; I, generally appearing at row three or four; 
I; and Ig commencing at approximately row eight and twelve. Irregularities in 
pit arrangement common, particularly in inner I arcs. 


FROM CENTRAL WALES 153 


TYPE MATERIAL. Holotype. It. 2792 (Pl. 10, fig. 1) Internal mould of cranidium. 

Paratypes. It. 2793 (Pl. 9, fig. 4) Mould of ventral surface of lower lamella. It. 
2794 (Pl. 9, fig. 5) Internal mould of cranidium with thorax and pygidium folded 
beneath cephalon. It. 2795 (Pl. 11, fig. 5) Internal mould of pygidium. It. 2796 
(Pl. ro, fig. 3) Internal mould of nearly complete specimen. It. 2797 (Pl. 10, fig. 4) 
Internal and external moulds of damaged cranidium. It. 2798 (PI. 10, fig. 2) Internal 
mould of damaged cranidium. It. 2799 (PI. 10, fig. 6) Internal mould of damaged 
cephalon. It. 2800 (PI. 11, fig. 12) Ventral surface of part of lower lamella. It. 2801 
(Pl. ro, fig. 5) Internal mould of damaged cranidium. It. 2802 (PI. 9, fig. 6) Internal 
mould of nearly complete specimen. It. 2803 (Pl. 10, fig. 7) Internal mould of 
nearly complete specimen. 


DIMENSIONS OF TYPE AND FIGURED MATERIAL. 


A Ay B I I K Ky 
Holotype 66 — 53 F3:0) lO) 3:0, 2 
It. 2793 —- — — 6125 oe 
It. 2794 — — c.61 — ¢1Ii2 — — 
It. 2796 75 — c. 61 oo I25 — — 
T2707 C57 — 6. 47, = — — — 
It. 2798 EO) 7 ae OA Mie 3671 Se a 
It. 2799 8:8 — 6:8 i — 30 — 
It. 2801 651 67 — — — 3I  — 
It. 2802 — — 4:0 1-4 
It. 2803 72 — 54 — 12-2 20 eli 
It. 2804 82 — Os) ner | ae Oye s0ys 
It. 2805 62 — 5:0 — 97 27° — 
No. of No. of ribs 
WwW x Z axial rings Left Right 
It. 2795 O:8 mon | 62-5 1o+ 5 5 
It. 2802 8-0 iA, 2-0 = 5 5 


All measurements in mm. For explanation of symbols see Text-fig.1. Note B- glabellar 
length, is measured from the anterior of the pre-glabellar field. 


TYPE LOCALITY AND HORIZON. The holotype and paratypes It. 2793-2799 are 
from the Llandeilo shales exposed in the left bank of the Dulas Brook, 60 yds north 
of spot height 727, 150 yds south-west of the old quarry 350 yds west of Maes- 
gwynne. Paratypes It. 2800-2803 are from shales of similar age exposed at the 
easterly end of the stream section 160 yds south-east of Tre coed. 


OTHER FIGURED MATERIAL. It. 2804 (PI. 10, fig. 8); It. 2805 (Pl. 9, fig. 8). 


DISTRIBUTION. The species is known with certainty only from the two localities 
yielding the type specimens, although it is probably present in the stream section 


154 ORDOVICIAN TRILOBITE FAUNAS 


15 yds south-west of the quarry at Maesgwynne, and in the lane leading to New- 
mead, but preservation at these latter localities is not good enough to allow positive 
identification. 


DESCRIPTION. Excluding the fringe and genal spines, complete individuals are 
roundly rectangular in outline, being slightly longer than wide. 

The cephalon is approximately semicircular with no marked angulation antero- 
laterally. The clavate, convex glabella commonly has a low median ridge extending 
behind a small median glabellar node. Three pairs of lateral glabellar furrows are 
present, generally taking the form of shallow, oval depressions on the sides of the 
glabella (Pl. 9, fig. 6). In some cases, however, the furrows appear much deeper, 
but this is attributed to distortion (Pl. 10, fig. 2). Suggestions of weakly developed 
alae are present in a few specimens (PI. 10, fig. 3). Anteriorly the glabella is trun- 
cated rather squarely by a shallow preglabellar furrow separating the glabella from 
a narrow ribbon-shaped preglabellar field. 

The occipital furrow is shallow and broad medially, deepening laterally into deep 
occipital pits. The occipital ring consists of little more than an expanded base to a 
well developed occipital spine. 

Anteriorly the axial furrows are deep and narrow, with well developed fossulae, 
which are bounded anteriorly by a ridge linking the genal regions and the pre- 
glabellar field, thus terminating the axial furrows behind the fringe. The furrows 
are gently curved and become shallower and wider to the posterior. 

The genal regions are quadrant-shaped and only gently convex. Some specimens 
show traces of two thin simple genal caecae on the external surface of the genae 
(Pl. ro, figs 6, 7). The external surface of both the genae and glabella is covered 
with numerous small pits (Pl. 10, fig. 4). No eye tubercles or ridges are developed. 
The posterior border furrow is straight, wide and shallow; lateral pits appear not 
to be developed. 

Internally the lateral glabellar furrows are developed as slightly raised areas, 
while apodemes correspond to the anterior fossulae. No trace of the median glabellar 
node or median ridge has been detected on internal moulds. 

Full details of the fringe are not known due to the lack of really well-preserved 
material. In general character, the fringe is of typical cryptolithid-type with a 
strong I,-, ridge on the upper lamella; slightly larger E; and I, pits and a basic 
radial arrangement of the pits of all arcs. A characteristic feature of the species is 
the frequent irregularities of pit distribution. 

There are between twenty-seven and thirty pits in the FE; and J, arcs on each half- 
fringe, the total number of which, as far as can be ascertained from the limited amount 
of material available, is not dependent on the size of the individual. Posterolaterally, 
auxilliary pits are commonly developed in the Ey arc (Pl. 10, fig. 1). The inner 
arcs are not well known, but anteriorly all the pits show a basic radial arrangement; 
laterally this radial pattern is lost due to the development of auxiliary pits in the 
inner arcs. The development of these extra pits appears to follow no set pattern, 
nor is their arrangement typically symmetrical. In general the arcs I,-3 are con- 
tinuous anteriorly, though in about one-fifth of the specimens the Iz arc is absent 


FROM CENTRAL WALES 155 


inrow I. I, generally commences at row 3, but in a few cases it appears in row 2, 
4 or 5 (see Table 25). Laterally arcs I5 and Ig commence at about row 8 and 12 
respectively. 

The genal flanges are well developed, extending a short distance behind the 
posterior margin of the cephalon. Between sixty and seventy irregularly placed 
pits are developed on each flange. In many specimens the inner portion of the ridge 
separating rows five and six is markedly swollen causing some distortion in the 
general radial pattern present anteriorly (Pl. ro, figs 1, 7). On the lower lamella 
the girder is only slightly more strongly developed than the pseudogirders separating 
the various I arcs. The pseudogirders and girder bear terrace lines on the outer 
surface. Two specimens, It. 2804 (Pl. Io, fig. 8) and It. 2805 (Pl. 9, fig. 8) are pro- 
visionally included in this species although they show slight differences in that they 
have a single pit of the EF; arc situated on the sagittal line. It. 2804 also shows 
considerable amount of irregularity in the development of the inner I arcs, par- 
ticularly laterally. The marginal facial suture is only rarely observed (Pl. Io, 
figs 2,8). The proximal end of the genal spines are directed more or less posteriorly, 
the distal ends being unknown. 

The thorax is rectangular and of typical trinucleid morphology. 

The triangular pygidium is about three times as wide as long. The convex axis 
has at least ten axial rings, whilst the pleural fields are gently undulate with a narrow 
border, five or six ribs and a small terminal area. The ribs are directed somewhat 
posteriorly, this deflection being increased distally. The number of ribs developed 
is not related to the pygidial length (see Table 27). 


Fic. 8. Reconstruction of the cephalon of Cryptolithus instabilis sp. nov. in dorsal view. 
(x | 3 ©: 


156 ORDOVICIAN TRILOBITE FAUNAS 


BIOMETRICAL DATA. 


TABLE 25 
Commencing row of are I4 
left half-fringe BSE ah Oe Baie Bia 
right half-fringe B23 A BIB ES 5 
Details of the row in which I4 arc commences in eight specimens of Cryptolithus instabilis 
sp. nov. 
TABLE 26 


y xx var. X y var. y i Te a var. «% a var.a n 
7A 10-92, 6:3644 6-38) 3°3800) 10-9179 0:920) 1:25 0-034) 10-735 G-OL200mN a 
1:B IL-60 5:19727 5°75 LE:SL9L (0-917) 10-919 “1-10) 00221 70-59) 10005608) 12 
B 717 1:9635 5°78 1:3603 0-966 0:967 1:03 0:0054 0:83 0:00356 15 

K 5°79 1:2042 3°07 0:339I 0-902 0:903 097 0:00906 0:51 0:00272 20 


Z 9°48 4:0836 2:82 0:5776 0:927 0:930 1:26 0:0237 0:38 0:00220 II 
W:xX 9:86 3°7754 1:57 O-1861 o-9g18 0-921 1:38 0:0290 — — i172 
1b, 1°57 O-145I 3:04 0:4482 0°853 0°856 0-91 O-OIIO 1:76 0:04207 22 


Bivariate statistics for Crvyptolithus instabilis sp. nov. for the total sample from the inlier. 
Allmeasurementsinmm. For explanation of symbols see Text-fig. 1. Note that B — ‘Glabellar 
length’ is here taken from the anterior of the preglabellar field. 


TABLE 27 
Number of ribs 5 6 
Pygidial length 2°4-3'0 2 2 
in mm 31-39 4 if 
i © 


Details of the number of ribs developed on the pygidium of Cryptolithus instabilis sp. nov. 
for the total sample. 


Discussion. The species, erroneously recorded as Tvinucleus (Cryptolithus) 
lloydi (Murchison, 1839) by Elles (1940), is closely related to the Llandeilian crypto- 
lithinids from the Shelve area. From Cryptolithus inopinatus Whittard, 1958 it 
is easily distinguished by the absence of the I4 arc medially and the delayed appear- 
ance of pits of the I5 arc to about row eight. Cryptolithus intertextus Whittard, 
1958 differs in that the radial arrangement of the pits is rapidly lost laterally due 
to the intercalation of interradial rows in the arcs Ig-4. Also, as in C. inopinatus, 
there are fewer pits of the I, arc absent medially than in C. imstabilis, while the 
cephalon of C. intertextus is relatively longer (sag.). Of all the Shelve crypto- 
lithinids, C. vadiatilis Whittard is perhaps the most closely related to C. instabilis, 
although it may be distinguished by the appearance of the I4 arc in row one or two 
and by its apparent lack of the Ig arc. Furthermore C. radiatilis appears not to 


FROM CENTRAL WALES 157 


attain the dimensions reached by C. imstabilis, and the outline of the cephalon is less 
rounded. C. abductus Piibyl and Vanék, 1969, which was considered closely re- 
lated morphologically to C. vadiatilis by Pribyl and Vanék, presumably chiefly 
on account of its well-developed radial arrangement of pits which persists to the 
posterior margin of the fringe, is readily distinguished by the presence of Eg arc, 
lack of arcs I5;-¢ and fewer pits in each arc. 


Cryptolithus sp. A 
(PE 11 figs 1; 45,6) 


FIGURED MATERIAL. It. 2806 (Pl. 11, fig. 1) Mould of part of dorsal surface of 
lower lamella. It. 2807 (Pl. 11, fig. 4) Internal mould of pygidium. It. 2808 (PI. 11, 
fig. 6) External mould of part of thorax. 


LOCALITY AND HORIZON. Near the base of the Lower Didymograptus murchisom 
shales on the right bank of the stream flowing north-west from the pass above 
Bwlch-y-cefn, about 100 yds downstream from the waterfall. 


DeEscrRiPTION. The three figured specimens are the only trinucleid fragments 
known from the locality and are assumed to belong to a single species. The frag- 
ment of the lower lamella reveals that the E; and I,-3 arcs are present, as is a strong 
girder and a well-developed pseudogirder between J, and Iz; both girder and pseudo- 
girder bear terrace lines. Approximately twenty-five pits are present in the Ej arc 
on the left half-fringe (right in ventral view), but the preservation does not allow 
an accurate count. The pits of the genal flange are smaller than the others. Long 
gently curved genal spines are developed. Although the preservation is rather 
poor, the thorax is seemingly typically trinucleid. The pygidium is triangular 
in outline being three and a half times as wide as long. At least six ribs are de- 
veloped on the pleural fields and seven axial rings are clearly visible on the axis. 

Discussion. If these specimens are correctly placed in Crvyptolithus then they are 
of particular interest for they are probably slightly older than the previous oldest 
known member of the genus recorded from strata below the top of the Upper 
Llanvirn of the Shelve region by Whittard (1958, pp. 71 ff.). 


? Cryptolithus sp. B 
(Pin shies 25.77) 


FIGURED SPECIMEN. It. 2809 Fragment of lower lamella. 

LOCALITY AND HORIZON. Stream section east of Wellfield Lodge, east of the main 
road, immediately above the point where the stream is piped under the road; 
shales assigned to the G. teretiusculus Zone. 


Description. A single fragment of a lower lamella shows only the Fj, I; and Ig 
arcs. The I, and Ig arcs are separated by a strong pseudogirder which is only slightly 


158 ORDOVICIAN TRILOBITE FAUNAS 


less prominent than the girder; both girder and pseudogirder bear terrace lines. A 
unique feature seen in this specimen is the arrangement of the pits in the J, arc 
(Pl. 11, fig. 7), where laterally alternate pits have been pushed outwards as if by 
overcrowding. The genal flange is irregularly pitted with pits slightly smaller than 
those in the arcs. 


Discussion. A further specimen of ?Cryptolithus is known from shales from the 
other side of the road, and while it is quite possible that this is conspecific with 
?Cryptolithus sp. B, it is here described separately as ?Cryptolithus sp. C until more 
material is available. 


?Cryptolithus sp. C 
(Pll 1a) figs'3 88) 


FIGURED SPECIMEN. It. 2810 External mould of fragment of cephalon. 


LOCALITY AND HORIZON. Stream section at Wellfield Lodge immediately down- 
stream of the point where the stream emerges after being piped under the road; 
shales assigned to the G. tevetiusculus Zone. 


DEscRIPTION. A single fragmentary specimen is of note in that of the arcs ap- 
parently internal to the girder, only the I; and Ig arcs are continuous medially. 
The Is arc does not commence until row three; I, beginning at about row eight or 
nine. In this respect it is not unlike Bettonia chamberlaini (Elles) from the Llanvirn, 
although no adventitious pits are present medially. 

Until the position of the girder is definitely known it is impossible to place this 
form generically with any certainty. Further the lack of any frontal adventitious 
pits suggests it belongs to Cvyptolithus, their absence does not necessarily preclude 
it from Bettonia. 

Discussion. Two further trinucleids are known from this locality; one, It. 2830 
appears to have some affinity to Bettonia superstes Whittard, the other is too poorly 
preserved to be generically placed. 


Genus BETTONIA Whittard, 1956 


DIAGNOSIS. See page 120. 
Type species. Tvinucleus chamberlaim Elles, 1940. 


DISTRIBUTION. Known from the upper beds of the Lower Llanvirn D. bifidus 
Zone; D. speciosus subzone) and the Llandeilo (G. tevetiusculus Zone) of the Builth 
region; from the Weston and the Betton Beds (D. murchisont Zone) and possibly 
also from the Meadowtown Beds (G. teretiusculus Zone) of the Shelve area. 

Discussion. Whittard originally erected this genus to accommodate five or 
six poorly known species which were superficially similar to Cryptolithus Green, 
1832, but differed in that they possessed a varying number of adventitious pits 


FROM CENTRAL WALES 159 


external to the E; arc. In the description of his type species, Bettonia frontalis 
Whittard, 1956, he acknowledged that it was very like ‘Tvinucleus’ (Cryptolithus) 
gibbosus Elles, 1940, from Builth and that differences, if any, were only likely to be 
found in the number and arrangements of the adventitious pits. He referred both 
T. (C.) gibbosus and T. chamberlain: to Bettonia. 

The study of a large amount of material from the type locality of Bettonia chamber- 
laint (Elles, 1940) and B, gibbosa has shown these two species to be identical. 
Furthermore, the population exhibits considerable variation both in arrangement 
and number of pits in the E; and I, arcs frontally and in the number of adventitious 
pits developed which ranges from o-10 (see Text-fig. 10), which covers a greater 
range than that exhibited by all five of Whittard’s original species with the exception 
of Bettonia superstes. The variation found in the anteromedian distribution of the 
pits of the E; and J, arcs in B. chamberlain: together with B, frontalis, B. irregularis 
Whittard and B. paucipuncta Whittard may be considered as a basically simple 
radial pattern in which one or more pits may become slightly displaced (see Text-figs 
Io, 11). In view of the variation now known to be present within a single population 
of Bettonia, B. frontalis, B. irregularis, B. pauctpuncta together with B. gibbosa are 
here considered as junior synonyms of Bettonia chamberlaim (Elles, 1940). 

The occurrence within the sample of the population of B. chamberlain: of indi- 
viduals with no adventitious pits, and others with one or two pits only on one half 
of the fringe raises the question of the validity of the genus Bettonia as distinct 
from Cryptolithus. Further doubt is raised by the similarity, apart from the frontal 
adventitious pits, between Cryptolithus intertextus Whittard, 1958, and Bettonia 
superstes Whittard, 1956. However, until more samples are available ,the genus 
Bettonia is provisionally retained for forms in which the majority of individuals have 
adventitious pits developed, whilst Cryptolithus rarely, if ever, has them. Cryfto- 
lithus sp. Whittard (1956: 68, pl. 9, fig. 16) is considered to belong to B. chamberlaini. 
It is thought that B. swperstes might be better considered as being conspecific with 
C. intertextus, if this is so it would then leave B. chamberlaini as the sole representative 
of the genus Bettonza. 


Bettonia chamberlaini (Elles) 


(Pl. 11, figs 9-11, 13-15; Pl. 12, figs 1-7; Pl. 13, figs 1-8; Pl. 14, figs 1-5, 8-10; 
Text-figs 9-11) 


1940 Trinucleus chamberlaini Elles: 423-424, pl. 29, figs 10-12, non fig. 13 which is T. abruptus. 
1940 Tvinucleus (Cryptolithus) gibbosus Elles: 425-426, pl. 31, figs 3-9. 

1941 ‘Tvinucleus’ chamberlaini Elles; Whittington: 26. 

1941 ‘Tvinucleus’ (Cryptolithus) gibbosus Elles; Whittington: 26. 

1941 Cryptolithus? chamberlaini (Elles); Lamont: 449. 

1941 Cryptolithus gibbosus Elles; Lamont: 464. 

1956 Bettonia frontalis Whittard: 67-68, pl. 9, fig. 7. 

1956 Bettonia chamberlaini (Elles); Whittard: 67, 69, pl. 9, figs 13, 14. 

1956 Bettonia gibbosa (Elles); Whittard: 67-70, pl. 9, fig. 8. 

1956 Cryptolithus sp. Whittard: 68, pl. 9, fig. 16. 


160 ORDOVICIAN TRILOBITE FAUNAS 


1956 Bettonia paucipuncta Whittard: 68-69, pl. 9, figs 9-11. 
1956 Bettonia ivvegulavis Whittard: 69-70, pl. 9, fig. 12. 
1966 Bettonia frontalis Whittard; Whittard: 280-281, pl. 49, figs 1-4. 


DiaGnosis. Bettonia with nil to ten frontal adventitious pits external to Ej arc, 
with rare development of pits external to Ej posterolaterally. Arcs Ej, I,~2 continu- 
ous with about twenty pits in E; and l,, and fifteen in Ig, on each half-fringe; I3 
generally appears in row two or three and contains about fourteen pits; I, com- 
mencing between row four and twelve, consists of a variable number of small pits 
adjacent to genae. Median pit in EF; always present though commonly displaced; 
auxiliary pits in Ej commonly developed, but rare in other arcs. Pygidium tri- 
angular; axial rings exceed in number the weakly developed ribs. 

TYPE MATERIAL. Holotype. BU 261a (Chamberlain Collection) (Pl. 12, fig. 5) 
Internal mould of nearly complete specimen. 

Paratypes. BU 262 (Chamberlain Collection) (Pl. 13, fig. 4) Internal mould of 
cranidium, pygidium and part of thorax. BU 263 (Chamberlain Collection) (PI. 12, 
fig. 1) Internal mould of damaged nearly complete specimen. 


DIMENSIONS. 

A B By Be lh K Ky 
Holotype €5:8) 6, 40 43:8 7 3-0 — 330° 
BU 262 C756. 5: 47 3:6) -10°O 3-07 Ses 
BU 263 — 38 — -— — 20 — 

No. of No. of ribs 
W x ZL axalnngs ett Right 

Holotype S20 ekOm 62-3 ? — — 
BU 263 CxOF29S) 13 TE6 ? trace trace 


All measurements in mm. For explanation of symbols see Text-fig. 1. 


Fringe Data. Paratype BU 262 


Numbers of pits in various arcs 


Ey iy Ig I3 I4 
Left half-fringe 22 18 16 14 10+? 
Right half-fringe 22+ 16+ 16 1 50) 


EF), I,-2 are continuous; I3 commences at row two; Iq at row three. Five anterior 
adventitious pits are developed. Auxiliary pits e; xii, and xiv are present on both 
left and right half-fringes. Fifteen radial rows are developed on the left half-fringe 
and at least fourteen on the right. 

Only a fragment of the fringe is preserved in the holotype and no data are available. 
Fringe details are not available in the second paratype. 


FROM CENTRAL WALES 161 


TYPE LOCALITY AND HORIZON. All three type specimens are from the shales of 
Lower Llanvirn age in the cliff section on the left bank of the Howey Brook, half a 
mile east-south-east of Carregwiber. 


OTHER FIGURED MATERIAL. It. 2811 (Pl. 14, fig. 10); It. 2812 (Pl. 11, fig. 15; 
meee T) it. 2813)(Pl. 12; fig.7); It. 2814 (Pl. 12; fig. 6); It. 2815 (Pl) 11, fig. ro) ; 
meezero (Pili, fie. 14); It. 2817 (Pl. 12, fig: 2);/Tt. 2818 (Ply 12, fig..4); It. 2819 
Beer tie. 3) 1t) 2820 (Pl. 13, fig. 7); It. 2821 (Pl 13) fig. 6); Tt. 2622 (Pl. 14, fig: 2); 
ieee (Pl, 13) fie. 8); It. 2825 (Pl xr, fig. 11); It. 2826 (Pl rn, fig. 9); It. 2827 
(Pl. 11, fig. 13); It. 2828 (Pl. 14, fig. 4); It. 2829 (PI. 14, fig. 5); GSM 86785 (Pl. 12, 
fig. 3); GSM 86786A (PI. 14, fig. 8); GSM 86789 (Pl. 14, fig. 3); SM A 10082 (PI. 13, 
ne-5); BU 20rb (PI. 13, fig. 1); BU 264 (PI. 13, fig. 2); BU 368 (Pl. 14, fig. 9). 

DISTRIBUTION. The species is known from the upper beds of the Lower Llanvirn 
(D. speciosus Subzone) of the Builth region; and from the Betton and the Weston 
Beds (D. murchisoni Zone) of the Shelve area. In the Builth region it is very 
abundant at the type locality and relatively common at the small quarries 600 yds 
east of Upper Gilwen; it also occurs at various other localities at the same horizon 
in the Builth inlir. 


DEscrRIPTION. Excluding the genal spines and the fringe, complete specimens 
are roundly quadrate in outline. 

The cephalic outline varies between semicircular and subrectangular, with the 
anterolateral angulation being variably developed. Excluding the occipital spine, 
the cephalon is generally about twice as wide as long. 

The pyriform glabella is strongly convex and elevated well above the genal regions. 
In undeformed specimens it is generally about twice as long as wide. Three pairs of 
short lateral glabellar furrows typically take the form of rather indistinct shallow 
depressions on the near vertical sides of the glabella. The anterior pair occur at 
about two-fifths, the median pair at three-fifths and the posterior pair at about 
four-fifths along the glabella, measured from the anterior. Rarely a small median 
glabellar node is preserved in internal moulds (PI. 13, fig. 7); apparently no such 
node is developed on the dorsal surface (Pl. 12, fig. 4). Commonly external moulds 
fail to show any surface markings, however, a few well-preserved specimens, par- 
ticularly small holaspides, show a coarse reticulation on the glabella, and a slightly 
less coarse development on the genae (PI. 12, fig. 4; Pl. 14, fig. 4). 

The occipital ring forms an expanded base to the well-developed occipital spine 
(Pl. 12, fig. 4). The occipital furrow deepens laterally to form deep occipital pits 
which are directed anterolaterally. 

The axial furrows, deep anteriorly with well-developed anterior fossulae, follow 
the lateral margins of the glabella closely becoming wider posteriorly. Alae are not 
developed. 

The genae are quadrant-shaped with the inner margin gently concave and the 
posterior margin directed slightly anteriorly. They are moderately convex with 
fairly steeply sloping outer regions. Occasional specimens (BU 262, Pl. 13, fig. 4) 
show two faint caecae directed posterolaterally across the gena from about the mid- 


162 ORDOVICIAN TRILOBITE FAUNAS 


point of the inner margin towards the genal angle. The posterior border furrow 
is straight, broad and fairly shallow and has no lateral pit. 

Internally the lateral glabellar furrows form poorly developed raised platforms. 
A small apodeme corresponds to each of the anterior fossulae. 

The hypostoma is not known. 

In spite of commonly developed cracks on the fringe of many specimens, particu- 
larly around the margins of the genae, it seems that the genal roll was moderately 
steeply declined, and the brim relatively flat; the change in curvature of the upper 
lamella probably being located along the strong ridge between J, and Ig. The 
fringe is of constant width with a short tongue extending behind the genae, lateral 
to the fulcrum. Five arcs of pits, E;, 1-4, are developed. The pits of the various 
arcs are arranged essentially radially, except near the genal angles, with the pits 
of E; and J, being larger than the remainder. The Ej, I,-2 arcs are continuous; 
Iz arc generally commences at either row two or three and I, appears somewhat 
variably between row four and twelve. Generally about fifteen radial rows are 
developed on each half-fringe, with the anterolateral angulation occurring, if present, 
at about row twelve. Anteromedially the rows of pits diverge slightly and a median 
pit is present in the E; arc. Variations in the pattern of pits are common, and are 
caused by the displacement of one or more pits; they may all be referred to the 
basic pattern however (see Text-figs 10, 11). The number of anterior adventitious 
pits external to E; varies from nil to ten, and they are rarely distributed sym- 
metrically with respect to the sagittal line. Rarely adventitious pits are also located 


Fic. 9. Reconstruction of the cephalon of Bettonia chamberlaini (Elles) in dorsal view. 
COS! 


FROM CENTRAL WALES 163 


—5 000 aie Supp ee Ge ee 
CoN, oO mL OLOlo ina etre is Ose & 
[e) 


00° e) 
ooo 
OE aad) rei 2 VS fy (fe) ©) 
Bee Re Fa ra) Ooo 
° a Te 
A B Cc 
pe eae ——oee’s 
aoe 0 0°0000 O SSO 
° ome) re ee ome ONC OFAC) Oi 
° So Oo 0.9. © 5 =o a, OF oO 5 


e 
o°o ) S80 0 ° SOS Oakey Celie) 
Cley Se rena) ©OO® © © Le “Go 4 oo ole 
Po 6 0. 9 2 Bo OG < OO @ © rae 
°° OVO@ © ce) ©) ©) °° 
22 Resi ae hae > 
G H I 


Fic. to. Diagram illustrating the variation in numbers and distribution of pits in the 
anteromedian portion of the fringe in Bettonia chamberlain (Elles) from the type locality. 
The diagrams are arranged showing a progressive increase in the number of anterior ad- 
ventitious pits (shown as solid circles) present external to the E; arc. The median 
pit of the E; arc, at times displaced laterally, is arrowed. All diagrams x 7. A— 
It. 2820 (Pl. 13, fig. 7); B—BU 261a (PI. 12, fig. 5); C—It. 2821 (Pl. 13, fig. 6); D— 
BU 261b (PI. 13, fig. 1); E—It. 2813 (Pl. 12, fig. 7); F—BU 264 (Pl. 13, fig. 2); G— 
BU 262 (Pl. 13, fig. 4); H—It. 2817 (Pl. 12, fig. 2); I—It. 2819 (Pl. 13, fig. 3). 


A. —s ©? ee Nin. eorex 
000 6% 0°60 Ciccone a woe thee 
° OY) 
° 2) 00900 
00° O94 0°0/0 09 o ie) O90 
ooo Oo ©} OOO OCG) 
0 0 ° °° oo 2 Op OL Hs aS 
0° SASS) Jie 
° 


Fic. 11. Diagram illustrating the variation in numbers and distribution of pits in the 
anteromedian portion of the fringe in the type specimens of Whittard’s species Bettonia 
paucipuncta, Bettonia ivregularis and Bettonia frontalis from Shropshire. Anterior 
adventitious pits shown as solid circles. The median pit of the Ej arc, at times displaced 
laterally, is arrowed. Note that all these distributions fall within the variation shown 
in Fig. 10 for the type locality sample of Bettonia chamberlain (Elles). All diagrams 
x 7. A—GSM 86786A B. ‘paucipuncta’ (Pl. 14, fig. 8); B—GSM 86789 B. ‘ivregularis’ 
(Pl. 14, fig. 3); C—GSM 86785 B. ‘frontalis’ (Pl. 12, fig. 3). 


164. ORDOVICIAN TRILOBITE FAUNAS 


posterolaterally external to E; (Pl. 12, fig. 2); auxiliary pits are common in the Ej 
arc, much less frequent in I; and rare in the other arcs. The auxiliary pits are 
rarely symmetrically distributed. The genal flanges lack a radial pit arrangement 
and although some variation is found, the arrangement is typically like that of 
Text-fig. 9. Occasional abnormalities of pit distribution usually take the form of 
a slight distortion of the radial pattern. One individual (Pl. 14, fig. 2) however 
has an EF pit missing laterally on both halves of the fringe. 

The pit distribution on the lower lamella corresponds with that of the upper 
lamella. A strong, apparently smooth girder merges posterolaterally with the base 
of the genal spines; the ridge between I; and Ig is represented ventrally by a pseudo- 
girder, which may be as strongly developed as the girder, and shows faint traces of 
terrace lines (Pl. 14, fig. 1). 

No correlation exists between the size of individuals and the number of pits present 
in any arc, or the number of anterior adventitious pits present; neither is there any 
correlation between size and the number of radial rows developed, nor in the 
commencement of the Iz and Ig arcs (for full fringe data see pages 165-6). 

The genal spines are long, slender and gently incurved, extending some way behind 
the pygidium, 

The suture line is not seen in the Builth material, but is clearly visible on GSM 
86786A (Pl. 14, fig. 8), from Shelve (the original holotype of B. paucipuncta), where 
it passes round the declined marginal band and continues along the posterior margin 
of the cephalon, disappearing near the fulcrum. 

The thorax is of normal trinucleid pattern and requires no detailed description. 
It is about two and a half times as wide as long, the maximum width occurring at 
the third segment. The axis occupies about two-fifths of the total thoracic width 
anteriorly, tapering slightly to the rear. 

The triangular pygidium is about two and three-quarter times as wide as long, 
with a straight anterior margin, (excluding the articulating half-ring), and steeply 
declined smooth posterior and lateral borders. The inner margin of the posterior 
border is defined by a low narrow rim. The moderately convex tapering axis oc- 
cupies slightly less than one-fifth of the anterior width of the pygidium. Traces of 
axial rings are seen in some specimens and up to eight are known. The axial fur- 
rows converge slightly, and become weaker to the posterior. The flat pleural 
fields have an anterior border and one, or possibly two, very weakly developed ribs. 

OntoGENy. Although several specimens smaller than the smallest certain 
holaspis are known, the preservation is such that the number of thoracic segments 
developed cannot be precisely determined. All these small specimens, whether 
they are meraspides or small holaspides, resemble adult specimens except 
in size. 

BIOMETRICAL DATA. Although the species is extremely abundant at the type 
locality, the specimens are so closely packed together that they overlap and crush 
one another thus making measurements impossible on the majority of specimens. 
However some data are available for a moderately sized sample and these are given 
below in Tables 28-35. 


FROM CENTRAL WALES 165 


TABLE 28 


Memanpits LO) 1k 12) 13 054 15. 16 417 18 99k) 12ZOwi2ZT 122023 24 25 


Ej arc —- — — — — — — I 3—- 2 7 4— — I 
(mean = 20-61; var. = 3-6630; n = 18) 
I, arc —- — — ~—~ — — I ~—~ 3 6 3—- 2 5 — 
(mean = 19°44; var. = 30624; n = 16) 
Ip arc —- — —~ — — 5 2 1 —- ~—~ ~ — 
(n = 8) 
Ig arc —- —,2 22— 22> —- —- ~—- ~- -—- - —- — 
(n = 8) 
I, arc I— — I— Fe — ~~ ~~ ~ ~~ ~~ ~~ — 
(n = 3) 


Frequency distributions for the number of pits developed in arc E; for Bettonia chamberlain 
(Elles) from the type locality. 


TABLE 29 
Row in which Ig first appears 2 3 4 5 
Number of specimens 18 a 2 I (28) 


Frequency distribution for the commencement of arc I3 in Bettonia chamberlaini (Elles) 
from the type locality. Arcs Ej, I;-2 are continuous anteromedially. 
TABLE 30 


Row in which I, first appears Ame5esOn 7 8 Oo AO EL 12 
Number of specimens TN MT Ne TT (= 7) 


Frequency distribution for the commencement of arc I, in Bettonia chamberlaini (Elles) 
from the type locality. 


TABLE 31 
Row Io II 12 £413 _ rounded outline 
Number of specimens 2 2 5 4 4 


Frequency distribution for the position of the anterolateral angulation where present in 
Bettonia chamberlaini (Elles) from the type locality sample. 


TABLE 32 
Number of pits Omer 2 aS Aen 5 6) AZb Ts See KO) 10 
Simibes OSpecimens 2) 11 © ET Leaf © EE I — %r (n=r4) 


Frequency distribution for the number of anterior adventitious pits developed in Bettonia 
chamberlaini (Elles) from the type locality sample. 


166 


ORDOVICIAN TRILOBITE FAUNAS 


Number of radial rows 
Number of specimens 


TABLE 33 
14 15 
2 4 


16 
it 


17 
nf 


Frequency distribution for the number of radial rows developed in Bettonia chamberlaini 
(Elles) from the type locality sample. 


In all the above fringe data the half-fringe is taken as that part of the fringe to 


the left or right of the median pit in the Ej arc. 
the median pit is not included. 


In half-fringe counts on the E, are 


In some specimens a small error may be introduced 
Such errors are small and tend 


by the incorrect determination of the median pit. 
to cancel out in the overall data from the sample. 


oS BY x 
iy 2 JAN 8-16 
iG 3 183 8-17 
AX 3 18} 5°76 
18) 3 Jey 4°71 
B: Be 4°74 
B:K 4°34 
16 8 VEG 2°49 
WY 3 Z 6-41 
Wi Ox 6-41 
XGEZ 1:23 


var. X 
1:9346 
2°5038 
11479 
0°5007 
0:63605 
0-9990 
0:2807 


I-9128 
I-9128 
0:0704 


y 
5°74 
4°44 
4°53 
3°76 
2:96 
2°35 
1°44 


1-78 
1-23 
1-78 


var. y 
1:2082 
0:8664 
9°7179 
0°3888 
0:2265 
0°3134 
0:0885 


00-1689 
0:0835 
0-1654 


TABLE 34 

r Te 
0-889 0-890 
0-886 0°888 
SOM FDL 
0:895 0-896 
0-962 0:963 
0-881 0-884 
0-765 0-769 
0-864 0-866 
0:905 0-908 
0:°887 0-889 


o 
I-12 
1:08 
I-00 
I-1o 
0°95 
1:03 
0:07 
I-07 


1:08 
1:06 


var. a 
0:0096 
0:0045 
00013 
0-0199 
0:0074 
0:0036 
0:0099 


0:0178 
0:0129 
O-O1I2 


a 
0°79 
0°59 
0°79 
0:88 
0:60 
0-50 
0°56 


0-30 
0-21 
1°53, 


var. a 
0:00486 
0:00136 
0-00081 
0:01286 
0:00292 
0-00108 
0°00335 


0-00140 
0:00049 
0:02390 


Bivariate statistics for Bettonia chamberlaini (Elles) for the type locality sample. 


SM Ar0084 
NMW 68.376.G193 
NMW 68.376.G194 
NMW 68.376.G195 
NMW 68.376.G196 
BU 369 
BU 368 
NMW 68.376.G197 
NMW 68.376.G108 


Specimen 


TABLE 35 


A 
6-1 
6:2 
3°9 


7°5 


8-0 
6:3 
5:0 


33 
2°5 
250 


nh 
29 
af 
38 
14 
rT 
67 
41 


18 
18 


23 


Details of the length and width measurements for the cephalon and thorax, and for the 
position of the anterior pair of lateral glabellar furrows for Bettonia chamberlaint (Elles) from the 


type locality sample. 


FROM CENTRAL WALES 167 


No data are available for the number of pygidial axial rings and pleural ribs 
above that given in the description above. 


Discussion. See discussion of genus (page 158). 


Bettonia aff. superstes Whittard 
(Qed Ml, sles, 30) 


FIGURED SPECIMEN. It. 2830 Internal mould of damaged cranidium with three 
thoracic segments. 


LOCALITY AND HORIZON. Stream section at Wellfield Lodge immediately down- 
stream of the point where the stream emerges after being piped under the road; 
shales assigned to G. teretiwsculus Zone. 


Description. A single specimen is known from the Llandeilo of the Builth 
district which shows affinity to Bettonia superstes. Although the fringe is damaged 
anteriorly three adventitious pits can be seen and assuming symmetrical distribution, 
it is calculated that about eight such pits would be present on the complete fringe; 
posterolaterally however no adventitious pits are developed. A prominent ridge 
separates the E; and I, arcs, whose pits are slightly larger than the rest, from the 
inner arcs. About twenty-eight pits are developed in the Ej arc on the right half- 
fringe. Medially the arcs I,-3 are continuous, with I4 appearing at about row eight. 
Laterally the pits of the arcs Ig lose their radial arrangement due to the intercala- 
tion of auxiliary pits. The glabella and genal regions appear to be identical to those 
of other Bettonia and require no description. 

The thoracic segments are not well preserved but appear to be of the normal 
trinucleid type. The pygidium is not known. 


Discussion. The general features of this specimen are very similar to B. superstes. 
The fringe however differs in that there are no posterolateral adventitious pits, 
probably fewer anterior adventitious pits and slightly more pits in the E, arc in the 
Builth specimen. However in view of the amount of variation now known to be 
present in Bettonia chamberlaimi (Elles), it is considered undesirable to attempt 
a definite specific assignment until such time as details of the variation of B. swperstes 
are known. 


Subfamily MARROLITHINAE Noy. 


DIAGNOSIS. See page 120. 


Genus MARROLITAUS Bancroft, 1929 , 


DIAGNOSIS. See page 121. 
Type SPECIES. Tvinucleus ornatus var. favus Salter, 1848. 


DISTRIBUTION. The genus is recorded with certainty only from the Anglo-Welsh 
region and the Armorican Massif. In the Armorican Massif it is represented by 


168 ORDOVICIAN TRILOBITE FAUNAS 


M. bureau (Oehlert, 1895), from the M. bureau: beds of the May syncline, possibly 
of Lower Llandeilo age (see Whittard, 1956: 54). M. bureaui has also been recorded 
from Portugal (Delgado, 1908: 58, 80) and Spain (Born, 1926: 202, 204). The 
occurrence of Marrolithus in the Builth district is of interest as it is the first record 
of the genus, albeit only as a rarity, from this part of the Anglo-Welsh area. The 
distribution now includes south-west Wales, and the Builth, Shelve, and Berwyn 
regions of the Anglo-Welsh faunal province; with M. ultimus Bancroft having been 
transferred to Costonia (Whittard, 1956: 50), the genus is no longer recognized from 
the South Shropshire outcrops east of the Longmynd. 


Marrolithus sp. 
(Pl. 14, figs 6, 7) 


FIGURED SPECIMEN. It. 2781 Internal mould of cephalon. 


LocaLity AND Horizon. From the N. gracilis shales of the middle quarry, 
Llanfawr, Llandrindod. 


Description. The solitary cephalon is an internal mould with the lower lamella. 
The cephalon is 12-3 mm wide medially and 4-9 mm long sagittally. The slightly 
convex anterior margin meets the concave lateral margins at about go° and forms 
protuberant anterolateral angles. The posterior margin is more or less straight. 
The glabella is clavate, encroaching slightly onto the fringe, shows slight traces of 
reticulation, and has one pair of very shallow pit-like lateral glabellar furrows 
situated posteriorly. The axial furrows are fairly wide, but there are no traces of 
alae. Anterior fossulae are present. The short occipital ring bears no trace of a 
spine. The straight, open posterior border furrows terminate in very shallow lateral 
pits. The genal regions are semi-elliptical, flatly convex and smooth; eye ridges 
and tubercles are absent. The base of the genal spines is inclined at about 45° to 
the axial direction. 

The fringe is poorly preserved anteriorly so that a precise fringe count cannot 
be made. The fringe terminates level with the posterior cephalic margin, with a 
short tongue extending behind the genal regions; it is narrowest anteromedially 
(o-8 mm) and widest (radially) at the anterolaterial corners (3:0 mm), located at 
about row 18. The following arcs and pits are developed: 

Fj, I, continuous (E; with about 4o pits); Iz ?continuous; I3, I, both commence 
slightly lateral to the axial furrows and continue to the genal angles; I5 has about 
eight pits and Ig about four pits, situated at the anterolateral corners. 

The swollen areas consist of nine I, pits (approximately row 11-19), eight Ig pits 
(approximately row 12-19) and four Is pits (approximately row 15-18). All the pits 
on the swollen area are enlarged as are the pits of E; in rows 14-19 (approximately) 
and I, row 20. The increase in pit size along the anterior margin is gradual, but the 
decrease posteriorly along the lateral margin is more rapid. The girder is best 


FROM CENTRAL WALES 169 


developed anteriorly, becoming less marked anterolaterally and laterally to re- 
appear as a ventral ridge at the base of the genal spines. 
The thorax and pygidium are unknown. 


Discussion. The species seems to be most closely related to M. inornatus 
Whittard, 1956. The traces of reticulation on the internal mould suggests that the 
external surface of the exoskeleton may have been more strongly reticulated; this 
might distinguish the species from M. inornatus. The Builth specimen appears to 
differ in having a slightly larger swollen area, more markedly protuberant antero- 
lateral corners, and also in that the glabella encroaches slightly onto the flange, 
though this latter feature may be as a result of compression. As the variation in 
these characters is unknown the importance of such slight differences cannot yet 
be assessed. Until more is known, it is preferred to leave this specimen unassigned 
specifically. 


Genus PROTOLLOYDOLITHUS Williams, 1948 


DIAGNOSIS. See page 121. 
TYPE SPECIES. Tvinucleus ramsayi Hicks, 1875. 


DisTRIBUTION. The genus is known only from the Anglo-Welsh regions, being 
present in the Arenig of South Wales and Shelve and the Llandeilo of the Builth 
area. 


Discussion. The genus is here considered as the most primitive member of the 
Marrolithinae. Lu and later Dean (1966: 281-283) showed that “Tvinucleus’ 
primitivus Born, 1921, placed in Protolloydolithus by Whittard (1956), should be 
transferred to Hanchungolithus Lu, 1954, the genus is represented by only three 
species. The occurrence of Protolloydolithus reticulatus (Elles, 1940) at Builth is of 
interest because of its relatively high (Llandeilo) stratigraphic horizon; the other 
two species are confined to the Lower Llanvirn. 


Protolloydolithus reticulatus (Elles) 
(PIP x5; figs £; 5-9, 11; Pl. x6, fig. 2; Text-fig. 12) 


1940 Tvinucleoides veticulatus Elles: 427, pl. 29, figs 6-9. 
1941 ‘Trinucleoides’ veticulatus Elles; Lamont: 443. 
1941 Tvinucleoides veticulatus Elles; Whittington: 26. 
1956 Protolloydolithus reticulatus (Elles); Whittard: 41. 


Diacnosis. Protolloydolithus with between about forty and fifty pits in entire 
FE; arc; genal prolongations moderately developed; genae with fine reticulations and 


170 ORDOVICIAN TRILOBITE FAUNAS 


caecae. Pygidium about three and a half times as wide as long, with between five 
and seven pleural ribs and up to sixteen axial rings. 


TYPE MATERIAL. Holotype. BM I 7216 (PI. 15, fig. 1) Internal mould of almost 
complete specimen. 

Paratypes. BM I 7328 (Pl. 15, fig. 11) Internal and external moulds of damaged 
cephalon. It. 8604 (Pl. 15, fig. 7) Internal and external moulds of nearly complete 
thorax and pygidium. 


DIMENSIONS. 
B iy QO O1 Ry 
Holotype €..0°5 62150) 45 | OO) 13-0 
I 7328 c.6:0 ¢.15°0 — = 
No. of No. of ribs 
W x Vb axial rings Left Right 
Holotype @, WAKO) G, 1418) 35 Tr 6 = 
It. 8604 CUT -OF CMI On (6235 a 6 = 


All measurements in mm. For explanation of symbols see Text-fig. 1. 


TYPE LOCALITY AND HORIZON. It is almost certain that the holotype and the 
paratypes come from the stream section in shales of Llandeilo age to the east of 
Bach-y-graig, Llandrindod. The label accompanying the holotype gives the locality 
as ‘Cym-y-rhain Dingle on stream behind Pump House, Llandrindod Wells, Radnor- 
shire’. Labels with the paratypes give the locality variously as ‘Stream E. of 
Hillside’ and ‘Llandrindod Wells’. All new specimens collected are from the left 
bank of the stream section east of Bach-y-graig 65 yds east of the point where the 
footpath enters the wood at the western end of the section. 


OTHER FIGURED MATERIAL. It. 2782 (Pl. 15, fig. 6; Pl. 16, fig. 2); It. 2783 (Pl. 15, 
fig. 8); It. 2784 (Pl. 15, fig. 5); NMW 15.207.G3 (Pl. 15, fig. 9). 
DISTRIBUTION. The species is not known outside the type locality. 


DESCRIPTION. Excluding the genal prolongations and spines, complete speci- 
mens are subcircular, with a semicircular cephalon. 

The moderately convex glabella possesses a pseudofrontal lobe which extends for 
two-thirds of the glabellar length. The glabella is traversed anteriorly by a weakly 
developed furrow delimiting a small triangular preglabellar field that encroaches 
a short distance onto the fringe. Three pairs of pit-like lateral glabellar furrows are 
developed on the sides of the glabella. The anterior pair, which are the smallest, 
are situated at about two-fifths the distance along the glabella from the anterior. 
The median and posterior pairs are somewhat larger and deeper and occur at about 
two-thirds and four-fifths of the glabellar length respectively. Alae extend posteri- 
orly from just behind the anterior pair of lateral glabellar furrows. Lateral, and 
subparallel to the posterior part of each ala a low elongate swelling of uncertain 


FROM CENTRAL WALES 171 


significance is present in the floor of the axial furrows, which are wide at the posterior. 
The presence of this swelling in several specimens suggests it to be an original feature 
of the exoskeleton, and not due to any post mortem distortion. Medially, the ex- 
ternal surface of the glabella is pitted, with a low median glabellar node near the 
front. 

The occipital ring is short (sag.) slightly convex posteriorly, and bears no occipital 
spine. The occipital furrow is extremely shallow medially, deepening laterally 
to form shallow occipital pits. 

Anteriorly the axial furrows follow the lateral margins of the pseudofrontal lobe 
until opposite the anterior pair of lateral glabellar furrows; posteriorly from this 
point the straight furrows become wider and shallower. Poorly developed pits 
mark the site of the anterior fossulae. 

Internally the lateral glabellar furrows form small raised platforms. 

The genal regions are quadrant-shaped, with the inner margin slightly concave. 
The genae are only slightly convex, but with a moderately steeply declined outer 
margin. The exterior surface is covered with a fine reticulate pattern of raised 
ridges distributed over the genae in the normal trinucleid manner. Two fine genal 
caecae, originating approximately level with the anterior of the alae also cross 
this area posteriorly. The presence of only one caeca in some specimens is considered 
to be a reflection of imperfect preservation. 

The posterior border is sharply upturned behind the straight, shallow, though 
clearly developed posterior border furrow. It is highest at the fulcrum where it 


Fic. 12. Reconstruction of the cephalon of Protolloydolithus veticulatus (Elles) in dorsal 
Wi, Ge << Ge 


172 ORDOVICIAN TRILOBITE FAUNAS 


turns abruptly posterolaterally. The crest of the border appears to bear a few 
parallel terrace lines. 

Observations on the poorly preserved fringe show that an orderly Ej arc is de- 
veloped together with several internal arcs; of the latter only I, arc is orderly 
arranged. The E; arc has between nineteen and twenty-six pits developed on each 
half-fringe and is separated from the I, arc on the upper lamella by a sharp, high 
ridge with the J, pits situated on its inner slope. At least five irregularly arranged 
I arcs internal to I; are present anteriorly and show some tendency to radial arrange- 
ment medially. Laterally the number of pits increases and the distribution becomes 
entirely haphazard. The pits of these inner arcs are smaller than those of the Ej 
and I; arcs. Moderately large genal prolongations are developed and about seven or 
eight pits of the Ej arc lie behind the posterior margin of the cephalon. The pitted 
area extends medially as far as the fulcrum. Little is known of the lower lamella 
but there is no reason to suspect any discordance between the pits of the two lamel- 
lae. The strongly developed girder merges posteriorly into the genal spines. 

Although the genal spines are not preserved in their entirety they probably extend 
some way behind the pygidium. 

The suture is not seen, but it seems most likely that the suture is marginal, be- 
coming dorsal at the genal angles as in other trinucleids. 

As pointed out by Lamont (1941: 443) and Whittard (1956: 41), the thorax 
has only six segments and not seven as recorded by Elles (1940: 427). In outline 
it is rectangular, about three times as wide as long, the convex (¢.) axial rings 
contrasting with the flat pleural regions. The articulating furrows are narrow and 
deeper laterally than medially. The pleurae are crossed by a shallow oblique pleural 
furrow which extends into the posteriorly deflected, blunt terminations. The 
fulcral processes on the anterior edge are proportionately nearer the axial furrows 
than in most other trinculeid genera. 

The roundly triangular pygidium is about three and a half times as wide as long. 
The axis tapers gently and has at least sixteen axial rings developed which are poorly 
defined posteriorly. The tubercles mentioned by Whittard (1956: 41) on the axial 
rings have not been observed. The pleural fields have a narrow (sag.) anterior 
border and a triangular terminal area together with six, or less commonly five or 
seven, ribs. These widen distally to become progressively more posteriorly directed. 
The strongly declined posterolateral border bears terrace lines. Although relatively 
few data are available, there appears to be no correlation between the size of the 
pygidium and the number of ribs (see Table 38). No examples of the asymmetrical 
development of the ribs on the two halves of the pygidium are known. 


OnToGENy. A single poorly preserved specimen most probably represents a 
meraspis degree three or four (Pl. 15, fig. 8). It appears similar to the holaspid 
form apart from the number of thoracic segments and overall size. A further 
small cephalon (width approximately 5:0 mm) probably referable to this species, 
shows a slightly carinate glabella. 


BIOMETRICAL DATA. Because of poor preservation very few data are available for 
this species; such data as are available are given in Tables 36-38 below. 


FROM CENTRAL WALES 173 


TABLE 36 

Spec. No. A Ai B By Bz B3 I Ty K Ky 
It. 2783 —c¢c.r2 — —~ ~~ ~c¢. 35 — — — 
It. 2784 — —c.38 c.85 — — 
NMW 15.207.G3 — — 60 50 42 — 174 132 35 — 
It. 8809 — — 54 42 34 — —c.120 — — 
NMW 68.376.G200 CO 773 57°45 35° 23. — 42 18 
It. 8807 (A 70) 10-5) 30 = 


Details of measurements made on Protolloydolithus reticulatus (Elles). All measurements in 
mm. For explanation of symbols see Text-fig. 1. 


TABLE 37 


we var. xX y var. y r Te 4 var. o a var.a 
9:66 3:7862 2:79 0-3114 0:°937 0:938 0:99 0:0236 0:29 0:00200 
9:66 3:7862 1:39 O'1214 0:°936 0:937 1:24 0:0373 O18 0:00080 
1°39 O12I4 2:79 O-3114 0:924 0:927 0:80 o-0181 1:60 0:07463 


Kady 
Nyne 
SS SS 


Bivariate statistics for the pygidium of Protolloydolithus veticulatus (Elles). All measurements 
inmm. For explanation of symbols see Text-fig. 1. 


TABLE 38 
No. of pleural ribs 
Spec. No. Pygidiallength Left Right 
NMW 68.376.G2o1 18 7 Gi] 
It. 2784 2:2 5 
NMW 68.376.G202 22 7 7 
It. 8806 22 7 Gi 
NMW 68.376.G203 2°6 — 6 
NMW 68.376.G204 30 6 6 
NMW 68.376.G200 3:33 6 6 
It. 8808 3°3 6 6 
NMW 15.207.G3 33 6 6 


Table showing the lack of correlation between the number of pleural ribs developed and 
pygidial length in Protolloydolithus reticulatus (Elles). 


Discussion. Elles’s original placing of this species in the genus Trinucleoides 
Raymond, 1917 cannot be upheld, for whilst the well-developed alae of P. reticulatus 
bear some resemblance to the lateral lobes of Tvimuceoides reussi (Barrande, 1872), 
the structure of the fringe in the two species is completely different. 

Protolloydolithus ramsayi (Hicks, 1875) is similar to P. reticulatus but may be 
distinguished by its smaller genal prolongations, less well developed alae, probable 


174 ORDOVICIAN TRILOBITE FAUNAS 


higher number (six—eight) of arcs internal to J; and its relatively wider pygidium. 
The only other species referred to the genus, P. neintianus Whittard, 1956, is readily 
separated on the narrowness of the fringe anteriorly and the unfurrowed pleural 
fields of the pygidium. 

Morphologically the species shows no new features apart from the possible de- 
velopment of terrace lines along the crest of the posterior cephalic border which is a 
structure apparently previously unrecognized in the trinucleids. 


Genus TELAEOMARROLITAUS Williams, 1948 


DIAGNOSIS. See page 121. 
Type SPECIES. Tvinucleus radiatus Murchison, 1839. 


DISTRIBUTION. The genus is restricted to the basal Caradoc (N. gracilis Zone) 
of the Anglo-Welsh faunal province, being represented in the Llandeilo, Builth 
and Shelve regions. 


Discussion. Williams (1948: 85) considered Telaeomarrolithus to have been 
derived from the marrolithids by the collapse of the swollen area. The occurrence 
at Builth of T. zntermedius sp. nov. with a slightly swollen area ventrally and ex- 
panded pits in the E; arc of the lower lamella gives support to Williams’ belief that 
Telaeomarrolithus is more closely related to the marrolithids than to Tvinucleus. 
However, the presence of expanded pits solely in the Ej arc, a feature not found in 
any other marrolithinid, suggests that it may not be derived directly from Mar- 
volithus favus (Salter, 1848) as suggested by Williams, or indeed from any marro- 
lithinid known at present. 


Telaeomarrolithus intermedius sp. nov. 
(Pl. 15, figs 2-4, 10; Pl. 16, figs 1, 4-9; Text-fig. 13) 


Diacnosis. Telaeomarrolithus with about thirty-eight to forty-four pits in E, 
arc, of which five or six at anterolateral corners are markedly expanded on the lower 
lamella; occasional pits external to the girder but internal of E; developed antero- 
laterally; maximum of about seven pits in anterolateral rows; four in median rows. 


TYPE MATERIAL. Holotype. It. 2785 (Pl. 16, figs 1, 5) Internal and external 
moulds of cephalon. 

Paratypes. It. 2789 (PI. 16, fig. 4) Internal mould of cephalon. It. 2788 (Pl. 16, 
fig. 8) Internal and external moulds of possibly enrolled specimen showing part of 
thorax. It. 2786 (PI. 16, fig. 6) Internal mould of small cranidium. It. 2787 (PI. 16, 
fig. 9) Internal mould of damaged cranidium. It. 8606 (PI. 15, fig. 4) Mould of lower 
lamella. It. 8799 (Pl. 15, fig. 2) Internal mould of damaged cranidium. It. 8800 
(Pl. 15, fig. 3) External mould of cephalon. BM In. 48533 (Pl. 15, fig. 10) Internal 
mould of cranidium. USNM 160108 (PI. 16, fig. 7) External mould of disarticulated 
entire specimen. 


FROM CENTRAL WALES 175 


DIMENSIONS. 

A Ay B By Be Bs Ba 
It. 2785 OFS Olen pam 2M Eee CR2- 7 22"G 
It. 2786 Bie amine 29 — — — — 
1ie42787 C-4nenO 7 Ses Ome S08) 2 ee 
It. 2789 — _- GON 5442 = a3:0r F 
Ii 2790" “6NG*1 1C1,0'0> 6, 7-0" 45 31 — 
eA S533 7/7 OM S20 25-0" e430 hs OR S25 ee 


I it K Ky 
It. 2785 — ¢.1355 45 3:0 
It. 2786 — G:Oeie2eT) 610 
hig 787 —- -- eee ato) 
It. 2789 c.175  — — — 
It. 2790 — — 470 — 
In. 48533 7 ee LS 2 cn Se 


All measurements in mm. For explanation of symbols see Text-fig. 1. 


Fringe Data 
Number of pits Number of expanded 


in Ej arc pits in Ey arc Presence of 
Left Right Left Right Row O 
It. 2785 194 194 — a present 
It. 2789 a c. 20 _- — P 
It3 2790 — 19 = 5 ? 
In. 48533 204 214 6 5 present 
Max. Number of Number of I arcs Position of anterolateral 
I arcs medially angulation 
Left Right Left Right Left Right 
It. 2785 — — — — row 12 row II 
It. 2788 2 26 a = S 25 
It. 2789 — ?6 — 4 — c. row 12 
It. 2790 — ?6 — 23 — row II-12 
In. 48533 _ 25 4 4 row 12 row 13 


TYPE LOCALITY AND HORIZON. UN. gracilis shales exposed in the middle quarry, 
Llanfawr, Llandrindod. 

DISTRIBUTION. The species is known only from the type locality. 

DeEscripTION. The cephalon is about twice as wide as long, excluding the genal 


176 ORDOVICIAN TRILOBITE FAUNAS 


spines. The lateral margins are straight and slightly divergent anteriorly; anterior 
margin arched forwards medially; anterolateral corners angulate. 

The glabella is convex, with the pseudofrontal lobe occupying the anterior three- 
fifths; it is of moderately convex profile anteriorly and gives the impression of 
encroaching onto the fringe in compressed specimens. The poorly preserved 
anterior lateral glabellar furrows are weakly developed. The median pair, de- 
limiting the posterior of the pseudofrontal lobe, are better developed and consist 
of elongate (¢v.), rather shallow pits. The posterior pair are again elongate pits, but 
are directed slightly anteromedially. A small median glabellar node is situated 
about half-way along the glabella. A coarse reticulate pattern is developed medially 
on the glabella. Alae extend posteriorly from the rear of the pseudofrontal lobe. 
A weakly developed occiput is present. 

The occipital ring is short (sag.) consisting of little more than a median continuation 
of the low ridge forming the posterior margin of the genal regions. The occipital 
furrow is shallow; no occipital spine is developed. 

The shallow axial furrows are most clearly defined anteriorly where a pair of 
anterior fossulae are developed. 

The genal regions are quadrant-shaped and apart from the steeply declined outer 
margin are only slightly convex. Traces of a course reticulation are present distri- 
buted in the typical trinucleid manner. In some specimens a small lateral eye 
tubercle appears to be developed on each gena, close to the axial furrows and slightly 
anterior of the median lateral glabellar furrows, although eye ridges are lacking 
(Pl. 16, fig. 4). The posterior margin is upturned to form a low ridge-like border 


Fic. 13. Reconstruction of the cephalon of Telaeomarrolithus intermedius sp. nov. in 
dorsal view. ¢. X 5. 


FROM CENTRAL WALES 17 


separated from the genae by a straight, shallow posterior border furrow which 
terminates in a small lateral pit. 

Internally the lateral glabellar furrows form raised platforms; the anterior fossulae 
and the lateral pits having corresponding apodemes. Internal traces of the reticula- 
tion on the median glabellar node are only rarely seen (PI. 16, fig. 1). 

The upper lamella of the fringe is widest anterolaterally, and narrowest medially. 
Between about nineteen and twenty-two radial rows are present on each half-fringe. 
The pits of the E; and J, arcs are larger than those of the other I arcs, and antero- 
laterally the pits of E; tend to be slightly enlarged. A few specimens show pits 
of two E arcs developed in up to four radial rows at the anterolateral corners (Pl. 15, 
figs 2, 10). Traces of such pits have only been detected on one lower lamella in 
which they appear to be developed internal to E; on the outer steep sides of the 
swolled area. The significance of these pits, and their apparent absence in some 
specimens is not known. Arcs I,-3 appear to be present medially, I, appearing 
in row two or three. At least six I arcs are developed anterolaterally. The radial 
arrangement of the pits only breaks up at the genal angles where moderate genal 
prolongations are developed with three or four pits of the E; and I; arcs located be- 
hind the posterior margin of the genal regions. Laterally the fringe is differentiated 
into two regions, the outer being characterized by more strongly developed ridges 
between the radial rows. Only the pits of the E; and Ij arcs lie in the outer zone, 
the arcs becoming more widely separated at the anterolateral corners. 

The inner part of the lower lamella is steeply declined to the very strongly de- 
veloped, smooth girder; the outer part being reflected sharply dorsally from the girder. 
The pit distribution corresponds to that of the upper lamella, but in addition four 
or five pits in the FE arc are generally markedly expanded at the anterolateral corners 
which occurs at about row twelve. In addition low, weakly developed ridges are 
present laterally between the various I arcs. From the material available it appears 
that either a row of pits or a ridge may lie along the sagittal line. 

The girder merges posterolaterally with the long, slightly divergent genal spines. 
On one paratype (It. 2789) of cephalic width approximately 17-5 mm, the genal 
spines are about 14:5 mm long. 

The course of the suture is not seen, but is presumably marginal, becoming dorsal 
only at the genal angles and may be non-functional (see discussion), 

The thorax is typically trinucleid and requires no further description. 

The sole known pygidium (PI. 16, fig. 7) is triangular in outline being about three 
and a half times as wide as long. Its overall morphology is extremely similar to 
that of the pygidium of Tvinucleus fimbriatus and isolated pygidia cannot be dis- 
tinguished. At least five pleural ribs and six axial rings are developed. The steeply 
declined posterior border bears terrace lines on the external surface. 


BIOMETRICAL DATA. In view of the small number of measurements possible, 
full details are given. In addition to those already given for the type of specimens, 
further measurements are given in Table 39. Since very few exact pit counts could 
be made, no further statistical data can be given for the pit distribution on the fringe 
above that given in the description. 


178 ORDOVICIAN TRILOBITE FAUNAS 


TABLE 39 
Spec. No. A Ay B Bi Be B3 B4 iy K Ky 
NMW 68.376.G205 590 62 42 32 25 — = S25) 2-85 aes 
NMW 68.376.G206 — FT Se eee —- — — 
NMW 68.376.G207 — — 55 43 35 — — 125 34 rg 
lte2 700 85 89 64 — — — 3:5 127 — 24 
It. 8605 50 FS 835s 85 — — 


Details of measurements made on the cephalon of Telaeomarrolithus intermedius sp. nov. in 
addition to those made on the type material. All measurements in mm. For explanation 
of symbols see Text-fig. 1. 


Discussion. Only thirty specimens of this new species are known from the middle 
quarry, Lanfawr and it is thus relatively rare compared with the majority of species 
at that locality. 

The morphological features developed in this species make generic placing a little 
difficult. Dorsally the cephalic exoskeleton shows strong similarities to Tvinucleus 
jimbriatus with its well developed radial sulci and anteriorly swollen glabella. How- 
ever the presence of two distinct areas on the fringe laterally, the angulate outline 
and the presence of markedly swollen pits in the E; are on the lower lamella are 
thought to indicate that the species is best placed in Telaeomarrolithus. The new 
species is easily distinguished from the type species by its expanded pits on the lower 
lamella, the presence of two pits external to the girder in the anterolateral rows, 
the smaller number of pits in each arc, and the smaller number of I arcs represented 
anterolaterally. Telaeomarrolithus sp. indet. described by Whittard (1956: pl. 9, 
fig. 6) is too poorly preserved for any proper comparison, although the rather rounded 
anterolateral angles are more like those of T. vadiatus than that of T. intermedius. 

About two-thirds of the internal moulds of T. intermedius have the impression 
of the ventral surface of the lower lamella preserved, indicating that the lower 
lamella was still attached to the cephalic exoskeleton. This type of preservation 
is only rarely found in specimens of Tvinucleus fimbriatus from the same locality. 
In view of this, and that the trilobite exoskeletons are generally disarticulated, it 
seems possible that the marginal suture of T. intermedius was no longer functional. 
It is interesting to note that the four specimens of T. vadzatus referred to by Williams 
(1948: 83) together with a further specimen from Llandeilo all show the same mode 
of preservation and it may be that an ankylosed marginal suture is characteristic 
of Telaeomarrolithus, 


Telaeomarrolithus radiatus (Murchison) 
(Pl, 16; ne. 3) 


1839 Trinucleus vadiatus Murchison 660, pl. 23, figs 3a, 3b. 
1948 Telaeomarrolithus vadiatus (Murchison); Williams: 83, text-fig. 11, pl. 6, fig. ro. 


TYPE MATERIAL. Syntypes. GSM Geol. Soc. Coll. 6836; GSM Geol. Soc. Coll. 
6837. 


FROM CENTRAL WALES 179 


Discussion. Murchison’s localities for Tvinucleus radiatus read, ‘Trilobite Dingle, 
Welsh Pool, Caradoc and Meifod Hills etc.’, (Murchison, 1839: 660), but there is some 
doubt as to the locality of the figured syntypes, for the original label gives the 
locality as ‘Llandeilo Flags, Builth’. However the lithology of the syntypes does 
not match anything known from the Builth region, but is similar to that of Williams’s 
specimens from Crug, near Llandeilo. It thus seems more probable that the types 
come from the Llandeilo, rather than the Builth area. This is supported by the 
fact that no other specimens of T. vadiatus are known from the Builth region and it 
is thus proposed to remove 7. vadiatus from the faunal lists of the region. 


IV. ACKNOWLEDGEMENTS 


The bulk of the material used for this study was collected during the tenure, at 
the Queen’s University of Belfast, of a research studentship awarded by the Natural 
Environment Research Council to whom I am grateful for financial assistance. 
All new type and figured material is deposited in the collections of the British Museum 
(Natural History), London, together with some further specimens. I am much 
indebted to Professor Alwyn Williams and Dr A. D. Wright for their supervision 
and encouragement whilst the work was in progress. My thanks are also given to 
Professor H. B. Whittington for much helpful advise and discussion in the later 
stages of the work, to Dr D. L. Bruton for kindly reading the manuscript, and to 
Mr John Lewis for his skill in drawing all the Text-figures. I am also indebted to 
Sir William Pugh and the late Professor O. T. Jones for generously supplying infor- 
mation concerning fossiliferous localities. 

I thank Dr D. A. Bassett, National Museum of Wales, Cardiff; Mr A. G. Brighton 
and Dr C. L. Forbes, Sedgwick Museum, Cambridge; Dr F. H. Broadhurst, Uni- 
versity of Manchester; Dr W. T. Dean, formerly at The British Museum (Nat. Hist.) ; 
Dr P. M. Kier, United States National Museum, Washington, D.C.; Mr C. W. New- 
man, Radnorshire County Museum, Llandrindod Wells; Mr H. P. Powell, University 
of Oxford; Dr A. W. A. Rushton, Institute of Geological Sciences; Dr I. Strachan, 
University of Birmingham and Mr J. T. Wattison, Stoke-on-Trent, for the loan of 
specimens in their care. 


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SHAW, A. B. 1957. Quantitative trilobite studies II. Measurements of the dorsal shell of 
non-agnostidean trilobites. J. Paleont., Tulsa 31: 193-207. 

SHAw, A. B. & STUBBLEFIELD, C. J. 1950. Tvinucleus Murchison, 1839 as a nomen conservan- 
dum. J]. Paleont., Tulsa 24: 624-625. 

STETSON, H. C. 1927. The distribution and relationships of the Trinucleidae. Bull. Mus. 
comp. Zool., Harv., Cambridge 68: 87-104, 1 pl. 

ST@RMER, L. 1930. Scandinavian Trinucleidae, with special reference to Norwegian species 
and varieties. Skv. Norsk Vidensk.-Akad. Mat. Naturv. Kl., Oslo 1 (4): 1-111, pls 1-14. 

STUBBLEFIELD, C. J. & WHITTINGTON, H.B. 1956. Proposed use of plenary powers to validate 
the generic names Tvinucleus Murchison, 1839, and Tvetaspis M’Coy, 1849 (Class Trilobita). 
Bull. zool. Nomencl., London 12: 49-54. 

VocpEs, A. W. 1890. A bibliography of Palaeozoic Crustacea from 1698 to 1889 including 
a list of North American species and a systematic arrangement of genera. Bull. U.S. 
geol. Suvv., Washington 63: 1-177. 

WaHittTarD, W. F. 1955-67. The Ordovician trilobites of the Shelve Inlier, West Shropshire. 
Palaeontogy. Soc. [Monogy.], London: 1-40, pls 1-4, 1955; 41-70, pls 5-9, 1956; 71-116, 
pls 10-15, 1958; 117-162, pls 16-21, 1960; 163-196, pls 22-25, 1961; 197-228, pls 26-33, 
I1961a; 229-264, pls 34-45, 1964; 265-306, pls 46-59, 1966; 307-352, 1967. 

Wuittincton, H. B. 1940. On some Trinucleidae described by Joachim Barrande. Am. J. 

Sci., New Haven 238: 241-259, pls 1-4. 

1941. The Trinucleidae—with special reference to North American genera and species. 

J. Paleont., Tulsa 15: 21-41, pls 5, 6. 


182 ORDOVICIAN TRILOBITE FAUNAS 


Wuittincton, H. B. 1941a. Silicified Trenton Trilobites. J. Paleont., Tulsa 15: 492-522, pls 
72-13- 

1959. Silicified Middle Ordovician trilobites: Remopleuridae, Trinucleidae, Raphio- 
phoridae, Endymionidae. Bull. Mus. Comp. Zool., Harv., Cambridge 121: 371-496, 
pls. 1-36. 

Witiiams, A. 1948. The Lower Ordovician Cryptolithids of the Llandeilo District. Geol. 
Mag., Lond. 85: 65-88, pl. 6. 


C. P. HueGuHEs, B.Sc., Ph.D., F.G.S. 
Department of Geology 

UNIVERSITY OF CAMBRIDGE 
SEDGWICK MusEUM 

CAMBRIDGE 


EXPLANATION OF PLATES 


Most of the trilobites figured are in collections of the British Museum (Natural 
History) and their numbers are prefixed BM, I., In., or It. Other specimens are in 
collections in the following institutions: Birmingham University (BU), Institute 
of Geological Sciences, London (GSM), National Museum of Wales, Cardiff (NMW), 
Oxford University Museum (OUM), Sedgwick Museum, Cambridge (SM), United 
States National Museum, Washington D.C. (USNM) and the private collections of 
Mr J. T. Wattison (H). All specimens were whitened with ammonium chloride 
before photographing. All photographs are by the author and none is retouched. 


PLATE 1 
Trinucleus fimbriatus Murchison p. 122 


Basal Caradoc, middle quarry, Llanfawr, Llandrindod. 
G.R. SO.066617. 

Fic. 1. Latex impression from internal mould showing general characteristics of dorsal 
exoskeleton. Wattison Collection H.22 x 3. 

Fic. 2. Latex impression from external mould showing faint terrace lines on posterior 
borders lt 27835 ao: 

Fic. 3. Internal mould of cranidium showing a depression lateral to the posterior lateral 
glabellar furrow. It. 2726. x 5. 

Fic. 4. Internal mould of cranidium showing the pits of the inner I arcs anteromedially. 
It. 2735. x 4. (Specimen donated by Radnorshire County Museum, Llandrindod Wells.) 

Fic. 5. Latex impression from external mould of meraspis ?degree 4 cranidium showing 
posterolateral outline of fringe (see also Text-fig. 3). It. 2732. ™ 5. 

Fic. 6. Internal mould of cranidium showing irregularities in the fringe. It. 2722. x 2:5. 

Fic. 7 Latex impression from external mould of cranidium showing surface sculpture 
IME, APO Sf Zn 

Fic. 8. Internal mould of cranidium showing irregularities in the pit distribution on the left 
Side alit2 720 sang 

Fic.g9. Internal mould of cranidium showing the fusion of two ridges on the fringe. It. 2727. 
4 -Sho 


PLATE rt 


Bull. By. Mus. nat. Hist. (Geol.) 20, 4 


PLEADE 2 
Trinucleus fimbriatus Murchison p. 122 


Basal Caradoc, middle quarry, Llanfawr, Llandrindod. 
G.R. SO.066617. 


Fic. 1. Internal mould of lower lamella. It. 2731 x 2. 

Fic. 3. Internal mould of ?meraspis cranidium showing irregularities in the fringe. It. 2724. 
SAL 

Fic. 4. Internal mould of small holaspis. It. 2719. x 3. 

Fic. 5. Internal mould of lower lamella with genal spines. It. 2728. xX 2:5. 

Fic. 6. Enrolled specimen showing five thoracic segments folded over and the posterior 
pygidial margin fitting against the inner margin of the fringe. It. 2721. & 3. 

Fic. 8. Internal mould of meraspis degree 5 (see also Text-fig. 3). It. 2725. ™ 3:5. 

Fics 9, to. Dorsal and oblique lateral views of internal mould of complete specimen. It. 
8798. X 1°5. 

Fic. 11. Internal mould of anterior thoracic segment showing the lack of articulating half 
ring. It. 2734. X 4. 

Fic. 12. Enlargement of part of Pl. 1, fig. 7. Latex impression from external mould of 
cranidium showing median glabellar node. It. 2730. ™ Io. 

Fic. 13. Internal mould of cranidium showing occipital ring and furrows, fulcral processes 
and lateral pits. It. 2720. x 2:5. 

Fic. 14. Internal mould of small meraspis showing outline of fringe posterolaterally (see 
also Text-fig. 3). It. 2723 x 8. 


Basal Caradoc, quarry at Gwern-yfed-fach, half a mile south-east 
of Builth Road station 
G.R. SO.030526. 
Fic. 2. Lectotype. Latex impression from external mould of cranidium. GSM Geol. Soc. 
Coll. 6836a. xX 2°5. 
Fic. 7. Internal mould of cephalon showing external mould of lower lamella. BM 59499. 
SS: 


TRIE ACID ID; 72 


Bull. By. Mus. nat. Hist. (Geol.) 20, 4 


» ‘ae 
St hd 
wl 


yar" 


PLATE 3 
Trinucleus fimbriatus Murchison p. 122 


Basal Caradoc, quarry at Gwern-yfed-fach, half a mile 
south-east of Builth Road station. 
G.R. SO.030526. 


Fic. 1. Internal mould of cephalon with displaced lower lamella showing through upper 
lamella. GSM 35356. x 3. (Figured as Tvinucleoides salteri, Elles, 1940, pl. 30, fig. 9.) 


Trinucleus abruptus sp. nov. p. 132 


Lower Llanvirn, small quarries 600 yards east of 
Upper Gilwern. G.R. SO.092582. 


Fic. 2. Paratype. Internal mould of virtually complete specimen. BM 36921. X 2:5. 
(Figured as Tvinucleus cf. foveolatus Angelin; Elles, 1940, pl. 31, figs I, Ia.) 

Fic. 3. Paratype. Internal mould showing left genal spine. It. 2736. x 3. 

Fic. 4. Paratype. Internal mould of nearly complete specimen. OUMB.179. xX 2:5. 

Fic. 7. Holotype. Internal mould of nearly complete specimen. BM 36920. xX 4. 
(Figured as Tvinucleus cf. foveolatus Angelin; Elles, 1940, pl. 31, figs 2, 2a.) 


Lower Llanvirn, cliff section on left bank of Howey Brook 
half a mile east-south-east of Carregwiber. 
G.R. SO.089582. 


Fic. 6. Paratype. Latex impression from external mould of cranidium showing small 
median glabellar node and fine reticulate sculpture. It. 2738. x 6. 


Trinucleus cf. acutofinalis Whittard p. 137 


Upper Llanvirn, in left bank of stream 200 yards south-west of 
Wern-Ddu Barn. G.R. SO.080610. 


Fic. 5. External mould of anterior thoracic segment. It. 2739. X 5. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 4 


ARW EE 


¥ 


-. 


\. Pd 
ed 


PLATE 4 
Bergamia prima (Elles) p. 140 
Llandeilo, stream section 15 yards south-west of the old quarry 
350 yards west of Maesgwynne. G.R. SO.059566. 
Fics 1, 2. Internal mould of lower lamella showing the two arcs of pits external to the 
girder. It. 2745. Fig.1. xX 10; Fig.2. xX 4. 


Llandeilo, old quarry 350 yards west of Maesgwynne. 
G.R. SO.059566. 
Fic. 6. Holotype. Latex impression from external mould. BU 257. 
as Trinucleus fimbriatus mut. primus, Elles, 1940, pl. 30, fig. I, upper specimen.) 


xX 4°5. (Figured 


Anebolithus sp. p. 139 


Lower Llanvirn, small quarries 600 yards east of Upper Gilwern. 
G.R. SO.092582. 


Fics 3, 5. Internal and external moulds of lower lamella. It. 2744. x 3. 


Trinucleus cf. acutofinalis Whittard p. 137 


Upper Llanvirn, in left bank of stream 200 yards south-west of 
Wern-Ddu Barn. G.R. SO.0806r10. 


Fic. 4. Internal mould of pygidium and part of thorax. It. 2741. ™ 5. 
Fic. 8. Latex impression from external mould of cranidium showing the fringe pits. It. 2742. 
x Be 
Upper Llanvirn, in right bank of stream 200 yards south-west of 
Wern-Ddu Barn. G.R. SO.080610. 
Fic. 7. Latex impression from external mould of nearly complete specimen. It.2743. X 7. 


PVAChE. 4 


Bull. By. Mus. nat. Hist. (Geol.) 20, 4 


PLATE 5 
Bergamia prima (Elles) p. 140 


Llandeilo, old quarry 350 yards west of Maesgwynne. 
G.R. SO.059566. 


Fics 1,2. Holotype. External and internal moulds of nearly complete specimen. BU 257. 
x 4. (Figured as Tvinucleus fimbriatus mut. primus, Elles, 1940, pl. 30, fig. 1, lower specimen.) 
Fic. 5. Internal mould of complete specimen showing median glabellar node. It. 2753. 


X 3°5- 


Llandeilo, stream section 15 yards south-west of the old quarry 
350 yards west of Maesgwynne. 
G.R. SO.059566. 


Fics 3, 4. Internal mould of lower lamella showing the two arcs of pits external to the 
ginderny wits 2 7A One sheers eee ENO ie edn 
Fic. 6. Internal mould of complete specimen. It. 2749. xX 3. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 4 


Se age lat 
ir. 1, LEE 


wbx. 


PLATE 6 


Bergamia prima (Elles) p. 140 


Llandeilo, old quarry 350 yards west of Maesgwynne. 
G.R. $O.059566. 


Fics 1, 4. Oblique and dorsal views of specimen showing an external mould of the lower 
lamella. It. 2750. Fig. 1. x 5; Fig. 4. X 3:5. 

Fic. 6. Latex impression from external mould of anterior thoracicsegment. It.275I. xX 5. 

Fic. 8. Enrolled specimen showing internal mould of thorax and pygidium and external 
mould of one gena. It. 2752. x 6. 


Llandeilo, stream section 15 yards south-west of the old quarry 
350 yards west of Maesgwynne. 
G.R. SO.059566. 


Fics 2,3. Internal mould of lower lamella showing the E; and Eg arcs being barely more than 
twin pits anterolaterally. It. 2747. Fig.2. x 5; Fig.3. xX Io 
Fic. 5. Internal mould of meraspis ?degree 4. It. 2748. x Io. 


Bergamia whittardi sp. nov. p. 146 


Uppermost Llandeilo, small quarry at south-western end of 
Pen-cerig Lake. G.R. SO.043541. 


Fig. 7. Enrolled ?meraspis. It. 2773. x Io. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 4 PLATE 6 


PLATE 7 


Bergamia whittardi sp. nov. p. 146 


Uppermost Llandeilo, small quarry at south-western end of 
Pen-cerig Lake. G.R. SO.043541. 

Fic. 1. Internal mould of thorax showing lack of articulating half ring on anterior segment. 
Wits 20, >< G- 

Fic. 2. Internal mould of transitory pygidium. It. 2772. x 15. 

Fic. 3. Paratype. Internal mould of part of lower lamella showing incomplete Eg arc. 
Lit 2 715 Ose 

Fic. 4. Internal mould of ?meraspis cephalon. It. 2776. x Io. 

Fic. 5. Latex cast from external mould of lower lamella showing the pit distribution on the 
genal flange. It. 2771. x 8. 

Fic. 6. Holotype. Internal mould of part of lower lamella, showing Ee» arc developed 
anteriorly. BU 260a. x 8. (Figured as Tvinucleus fimbriatus mut. primus, Elles, 1940 
pl. 30, fig. 5.) 

Fic. 7. Paratype. Internal mould of part of lower lamella showing incomplete Eg arc. 
lits275 On <6: 

Fic. 8. Internal mould of transitory pygidium. It. 2766. x 12. 

Fic. 9. Internal mould showing upper and lower lamellae. It. 2761. x 6. 

Fic. 10. Paratype. Internal mould of nearly complete specimen. It. 2758. x 8. 

Fic. 11. Internal mould of small holaspis. It. 2778. x Io. 

Fic. 12. Paratype. Internal mould of cranidium showing pit distribution and surface 
sculpture. It.2754. xX 5. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 4 


oe 


a 


Somat 
ge 


‘4 


a Ryexereagee 


Nose, 


wy 


Ww 


WEG 


soa 


Fic. 


x 6. 


Fic. 
Fic. 


xX 10. 


Fic. 
Fic. 
Fic. 
Fic. 
Fic. 


xX 10. 


Fic. 
Fic. 


Fic. 


Wasi CNRayce 


© 


rt. 


Io. 


PLATE 8 


Bergamia whittardi sp. nov. p. 146 


Llandeilo, 120 yards south-east of Tre coed on left bank of stream. 
G.R. $O.054552. 


Paratype. Internal mould showing parts of the upper and lower lamellae. It. 2760. 


Uppermost Llandeilo, small quarry at south-western end of 
Pen-cerig Lake. G.R. $O.043541. 
Internal mould of meraspis cephalon (see also Text-fig. 7). It. 2775. x Io. 
Paratype. Latex impression from external mould of small holaspis. It. 2755. 


Internal mould of meraspis cranidium (see also Text-fig. 7). It. 2768. x Io. 
Enrolled specimen. It. 2770. x 7. 

Internal mould of meraspis cephalon. It. 2774. ™ Io. 

Paratype. Internal mould of pygidium. It. 2757. x 6. 

External mould of pygidium showing terrace lines on posterior border. It. 2769. 


Paratype. Internal mould of cranidium. Wattison Collection H.14. ™ 5. 
External mould of meraspis cephalon (see also Text-fig. 7). It. 2763. Io. 


Trinucleinid gen. et sp. indet. p. 151 


Upper Llanvirn, track 60 yards south-west of Bwlch-y-cefn. 
G.R. SO.120610. 


External mould of part of thorax and pygidium. It. 2779. xX 5. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 4 PEALE 8 


~~ - -_ <a 


< 


F) 
Ae AT he 


PLATE 9 


Bergamia whittardi sp. nov. p. 146 


Uppermost Llandeilo, small quarry at south-western end of 
Pen-cerig Lake. SO.043541. 


Fic. 1. External mould of meraspis degree 4 (see also Text-fig. 7). It. 2765. x 12. 


Fic. 2. Internal mould of pygidium showing extension of axis onto posterior border. 


Re  S€ Br 


Trinucleinid gen. et. sp. indet. p. 151 


Upper Llanvirn, in left bank of tributary to Howey Brook, 
35 yards below lowest waterfall. 
G.R. SO.092591. 


It. 


Fics 3, 7. Internal and external moulds of poorly preserved specimen. It. 2780. »™ 4. 


Cryptolithus instabilis sp. nov. p. 152 


Llandeilo, left bank of Dulas’ Brook, 150 yards south-west of 
the old quarry west of Maesgwynne. 
G.R. S$O.058564. 


Fic. 4. Paratype. External mould of lower lamella. It. 2793. x 5. 
Fic. 5. Paratype. Enrolled specimen. It. 2794. xX 3. 


Fic. 8. Internal mould of cranidium showing a single pit developed medially. It. 2805. 


x 6. 


Llandeilo, 160 yards south-east of Tre coed on 
left bank of stream. G.R. SO.054552. 


Fic. 6. Paratype. Internal mould showing occipital spine extending to fourth thoracic 


segment. It. 2802. x 5. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 4 PLATE 9 


Sak 


a” 
"4 


PAC AGE eo 


Cryptolithus instabilis sp. noy. p. 152 


Llandeilo, left bank of Dulas Brook, 150 yards south-west of the 
old quarry west of Maesgwynne. G.R. SO0.058564. 


Fic. 1. Holotype. Internal mould of cranidium. It. 2792. X 4. 

Fic. 2. Paratype. Internal mould of cranidium showing only three pits in the median row 
and well developed lateral glabellar furrows. It. 2798. 3. 

Fic. 3. Paratype. Internal mould showing lower lamella and weakly developed alae. 
It. 2796. X 4. 

Fic. 4. Paratype. Latex impression from external mould showing sculpture on the glabella 
and gena, and presence of median glabellar ridge. It. 2797. x 8. 

Fic. 6. Paratype. Internal mould showing pit distribution. It. 2799. X 3°5. 


Llandeilo, 160 yards south-east of Tre coed on left bank of stream. 
G.R. $0.054552. 


Fic. 5. Paratype. Dorsal surface showing sculpture and genal caecae. It. 2801. X 5. 
Fic. 7. Paratype. Internal mould with some exoskeleton adhering. It. 2803. x 3:5. 


Llandeilo, stream section 15 yards south-west of the 
old quarry 350 yards west of Maesgwynne. G.R. SO.059566. 
Fic. 8. Dorsal surface of cranidium showing irregularities in lateral distribution of I arcs 
and also a single pit developed medially. It. 2804. x 4. 


PLATE to 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 4 


mS 
hes 


LAVAS eg, 
Vs 


JPICIN DIS; wei 
Cryptolithus sp. A p. 157 


Upper Llanvirn, right bank of stream 100 yards below 
waterfall in pass north-east of Bwlch-y-cefn. 
G.R. $O.123612. 


Fic. 1. Internal mould of lower lamella. It. 2806. x 3. 
Fic. 4. Internal mould of pygidium. It. 2807. x Io. 
Fic. 6. External mould of part of thorax. It. 2808. ™ 5. 


?Cryptolithus sp. B p. 157 


Llandeilo, stream section at Wellfield Lodge immediately above 
where the stream is piped under the road. 
G.R. S$O.044528. 


Fics 2, 7. External and internal moulds of fragment of lower lamella. It. 2809. x 5. 


?Cryptolithus sp. C p. 158 
Llandeilo, stream section at Wellfield Lodge immediately 


below where the stream is piped under the road. 
G.R. $O.044528. 


Fics 3, 8. External mould and latex impression of fragment of cephalon. It. 2810. » 5. 


Cryptolithus instabilis sp. nov. p. 152 


Llandeilo, left bank of Dulas Brook, 150 yards south-west of 
the old quarry west of Maesgwynne. 
G.R. SO.058564. 


Fic. 5. Paratype. Internal mould of pygidium. It. 2795. x 5. 


Llandeilo, 160 yards south-east of Tre coed on left bank of stream. 
G.R. SO0.054552. 


Fic. 12. Paratype. Internal mould of fragment of lower lamella showing proximal part of 
genal spine. It. 2800,  X 3. 


Bettonia chamberlaini (Elles) p. 159 


Lower Llanvirn, cliff section on left bank of Howey Brook 
half a mile east-south-east of Carregwiber. 
G.R. SO.089582. 


Fic. 9. Internal mould of small holaspis. It. 2826. x Io. 

Fic. 10. Internal mould of meraspis ?degree 5. It. 2815. x Io. 

Fic. 11. Internal mould of fragment of lower lamella. It. 2825. x 2:5. 

Fic. 13. External mould of ?transitory pygidium. It. 2827. x Io. 

Fic. 15. Latex impression from external mould of lower lamella. It. 2812. 4. 


Lower Llanvirn, small quarries 600 yards east of Upper Gilwern. 
G.R. SO.092582. 


Fic. 14. Enrolled specimen. It. 2816. xX 4. 


PAE a2 
Bettonia chamberlaini (Elles) p. 159 


Lower Llanvirn, cliff section on left bank of Howey Brook 
half a mile east-south-east of Carregwiber. 
G.R. SO0.089582. 


Fic. 1. Paratype. Internal mould of small holaspis. BU 263. x 6. 

Fic. 2. Internal mould of cranidium (see also Text-fig. 10). It. 2817. x 5. 

Fic. 4. Latex impression from external mould of cranidium showing occipital spine and 
surface sculpture It. 2818. x 7. 

Fic. 5. Holotype. Internal mould of nearly complete specimen with damaged fringe (see 
also Text-fig. 10). BU 261a. x 4. 

Fic. 6. Internal mould of small holaspis. It. 2814. x 8. 

Fic. 7. Latex impression from external mould showing adventitious pits and sculpture 
on gena (see also Text-fig. 10). It. 2813. x 5. 


Upper Llanvirn, about 15 yards below confluence of 
Holywell and Whitehouse Brooks, Rorrington, Shropshire. 


Fic. 3. Internal mould of cranidium (see also Text-fig. 11). GSM 86785. x 5. (Figured 
as holotype of Bettonia frontalis, Whittard, 1956, pl. 9, fig. 7.) 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 4 PMA E 12 


sr 7 


PEATE 13 


Bettonia chamberlaini (Elles) p. 159 


Lower Llanvirn, cliff section on left bank of Howey Brook 
half a mile east-south-east of Carregwiber. 
G.R. SO.089582. 


Fic. 1. Internal mould of lower lamella (see also Text-fig. 10). BU 261b. ™ 5. 

Fic. 2. Internal mould of cranidium (see also Text-fig. 10). BU 264. x 5. 

Fic. 3. Internal mould of damaged cranidium (see also Text-fig. 10). It. 2819. x 5. 

Fic. 4. Paratype. Internal mould of damaged specimen (see also Text-fig. 10). BU 262. 
x 4. 


Fic. 5. Internal mould of cranidium. SM Ato,o82. x 4. (Figured as holotype of T77- 
nucleus (Cryptolithus) gibbosus, Elles, 1940, pl. 31, fig. 3.) 

Fic. 6. Internal mould of lower lamella (see also Text-fig. 10). It. 2821. x 4. 

Fic 7. Internal mould of cranidium showing small median glabellar node, and no adventitious 
pits external to E; (see also Text-fig. 10). It. 2820. ™ 5. 

Fic. 8. Internal mould of nearly complete specimen. It. 2823. x 5. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 4 PLATE 13 


mujer BPE LTE ae Oe ake 


PLATE 14 


Bettonia chamberlaini (Elles) p. 159 


Lower Llanvirn, cliff section on left bank of Howey Brook 
half a mile east-south-east of Carregwiber. 
G.R. SO0.089582. 

Fic. 1. Enlargement of part of Pl. 11, fig. 15 showing terrace lines on the pseudogirder. 
Ihe, ASA, <i 

Fic. 2. Internal mould of cranidium showing symmetrical absence of an Ej pit laterally. 
Ith2 8225 <5: 

Fic. 4. Latex impression from external mould of small cranidium showing coarse reticulation 
on glabella and gena. It. 2828. x Io. 

Fic. 5. Internal mould of meraspis ?degree 5. It. 2829. x 8. 

Fic. 9. Internal mould of thorax and pygidium. BU 368. x 6. 


Upper Llanvirn, about 15 yards below confluence of 
Holywell and Whitehouse Brooks, Rorrington, Shropshire. 


Fic. 3. Internal mould of cranidium (see also Text-fig. 11). GSM 86789. x 5. (Figured 
as holotype of Bettonia irvvegularis, Whittard, 1956, pl. 9, fig. 12.) 


Upper Llanvirn, lane leading to Lyde, 170 yards south-east of 
Mincop, Shropshire. 


Fic. 8. Latex impression from external mould of cephalon (see also Text-fig. 11). GSM 
86786A. 5. (Figured as holotype of Bettonia paucipuncta, Whittard, 1956, pl. 9, fig. 9.) 


Lower Llanvirn, small quarries 600 yards east of 
Upper Gilwern. G.R. SO.092582. 


Fic. 10. Internal mould of complete specimen (see also Text-fig. 10). It. 2811. X 5. 


Marrolithus sp. p. 168 


Basal Caradoc, middle quarry, Llanfawr, Llandrindod. 
G.R. SO.066617. 


Fics 6, 7. Latex impression and internal mould of cephalon with mould of ventral surface 
of lower lamella. It. 2781. X 3°5. 


Bettonia afi. superstes Whittard p. 167 


Llandeilo, stream section at Wellfield Lodge immediately 
below where the stream is piped under the road. 
G.R. SO0.044528. 


Fic. 11. Internal mould of cranidium and anterior thoracic segments. It. 2830. x 4. 


PLATE 15 
Protolloydolithus reticulatus (Elles) p. 169 
Llandeilo, stream section east of Bach-y-graig, exact locality unknown. 


Fic. 1. Holotype. Internal mould. I. 7216. x 3. (Figured as Tvinucleoides reticulatus, 
Elles, 1940, pl. 29, fig. 6.) 

Fic. 7. Paratype. Internal mould of thorax and pygidium. It. 8604. x 4. (Figured 
as Tvinucleoides veticulatus, Elles, 1940, pl. 29, fig. 8.) 

Fic. 9. Latex impression from external mould of complete specimen showing general 
features. NMW 15.207.G3. X 3. 

Fic. 11. Paratype. Internal mould ofcranidium. 1.7328. x 3. (Figured as Tyvinucleoides 
veticulatus, Elles, 1940, pl. 29, fig. 7.) 


Llandeilo, left bank of stream section east of Bach-y-graig, 
45 yards east of the point where the footpath enters the 
wood at the western end of the section. G.R.SO.071610. 
Fic. 5. Internal mould of nearly complete specimen showing right genal spine. It. 2784. 
x 4. 
Fic. 6. Latex impression from external mould showing faint terrace lines along the crest of 
the posterior border. It. 2782. x Io. 
Fic. 8. Internal mould of poorly preserved meraspis. It. 2783. x 15. 


Telaeomarrolithus intermedius sp. nov. p. 174 


Basal Caradoc, middle quarry, Llanfawr, Llandrindod. 
G.R. SO.066617. 
Fic. 2. Paratype. Internal mould of damaged cranidium showing two E arcs anterolaterally. 
Ie 7G. Fe 
Fic. 3. Paratype. Latex impression from external mould of cephalon showing surface 
sculpture and median glabellar node. It. 8800. x 3. 
Fic. 4. Paratype. Internal mould of lower lamella showing expansion of pits at anterolateral 
COmMeTS lta OOON mE arAs 
Fic. to. Paratype. Internal mould of cranidium showing two E arcs developed at antero- 
lateral corners. In. 48533. X 4. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 4 PLATE 15 


sa a a Ns 
. 2. 


SUITE 
ig SiH 


€ wat 
is et 3 


PLATE 16 
Telaeomarrolithus intermedius sp. nov. p. 174 


Basal Caradoc, middle quarry, Llanfawr, Llandrindod. 
G.R. SO.066617. 


Fic. 1. Holotype. Internal mould of cephalon showing lower lamella. It. 2785. x 3. 

Fic. 4. Paratype. Internal mould showing posteriorly divergent genal spines. It. 2789. 
3. 

Fic. 5. Holotype. Latex impression from external mould of cephalon showing details of 
upper lamella and surface sculpture. It. 2785. x 3. 

Fic. 6. Paratype. Internal mould of small cephalon. It. 2786. x 6. 

Fic. 7. Paratype. Latex impression from external mould of nearly complete specimen. 
USNM 160108. » 4. 


Fic. 8. Paratype. Internal mould of enrolled specimen. It. 2788. x 3. 
Fic. 9. Paratype. Internal mould of damaged cranidium. It. 2787. »& 5. 


Protolloydolithus reticulatus (Elles) p. 169 


Llandeilo, left bank of stream section east of Bach-y-graig, 
45 yards east of the point where the footpath enters the wood at the 
western end of the section. G.R. SO.071610. 


Fic. 2. Internal mould showing general nature of pit distribution. It. 2782. x 3. 


Telaeomarrolithus radiatus (Murchison) p. 178 
Basal Caradoc, ?200 yards south-south-east of Crig, Carmarthenshire. 


Fic. 3. Internal mould of cephalon showing lower lamella. GSM Alwyn Williams Coll. 
T5202 aXe 


Bull. By. Mus. nat. Hist. (Geol.) 20, 4 


Pa 


Xe 


A LIST OF SUPPLEMENTS 
TO THE GEOLOGICAL SERIES 
OF THE BULLETIN: OF 
THE BRITISH MUSEUM (NATURAL HISTORY). 


. Cox, L. R. Jurassic Bivalvia and Gastropoda from Tanganyika and Kenya. 
Pp. 213; 30 Plates; 2 Text-figures. 1965. {6. 

. Et-Naccar, Z. R. Stratigraphy and Planktonic Foraminifera of the Upper 
Cretaceous—Lower Tertiary Succession in the Esna-Idfu Region, Nile Valley, 
Egypt, U.A.R. Pp. 291; 23 Plates; 18 Text-figures. 1966. {10. 

. Davey, R. J., Downtz, C., SARGEANT, W. A. S. & Wititams, G. L. Studies on 
Mesozoic and Cainozoic Dinoflagellate Cysts. Pp. 248; 28 Plates; 64 Text- 
figures. 1966. {7. 

. APPENDIX. Davey, R. J., Downig, C., SARGEANT, W. A. S. & WILLIAMS, G, L. 
Appendix to Studies on Mesozoic and Cainozoic Dinoflagellate Cysts. Pp. 24. 
1969. 8op. 

. Evtiott, G. F. Permian to Palaeocene Calcareous Algae (Dasycladaceae) of the 
Middle East. Pp. 111; 24 Plates; 17 Text-figures. 1968. 5.124. 


. Ruopes, F. H. T., Austin, R. L. & Druce, E. C. British Avonian (Carboni- 


ferous) Conodont faunas, and their value in local and continental correlation. 
Pp. 315; 31 Plates; 92 Text-figures. 1969. 11. 


. Cuitps, A. Upper Jurassic Rhynchonellid Brachiopods from Northwagesmn 


Europe. Pp. 119; 12 Plates; 40 Text-figures. 1969. £4.75. 

. Goopy, P. C. The relationships of certain Upper Cretaceous Teleosts with 
special reference to the Myctophoids. Pp. 255; 102 Text-figures. 1969. £6.50. 
. Owen, H. G. Middle Albian Stratigraphy in the Paris Basin. Pp. 164; 
3 Plates; 52 Text-figures. 1971. 6. 


. Sippigur, Q. A. Early Tertiary Ostracoda of the family Trachyleberididae 


from West Pakistan. Pp. 98; 42 Plates; 7 Text-figures. 1971. £8. 


id q 
tut Printed in England by Staples Printers Limited at their Kettering, Northants, establishment 


ee = 


PALAEOZOIC CORAL FAUNAS FROM 
VENEZUELA, I. SILURIAN AND PERMO- 
CARBONIFEROUS CORALS FROM THE 
MERIDA ANDES 


AVS My 
cS So 


aS 
He 


ny 


BY 
COLIN THOMAS SCRUTTON 


Department of Geology, University Sees Newcastle upon Tyus 


Pp. 183-227; 5 Plates, 8 Text-figures 


BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 
GEOLOGY Vol. 20 No. 5 
LONDON : 1971 


THE BULLETIN OF THE BRITISH MUSEUM 
(NATURAL HISTORY), tnstituted in 1949, 1s 
issued in five series corresponding to the Departments 
of the Museum, and an Historical series. 

Parts will appear at irregular intervals as they become 
ready. Volumes will contain about three or four 
hundred pages, and will not necessarily be completed 
within one calendar year. 

In 1965 a separate supplementary series of longer 
papers was instituted, numbered serially for each 
Department, 

This paper is Vol. 20, No. 5 of the Geological 
(Palaeontological) series. The abbreviated titles of 
periodicals cited follow those of the World List of 
Scientific Periodicals. 


World List abbreviation 
Bull, Br. Mus, nat. Hist. (Geol.). 


© Trustees of the British Museum (Natural History), 1971 


TRUSTEES OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 


Issued 22 June, 1971 Price £2-40 


PALAEOZOIC CORAL FAUNAS FROM 
VENEZUELA, I. SILURIAN AND PERMO- 
CARBONIFEROUS CORALS FROM THE 
MERIDA ANDES 


By C, T. SCRUTTON 


CONTENTS 
Page 
I. INTRODUCTION . : 9 : . C : : : 186 
II. ACKNOWLEDGEMENTS . : 186 
III. PALAEOZOIC STRATIGRAPHY OF THE SOUTHERN MéRtDa Anpes 5 188 
IV. AGES AND RELATIONSHIPS OF THE CORAL FAUNAS j P j 190 
(a) ‘Caparo Formation’ equivalents : ; ; : 6 190 
(i) Caparo II—Lower Llandovery : 5 . . 190 
(ii) Caparo 1V—Ludlow . p : : : : IOI 
(b) Palmarito Formation . : : . : : : 191 
V. SYSTEMATIC DESCRIPTIONS é : : : : 6 : 192 
RuGosa A - : A 3 192 
Family indeieaemides Potta 6 : : j : : 192 
Genus Syvingaxon Lindstrom ° : : 0 : 194 
S. avnoldi sp. nov. . : : : : : 196 
S. suvipaense sp. nov. . 9 : 4 : 197 
Genus Columnaxon nov. ‘ ‘ : : ‘ i 199 
C. angelae sp. nov. . F j : : 199 
Family Lophophyllidiidae Moore & Jeffords : : é 201 
Genus Lophophyllidium Grabau : . : é 201 
L. pelaeum (Jeffords) é : : 0 202 
L. sp. cf. L. wewokanum Jeffords : c c 203 
ihn, 5), : ‘ c ¢ . 204 
Genus Lophamplexus Moore & Jeffords é : 2 205 
ESPs : . : : ; : 205 
Family Streptelasmatidae Nechelson : 0 : : : 206 
Genus Strepielasma Hall. : 0 . 0 0 207 
S. shagami sp. nov. . : j : : ; 208 
S. sp. é c : c - : 0 210 
Genus Leolasma Kaljo : . : : ° . 210 
L. haljoi sp. nov. : ; : : : a 211 
Family Spongophyllidae Dybowski_ . : : 0 : 213 
Genus Cymatelasma Hill & Butler : : : : 213 
C. avicaguaense sp.nov. . c : 6 : 214 
Family Tryplasmatidae Etheridge : ‘ é ¢ . 216 
Genus Tryplasma Lonsdale : : : : : 216 
T. sp. cf. T. norvdica Stumm : : : 6 216 


TSP ae: : c : : . . : 27, 


186 PALAEOZOIC CORAL FAUNAS 


TABULATA . : ‘ : ; : : ¢ : : 218 

Family Coenitidae Sardeson . : : : : c 218 

Genus Coenites Eichwald . : : 3 : : 218 

(Gre  ¢ ‘ : E 5 2 : 2 219 

Family Halysitidae Edwards & Haime ; : : ; 219 

Genus Cystihalysites Chernyshev j : ‘ é 219 

C. brownsportensis (Amsden) : : ; : 220 

Genus Acanthohalysites Hamada : : : : 221 

APES ae é : : : : : : 221 

VI. REFERENCES : c : 5 c : 0 : 5 222 

VII. APPENDIX. LOCATION OF SAMPLES . : ; : : : 226 
SYNOPSIS 


Rugose and tabulate corals of Lower Llandovery, Ludlow and Permo-Carboniferous ages are 
described from localities in the southern part of the Mérida Andes of western Venezuela. The 
Palaeozoic stratigraphy of the area is briefly reviewed and the ages and relationships of the coral 
faunas are discussed. The new taxa Columnaxon angelae gen. et sp. nov., Syvingaxon aynoldt 
sp. nov., S. suvipaense sp. nov., Streptelasma shagami sp. nov., Leolasma kaljoi sp. nov. and 
Cymatelasma aricaguaense sp. nov. as well as species of Lophophyllidium, Lophamplexus, 
Tryplasma, Coenttes, Cystihalysites and Acanthohalysites are described. Observations are made 
on the concepts of some genera and families, particularly Syvingaxon and the Lindstroemiidae. 


I. INTRODUCTION 


THE rugose and tabulate corals described in this paper come from localities in the 
southern part of the Mérida Andes of western Venezuela (Text-fig. 1). The bulk 
of the material was collected by H. C. Arnold (then Compafiia Shell de Venezuela) 
during 1960-61 but additional material from R. Shagam (University of Pennsy]l- 
vania) and G. R. Pierce and W. R. Smith (both Creole Petroleum Corporation) 
has been included. Faunas of three different ages are present; Lower Llandovery, 
Ludlow and Permo-Carboniferous (?Pennsylvanian), the latter two with some 
North American affinities, Sixteen species are described belonging to twelve 
genera; six species and one genus are new. Discounting preliminary reports all 
the genera except Lophophyllidium are recorded for the first time from South 
America. The material is housed in the Department of Palaeontology, British 
Museum (Natural History). 


Il. ACKNOWLEDGEMENTS 


The author is grateful to Professor A. J. Boucot (Oregon State University), 
Dr J. G. Johnson (Oregon State University), Dr R. Shagam (University of Pennsyl- 
vania), Dr H. C. Arnold, Jr (Nederlandse Aardolie Maatschappij) and Dr J. M. 
Bowen (Shell International Petroleum Corporation) for discussion relating to the 
stratigraphy and age of the faunas from the Mérida Andes. Acknowledgement is 
also due to Compajiia Shell de Venezuela and the Creole Petroleum Corporation for 
permission to describe this material which they have presented to the British Museum 
(Natural History). 


FROM THE MERIDA ANDES, VENEZUELA 187 


720° 


Mucuchachi 
y 


(A1030,A1035/ 
Oy, 7 


Portachuelo 


Paso Caparo 


asa? SS ‘i 
eA 7\"}10° 
1583/2" 7 
j \ 
Ft TERS 
\L 
Y N84, 


$2275F Sf% 


$2275A:/ 
515400 S 


VENEZUELA g 
3 


ery 


Fic. 1. Sample locations in the southern Mérida Andes. The area covered by the large 
scale map is indicated in the inset. For further explanation see Appendix. 


188 PALAEOZOIC CORAL FAUNAS 


Dr P. K. Sutherland (University of Oklahoma), and Dr W. J. Sando (United 
States Geological Survey) have kindly read and commented on the systematic 
section of the manuscript. 

R. F. Wise and P. J. Green (both of the British Museum (Natural History)) 
respectively prepared thin sections and photographed material for this paper. 


III. PALAEOZOIC STRATIGRAPHY OF THE SOUTHERN MERIDA ANDES 


A review of the known Palaeozoic stratigraphy of the Mérida Andes was published 
by Cia. Shell de Venezuela & Creole Petroleum Corporation, 1964 (hereafter Shell 
and Creole, 1964). Their particular object was to demonstrate that the Devonian 
age assigned to the Mucuchachi Group by Pierce et al. (1961 : 352) was based on 
faunal misidentifications. The re-examination of the original material and of further 
collections made by H. C. Arnold shew faunas of Middle Ordovician, Silurian and 
Permo-Carboniferous age to be present in beds assigned to this group, but no 


Shell & Creole 1964 Shagam 1968 & MS. 
Arnold 1966 


Central Andes Caparo Central Andes Caporo Caparo 


Permian 


Pennsylvanian 


Mississippian 


Devonian 


c 
o 
° 
> 
3 
o 
° 


Silurian 


‘Caparo Formation’ 


Ordovician 


Fic. 2. Alternative interpretations of the Palaeozoic successions in the Mérida Andes, 
Venezuela. Pal = Palmarito Formation; Sab = Sabaneta Formation; Mu = Muchu- 
chachi Formation. For comments see text. 


FROM THE MERIDA ANDES, VENEZUELA 189 


evidence whatsoever of a Devonian fauna. They also shew that the Caparo For- 
mation, previously considered Middle Ordovician (Schuchert 1935 : 692) and to 
underlie the Mucuchachi Group, contained faunas of Middle Ordovician to Upper 
Silurian age. 

Pierce (1960 : 222; Pierce e¢ al. 1961 : 350, 352) had recognized three formations 
in the Mucuchachi Group, the Remolino Formation, Libertad Formation and Rio 
Momboy Formation in order of increasing age. Shell & Creole (1964 : 76), however, 
claimed that this division, based on erroneous palaeontological information, was 
inapplicable and unrecognizable in the field. They reassigned the Remolino 
Formation and part of the Libertad Formation to the Caparo Formation on field 
and faunal evidence. Thus, in their scheme, all known faunas of Middle Ordovician 
to Upper Silurian age occur in rocks assigned to the Caparo Formation and the only 
faunal evidence remaining for the restructured Mucuchachi Formation occurs 
‘high in the formation’ (Shell & Creole 1964 : 83) and indicates a Permo-Carbonifer- 
ous age. 

Two possible interpretations of the spatial relationships of the Mucuchachi 
Formation were put forward (Text-fig. 2). H.C. Arnold considered the Caparo 
and the lower part of the Mucuchachi Formations to be distinct facies contemporane- 
ously deposited in the same basin, whereas W. R. Smith related the Mucuchachi 
to the younger Palaeozoic sedimentary cycle including the Sabaneta and Palmarito 
Formations. Smith further thought that the older and younger Palaeozoic cycles 
were operative in geographically distinct basins. The latter viewpoint is also held 
by Shagam (pers. comm.) who postulates the lateral equivalence of the Mucuchachi 
and Sabaneta facies. 

Shagam (1968 : 171) reported large limestone blocks containing a fauna of late 
Llandovery age embedded in supposed Wenlock—Ludlow shales in the Caparo 
area. This limestone, which presumably represents a fourth faunal horizon in 
Shell & Creole’s so-called ‘‘Caparo Formation’’, is not yet known in its autochthonous 
situation. Shagam stressed the uncertainty surrounding much of the Lower 
Palaeozoic succession and expressed doubt as to its homogeneity. He postulated 
tectonic episodes between each of the four faunas so far recognized in this strati- 
graphical complex. To avoid the introduction of new stratigraphic units in this 
paper, which is primarily concerned with the coral palaeontology, the four faunal 
horizons in the Lower Palaeozoic rocks of the Caparo area are referred to by the 
roman numerals I (oldest) to IV (see Text-fig. 2). 

In the Upper Palaeozoic sequence, the Palmarito Formation rests conformably 
on the Sabaneta Formation. The terrestrial red beds of the latter have yielded 
spores indicating a possible Permian age for most of the Sabaneta Formation ac- 
cording to Shell & Creole (1964 : 83) and Arnold (1966 : 2371) although the lower 
part may belong to the Carboniferous. The succeeding Palmarito is marine and 
richly fossiliferous but even so, the age of the formation is not precisely fixed. 
The macrofauna was considered by Pierce et al. (1961 : 357) to indicate a Pennsy]l- 
vanian to Permian age, probably early Permian according to Arnold (1966 : 2378). 
Arnold (op. cit.), however, also reported preliminary ostracod identifications from 


190 PALAEOZOIC CORAL FAUNAS 


the Palmarito of Quebrada Queveda as including many species comparable with 
Pennsylvanian ostracods of the U.S.A. In addition, the two corals described here 
from the Palmarito section of Quebrada Queveda both compare best with North 
American Pennsylvanian species. Thus the present faunal and floral evidence 
suggests that the Palmarito marine transgression began in Pennsylvanian times 
and was not completed in the area until the Permian. Clearly however, detailed 
studies of the Upper Palaeozoic sequences and their biota are needed here to deter- 
mine more precisely the relationships of the various sedimentary units, both vertically 
and laterally. 


IV. AGES AND RELATIONSHIPS OF THE CORAL FAUNAS 


Very few systematic descriptions of Palaeozoic corals from South America have 
been published. The only previous work on Venezuelan material known to the 
writer is that of Weisbord (1926 : 224) which was revised by Wells (1943 : 95). 
This is all of Devonian age and will be referred to in more detail in a later paper 
dealing with faunas from the Sierra de Perija4. Other systematic work on South 
American Palaeozoic corals has been published by Douglas (1920: 44), Knod 
(1908 : 561), Kozlowski (1923 : 97), Meyer (1914 : 601, 624) and Thomas (1905 : 
267) but this only amounts to descriptions of about a dozen species. Mostly the 
same corals are also referred to in various fossil lists. 

Almost all the genera and species described here, therefore, are either new or are 
recorded from South America for the first time. Three distinct coral faunas are 
present, two from the‘‘Caparo Formation’’ equivalents of Lower Llandovery (Caparo 
II) and Ludlow (Caparo IV) ages respectively and one from the Palmarito Formation 
of Permo-Carboniferous (? Pennsylvanian) age. 


(a) “Caparo Formation” equivalents. 


(i) Caparo II—Lower Llandovery. A small collection of corals comes from a 
section on the Rio Caparo approximately 900 m downstream from the Paso Caparo, 
the locality 2 of Shell & Creole (1964, tab. 1). Shell & Creole list two faunas from 
this locality, one probably middle Ordovician in age and the other early Llandovery. 
The corals, Streptelasma shagami sp. nov., Leolasma kaljoi sp. nov. and Streptelasma 
sp., are not sufficiently sensitive to indicate an age within these limits. Leolasma, 
it is true, has previously only been recorded from the upper Middle and lower Upper 
Ordovician of the Baltic and China but the range of the genus is felt to be far from 
adequately known. Ordovician and Silurian streptelasmids from North America 
are in need of extensive revision and no useful comparisons can be made there. 
On the other hand, brachiopods from the same samples as the corals are dated 
Lower Llandovery by J. G. Johnson (pers. comm.). 

The corals described here are the Streptelasma spp., identified by H. D. Thomas 
and dated as Ordovician by him, which are listed by Shell & Creole (1964, table 1) 
under locality 2 as probably Ordovician. 


FROM THE MERIDA ANDES, VENEZUELA 191 


(i) Caparo IV—Ludlow. Several of the specimens described here were collected 
from a section on the Rio Aricagua, the locality 7 of Shell & Creole (1964, table 1). 
Again, two faunas are listed, one collected by H. C. Arnold for Shell and dated 
Niagaran and the other collected by Creole and dated late Llandovery to Ludlow. 
Nearly all the corals are in five samples from the very detailed collections made by 
Arnold and appear to represent a single faunal suite. One specimen in the Creole 
collection and three specimens collected by R. Shagam from the same locality can 
be approximately equated with Arnold’s samples (see Appendix) and also clearly 
belong to the same suite. The fauna contains Syringaxon arnold: sp. nov., Column- 
axon angelae gen. et sp. nov., Cymatelasma aricaguaense sp. nov. and Cystthalysites 
brownsportensis (Amsden). The presence of the latter suggests a younger Niagaran 
(Wenlock or early Ludlow) age, but unfortunately the new species are of no assistance 
and the genera are too long ranging to refine this age further. Brachiopods from 
the same samples as the corals indicate either Ludlow or Llandovery to Ludlow 
ages according to J. G. Johnson (pers. comm.). The homogeneity of the coral fauna 
suggests all the samples involved to be closely similar in age and thus a Ludlow 
horizon is indicated. 

The fauna has one species in common with North American Silurian faunas. 
The genus Cymatelasma, however, has only previously been recorded from the 
Silurian of England, and the new genus and species make no contribution to an 
assessment of the faunal affinities. 

A second fauna, also probably of Ludlow age, was collected by R. Shagam from 
a section on the Rio Suripa. The corals are Syringaxon suripaense sp. nov., Tryplasma 
sp. cf. T. nordica Stumm, Tryplasma sp., Coenites sp., Cystihalysites brownsportensis 
and Acanthohalysites sp. Again a Wenlock or early Ludlow age is suggested by 
the presence of C. brownsportensis: Tryplasma nordica is also of Wenlock or Ludlow 
age. J. G. Johnson (pers. comm.) describes brachiopods from the same samples 
as probably Ludlow in age. The corals show some North American affinities but, 
more interestingly, C. brownsportensis is the only species in common between the 
Rio Suripa and Rio Aricagua faunas. This may be the result of small sample 
sizes, ecological variation or a slight difference in age between the two outcrops; 
it is not possible to decide which factor or combination of factors is responsible 
on the available evidence. 


(b) Palmanito Formation. 


Only four specimens from two localities are available from this formation. Two 
samples from the Portachuelo section (Qda. Queveda) yielded Lophophyllidium 
pelaeum (Jeffords) and L. sp. cf. L. wewokanum Jeffords. One sample from the 
Qda. El Meson included Lophophyllidiwm sp. and Lophamplexus sp. L. pelaeum 
and L. wewokanum are both North American species of Pennsylvanian age whilst 
the Lophophyllidium sp. from the Qda. El Meson is most similar to a North American 
species also of Pennsylvanian age. Thus there is some evidence here that the parts 
of the Palmarito Formation represented by these samples is Pennsylvanian rather 
than Lower Permian in age. 


192 PALAEOZOIC CORAL FAUNAS 
V. SYSTEMATIC DESCRIPTIONS 


The terminology used in the following descriptions is that proposed by Smith 
(1945 : 4-9) and Moore, Hill & Wells (1956) unless otherwise indicated. 

The sample number is given in brackets after the British Museum (Natural 
History), Department of Palaeontology registered number for each specimen. 
Sample numbers prefixed ‘A’ are from H. C. Arnold’s collection, ‘S’ from R. Shagam’s 
collection and ‘K’ from the collections of the Creole Petroleum Corporation. All 
available locality details for the samples are given in the Appendix. Comments 
on the locality and horizon of specimens in this section of the paper refer to broad 
units only (i.e. Rio Aricagua section; Silurian, Ludlow) and reference should be 
made to the sample numbers in the Appendix for details. 


Order RUGOSA Edwards & Haime 1850 
Suborder STREPTELASMATINA Wedekind 1927 
Superfamily CYATHAXONIICAE Edwards & Haime 1850 
Family LINDSTROEMIIDAE Poéta 1902 


1902 Lindstroemiidae Poéta : 181. 

1962 Laccophyllidae; Philip : 170. 

1965 Lindstroemiidae; Federowski : 336. 
1965 Amplexocariniidae; Federowski : 350. 
1965 Lindstroemiidae; Kullmann : 63, pars. 
1967b Lindstroemiidae; Pedder : 110. 

1967b Amplexocariniidae; Pedder : 124. 
1968 Laccophyllidae; Goryanov : go. 


TypPE GENUS. Lindstroemia Nicholson & Thomson 1876 : 150. 


DiaGnosis. Small solitary corals. Major septa fused at axis in early ontogeny 
to form a pseudocolumella. In some forms this persists in the mature stages, in 
others the septa are withdrawn to form a perfect or imperfect axial tube by the 
deflection, or by the thickening and lateral contiguity, of their axial ends. Minor 
septa contratingent when present, becoming free in the calice. Minor septa flanking 
counter septum accelerated; the remainder cyclically inserted in late ontogeny. 
Tabulae tent-shaped to box-shaped. Dissepiments developed in a few forms. 


Discussion. The type species of Lindstroemia, L. columnaris Nicholson & 
Thomson (1876 : 150) from the Devonian of North America, is imperfectly known 
and the type material cannot be traced. Nevertheless, as Pedder (1967b : 110) 
remarked, Nicholson & Etheridge (1878, text-figs 4b, 4b’ on p. 84) provided figures 
of the interior of Lindstroenua columnaris which justify the family concept and 
indeed caused Stumm (1949 : 7, 8) to suggest that Lindstroenia might prove to be 
a senior synonym of Stereolasma Simpson (1900 : 205). 

The general characters of the corals assigned to this family have recently been 
discussed by Glinski (1963 : 323, 331), Fedorowski (1965) and Kullmann (1965 : 64 


FROM THE MERIDA ANDES, VENEZUELA 193 


et seq.). Glinski (1963 : 331 et seg.) demonstrated the close relationship of Svringaxon 
to Metriophyllum, bringing these two genera together in the same family but dis- 
tinguishing them at the subfamily level by the development of horizontal carinae 
in the Metriophyllinae. Pedder (1967b: 110), however, suggested that these 
carinae evolved independently in different lineages. 

Fedorowski (1965 : 336, 342) recognized the subfamilies Metriophyllinae and 
Syringaxoninae based mainly on differences in the ontogeny of the aulos in those 
genera possessing one. He claimed that members of the Syringaxoninae form the 
earliest stages of the axial tube by the deflection of the axial ends of the major 
septa, as opposed to a slight withdrawal of the septa from the axis, without de- 
flection, which produces the aulos in the Metriophyllinae. This account was ap- 
parently based in part on the ontogeny of specimens of Syringaxon bohemica bohemica 
(Barrande) from Poland. In the only other member of the Syringaxoninae des- 
cribed by Fedorowski (1965 : 344), Stewartophyllum polonicum (Sobolew), the 
ontogeny illustrated does not show a stage in which the aulos is formed by deflected 
septal ends, although he mentions other material belonging to this species which 
does. The writer has examined the sections cut by Butler to describe the ontogeny 
of Syringaxon siluriense (Butler 1935 : 120) and these also show no sign of such a 
stage in the development of the aulos. 

The writer believes that the precise form of the axial ends of the septa in these 
corals is largely a function of aulos diameter, septal number and thickness and 
possibly the amount of sclerenchyme available to coat the axial structure. Septa 
remain straight throughout ontogeny in those corals where increase in aulos size 
is accompanied by a concomitant increase in the thickness of the septal ends as 
is shown by Syrvingaxon siluriense (BM(NH) R25891, R29444, R30165) and the 
specimen of Stewartophyllum polonicum figured by Fedorowski (1965, fig. 1D). 
In corals where increasing size of the axial structure is not matched by septal 
thickening, a tube is formed by deflecting the septal ends, as in the early stages 
of Syringaxon bohemica bohemica as figured by Fedorowski and such corals as 
‘Barrandeophyllum’ perplexum Poéta (see Prantl 1938, pl. 3, fig. 16). Interpreted 
thus, no great significance is attached to the presence or absence of septal deflection 
in the construction of the aulos in the Lindstroemiidae. 

Kullmann (1965 : 64) accepted Glinski’s subfamilial division and diagnosed 
the Lindstroemiinae as exhibiting both cyclic and serial insertion of minor septa: he 
including the genus Petraia Miinster in the subfamily. This he based on a re- 
appraisal of the septal insertion in Syvingaxon as illustrated by S. siluriense and 
two new species, S. pinguis and S. postsiluriense. The minor septa flanking the 
counter septum are inserted early in ontogeny, after the insertion of 14 major 
septa in S. siluriense (Butler 1935 : 121) and after 10 major septa in S. pinguis 
(Kullmann 1965, fig. 5). In the former, the rest of the minor septa are inserted 
in a normal cyclic manner when the number of major septa has reached 18, the 
average mature septal number in the species being about 20. Similarly, in S. 
pinguis, there are 14 major septa present before the rest of the minor septa are 
inserted more or less simultaneously, this being the average septal number in 


194 PALAEOZOIC CORAL FAUNAS 


maturity. Butler (1935 : 122) regarded this basically as cyclic insertion of the 
minor septa, noting the early insertion of the two counter lateral minors and pointing 
out its occurrence in some other unrelated corals. Kullmann (1965 : 67) on the 
other hand, claimed that the situation in Syvingaxon was homologous with that in 
Petvaia in which minor septa are inserted serially with the metasepta from the 
earliest ontogenetic stages. The writer feels that Kullmann has considerably 
overstressed the significance of the early insertion of the counter lateral minor 
septa and that Butler’s interpretation is the more reasonable. Petraia is excluded 
from the family Lindstroemiidae here. 

Pedder’s (1967b : 110) understanding of the Lindstroemiidae is essentially that 
accepted here. Fedorowski’s (1965 : 350) removal of Amplexocarinia Soshkina 
to a new family, the Amplexocariniidae (followed by Pedder 1967b : 124), has been 
noted but the structure of the type species, A. muralis Soshkina, has yet to be 
clearly demonstrated. Otherwise both septa and tabulae appear to be involved 
in the formation of the aulos in species of Amplexocarinia, very like the development 
of this structure in such species as Syvingaxon memorabilis Prantl (1938 : 30, pl. I, 
figs 7, 8; pl. 2, figs 11, 12). Prantl described the aulos in S. memorabilis as formed 
by the bending of the axial ends of the major septa with only slight thickening, 
and unless the figure is misleading (pl. 3, fig. 11), the tabulae are developed with 
striking similarity to those illustrated in A. tortwosa by Fedorowski (1965, pl. 4, 
fig. 6). Amplexocarimia is retained in the Lindstroemiidae here. 


Genus SYRINGAXON Lindstrom 1882 


1882 Syvingaxon Lindstrom : 20. 

1900 Laccophyllum Simpson : 201. 
1902 Nicholsonia Pocta : 184. 

1902 Barrandeophyllum Poéta : 190. 
1902 Alleymia Pocta : [vi]. 

1928 Laccophyllum; Grabau : 82. 
1928 Alleynia; Grabau : 84. 

1928 Barrandeophyllum; Grabau : 87. 
1935 Syvingaxon; Butler : 117. 

1938 Syrvingaxon; Prantl : 21. 

1938 Barrandeophyllum; Prantl : 34. 
1945 Syvingaxon; Smith : 58. 

1949 Syvingaxon; Stumm : Io. 

1949 Barrandeophyllum; Stumm : 10. 
1951 Syvingaxon; Schouppé : 207. 
1954 Syvingaxon; Schouppé : 395. 
1956 Syvingaxon; Fligel : 33. 

1962 Syrvingaxon; Fliigel & Free : 224. 
1963 Syvingaxon; Glinski : 331. 

1965 Syvingaxon; Sutherland : 34. 
1965 Syvingaxon; Fedorowski : 343. 
1965 Syvingavon; Kullmann : 65. 
1965 Barvandeophyllum; Kullmann : 87. 
1968 Syvingaxon; Goryanoy : OI. 
1968 Bavrandeophyllum; Goryanovy : 96. 


FROM THE MERIDA ANDES, VENEZUELA 195 


TYPE SPECIES. Cyathaxonia siluriensis M’Coy 1850: 281; 1851 : 36, pl. IC, 
figs 11, 11a. High Bannisdale Slates or lowermost Kirkby Moor Flags (wde R. B. 
Rickards), Silurian, Ludlow, Je:ntwardinensis zone; Underbarrow, near Kendal, 
Westmorland (see Pl. 1, fig. 6). 


Diacnosis. Small simple, conical or cylindrical corals. A more or less perfect 
axial tube is formed in the late neanic and ephebic stages by the thickening and 
lateral contiguity or sideways deflection of the axial ends of the major septa. Minor 
septa usually developed, contratingent becoming free in the calice. No horizontal 
carinae but peripheral septal nodes present in some species. Tabulae horizontal 
in the axial tube and steeply sloping downwards to the periphery outside it; no 
dissepiments. 


Discussion. Recent interpretations of Syvingaxon have been based on Butler’s 
(1935) paper in which he described in detail material he assigned to the type species, 
S. siluriense. Sutherland (1970) has now redescribed the holotype of S. siluriense 
(figured here on Pl. 1, fig. 6) which is clearly congeneric and almost certainly con- 
specific with Butler’s material. Butler (1935 : 118) thought that both Laccophyllum 
Simpson and Alleynia Poctta appeared to be synonyms of Syvingaxon but he did 
not finally commit himself. Subsequently Prantl (1938: 21) advocated the 
synonymy of Alleynia with Syringaxon on the basis of a comparison of the septal 
development in the two type species and Smith (1945 : 58, pl. 1, fig. 18) figured a 
syntype of Laccophyllum acuminatum, the type species of Laccophyllum, which is 
undoubtedly congeneric with Syvingaxon siluriense. 

Opinions have differed on the relationship between Syvingaxon and Barrandeo- 
phyllum. Prantl (1938 : 34) reviewed earlier concepts of Barrandeophyllum and 
himself considered it worthy of generic status, distinguished from Syvingaxon by 
the irregularity of its aulos, usually elliptical in section, by a sparing development 
of dissepiments and limited additional sclerenchyme. Prantl’s dissepiments are 
actually the peripheral tabulae. Stumm (1949: 10), Hill (1956 : 258) and Kull- 
mann (1965 : 87) also consider the two genera distinct essentially on the same 
grounds. In addition, Stumm refers to a tendency in Barrandeophyllum for the 
diameter of the aulos to increase more rapidly with growth whilst Kullmann men- 
tions the larger size and septal number and more numerous tabulae usually found 
in species of Barrandeophyllum. 

Weissermel (1939 : 356; 1941 : 170), Schouppé (1951 : 207; 1954 : 396) and 
Fligel (1956 : 33) have all favoured a subgeneric relationship. Schouppé claimed 
the presence of ‘dissepimental interconnexions’ between the septa in Barrandeo- 
phyllum as taxonomically significant but Fligel & Free (1962 : 231) quite rightly 
point out that these are merely sections of tabulae which tend to be more numerous 
in species assigned to Barrandeophyllum than in those assigned to Syringaxon. 

Only Wang (1950: 204) and Fltgel & Free (1962 : 224 e¢ seq.) have placed 
Barrandeophyllum in synonymy with Syringaxon. Fligel & Free expressed reser- 
vations, however, and recorded (1962 : 231, footnote 2) an apparent difference 
between the septal microstructure developed in a specimen of B. bohemicum and 


196 PALAEOZOIC CORAL FAUNAS 


that in their species of Syringaxon. This is considered here in all probability to be 
due to the effects of recrystallization in the latter material. 

Thus all characters that have been quoted as distinguishing Barrandeophyllum 
from Syringaxon have either been misinterpreted or are of a quantitative nature. 
There appears to be no basic structural divergence to warrant separation at the 
generic level. Differences in size, growth-form and degree of perfection in the 
formation of the aulos are here considered to be of specific significance only and 
Barrandeophyllum is therefore placed in synonymy with Syringaxon. 


Syringaxon arnoldi sp. nov. 
(Pl. 1, figs 1-5; Text-fig. 3) 


DERIVATION OF NAME. After the collector, Dr H. C. Arnold, Jr of Nederlandse 
Aardolie Maatschappij. 


DiAGNosis. Syringaxon, 4:1 to 5: mm diameter with 15 to 18 major septa at 
base of calice. Minor septa contratingent; counter-lateral minor septa equal in 
length to counter septum, others half radius in length. Aulos wide but with narrow 
axial tube largely infilled in pre-ephebic stages. Tabulae sparse within aulos and 
rare outside it. 


HoLotyrPe. R 46740 (A2558). Rio Aricagua section; Silurian, Ludlow. 


PARATYPES. R46741-2 (A2561), R46743-4 (A2582), R46745 (K162950). Same 
locality and horizon as holotype. 

DESCRIPTION. Small, conico-cylindrical corals up to 6 mm in diameter and 
ro mm in length. Epitheca with strong inter-septal ridges. 

In cross-section, uncrushed corals are circular with a longitudinally corrugated 
epitheca and a peripheral stereozone 0-3 to 0-¢ mm thick. At the base of the 
calice, the major septa extend almost to the axis where their thickened, club shaped 
ends are more or less laterally contiguous and invested in sclerenchyme to form a 
regular, thick walled aulos 1-4 to 1-7 mm in diameter. There is no deflection of the 
septal ends in the aulos which has a maximum internal diameter of 0-8 mm. The 
major septa are waisted between the aulos and the outer wall, thinning to 0-15 mm 
or less across with the cardinal septum almost invariably thinner than the other 
major septa. The minor septa are contratingent and usually reach half the coral 
radius in length: the counter-lateral minor septa are equal in length to the counter 
septum, 

Above the calice base, the aulos degenerates first on the cardinal side and lastly 
on the counter side. The major septa begin to withdraw peripherally and the 
minor septa become free at their axial ends 0-5 mm above the first breach in the 
aulos: 2 mm above the base of the calice, the septa are reduced to ridges up to 
0-5 mm in length and virtually inseparable into major and minor series. 

In longitudinal section, the aulos is largely infilled in pre-ephebic stages, leaving 
scattered axial bowl or funnel shaped voids capped by shallowly depressed tabulae 


FROM THE MERIDA ANDES, VENEZUELA 197 


in the neanic stage. Between the aulos and the peripheral stereozone, one tabula 
sloping axially and upwards was seen in the region of the counter septum in the 
holotype (Pl. 1, fig. 2). On the cardinal side, three arched plates are present at 
the periphery but their form towards the aulos is obscured by septa in the plane of 
section. Signs of tabulae are extremely rare in the paratypes. 

At the base of the calice, the corals vary in diameter between 4:1 and 5:I mm 
with 15 to 18 major septa. Septal ratios vary between 3:3 and 3-7. The measure- 
ments are plotted in Text-fig. 3. 


20 


d (mm) 


Fic. 3. Number of major septa plotted against diameter for specimens of Syvingaxon 
ayvnoldi. The holotype is indicated by an asterisk. The dashed lines join points repre- 
senting different sections of the same specimen. 


Discussion. Syringaxon arnoldi is easily distinguished from the North American 
species S. acuminatum (Simpson) by the much larger thin walled aulos, thin septa 
and well developed tabulae in the latter. S. adaense Sutherland (1965 : 34) from 
the Henryhouse Formation of Oklahoma is also clearly distinct, through its extremely 
short minor septa in particular. Syringaxon arnoldi resembles most closely the 
German Eifelian species S. wedekindi Glinski (1963 : 331, fig. 5) although it is 
difficult from the cursory description and drawing to make a proper comparison. 
S. wedekindi apparently has a septal ratio of 2-7, considerably less than that for 
S. arnoldi, and the detailed septal shape, with a strong peripheral expansion, is 
distinctive. 


Syringaxon suripaense sp. nov. 
(Pl. 1, figs 7, 8; Text-fig. 4c) 


DERIVATION OF NAME. After the type locality on the Rio Suripa. 


DiaGnosis. Syringaxon, 5:0 to 5-7 mm in diameter with 18 to 1g major septa 
at base of calice. Minor septa contratingent; counter-lateral minor septa equal 


198 PALAEOZOIC CORAL FAUNAS 


counter septum, others half radius or slightly more in length. Nodes present on 
major and minor septa close to periphery. Aulos medium to thin walled, may be 
irregular in shape. 


HoLotyPe. R46746 (S2275D). Rio Suripa section; Silurian, Ludlow. 
PARATYPE. R46747 (S2275D). Same locality and horizon as holotype. 


DEscrIPTION. Two fragments of small solitary corals embedded in grey mud- 
stone. External shape unknown. 

In cross-section, the corals are subcircular with a strongly longitudinally corru- 
gated epitheca reflecting pronounced interseptal ridges. The peripheral stereozone 
is 0-2 mm thick. The major septa are thin, about 0-15 mm across, and reach 
within a short distance of the axis at the base of the calice. The axial ends of the 
septa have a pronounced club-shaped thickening bringing them into lateral contact 
to form a medium to thin walled aulos. There is little additional material reinforcing 
the structure. The aulos may be regular or irregular in shape and has an internal 
diameter of about 0-8 mm. The minor septa are the same thickness as the major 
septa and contratingent with them. They may reach 0-6 of the radius in length 
except for the counter-lateral minor septa which are equal in length to the counter 
septum. Both major and minor septa develop irregular rounded or sharp edged 
nodes (Knoten of Kullmann 1965), 0-5 mm from the epitheca, which may double 
or treble the normal septal thickness. The nodes partially close the space between 
adjacent major septa to produce a keyhole appearance at the peripheral end of the 
gap (see particularly Pl. 1, fig. 7 and Text-fig. 4c). 

No longitudinal sections of the species are available. Signs of tabulae between 
the major septa in cross-section are extremely rare although sections of horizontal 
elements appear more commonly between the major septa and their contratingent 
minors. 

Coral diameters at the base of the calice are 5-o mm with 18 major septa and 
5:7 mm with 19 major septa. Septal ratios are 2-8 and 3:0. 


| 


a Cc 

Fic. 4. The development of septal nodes in species of Syvingaxon; a. S. cantabricum, 
b. S. parvum, c. S. suripaense. Figs 4a and 4b after Kullmann (1965, text-figs 7d, e). 
All x 8. 


FROM THE MERIDA ANDES, VENEZUELA 199 


Discussion. The development of septal nodes distinguishes S. suripaense from 
all syringaxoniids but two species assigned to Barrandeophyllum by Kullmann 
(1965 : 88, 91), B. cantabricum and B. parvum from the Emsian of North Spain 
(see Text-fig. 4). B. cantabricum, however, is a much larger species, reaching 13 mm 
in diameter. The septal nodes take a slightly different form from those of the 
Venezuelan material and the counter-lateral minor septa are significantly shorter 
than the counter septum. B. parvum, on the other hand, is more similar to S. 
surtpaense although somewhat smaller and distinguished by a very small aulos. 


Genus COLUMNAXON nov. 


DERIVATION OF NAME. Descriptive of the axial columella characteristic of the 
genus. 

Diacnosis. Very small, simple, conico-cylindrical corals. Aulos present in 
early ontogeny. In ephebic stage, counter septum forms a columella against 
which other major septa abut to form a solid axial column. In the calice, major 
septa withdraw, the counter septum last, to leave a free columella. Minor septa 
contratingent at calice base, free in calice; counter-laterals accelerated. Tabulae 
simple, sloping down from axial structure to periphery and flat within aulos of 
early ontogeny. 


TYPE SPECIES. Columnaxon angelae sp. nov. 


Discussion. Columnaxon is essentially Syringaxon in which, in the ephebic 
stage, the counter septum grows into the aulos and dilates to close the axial tube. 
This columella formed by the counter septum persists into the calice and becomes 
isolated by the withdrawal of the major septa, finally severing contact with the 
counter septum to form a free standing boss or spine. 

This structural modification of Syvingaxon is interesting as the result is strongly 
homoeomorphic with the Carboniferous genus Cyathaxonia. The columella in 
Cyathaxonia, however, is formed independently of the major septa and not as a 
dilation of the axial end of the counter septum as in Columnaxon. Also, minor 
septa in Cyathaxonia are inserted alternately with the major septa. In Columnaxon 
the septal insertion is not known but is thought to be the same as in Syvingaxon 
which is, with the exception of the accelerated counter-lateral minors, cyclic. 
Columnaxon also shows a gross homoeomorphy with Lophophyllidium. The latter 
genus, however, lacks the strongly accelerated counter-lateral minor septa of 
Columnaxon and possesses a weak cardinal septum in a distinct fossula. 


Columnaxon angelae sp. nov. 
(Pl. 1, figs 9-12; Text-fig. 5) 


DiaGnosis. Coluwmnaxon g mm long, 5:5 mm maximum diameter with 16 major 
septa. 


200 PALAEOZOIC CORAL FAUNAS 


HoLotyPe. R46748 (A2579). Rio Aricagua section; Silurian, Ludlow. 


ADDITIONAL MATERIAL. R46749 (SC1), R46750 (S1302). Same locality and 
horizon as holotype. 


DESCRIPTION. Small, straight, conico-cylindrical coral, 9g mm long and 5:5 mm 
maximum diameter. There are 16 major septa. 

In cross-section, the coral is circular with a longitudinally corrugated epitheca 
reflecting strong interseptal ridges. A peripheral stereozone 0-5 mm thick is 
developed. Midway to the axis, the counter and cardinal septa are about o-I mm 
thick and the other major septa about 0-2 mm thick. The septa expand gradually 
towards the periphery. In the sub-calicular sections, all major septa except the 
counter reach 0:85 of the radius in length. Their axial ends are dilated and in 
lateral contact, forming, with a little additional sclerenchyme, a strong periaxial 
wall. The counter septum, however, extends through the wall to the axis with a 
considerably expanded, club shaped end about 0-5 mm across which more or less 
completely blocks the axial tube (see Text-fig. 5g). Evidence from the longitudinal 
section suggests that in early ontogeny a more normal aulos may be present and that 
the counter septum does not grow into the axis until the late neanic or early ephebic 
stage (see PI. i, fig. 9). 

In the sub-calicular section the minor septa are about half the radius in length 
and contratingent. The counter-lateral minors, however, are very nearly as long, 
three-quarters of the radius, as the major septa (excepting the counter), although 
notably thinner. 

At the base of the calice, the major septa withdraw from the axis first in the 
cardinal area and last in the counter area (Text-fig. 5). Minor septa also become 
free standing first adjacent to the cardinal septum and progressively later towards 
the counter. The counter-lateral minor septa are an exception and detach from the 
counter at about the same level as the minor septa in the alar area become free. 


Fic. 5. Late stage development in the holotype of Columnaxon angelae. Spacing of 
cross-sections: a (R46748a)—o-6 mm—b (R46748b)—o-6 mm—c (R46748c)—o-6 mm— 
d (R46748d)—1-2 mm—e (R46748f)—1-8 mm—f (R46758i)—1-2 mm—g (R46748k). 
ANU S< dle 


FROM THE MERIDA ANDES, VENEZUELA 201 


The counter septum becomes uniformly thin from the periphery to the sharply 
defined quadrate columella slightly elongated in the counter-cardinal plane and 
0-75 X 0-6 mm in section. Finally, the counter septum withdraws very rapidly 
leaving the columella, now 0-7 X 0:5 mm, isolated in the axis. It is not known 
how much higher in the calice the columella extends. 

In the longitudinal section (PI. 1, fig. 9), the axial column is solid and about 1-6 mm 
wide in the distal (late neanic—early ephebic) 0-7 mm. Below this, however, a 
bowl-shaped void is capped by a flat, slightly inclined tabula indicating that an 
aulos is open at this stage of ontogeny. The column decreases in width proximally 
and a very fine axial canal, in which traces of tabulae can be seen, is present in the 
lower I-5 mm preserved: the tip of the coral has been eroded. The interseptal 
spaces outside the axial structure appear to be poorly partitioned. Traces of two, 
or possibly three tabulae are visible on the counter side, concave up peripherally 
and apparently directed axially and upwards to the core, although towards the 
centre a septum in the plane of section obscures them. 


Discussion. This description is based on the holotype alone as the two other 
specimens of Columnaxon available cannot be confidently assigned to the same 
species. R46749, 3-8 mm in diameter with 15 major septa, may represent a slightly 
earlier ontogenetic stage than any seen in the holotype with the aulos only partially 
infilled by the counter septum. It has, however, rather distinctive axial thickening 
of the major septa. R46750, on the other hand, is a calicular section 3-7 mm in 
diameter with 14 major septa. It has a thin (0-2-0-25 mm) peripheral stereozone 
which is highly crenulate and a very elongate columella I x 0:3 mm in section. 
The holotype at a comparable stage of development is 5-3 mm in diameter with 
16 major septa. These may be variants of the same species or taxonomically 
distinct and a decision is best left until additional material allows specific variation 
to be assessed. 


Family LOPHOPHYLLIDIIDAE Moore & Jeffords 1945 
Genus LOPHOPHYLLIDIUM Grabau 1928 


1928 Lophophyllidium Grabau : 98. 

1928 Sinophyllum Grabau : 99. 

1941 Lophophyllidium; Moore & Jeffords : 78. 
1942 Lophophyllidium; Jeffords : 211. 

1945 Lophophyllidium; Moore & Jeffords : 93. 
1947 Lophophyllidium; Jeffords : 15, 21. 

1947 Stereostylus Jeffords : 16, 38. 

1953 Lophophylliidium; Formichev : 180. 

1953 Agarikophyllum Formichev : 196. 

1955 Lophophyllidium; Minato : 151. 

1961 Lophophyllidium; Fontaine : 77. 

1961 Sinophyllum; Fontaine : 79. 

1961 Khmerophyllum Fontaine : 81. 

1961 Stereostylus; Fontaine : 83. 

1962 Lophophylidium; Ross & Ross : 1181. 


202 PALAEOZOIC CORAL FAUNAS 


1962 Steveostylus; Ross & Ross : 1185. 
1964 Lophophyllidium; Rowett & Sutherland : 25. 
1966 Steveostylus; Bebout : ft. 


TYPE SPECIES (original designation). Cyathaxonia prolifera McChesney 1860 : 75 
and 1865, pl. 2, figs 1-3. Upper Pennsylvanian, 8 miles south of Springfield, 
Illinois, U.S.A. 


Diacnosis. Solitary corals possessing a columella formed by the expansion of 
the axial end of the counter septum from which it may separate in the ephebic 
stage. Major septa except cardinal long and usually rhopaloid. Tabulae tent- 
shaped; no dissepiments. 


Discussion. The lophophyllidid corals were extensively reviewed by Moore 
& Jeffords (1941, 1945) and Jeffords (1942, 1947). The writer follows Duncan 
(1962 : 65) and Rowett & Sutherland (1964 : 25) in considering slight structural 
differences in the columella and the degree of thickening of the skeletal elements 
in these corals not to be of generic significance. Thus, in agreement with them, 
Stereostylus is placed in synonymy with Lophophyllidium. The subgenus Agariko- 
phyllum Formichev (1963) and the genus Khmerophyllum Fontaine (1961) have also 
been erected on supposedly significant modifications of columella structure. In 
both cases, however, generic differentiation from Lophophyllidium is thought not 
to be warranted. 

Lophophylliidium has been recorded several times previously from South America 
—from the Permian of Bolivia (see Ahlfeld & BraniSa 1960 : 100) and from the 
Carboniferous of Peru by Douglas (1920: 44). It has unfortunately not proved 
possible to compare the present material with these earlier records. 


Lophophyllidium pelaeum (Jeffords 1947) 
(Pl. 1, figs 13-15) 


1947 Steveostylus pelaeus Jeffords : 48, fig. 7, pl. 16, figs 1-8, pl. 20, figs 1 and 7. 
1966 Steveostylus byushensis Bebout : 3, pl. 2, figs 1-3. 


MATERIAL. R46751 (Az1030). Qda. Queveda section; Permo-Carboniferous 
(? Pennsylvanian). 


DESCRIPTION. Small conical coral, outer form uncertain but epitheca with 
strong septal grooves. 

In the late neanic stage, the peripheral stereozone averages 0-5 mm thick. The 
major septa are slim, 0-2—0-25 mm across at their narrowest, and usually very slightly 
rhopaloid, their axial ends fused about two prominent alar fossulae (Pl. 1, fig. 13). 
The counter septum is not clearly distinguished but comparable in length with 
adjacent septa. The cardinal septum is slightly shorter than its adjacent septa 
but no pronounced cardinal fossula is present. In septal formula is C3A10KQA4C 
at a diameter of Io mm. Minor septa may be present as rudimentary swellings 
between some of the major septa. Tabulae are intercepted quite frequently. 


FROM THE MERIDA ANDES, VENEZUELA 203 


In the ephebic stage (Pl. 1, fig. 14), the peripheral stereozone is thinner, 0-3- 
o-5 mm thick. All septa except the counter are variably withdrawn from the 
axis. The cardinal septum is very short, 1-5 mm in length, tapering to a point in 
a narrow, key-hole shaped cardinal fossula. Other major septa are 0-15 mm thick, 
weakly rhopaloid and vary in length between two-thirds and almost the full radius. 
The counter septum extends to the axis with a rhopaloid end, no clear cut column 
being formed. The septal formula is not clear; there are 31 major septa at a mean 
diameter of 12 mm. Minor septa are developed only in the counter quadrants, 
increasing in length towards the counter septum. Only one tabula is cut in this 
section and shows strong axial displacement in the cardinal fossula. 

The longitudinal section is cut slightly off centre and septa obscure some of the 
details. The tabulae are thin, largely complete, well spaced and slope steeply 
axially and upwards in the peripheral areas. 


Discussion. The Venezuelan specimen agrees very closely with Stereostylus 
pelaeus Jeffords from the Missourian (Upper Pennsylvanian) of Oklahoma and 
Kansas. S. brushensis Bebout is slightly smaller than S. pelaeus but otherwise 
does not appear to differ significantly from that species. S. bruhsensis is recorded 
from the Conemaugh of Ohio which is correlated with the Missourian of the mid- 
continental U.S.A. 


Lophophyllidium sp. cf. L. wewokanum Jeffords 1947 
(Pl. 1, figs 16-18) 


ef. 1947 Lophophyllidium wewokanum Jeffords : 24, figs 5, 6; pl. 4, figs 4-7; pl. 7, fig. 5; 
pl. ro, figs 4-5; pl. 11, fig. 3. 

?cef. 1947 Lophophyllidium plummeri Jeffords : 33, figs 1, 5-6; pl. 5, fig. 4; pl. 7, figs 2, 6, 7; 
pl. 10, figs 2, 3; pl. 11, figs I, 2, 5, 6. 


MATERIAL. R46752 (Ar035). Oda. Queveda section; Permo-Carboniferous 
(? Pennsylvanian). 


DESCRIPTION. Conical coral of 15 mm maximum mean diameter with strong 
septal grooves. 

The peripheral stereozone is largely beekitized but about 0-8 mm thick. In 
the section immediately below the calice (Pl. 1, fig. 18), the septa are moderately 
thick, 0-3-0-4 mm across at their mid point, expanding slightly to the periphery 
and rhopaloid. Apart from the cardinal septum, the major septa are slightly 
variable in length around o-7 of the radius. The counter, counter-lateral and alar 
septa may just touch the columella which is large, oval to quadrate and measures 
2°6 x 2:4 in cross-section. There is a discontinuity between the counter septum 
and the columella. The cardinal septum is very short, less than half the radius, in 
a quadrate fossula formed by the slightly pinnate arrangement of the cardinal 
quadrant septa. The septal formula is C5A7K7A4C at a diameter of 12 mm. 
Minor septa are not apparently developed at this level. Tabulae appear widely 


204 PALAEOZOIC CORAL FAUNAS 


spaced, regularly concentric except in the cardinal fossula where they are displaced 
axially. The microstructure is obscure, many septa showing a chevron pattern 
which is probably the result of recrystallization. 

In the base of the calice, the columella is oval and smaller, 2-6 x 2:1 mm, with 
its long axis in the counter-cardinal plane. Its reduction in size is continued quite 
rapidly as at a low level in the calice, with the major septa still two-thirds the radius 
in length and with the counter septum still abutting the columella, its dimensions 
are 2°5 X 1:75 mm (PI. 1, fig. 16). Minor septa begin to appear at the base of the 
calice but remain as little more than low ridges. The cardinal septum shortens 
and projects only 1 mm from the wall in the base of the calice. The number of 
major septa increases from 27 at a diameter of 12 mm just below the calice to 29 at 
a mean diameter of 13:5 mm in the calice itself. 

The longitudinal section is dominated by the broad axial columella. The tabulae 
are thin, mostly complete, generally flat and steeply sloping axially and upwards 
towards the columella, flattening out in the axial area. They are often crested 
in part by septal material. On the cardinal side, what appear to be growth-lines 
in a septum partly in the plane of section are broadly trough shaped between the 
periphery and columella. 


Discussion. The Venezuelan specimen has features in common with Lopho- 
phyllidium wewokanum Jeffords from the Desmoinesian of Oklahoma and Lopho- 
phyllidium plummeri Jeffords from the Virgilian of Texas. In fact, it would appear 
that Jeffords (1947 : 34) only distinguished these two species on the basis of their 
stratigraphical separation and a purely morphological distinction between them 
would be very difficult to maintain. The present specimen differs from them in a 
number of small points such as the quadrate cardinal fossula, the diminution of the 
columella in the lower calice whilst still contiguous with the counter septum and the 
weaker minor septa. Both L. wewokanum and L. plummeri have triangular fossulae 
and large isolated columellae in the lower calice, and L. plummeri has quite well 
developed minor septa. 


Lophophyllidium sp. 
(Plz, fies 2, 2) 


MATERIAL. R46753 (A2722). Oda. El Mesén section. Permo-Carboniferous 
(2? Pennsylvanian). 


DESCRIPTION. Corallite shape is unknown but the epitheca develops shallow 
septal grooves. 

At the base of the calice (PI. 2, fig. 1), the peripheral stereozone is 0-4 mm thick. 
The major septa are slim, expanding slightly towards the periphery and weakly 
thopaloid. They are withdrawn from the axis, the alars about 0-6 of the radius 
in length, and the other major septa shorter and slightly variable in length. The 
cardinal septum and the two flanking major septa are very short with tapering 
axial ends leaving a rather wide cardinal fossula. The counter septum extends 


FROM THE MERIDA ANDES, VENEZUELA 205 


towards the axis with a slim spindle shaped dilatation. The thin axial end then 
joins the columella at one side and appears to be partly wrapped round it. The 
columella is slim and oval, 2:3 x I-2 mm in section, elongated in the counter- 
cardinal plane. The septal formula is C6A7K7A7C at a diameter of 12mm. Minor 
septa are very short and thorn-like. The tabulae appear widely spaced. 

A section in the calice, with 32 major septa at a diameter of 13 mm, shows a 
strong isolated columella 2:2 x 0-9 mm in section with the major septa, including the 
counter, smoothly tapered and half the radius or slightly less in length. The 
cardinal septum is reduced to one-fifth the radius with the two flanking major 
septa slightly longer. The minor septa are short but evenly developed. 

No longitudinal section is available. 


Discussion. This specimen compares most closely with Lophophyllidium 
elongatum Jeffords (1942 : 234, pl. 4, figs 1-3) from the Missourian (Upper Pennsyl- 
vanian) of Oklahoma. There seem to be too many distinctions in detail, however, 
for the Venezuelan specimen to be assigned to this species. L. elongatum varies 
between 10-3 and 19 mm in diameter with 28 to 30 major septa accelerated in 
the counter quadrants, with very long major septa in the base of the calice and a 
narrow triangular fossula. The specimen described here has a higher septal ratio 
and lacks the acceleration of the counter quadrant normally so characteristic of 
the lophophyllidiids. Also, the major septa are shorter than in L. elongatum and 
the two septa flanking the cardinal septum are noticeably reduced in length. 


Genus LOPHAMPLEXUS Moore & Jeffords 1941 


1941 Lophamplexus Moore & Jeffords : go. 
1945 Lophamplexus; Moore & Jeffords : 120. 
1947 Lophamplexus; Jeffords : 62. 


TYPE SPECIES (original designation). Lophamplexus eliast Moore & Jeffords 
1941 : oI, pl. 3, figs 2, 3; pl. 8, fig. 1. Lower Permian (Wolfcampian); Grand 
Summit, Cowley County, Kansas, U.S.A. 

Dracnosis. Solitary corals, possessing a columella formed by the expansion 
of the axial end of the counter septum in early stages, which becomes discontinuous 
or is lacking in maturity. Major septa much shortened and cardinal fossula in- 
distinct in mature stages. Minor septa may be weakly developed. Tabulae 
simple tent-shaped or flat-topped domes; no dissepiments. 


Discussion. Lophamplexus does not appear to have been recorded before outside 
North America where it is known from the Pennsylvanian and Lower Permian. 


Lophamplexus sp. 
(Pl. 2, figs 3-6) 


MATERIAL. R46754 (A2722). Qda. El Meson section. Permo-Carboniferous 
(? Pennsylvanian). 


206 PALAEOZOIC CORAL FAUNAS 


DESCRIPTION. Slim, conical coral with very weak septal grooves. 

In the late neanic stage (Pl. 2, fig. 3), the major septa are slim and taper gently 
to meet at the axis in the counter quadrants, with the counter septum itself slightly 
rhopaloid. In the cardinal quadrants, the septa are variably withdrawn from the 
axis leaving a large cardinal fossula in which the cardinal septum is slightly longer 
than the flanking septa. The tabulae appear quite closely spaced. The diameter 
is about 9 mm with 27 major septa. 

In the early ephebic stage (Pl. 2, fig. 4), the peripheral stereozone is 0-4-0-5 mm 
thick. The major septa are very variable in length, between one-third and two- 
thirds the radius. The counter septum, however, extends to the axis and is weakly 
rhopaloid. The cardinal septum which is half the radius in length is flanked by 
very short major septa. Traces of minor septa are present between most major 
septa and are particularly well developed either side of the cardinalseptum. Tabulae 
appear closely spaced at the periphery but leave a clear axial area. The diameter 
is 10 mm with 27 major septa. 

In higher sections (Pl. 2, fig. 5) the counter septum also withdraws from the axis, 
leaving an axial area one third to one half the diameter across free of septa. Several 
major septa, including the counter septum may develop rhopaloid ends. At the 
base of the calice the diameter is 11 mm with 30 major septa. 

The longitudinal section is cut from the proximal part of the corallite and shows 
a strong axial core which appears to involve several septa in the plane of section. 
The tabulae are strong, generally complete and slope steeply axially and upwards 
flattening slightly near the axis. 


Discussion. This specimen cannot be assigned to a described species of Lopham- 
plexus at the moment and may prove to be a new species. Further material is 
required, however, to furnish information not available from the present specimen 
and to determine if certain characters, such as the relatively long cardinal septum, 
are consistently maintained. 


Superfamily ZAPHRENTICAE Edwards & Haime 1850 
Family STREPTELASMATIDAE Nicholson 1889 


1956 Streptelasmatinae; Hill : 268, pars. 
1965 Streptelasmatidae; Kullmann : 139. 
1969 Streptelasmatidae; Neuman : 7. 


TyPE GENUS. Streptelasma Hall 1847 : 17. 


Dracnosis. Solitary corals with a narrow peripheral stereozone. Axial ends 
of major septa either lobed or discontinuous and usually involved in a loose axial 
structure, or amplexoid in ephebic stages. Cardinal fossula may or may not be 
distinguished. Tabulae generally complete; arched. No dissepiments. 


Discussion. Ivanovskii (1965 : 57) has divided the Streptelasmatinae of Hill 
(1956 : 268) among three families mainly on the basis of the development of stereo- 


FROM THE MERIDA ANDES, VENEZUELA 207 


plasm and septal thickening in early ontogeny. Whilst these factors have in some 
cases played a part in the diagnosis of streptelasmatid genera, divisions at family 
level are more soundly based on major structural modifications which are considered 
to have phylogenetic significance. Skeletal thickening alone in the streptelasmatids 
does not appear to be of fundamental taxonomic importance and Ivanovskii’s 
scheme cuts across more natural relationships. For example, Stveptelasma, Cras- 
silasma and Dinophyllum are all placed in separate families despite their basic 
structural similarities; similarly Leolasma and Kenophyllum. 

Kullmann (1965 : 140), on the other hand, recognized two groups within the 
Streptelasmatinae of Hill. He separated off the genus Heterophrentis and allied 
forms as a new subfamily, the Heterophrentinae, in which a strong cardinal fossula 
is developed and the axial structure of lobed septal ends is lost through the with- 
drawal of the septa from the axis in the ephebic stage. Neuman’s (1969) work, 
however, suggests that both features are quite variable within streptelasmatid 
genera and the value of Kullmann’s classification is regarded as questionable. 

Of the Streptelasmatinae of Hill, Ditoecholasma has been placed in a new family 
by Sutherland (1965 : 35) and Palaeophyllum has been shown to belong to the 
Stauriidae (Hill 1961). 


Genus STREPTELASMA Hall 1847 


1847 Streptelasma Hall : 17. 

21930 ©Streptelasma; Smith : 311, pars. 

1937 Streptelasma; Cox : 2, pars. 

1958b Brachyelasma; Kaljo : 102. 

1960 Byvrachyelasma; Pestana : 868. 

1963b Streptelasma; Stumm : 25, pars. 

1963 Bvrachyelasma; Ivanovskii : 42, cum syn. 
1965 Brachyelasma; Ivanovskii : 62, 104. 
1969 Stveptelasma; Neuman : 8, cum syn. 


DiaGnosis. Solitary corals with a narrow peripheral stereozone and interseptal 
loculi present throughout ontogeny. Septa of two orders, the minor very short, 
the major usually extending more or less to the axis where the septal ends are ir- 
regularly twisted to form a weak axial structure. Major septa may be amplexoid 
in the ephebic stage. Tabulae complete and incomplete arched plates. 


TYPE SPECIES (see Roemer 1861: 19). S. corniculum Hall 1847 : 69, pl. 25, 
figs ta-d. Trenton Limestone, Ordovician (Champlainian) ; Middleville, New York, 
U.S.A. 


Discussion. Neuman (1969 : 10) has recently chosen and described a lectotype 
for Streptelasma cormiculum. He showed that the type species of Stveptelasma is 
congeneric with Dybowskia prima Wedekind (1927 : 18, pl. 1, figs 10, 11) (= Brachye- 
lasma primum), the type species of Brachyelasma, and that the group of species up 
until then referred to Stveptelasma required a new generic name. Neuman (1969 : 
28) has erected the genus Helicelasma for these species. 


208 PALAEOZOIC CORAL FAUNAS 


Neuman (1969 : 9, fig. 3) recognized two groups of species within the genus 
Streptelasma thus emended, one characterized by amplexoid septa in the late neanic 
and ephebic stages, the other characterized by the persistence of loosely inter- 
twined major septa in the axial region up to the immediately subcalicular level 
of the corallite. Both the type species of Stveptelasma and its junior subjective 
synonym Brachyelasma fall into the ampleximorph group. Although Neuman 
claimed that intermediates exist between these two groups, he gave no details of 
these. In general, the two groups of species appear to be so well distinguished 
that the writer considers that separation at the subgeneric level may well prove to 
be justified. 

Neuman (1969 : 7-8) also commented on the various subgeneric relationships 
previously suggested between these and other Ordovician members of the Streptelas- 
matidae. In particular, he regarded Streptelasma as emended and Helicelasma as 
warranting full separate generic status and this is followed here. 

Streptelasma sensu Neuman is best known from the (?) Middle and Upper Ordo- 
vician to Llandovery of Scandinavia, the Baltic region and the U.S.S.R. The 
genus has also been recorded, usually as Brachyelasma, from the Upper Ordovician 
of Ireland (Kaljo & Klaamann 1965 : 421) and the Middle and Upper Ordovician 
of North America (Hall 1847 : 17; Pestana 1960 : 868). 


Streptelasma shagami sp. nov. 
(Pl. 2, figs 7-10; Text-fig. 6) 


DERIVATION OF NAME. After the collector of the type material, Dr R. Shagam 
(University of Pennsylvania). 


Diacnosis. Conical corals reaching 26 mm diameter with 41 major septa. 
Skeletal elements unthickened throughout ontogeny and little stereoplasm developed. 
Major septa slim with some intermingling at the axis. Cardinal septum short in 
neanic stage, equal in length to other major septa in ephebic stage; weak fossula. 
Minor septa 2-4 mm long in basal calice. Tabulae well spaced, strongly arched 
in axis with flat or shallowly depressed crests. 


HoLotyPe. R46755 (S1583). Rio Caparo, near the Paso Caparo; Silurian, 
Lower Llandovery. 


PARATYPES. R46756-9 (S1583), R46760 (K80748). Same locality and horizon 
as holotype. 


DEscRIPTION. Incomplete conical corals embedded in matrix. Early onto- 
genetic stages unthickened. The peripheral stereozone is thin and highly longitudin- 
ally corrugated. The major septa are strongly pinnate, the longer septa meeting 
at the axis, the shorter ones leaning against the longer. 

In the later neanic stages (Pl. 2, fig. 7), the peripheral stereozone is 0-5 mm or 
less in thickness. The septa are usually sinuous, occasionally straight, and variable 
in length although all reach or nearly reach the axis. They may be uniformly 


FROM THE MERIDA ANDES, VENEZUELA 209 


thick, about 0:25 mm, or slightly rhopaloid. There is some intermingling of the 
axial ends of the septa and they may fuse in groups of three or four: they may 
also be lightly invested with sclerenchyme in the axial area. The cardinal septum 
is shorter than the other majors, about a half the radius in length, in a poorly 
developed long narrow fossula. Rudimentary minor septa appear in the stereozone 
between most major septa. Horizontal elements are sporadic in the planes of section. 

At the base of the calice (Pl. 2, figs 8, 10), the strongly grooved peripheral stereo- 
zone may reach I mm, and the septa 0-3—0-35 mm in thickness. Characteristically, 
the cardinal septum increases in length to equal the other major septa, although 
a weak fossula may still be detected—in the holotype (PI. 2, fig. 8), the septa adjacent 
to the cardinal septum are shortened. Also, the counter septum shortens slightly 
and may only be a third of the radius in length. There is a slight withdrawal of 
the other major septa from the axis. Minor septa are short but well developed, 
< 2mm long in the holotype but may reach 4 mm in the larger specimens. Traces 
of tabulae are scattered. 

In longitudinal section (Pl. 2, fig. 9), tabulae are well developed, thin, complete 
or incomplete large curved plates. They are arranged as axial flat-topped or 
shallowly depressed domes sloping steeply downwards peripherally and developing 
narrow troughs against the wall in some instances. The arrangement in the axial 
area 1s obscured by septal traces. The tabulae are spaced 2-3 mm vertically apart. 
There are no dissepiments. 

Ephebic stage sections of specimens in the type series show a great range in sizes 
from 11-8 to 26-3 mm mean diameter in calicular sections. Mature septal ratios 
range from 2:55 to 1:56 with increasing mean size. The data are shown graphically 
in Text-fig. 6. 


40 


30 


20 


5) 10 15 20 25 30 


d (mm) 


Fic. 6. Number of major septa plotted against diameter for specimens of Stveptelasma 
shagami. The holotype is indicated by asterisks. The dashed lines join points represent- 
ing different sections of the same specimen. 


210 PALAEOZOIC CORAL FAUNAS 


Discussion. Streptelasma shaganu has some similarity to S. poulseni Cox (1937 : 
9) from the Richmondian (Ordovician) of Greenland. The Venezuelan species, 
however, is distinguished by its more strongly arched tabulae and a lower septal 
ratio. 


Streptelasma sp. 
(EAL A, ste Tee, 30) 


MATERIAL. R46761 (A2077). Rio Caparo, near the Paso Caparo; Silurian, 
Lower Llandovery. 


DESCRIPTION. The specimen is an incomplete conical coral, partly decorticated. 

In cross-section, the peripheral stereozone is 0-7 mm thick with well developed 
septal grooves. The major septa are short and thin, tapering gradually towards 
the axis. They are slightly less than half the radius in length. Only half of the 
corallite is seen in cross-section and in this neither a fossula nor any of the primary 
septa can be identified. The minor septa are very thin and variable in length, 
apparently extending axially as crests on the tabulae with a maximum axial exten- 
sion of 2mm. Tabulae are intersected, widely spaced, in the peripheral area. 

In longitudinal section, the tabulae are thin and mainly incomplete. They are 
shallowly depressed across the axis and strongly domed in the peripheral area 
where subsidiary vesicular elements may occur. There is evidence of septal develop- 
ment on the crests of the tabulae. At the periphery, the plates may curve up slightly 
against the stereozone to form a small trough. In the axis, the spacing is somewhat 
irregular, averaging 7 tabulae in 10 mm. 

There are an estimated 42 major septa at a diameter of 24 mm. 


Discussion. Despite the limits of the material, which preclude specific identi- 
fication, this specimen can be confidently assigned to the genus Stveptelasma. 


Genus LEOLASMA Kaljo 1956 


1956 Leolasma Kaljo : 36. 
1965 Leolasma; Ivanovskii : 59. 


DiaGnosis. Solitary conical corals. Septa of two orders, the major extending 
to the axis and dilated to completely close the lumen in early ontogeny. In mature 
stages, the major septa are dilated peripherally to form, with the minor septa, 
a moderately wide stereozone. Their axial ends are rhopaloid and fuse to form a 
more or less compact axial boss. Cardinal fossula narrow. Tabulae sparsely 
developed or absent. 


TYPE SPECIES (by original designation). Leolasma reimani Kaljo 1956 : 36, 
pl. 9, figs 3-5. Upper Ordovician, Vazalemmaskii horizon; Rakvere, Estonia. 


Discussion. In his original diagnosis, Kaljo (1956 : 36) remarks that tabulae 


FROM THE MERIDA ANDES, VENEZUELA 211 


are absent and does not mention a cardinal fossula. Ivanovskii (1965 : 59), how- 
ever, mentions sparse tabulae in his diagnosis for Leolasma and from published 
illustrations of L. reimani (Kaljo 1956, pl. 9, fig. 5; Ivanovskii 1965, pl. 2, figs Ia, b) 
a narrow cardinal fossula similar to that in the Venezuelan material appears to be 
present. 

Leolasma appears to be very close to the genus Kenophyllum Dybowski which 
was revised by Kaljo (1958a: 22). Kaljo diagnosed Kenophyllum as lacking 
tabulae and, from his illustration of the type species K. subcylindricum, sclerenchyme 
is involved with the septa in the formation of the axial structure. Thus the present 
material compares more closely with Leolasma than Kenophyllum although the 
slight differences between the two may prove not to be of generic significance. 

Leolasma is known from the upper Middle and lower Upper Ordovician of the 
Baltic area and China and is recorded here from the Lower Llandovery of the 
Mérida Andes. 


Leolasma kaljoi sp. nov. 
(Pl. 2, fig. 13; Pl. 3, figs 1-8; Text-fig. 7) 


DERIVATION OF NAME. After Dr D. L. Kaljo (Institute of Geology, Academy 
of Sciences of the Estonian S.S.R.). 


Diacnosis. Leolasma with peripheral stereozone one quarter to one-third the 
radius. Cardinal fossula well developed with cardinal septum shortening rapidly 
in subcalicular stages. Tabulae simple, flat plates sloping axially and upwards, 
developed only in the ephebic stage: earlier stages completely infilled by laterally 
contiguous septa. 


HoLotyPe. R46762 (A2077). Rio Caparo near the Paso Caparo; Silurian, 
Lower Llandovery. 

PARATYPES. R46763-7 (A2077), R46768 (A2079), R46769-75 (S1583). Same 
locality and horizon as holotype. 

DESCRIPTION. Straight, conical corals reaching at least 30 mm high with a 
calice about Io mm deep with steep sides and a shallow bowl shaped floor. 

In the early stages (Pl. 3, fig. 6), the lumen is completely infilled by major septa 
reaching the axis, laterally contiguous along their whole length and alternating 
in the peripheral third to quarter of the radius with slim wedge shaped minor 
septa. The arrangement of the major septa varies between radial and slightly 
pinnate and a counter clockwise axial vortex may develop in some specimens. 

The septa first separate in the cardinal fossula leaving a narrow elongate cavity 
bisected by a thin cardinal septum (PI. 3, fig. 1). Subsequent spaces appear between 
major septa immediately on the axial side of the minor septa (Pl. 3, fig. 2). The 
major septa thin rapidly in their mid-length leaving a wide peripheral stereozone 
usually between a quarter and a third the radius wide, equivalent to the length 
of the minor septa, and an axial column of fused septal ends (PI. 3, fig. 3). The 


212 PALAEOZOIC CORAL FAUNAS 


septa in the axis are straight or a slight vortex may persist from earlier stages. 
Between the first separation of the septa and the base of the calice, the cardinal 
septum shortens rapidly and the axial column decreases in diameter and finally 
breaks up with the separation of the rhopaloid axial ends of the septa (Pl. 3, fig. 4). 
In the holotype, the cardinal septum decreases in length from 5 mm to 2:3 mm 
in 1:54 mm vertical growth and the major septa begin rapid withdrawal from the 
axis in the base of the calice about 3-5 mm above the level at which only a small 
cardinal fossula is open. In the calice, the peripheral stereozone is about one-third 
the radius in thickness except in the cardinal fossula where it is strongly notched. 
The cardinal septum is extremely short. The septal microstructure shows the water- 
jet pattern of divergent fibres typical of uniserial monacanthine trabeculae and is 
very well preserved in some specimens (PI. 2, fig. 13). 

Longitudinal sections are filled by septal tissue in which the trabeculae are 
directed axially and upwards at angles varying about 70° to the wall. Signs of 
tabulae are seen in one section only (PI. 3, fig. 8) where complete flat plates 0-8 mm 
apart slope axially and upwards at about 30°. 

Specimens range in size up to 17 mm in diameter with 38 major septa. Data 
are presented graphically in Text-fig. 7, Septal ratios range from 2-22 to 3-18 in 
mature sections. 


Discussion. Leolasma kaljoi is distinguished from L. reimant Kaljo by the 
development of tabulae and the possession of a much stronger cardinal fossula. 
Otherwise, the two species appear to be very similar. 


40 


30 


20 


5 10 15 20 
d (mm) 


Fic. 7. Number of major septa plotted against diameter for specimens of Leolasma kaljot. 
The holotype is indicated by asterisks. The dashed lines join points representing 
different sections of the same specimen. 


FROM THE MERIDA ANDES, VENEZUELA 213 


Suborder COLUMNARIINA Rominger 1876 
Family SPONGOPHYLLIDAE Dybowski 1873 
1964 Spongophyllidae; Pedder : 436. 


Discussion. The writer follows Pedder and others in considering the family 
Ptenophyllidae Wedekind 1923 as synonymous with the Spongophylldae. 


Genus CYMATELASMA Hill & Butler 1936 


1936 Cymatelasma Hill & Butler : 516. 


TYPE SPECIES. Cymatelasma corniculum Hill & Butler 1936 : 518, pl. 16, figs 2-8. 
Woolhope Limestone, Silurian, Wenlock; road cutting south of Stony Hill Farm,- 
Woolhope, Herefordshire. 


Diacnosis. Simple rugose corals with marked septal dilatation in early stages, 
usually reducing during ontogeny to a peripheral stereozone in the adult. The 
septa are waved parallel to their upper edges and carinae may develop along the 
crests of the waves. In the ephebic stage, the major septa are unequal in length 
and distinctively arranged in pinnate groups. Tabulae complete or incomplete: 
tabularium inversely conical or bowl-shaped. No dissepiments. 


Discussion. Since Hill & Butler (1936) erected the genus and four species of 
Cymatelasma from beds of Llandovery to Ludlow age in the Welsh Borderland and 
the English Midlands, the genus appears to have been unused. Only passing 
comments on the genus are known to the writer. 

Wang (1950: 216), with no explanation, reassigned Hill & Butler’s original 
species to Pycnactis (the type species), Dinophyllum and Spongophylloides. This 
dispersion seems completely unjustified as the genus from Hill & Butler’s thorough 
descriptions appears to be a well defined homogeneous unit readily distinguished 
through septal structure, symmetry and lack of dissepiments from Pycnactis and 
Dinophyllum. 

Cymatelasma is, however, most closely related to Spongophylloides and the species 
Spongophylloides cocket Sutherland (1965 : 16) includes in its range of variation 
specimens in which the dissepimentarium is almost completely replaced by a septal 
stereozone. Sutherland (of. cit.), in a useful comparison of the two genera, points 
out that they are distinguished only by the development of lonsdaleoid dissepiments 
in Spongophylloides and that S. cocke: appears to show a continuous gradation 
between the two generic types. At present there is still some value in regarding 
the two genera as distinct and the Venezuelan species can be unequivocally assigned 
to Cymatelasma. If, however, Spongophylloides pusillus and Cymatelasma carinatum 
from the English Wenlock Limestone do prove to be a single variable species, a 
possibility suggested by Sutherland (of. czt.), then the status of Cymatelasma may 
need to be reconsidered. 


214 PALAEOZOIC CORAL FAUNAS 


Pedder (1967a : 3) remarked on the resemblances between Cymatelasma, Entero- 
lasma and young individuals of Lyrielasma. Lyrielasma and Cymatelasma are 
undoubtedly closely related, the former genus differing essentially through the 
development of a dissepimentarium in later ontogeny, its exclusively (or nearly 
so) fasciculate growth form and a less consistently developed pinnate septal sym- 
metry. It is possible that Lyrielasma is descended from Cymatelasma but the 
present known distribution patterns of the two genera do not encourage this 
suggestion. 

The type species of Enterolasma, E. strictum, has never been adequately described 
and understanding of the genus is based chiefly on various accounts of E. waynense 
(Safford). Cymatelasma and E. waynense are superficially similar but the latter 
lacks a distinctive pinnate septal symmetry and possesses an arched tabularium 
similar to that in streptelasmatids. 

The diagnosis given for Cymatelasma here is slightly modified from that given by 
Hill & Butler to take account of the new species. The South American record 
suggests that the distribution of Cymatelasma is far from adequately known and 
representatives of the genus are likely to be found in the Silurian of North America. 


Cymatelasma aricaguaense sp. nov. 
(Pl. 3, figs 9-15; Pl. 4, fig. 1; Text-fig. 8) 
DERIVATION OF NAME. After the type locality on the Rio Aricagua. 


Diacnosis. Ceratoid Cymatelasma. Major septa 36 at diameters of 11 to 
14:5 mm, characteristically pinnate, lobed but not fused at their axial ends and 
bearing carinae sloping slightly axially and downwards. Tabulae incomplete; 
tabularium bowl-shaped. 


HoLotyPe. R46776 (A2558). Rio Aricagua section; Silurian, Ludlow. 


PARATYPES. R46777-78 (A2558), R46779q (Az2561), R46780 (A2562), R46781 
(SCr). Same locality and horizon as holotype. 

DEscRIPTION. Incomplete ceratoid corals with very weak septal grooves. 

The peripheral stereozone is usually 1-5 to 2mm but may reach 4 mm in thickness. 
Septa of two orders, the majors extending into the axial area but characteristically 
arranged and variable in length. The cardinal and counter septa are longest and 
almost join at the axis. The alar and the mid metasepta in the counter quadrants 
also nearly reach the axis, with the other septa shorter and arranged in pinnate 
groups in the six segments thus formed (Pl. 3, figs 9, 11, 12). The major septa are 
moderately thin, generally tapering slightly towards the axis but with small ir- 
regularities in thickness along their length. The sides of the septa bear small 
scattered thorny projections which are the sections of carinae sloping gently into 
the axis. The axial ends of the septa are usually lobed, often with thorns on the 
lobes, but they do not intermingle and only rarely do adjacent septa fuse. The 


FROM THE MERIDA ANDES, VENEZUELA 215 


swellings are usually larger on the axial ends of the cardinal and counter septa. 
The minor septa are variable in length but never project more than 0-5 mm beyond 
the peripheral stereozone. In late neanic—early ephebic sections, only rudimentary 
minor septa deep in the stereozone are present between some of the major septa 
(EIS 3; fig: 12). 

In longitudinal section, the stereozone is evenly developed from a minimum 
observed corallum diameter of 4mm. Trabeculae are directed axially and upwards 
at 20-30° to the horizontal, becoming steeper towards the axis. The tabulae are 
mainly large incomplete curved plates, sloping into the axis steeply at the periphery 
but apparently with a flatter axial series. Their distribution is confused by the 
many septal traces and sections of the carinae. The lobed axial ends of the septa 
appear as a poorly defined spongy axial ‘column’. In sections at right angles to 
their length, the septa appear strongly zigzagged with the carinae developed on the 
crests. On the sides of the septa the carinae are occasionally discontinuous along 
their length. They are otherwise regularly developed with an average vertical 
spacing of 0-5 mm and slope very gently into the axis. 

The largest specimen is 14:5 mm in diameter with 36 major septa; the complete 
data are shown in Text-fig. 8. The septal ratio varies between 2-48 and 3-3 in 
maturity. 


Discussion. Cymatelasma aricaguaense is immediately distinguished from all 
the species described by Hill & Butler through the possession of incomplete tabulae. 
Otherwise the Venezuelan species is most similar to C. cavinatum Hill & Butler, 
although lacking the accelerated counter lateral minor septa of the latter. C. 
avicaguaense also has the characteristic septal symmetry more prominently de- 
veloped than in C. carinatum. 


38 
36 
34 
32 
30 


28 


10 12 14 


d (mm) 


Fic. 8. Number of major septa plotted against diameter for specimens of Cymatelasma 
avicaguaense. The dashed line joins asterisks representing different sections of the 
holotype. 


216 PALAEOZOIC CORAL FAUNAS 


Suborder CYSTIPHYLLINA Nicholson 1889 
Family TRYPLASMATIDAE Etheridge 1907 
Genus TRYPLASMA Lonsdale 1845 


1845 Tvyplasma Lonsdale : 613. 
1904 Aphyllostylus Whiteaves : 113. 
1950 Tvyplasma; Schouppé : 8o. 
1956 Tvyplasma; Stearn : 91. 
1961 Tvyplasma; Strusz : 343. 
1963a Tvyplasma; Stumm : 4. 
1963 Tvyplasma; Oliver : 13 cum syn. 
1964 Tvyplasma; Stumm : 50. 
1965 Tvyplasma; Sutherland : 30. 
1966 Holacanthia Sytova : 208. 
1969 Cantrillia; Ivanovskii : 29, pars. 
1969 Holocanthia; Ivanovskii : 31. 
1969 Tryplasma; Ivanovskii : 33. 
1969 Rhabdacanthia Ivanovskii : 45. 
1969 Wenlockia; Ivanovskii : 52, pars. 
TYPE SPECIES (by subsequent designation of Etheridge 1907 : 42). T. aequabile 
Lonsdale (1845 : 613, 633, pl. A, figs 7, 7a); Silurian, River Kakva, east side of 
northern Urals, U.S.S.R. 


DiaGnosis. Solitary and fasciculate rugose corals with acanthine septa and a 
narrow peripheral stereozone. Tabulae usually complete; no dissepiments. 


Discussion. Ivanovskii (1969) has recently presented a comprehensive review 
of the Tryplasmatidae in which he advocated a series of generic divisions based on 
growth form and trabecular type. These two characters, however, appear in most 
cases in the tryplasmatids to be of doubtful genetic significance. The separation 
of solitary and fasciculate forms in the absence of other structural modifications 
seems inadvisable, particularly as species such as T. malvernense Hill show both 
growth forms. Further, the distinction between trabecular types is, at least to 
some extent, a function of preservation and holacanths may well be the recrystallized 
remains of original monacanthine or rhabdacanthine trabeculae. In both species 
of Tvyplasma described here, rhabdacanths can be recognized in the septa where 
the microstructure is slightly better preserved although most trabeculae show varying 
degrees of alteration towards a holacanthine state. For these reasons, the genus 
Tryplasma is maintained here in the sense of earlier workers and the genera Hola- 
canthia Sytova and Rhabdacantma Ivanovskii are not recognized. 


Tryplasma sp. cf. T. nordica Stumm 1963 


(Pl. 4, figs 2-4) 


cf. 1963a Tryplasma nordica Stumm : 4, pl. 2, figs 14—16. 
cf. 1963 Tryplasma nordica Stumm; Oliver : 13, pl. 7, figs 1-7. 


MATERIAL. R46782-4 (S1540A). Rio Suripa section; Silurian, Ludlow. 


FROM THE MERIDA ANDES, VENEZUELA 217 


DEscriPTION. Cylindrical fragments of a Tvyplasma with neither calice nor 
proximal end preserved nor any indication of increase. 

The coral is subcircular in cross-section with a longitudinally corrugated epitheca 
reflecting septal grooves on the exterior. Diameters range between 5 and 5-5 mm 
with 22 major septa. The septa are discrete acanthine rhabdacanths, where the 
microstructure is preserved, embedded in lamellar calcite which forms a thin peri- 
pheral stereozone 0-3 mm thick (Pl. 4, fig. 4). Major and minor septa may be 
distinguished. Their appearance in cross-section is variable and occasionally the 
plane of section may fail to cut some or all of a ring of spines. The longest major 
septum seen was 0-7 mm long, the minor septa reaching up to half this length. 
Discontinuity or lobing of septa in cross-section due to the interception of two 
thabdacanths in vertical series was occasionally seen. 

In longitudinal section, the rhabdacanths are arranged on average 0-2 mm 
apart in regular vertical rows. The septa project into the lumen at a slightly 
variable but very low angle. The tabulae are usually complete and flat, although 
they may be slightly upturned peripherally. Occasionally incomplete tabulae 
slope steeply down into the axis. The tabulae are wide and irregularly spaced, 
averaging Imm apart. Dissepiments are not developed. 


Discussion. The specimens agree more closely with the T. nordica from the 
Silurian (Wenlock or Ludlow) of Quebec described and figured by Oliver (1963) 
than with any other species of Tvyplasma, particularly among those from North 
America. TJ. nordica is, however, larger with relatively, a somewhat lower septal 
number (48 to 60 septa of both orders in corals of 7-0 to 10-5 mm diameter according 
to Oliver) compared to the present material. The septa of the former are also 
longer and the tabulae more U-shaped. From Stumm’s (1963a) description, the 
type specimens of T. nordica from the Silurian of Maine are less comparable to the 
Venezuelan specimens than Oliver’s material. 


Tryplasma sp. 


(Pl. 4, figs 5-9) 
MATERIAL. R46785 (S1540A). Rio Suripa section; Silurian, Ludlow. 


DESCRIPTION. Several small cylindrical corallites, well spaced and subparallel 
in a mudstone matrix, probably all belonging to one fasciculate colony. 

The corallites are circular to subcircular, varying between 2:3 and 4-5 mm and 
averaging 2-8 mm in diameter. There are Ig major septa in a corallite 2-3 mm in 
diameter and about 28 in one 4-5 mm in diameter. The septa are acanthine 
thabdacanths where details of microstructure can be observed. Their appearance 
in cross-section is highly variable and sometimes only one or two spines may be 
sectioned. They are set in lamellar calcite forming a peripheral stereozone 0-2— 
0-4 mm thick. Both major and minor septa may be distinguished, the latter reach- 
ing half the length of the former. The longest major septum seen in cross-section 
was I mm measured from the periphery. 


218 PALAEOZOIC CORAL FAUNAS 


In longitudinal section, the rhabdacanths project into the lumen with an elevation 
of 40°—there is little variation. One rhabdacanth measured 0-2 mm in diameter 
(Pl. 4, fig. 7). The septal spines are arranged 0:35 mm apart in vertical series. 
Tabulae are complete and flat or very slightly domed, their spacing varying between 
0-4 and 1-7mm. Dissepiments are not developed. 

One instance of axial increase was seen in longitudinal section (Pl. 4, fig. 9). 
Only two daughter corallites were sectioned although more could be present out 
of the plane of section. In another corallite, a hysterocorallite was seen developing 
against the wall of the parent (Pl. 4, fig. 8). Whether this is a case of increase or 
an extreme form of rejuvenescence is uncertain. 


Discussion. Among the several described species of Tryplasma which are 
fasciculate and have corallites of small diameter, T. gracilis (Whiteaves) and T. 
lonsdalei Etheridge appear to be the most similar to the present material. T. 
gracilis was redescribed by Stearn (1956 : 91, pl. 6, figs 1, 8) on weathered out but 
unsectioned topotype and other material from the Upper Ordovician Stonewall 
Formation of Southern Manitoba. It agrees with the specimens described here in 
size and growth form, including an apparent lack of connecting processes in the 
colony, but further comparison is difficult in the absence of sections of T. gracilis. 
Etheridge (1907) described several species of Tvyplasma which have points in 
common with the Venezuelan material. Of these, the closest is T. lonsdalei var. 
minor Etheridge (1907 : 81, pl. 16, figs 3, 4; pl. 24, fig. 9; pl. 25, figs 6, 7; pl. 26, 
fig. Ir), which has only slightly larger corallites and a comparable septal ratio to 
the Venezuelan material but differs from it by possessing connecting processes, 
slightly longer septa and more regular tabulae. Both Hill (1940 : 406) and Strusz 
(1961 : 343) agree in not differentiating Etheridge’s varieties of T. lonsdale: and 
Hill describes rhabdacanthine septa in the species. In Australia, T. lonsdales 
ranges in age from the Lower Devonian down to the Lower Silurian or Upper 
Ordovician. 

At the present time, it is not possible to assign the Venezuelan coral to either 
T. gracilis or T. lonsdalet with confidence. A definite identification must await 
the collection of further material and more complete information on T. gracilis. 


Order TABULATA Edwards & Haime 1850 
Suborder FAVOSITINA Sokolov 1962 
Family COENITIDAE Sardeson 1896 


Genus COENITES Eichwald 1829 


1829 Coenites Eichwald : 179. 
1939 Coenites; Lecompte : 62. 
1964 Coenites ; Chudinova : 47. 


TyPE sPEcIES (see Miller 1897: 727). C. guniperinus Eichwald 1829 : 179. 
Drift specimen, Lithuania (a neotype for C. juniperinus has been described from 


FROM THE MERIDA ANDES, VENEZUELA 219 


the Yagarakhuskii horizon (Wenlock) ; Saaremaa, Estonia by Klaamann 1964 : 116). 


Diacnosis. Branching, laminar or finely zoned massive colonies. Corallites 
small and short, their walls thin proximally but much thickened distally, opening 
obliquely at the surface of the colony. Calices cresentic. Tabulae few and mural 
pores rare. Septa occasionally represented by three processes in the calice. 


Coenites sp. 
(Pl. 4, figs 10, II) 


MATERIAL. R46786 (S2275F). Rio Suripa section. Silurian. Ludlow. 


Description. A thin laminar encrusting colony 1-5 mm thick consisting of a 
single expansion which splits into two levels in one area. 

Corallites about 0-I mm across the short axis in longitudinal section, inclined at 
a low angle to the colony base and curving up slightly to meet the surface of the 
colony at an angle of 30-40°. Corallite walls thicken gradually from base to surface 
of the colony where they may reach o-1 mm or slightly more in thickness. Mural 
pores are infrequent and about 0-05 mm diameter. The tabulae are flat, complete, 
variably spaced 0-25 mm or more apart. 

The calices are gently curved, parallel sided slits with rounded ends 0-075 mm 
across and about 0-5 mm long. Septa are apparently not developed. 


Discussion. This specimen may be referable to Coenites laminatus Hall (1852 : 
143, pl. 39, figs 6a-d) which is widely recorded in rocks of Silurian age in North 
America. Unfortunately a modern description and adequate illustrations of the 
species are not available for a proper comparison to be made. 


Suborder HALYSITINA Sokolov 1962 
Family HALYSITIDAE Edwards and Haime 1850 
Genus CYSTIHALYSITES Chernyshev 1941 


1941 Cystihalysites Chernyshev : 70. 
1962 Cystihalysites; Norford : 34. 
1964 Cystihalysites; Sutton : 452, cum syn. 


TYPE SPECIES. Cystihalysites mirabilis Chernyshev 1941: 70, pl. 2, figs 5-7; 
pl. 3, figs 1-6. Upper Silurian; middle course of the Khandyga River, E. Verk- 
hoyan’ya, U.S.S.R. 


Diacnosis. Colonies formed of chains of long dimorphic corallites which divide 
and anastomose to form fenestrules. Autocorallites rounded or elliptical, some- 
times developing septal spines and separated by rectangular mesocorallites. Tabulae 
of autocorallites usually complete, occasionally with vesicles on the corallite walls. 


220 PALAEOZOIC CORAL FAUNAS 


Tabulae of mesocorallites strongly arched or incomplete and vesicular. Auto- 
corallites and mesocorallites separated by a true wall or peripheral faces of meso- 
corallite tabulae. Increase interstitial and peripheral. (After Sutton 1964 : 453). 


Discussion. Nothing need be added here to the useful review of the genus 
given by Sutton (1964 : 452). 


Cystihalysites brownsportensis (Amsden) 1949 


(Pl. 5, figs 1-4) 


1949 Halysites catenularia brownsportensis Amsden : 94, pl. 18, figs 1-3. 

1955 Halysites brownsportensis Amsden; Buehler : 65, pl. 9, figs 4-6; pl. Io, fig. 6. 
1957 Cystihalysites bvownsportensis (Amsden) Hamada : 403, text-figs 1 (8), 2c. 
1962 Halysites bvrownsportensis Amsden; Jull, text-fig. 1d. 


DiaGnosis. Cystihalysites with oval autocorallites 2 x 1-5 mm to 2:4 X 2 mm, 
developing short septal spines. Mesocorallites large, up to 1-5 mm long parallel 
to chain, containing small thin walled highly vesicular tabulae. 

MATERIAL. R46787 (A2558), Rio Aricagua section. R46788 (S2275F), Rio 
Suripa section. Both Silurian, Ludlow. 

DESCRIPTION. Damaged colonies, the largest piece 80 x 50 mm in area, com- 
posed of chains of dimorphic corallites. Crushing has broken the chains down to 
unbranched units up to 7 autocorallitesin length. Allsigns of budding are extremely 
rare, suggesting large lacunae. 

Autocorallites oval, internally smooth or weakly scalloped in cross-section. 
Internal diameters vary between 1-2 x 1°8 mm and 1-3 X 2:3 mm; external 
diameters 1-5 X 2 mm to 2:0 X 2:4 mm. Short septal spines are rarely seen 
(Pl. 5, fig. 3). The mesocorallites are large and square, 0-5 X 0-5 mm internally, 
or rectangular with the long axis, which may reach 1-5 mm internally, parallel to 
the chain. Auto- and mesocorallites are contained within a common wall varying 
between 0-15 and 0-3 mm thick and are separated by a thin partition 0:05 to o-I mm 
thick. There are no balken. Cross-sections of tabulae in the autocorallites are 
strongly curved and may even be circular. In the mesocorallites a thin walled 
network of vesicular tissue of about 0-2 mm diameter mesh and two to three ranks 
in width is developed. The autocorallites are spaced 2:7 to 3-9 mm centre to 
centre along the chains. 

In longitudinal section the tabulae of the autocorallites are regularly developed, 
complete, arched, flat or saucer-shaped with few subsidiary plates. From colony 
to colony between 9g (rarely as few as 6) and 13 tabulae develop in 5 mm vertical 
growth. Traces of septal spines may be seen in subcentral sections developed in 
regular series 0-25 mm apart vertically. The mesocorallites are filled with thin 
walled, highly vesicular tabulae, usually 4 or 5 in 1 mm vertical growth and up to 
6 ranks along the length of the chain in well developed mesocorallites. The wall 
separating auto- and mesocorallites is apparently formed by the thickened outer 
faces of the peripheral mesocorallite tabulae. 


FROM THE MERIDA ANDES, VENEZUELA 221 


Discussion. Apart from possessing very slightly larger autocorallites, the 
Venezuelan specimens agree in every respect with Amsden’s and Buehler’s figures 
and description of Halysites brownsportensis. This species is recorded from the 
Niagaran (Wenlock and Ludlow) of North America. 


Genus ACANTHOHALYSITES Hamada 1957 


1957 Acanthohalysites Hamada : 404. 
1961 Acanthohalysites; Strusz : 353. 


Type spEcIES. Halysites australis Etheridge 1808 : 78, pl. 17, figs 1-8. Silurian; 
Bell River, Wellington, N.S.W., Australia. 


Diacnosis. Dimorphic Halysitidae with septal spines developed in the auto- 
corallites. Lacunae larger than autocorallites. Mesocorallites with non-cystose 
tabulae. 


Discussion. Acanthohalysites and Cystihalysites are distinguished only through 
the development of cystose tabulae in the mesocorallites of species of Cystihalysites ; 
Hamada (1957 : 397) was unaware of the septal spines developed in that genus. 


Acanthohalysites sp. 
(Pl. 5, figs 5, 6) 


MATERIAL. R 46789 (S1540A). Rio Suripa section; Silurian, Ludlow. 


DESCRIPTION. Fragmental dimorphic chains 1-5 to I-9 mm across up to 7 auto- 
corallites in length unbranched. Shape and size of lacunae unknown. 

The autocorallites are subcircular to strongly oval in cross-section with maximum 
internal dimensions of 1-8 x 1-3 mm. The internal face is often clearly scalloped 
and occasionally septal spines are seen well developed. The longest spine projects 
0:25 mm into thelumen. In other autocorallite sections, spots of tissue in the lumen 
probably represent the tips of septal spines. Autocorallites and mesocorallites are 
enclosed by a common wall 0-2 to 0-3 mm thick within which they are separated 
by partitions also 0-2 to 0-3 mm thick. The mesocorallite lumen is very small, 
rectangular or circular, or it may be closed completely: its maximum size is about 
0:45 X 0:25 mm, elongated across the width of the chain. The distance centre to 
centre between autocorallites along the chain is 2-2 to 2-6 mm. 

In longitudinal section, the autocorallites contain complete, flat to saucer-shaped 
tabulae regularly spaced 13 to 15 in 5 mm vertical growth. Incomplete tabulae 
are extremely rare. In a subcentral section, regular series of septal spines are seen 
0-15 to 0:25 mm apart vertically (Pl. 5, fig. 5, upper half of central corallite). The 
mesocorallites are very narrow and may be intermittently closed. The tabulae 
appear to be flat or saucer-shaped but their spacing is indeterminate. 


222 PALAEOZOIC CORAL FAUNAS 


Discussion. The Venezuelan specimen does not appear to be referable to an 
established species of Acanthohalysites but its indifferent preservation and frag- 
mentary nature makes the erection of a new species undesirable. 


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LecompTE, M. 1939. Les tabulés de Dévonien moyen et supérieur du bord sud du bassin 
de Dinant. Mém. Mus. rv. Hist. nat. Belg., Bruxelles 90 : 1-229, pls 1-23. 

LinpstTROM, G. 1882. Anteckningar om silurlagren pa Carlsdarne. Ofvers. K. VetenskAkad. 
Forh. Stockh. 39, 3 : 5-30. 

LoNSDALE, W. 1845. Description of some Palaeozoic corals of Russia. In Murcuison, R. I., 
DE VERNEUIL, E. & VON KEYSERLING, A. The geology of Russia in Europe and the Ural 
Mountains 1 : 591-634. London. 

McCueEsnEy, H. H. 1860-1865. Descriptions of new species of fossils from the Palaeozoic 
vocks of the western states, pp. 1-56 (Jan. 1860); pp. 57-76 (May 1860); pp. 77-96 (Feb. 1861); 
pp. [3] and pls 1-11 (Apr. 1865). Chicago. 

M’Coy, F. 1850. On some new genera and species of Silurian Radiata in the collection of 

the University of Cambridge. Ann. Mag. nat. Hist., London 2, 6 : 270-290. 

1851-55. In SEDGwick, A. A Synopsis of the Classification of the British Palaeozoic 
vocks, by the Rev. Adam Sedgwick, .. . with a systematic Description of the British Palaeozoic 
Fossils in the Geological Museum of the University of Cambridge by Frederick M’Coy. i-iv, 
I-184 (1851); i-[x], 185-406 (1852); Introduction, i—xcviii, 407-661 (1855); pls iA-iL, 
i1A-1iD, iiA-11D. London and Cambridge. 

Meyer, H. L. F. 1914. Beitrage zur Geologie und Palaontologie von Siidamerika, 22. 
Carbonfaunen aus Bolivia und Peri. Neues Jb. Miner. Geol. Paléont. BeilBd, Stuttgart 
37 : 590-652, pls 13, 14. 

MILLER, S. A. 1889-1897. North American geology and palaeontology . . . 3vd Edition, pp. 
1-664 (1889). First Appendix, pp. 665-718 (1892). Second Appendix, pp. 719-793 
(1897). Cincinnati. 

Minato, M. 1955. Japanese Carboniferous and Permian corals. J. Fac. Sci. Hokkaido 
Umiv. (4, geol. min.) 9, 2 : 1-202, 43 pls. 

Moore, R. C. & JEFForDs, R. M. 1941. New Permian corals from Kansas, Oklahoma and 
Texas. Bull. Kans. Univ. geol. Suvv., Lawrence 38 : 65-120, pls 1-8. 

1945. Descriptions of Lower Pennsylvanian corals from Texas and adjacent areas. 
Publs Bur. econ. Geol. Univ. Tex., Austin 4401 : 77-208, 214 figs. 

Moore, R. C., Hitt, D. & WELLS, J. W. 1956. Glossary of morphological terms applied to 
covals. In Moore, R. C. (Ed.) Treatise on Invertebrate Paleontology, F : 245-251. Law- 
rence. 

NEuMAN, B. 1969. Upper Ordovician streptelasmatid corals from Scandinavia. Bull. 
geol. Instn Univ. Uppsala, N.S. 1, 1 : 1-73, 59 figs. 

NicHotson, H. A. & ETHERIDGE, R. 1878. A monograph of the Silurian fossils of the Girvan 
district in Ayrshive, 1, fasc. I : 1x + 1-135, pls 1-9. Edinburgh and London. 

Nicuotson, H. A. & THomson, J. 1876. Descriptions of some new or imperfectly understood 
forms of Palaeozoic corals (Abstract). Proc. R. Soc. Edinb. 9 (95) : 149-150. 

Norrorp, B.S. 1962. The Silurian fauna of the Sandpile Group of northern British Columbia. 
Bull. geol. Surv. Can., Ottawa 78 : x + 1-51, pls 1-16. 

OLivER, W. A., Jr. 1963. Silurian rugose corals from the Lake Témiscouata area, Quebec. 
Prof. Pap. U.S. geol. Suvv., Washington 430-B : 10-109, pls 5-8. 

PEpDDER, A. E.H. 1964. Correlation of the Canadian Middle Devonian Hume and Nahanni 

formations by tetracorals. Palaeontology, London 7 : 430-451, pls 62-73. 

1967a. Lyrielasma and a new related genus of Devonian tetracorals. Pyvoc. R. Soc. 
Vict., Melbourne, N.S. 80 : 1-30, pls 1-7. 
1967b. Lower Devonian streptelasmatid, lindstroemiid and possible amplexocariniid 

corals from Victoria. Pyvoc. R. Soc. Vict., Melbourne, N.S. 80 : 107-130, pls 14-16. 

Pestana, H. R. 1960. Fossils from the Johnson Spring Formation, Middle Ordovician, 
Independence Quadrangle, California. J. Paleont., Tulsa 34, 5 : 862-873, pls 109-112. 

Puitip, G. M. 1962. The palaeontology and stratigraphy of the Siluro-Devonian sediments 
of the Tyers area, Gippsland, Victoria. Proc. R. Soc. Vict., Melbourne, N.S. 75 : 123-246, 
pls 11-36. 


FROM THE MERIDA ANDES, VENEZUELA 225 


Pierce, G. R. 1960. Geologia de la cuenca de Barinas. Boln Geol. Dir. Geol. Publ. Espec., 
Caracas 3, 1 : 214-270. 
PIERCE, G. R., JEFFERSON, C.C., Jr. & Smirn, W. R. 1961. Fossiliferous Palaeozoic localities 
in Mérida Andes, Venezuela. Bull. Am. Ass. Petrol. Geol., Tulsa 45 : 342-375. 
Poéta, P. 1902. Anthozoaives et Alcyonaives. In BARRANDE, J. Systéme Silurien du 
centre de la Bohéme 8, 2 : vili + 1-347, pls 20-118. Prague. 
PRANTL, F. 1938. Some Laccophyllidae from the Middle Devonian of Bohemia. Ann. 
Mag. nat. Hist., London 11, 2 : 18-41, pls 1-3. 
RoeMEr, C. F.- 1861. Die Fossile Fauna dey Silurischen Diluvial-Geschiebe von Sadewitz bei 
Oels in Nieder-Schlesien, pp. xvi + 1-81, pls 1-8. Breslau. 
Ross, C. A. & Ross, J. P. 1962. Pennsylvanian, Permian rugose corals, Glass Mountains, 
Texas. J. Paleont., Tulsa 36, 6 : 1163-1188, pls 160-163. 
Rowett, C. L. & SUTHERLAND, P. K. 1964. Wapanucka Rugose Corals. Bull. Okla geol. 
Surv., Norman 104 : 1-124, pls 1-9. 
ScHouppr, A. VON. 1950. Kritische Betrachtungen zu den Rugosen-Genera des Formen- 
krieses Tvyplasma Lonsd.—Polyorophe Lindstr. Sbey. dst. Akad. Wiss., Wien 1, 159 : 75-85. 
— 1951. Beitrag zur Kenntnis des Baues und der Untergliederung des Rugosen-Genus 
Syvingaxon Lindstrém. Sber. dst. Akad. Wiss., Wien 1, 160 : 207-2106. 
1954. Korallen und Stromatoporen aus dem ef der Karnischen Alpen. Neues Jb. Geol. 
Paldont. Abh., Stuttgart 99 : 379-450, pls 25-27. 
SCHUCHERT, C. 10935. Historical geology of the Antillean-Cavibbean vegion, xxvi + 1-811. 
New York. 
SHAGAM, R. 1968. Commentary on the Caparo Area. Boln inf. Asoc. venezol. Geol. Min. 
Petyol, Caracas 11 : 171-181. 
SHELL & CREOLE. 1964. See Compamiia Shell de Venezuela & Creole Petroleum Corporation, 
1964. 
Simpson, G. B. 1900. Preliminary descriptions of new genera of Paleozoic rugose corals. 
Bull. N.Y. St. Mus., Albany 8, 39 : 199-222. 
SMITH, S. 1930. Valentian corals from Shropshire and Montgomeryshire, with a note on a 
new stromatoporoid. Q. J/ geol. Soc. Lond. 86 : 291-330, pls 26-29. 
1945. Upper Devonian corals of the Mackenzie River region, Canada. Spec. Pap. 
geol. Soc. Am., New York 59 : viii + 1-126, pls 1-35. 
STEARN, C. W. 1956. Stratigraphy and palaeontology of the Interlake Group and Stonewall 
Formation of southern Manitoba. Mem. geol. Surv. Can., Ottawa 281 : iv + 1-162, 16 pls. 
Strusz, D. L. 1961. Lower Palaeozoic corals from New South Wales. Palaeontology, 
London 4, 3 : 334-361, pls 42-45. 
Stumm, E.C. 1949 Revision of the families and genera of the Devonian Tetracorals Mem. 
geol. Soc. Am., New York 40 : viii + 1-92, pls 1-25. 
1963a. Silurian corals from the Moose River synclinorium, Maine. Prof. Pap. U.S. 
geol. Suvv., Washington 430—A : 1-9, pls 1-4. 
1963b. Ordovician Streptelasmid rugose corals from Michigan. Conty. Mus. Paleont. 
Univ. Mich., Ann Arbor 18 : 23-31, 2 pls. 
—— 1964. Silurian and Devonian corals of the Falls of the Ohio. Mem. geol. Soc. Am., 
New York 93 : x + 1-184, 80 pls. 
SUTHERLAND, P. K. 1965. MHenryhouse rugose corals. Bull. Okla geol. Suvv., Norman 
109 : 1-92, 34 pls. 
1970. A redescription of the Silurian rugose coral Syringaxon siluriense (McCoy). J. 
Paleont., Tulsa 44, 6 : 1125-1128, pl. 152. 
Sutton, I. D. 1964. The tabulate coral genus Cystihalysites from Wenlock and Dudley. 
Palaeontology, London 7, 3 : 452-457, pl. 74. 
Sytova, V. A. 1966. In Sytova, V. A. & Uxitina, L. M. Rugozy isenskoi i biotarskoi 
svit. V kn.: “Stratigrafiya i fauna siluriiskikh 1 nizhnedevonskikh otlozhenii Nurinskogo 
sinklinoriya”’. Mater. Geol. tsent. Kazakhst., Moscow 6 : 198-253, pls 35-48. (Not seen.) 


226 PALAEOZOIC CORAL FAUNAS 


Tuomas, I. 1905. Neue Beitrage zur Kenntnis der devonischen Fauna Argentiniens. Z. 
dt. geol. Ges., Berlin 57 : 233-290, pls 11-14. 

WanG, H.C. 1950. A revision of the Zoantharia Rugosa in the light of their minute skeletal 
structures. Phil. Tvans. R. Soc., London (B) 234 : 175-246, pls 4-9. 

WEDEKIND, R. 1927. Die Zoantharia Rugosa von Gotland (Bes. Nordgotland). Sver. 
geol. Unders. Afh., Stockholm, Ser. Ca, 19 : 1-95, 30 pls. 

WEISBORD, N. E. 1926. Venezuelan Devonian Fossils. Bull. Am. Paleont., Ithaca 11 : 221- 


256 (1-36), pls 35-41 (1-7). 

WEISSERMEL, W. 1939. Die Korallen des Thiiringischen Devons. Jb. preuss. geol. Landesanst. 
Berg Akad., Berlin 59 : 353-360, pl. 14. 

—— 1941. Korallen aus dem Unterdevon des 6stlichen und westlichen Schiefergebirges 
Thiiringens. Z. dt. geol. Ges., Berlin 93 : 163-212, pls 5-7. 

WELLs, J. W. 1943. Anthozoa. Jn LippLez, R. A., Harris, G. D. & WELLS, J. W. The 
Rio Cachiri Section in the Sierra de Perija, Venezuela. Bull. Am. Paleont., Ithaca 27: 


363-368 (95-100), pl. 36 (10). 
WHITEAVES, J. F. 1904. Description of a new genus and species of rugose corals from the 
Silurian rocks of Manitoba. Ottawa Nat. 18 : 113-114. 


VII. APPENDIX—LOCATION OF SAMPLES 


The following is the most accurate information available to the writer on the 
location of samples referred to in this paper. All the localities are in the southern 
Mérida Andes, western Venezuela. Sample numbers are prefixed ‘A’ for H. C. 
Arnold’s collection, ‘S’ for R. Shagam’s collection and ‘K’ for the collections of the 
Creole Petroleum Corporation. Location of the samples is also shown in Text-fig. 1. 


Samples A1030, A1035 (Palmarito Formation, Permo-Carbontferous). 

Section on the Quebrada Queveda (a tributary of the Rio Mucuchachi) approxi- 
mately 0-7 km due west of Portachuelo, Mérida State. Azo30 is stratigraphically 
0:5 m above the base of the Upper Palmarito limestone and A1035 is 45:5 m (in- 
cluding a break in the succession of 44 m which may conceal a fault) below the base 
of that limestone. 


Samples A2077, A2079, S1583, K80748 (Caparo II, Lower Llandovery). 

Section Io to 15 m thick on the south bank of the Rio Caparo at a pronounced 
bend in the river approximately goo m downstream of the Paso Caparo, Mérida 
State. Locality 2 of Shell & Creole (1964, table 1). 


Samples A2558-A 2582, S1302, SCr1, K162950 (Caparo IV, Ludlow). 

Upper part of the Silurian section on the Rio Aricagua, outcropping between 
approximately 4:1 km and 4:3 km upstream (measured direct) from the confluence 
of the Rio Aricagua and the Rio Caparo, Mérida State. Locality 7 of Shell & 
Creole (1964, table 1). 

The equivalence between Arnold’s collecting points (to which the measurements 
refer) and those of Shagam and Creole in the following table is approximate only. 


FROM THE MERIDA ANDES, VENEZUELA 227 


Stratigraphic thickness in metres above base of Silurian outcrop :— 


335 top of section 
$1302 
314 A2582 
308 A2579 
240°5 A2562 SCI 
237 A2561 t = 
oon A2ss8 | K162950 
0) base of section 


Sample 2722 (Palmarito Formation, Permo-Carbontferous). 

213 m above the base of the Palmarito Formation in the Quebrada El Meson, 
approximately 1-5 km west (measured direct) of its confluence with the Rio Aricagua, 
Mérida State. 


Samples S1540A, S2275D, S2275F (Caparo IV, Ludlow). 

Upper part of a section approximately 550 m thick measured from the strati- 
graphic base at the major elbow in the upper reaches of the Rio Suripa (see Text-fig. 
I) downstream to a point, about 200 m above a tributary entering from the west, 
where the stratigraphically highest sample was collected (S1540A), Barinas State. 
Samples S2275D and S2275F are approximately 100-150 m below sample S1540A 
in the sequence. 


C. T. Scrutton, B.Sc., D.Phil., F.G.S. 
Department of Geology 

UNIVERSITY OF NEWCASTLE UPON TYNE 
NEWCASTLE UPON TYNE 

NE1 7RU 


IIL ANIEIS, 
Syringaxon arnoldi sp. nov. 


Fic. 1. Cross-section (peel). R46740c (taken from holotype). x 6. 

Fic. 2. Longitudinal section in counter-cardinal plane; C on right (slide). R46740h (cut 
from holotype). x 6. 

Fic. 3. Cross-section (slide). R46741a. x 6. 

Fic. 4. Longitudinal section in counter-cardinal plane; C on left (slide). R46742h. x 6. 

Fic. 5. Cross-section (peel). R46745q. x 6. 

All Rio Aricagua section; Silurian, Ludlow. 


Syringaxon siluriense (M’Coy) 
Fic. 6. Cross-section (slide). A5468b (cut from holotype, Sedgwick Museum, Cambridge). 
Underbarrow, near Kendal, Westmorland, England; high Bannisdale Slates or lowermost 
Kirkby Moor Flags, Silurian, Ludlow, leintwardinensis zone. 6. 


Syringaxon suripaense sp. nov. 


Fic. 7. Cross-section (slide). R46746a (cut from holotype). x 6. 
Fic. 8. Cross-section (slide). R46747a. x 6. 
Both Rio Suripa section; Silurian, Ludlow. 


Columnaxon angelae gen. et sp. nov. 


Fic. 9. Longitudinal section in counter-cardinal plane; C on left (slide). R46748p (cut 
from holotype). x 6. 

Fic. 10. Cross-section (peel). R46750b. x 6. 

Fic. 11. Longitudinal section in counter-cardinal plane; C on left (slide). R46750e. x 6. 

Fic. 12. Cross-section (slide). R46749a. x 6. 

All Rio Aricagua section; Silurian, Ludlow. 


Lophophyllidium pelaeum (Jeffords) 


Fic. 13. Cross-section (peel). R46751b. x 3. 

Fic. 14. Cross-section (slide). R46751a. x 3. 

Fic. 15. Longitudinal section (slide). R46751c. x 3. 
Quebrada Queveda; Permo-Carboniferous (? Pennsylvanian). 


Lophophyllidium sp. cf. L. wewokanum Jeffords 


Fic. 16. Cross-section (peel). R46752a. x 3. 

Fic. 17. Longitudinal section in counter-cardinal plane; C on right (slide). R46752e. x 3. 
Fic. 18. Cross-section (slide). R46752c. x 3. 

Quebrada Queveda section; Permo-Carboniferous (? Pennsylvanian). 


All cross-sections orientated with the cardinal septum at top centre. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 5 PLATE 1 


PLATE, 2 
Lophophyllidium sp. 
Fic. 1. Cross-section (slide). R46753b. x 3. 


Fic. 2. Cross-section (peel). R46753a. xX 3. 
Quebrada El Meson section; Permo-Carboniferous (? Pennsylvanian). 


Lophamplexus sp. 


Fic. 3. Cross-section (peel). R46754a. x 3. 

Fic. 4. Cross-section (slide). R46754b. x 3. 

Fic. 5. Cross-section (peel). R46754c. x 3. 

Fic. 6. Longitudinal section in counter-cardinal plane; C on right (slide). R46754h. x 3. 
Quebrada El Meson section; Permo-Carboniferous (? Pennsylvanian). 


Streptelasma shagami sp. nov. 


Fic. 7. Cross-section (slide). R46755b (cut from holotype). x 2. 

Fic. 8. Cross-section (slide). R46755a (cut from holotype). x 2. 

Fic. 9. Longitudinal section in counter-cardinal plane; C on left (slide). R46755c (cut 
from holotype). x 2. 

Fic. 10. Cross-section (slide). R46756a. x 1°5. 

Both Rio Caparo, near the Paso Caparo; Silurian, Lower Llandovery. 


Streptelasma sp. 


Fic. 11. Cross-section (slide). R46761a. x 2. 
Fic. 12. Longitudinal section (slide). R46761c. x 2. 
Rio Caparo, near the Paso Caparo; Silurian, Lower Llandovery. 


Leolasma kaljoi sp. nov. 


Fic. 13. Cross-section (slide). R46762a (cut from holotype). x 6. 
Rio Caparo, near the Paso Caparo; Silurian, Lower Llandovery. 


All cross-sections orientated with the cardinal septum at top centre. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 5 


PLATE 3 
Leolasma kaljoi sp. nov. 


Fic. 1 (slide) and Fics 2—4 (peels). Serial cross-sections in base of calice. Fig. 1 (R46762a)— 
1-40 mm—Fig. 2 (R46762d)—1-34 mm—Fig. 3 (R46762e)—1-32 mm—Fig. 4 (R46762g). 
Cut from holotype. x 2°5. 

Fic. 5. Cross-section (slide). R46775a. x 2°5. 

Fic. 6. Cross-section (slide). R46766a. x 2°5. 

Fic. 7. Cross-section (slide). R46771a. xX 2:5. 

Fic. 8. Longitudinal section (slide). R46766b. x 3. 

All Rio Caparo, near the Paso Caparo; Silurian, Lower Llandovery. 


Cymatelasma aricaguaense sp. nov. 


Fic. 9. Cross-section (slide). R46778a. x 3. 

Fic. 10. Cross-section (slide). R46776a (cut from holotype). x 3. 

Fic. 11. Cross-section (slide). R46776b (cut from holotype). x 3. 

Fic. 12. Cross-section (slide). R46781a. x 3. 

Fic. 13. Longitudinal section (slide). R46779b. x 3. 

Fic. 14. Longitudinal section (slide). R46778c. x 3. 

Fic. 15. Longitudinal section (slide). R46776c (cut from holotype). x 3. 
All Rio Aricagua section; Silurian, Ludlow. 


All cross-sections orientated with the cardinal septum at top centre. 


7; 
a 


” 


“eb 
(4% 


PLATE 4 
Cymatelasma aricaguaense sp. nov. 


Fic. 1. Cross-section (slide). R46776b (cut from holotype). x 8. 
Rio Aricagua section; Silurian, Ludlow. 


Tryplasma sp. cf. T. nordica Stumm 


Fic. 2. Cross-section (slide). R46782a. x 5. 

Fic. 3. Longitudinal section (slide). R46783a. x 5. 
Fic. 4. Longitudinal section (slide). R46784g. x 16. 
Rio Suripa section; Silurian, Ludlow. 


Tryplasma sp. 


Fics 5, 6. Cross-sections (slides). R46785c. x 5. 

Fic. 7. Longitudinal section (shde). R46785a. x 4o. 

Fic. 8. Oblique sections (slide). R46785b. x 5. 

Fic. 9. Longitudinal and oblique sections (slide). R46785a. x 5. 
Rio Suripa section; Silurian, Ludlow. 


Coenites sp. 
Fic. 10. Cross-section (slide). R46786a. x Io. 
Fic. 11. Longitudinal section (slide). R46786b. x to. 
Rio Suripa section; Silurian, Ludlow. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 5 PLATE 4 
} f wo, ; so ow 
rs 


PLATE 5 
Cystihalysites brownsportensis (Amsden) 


Fic. 1. Cross- and longitudinal sections (slide). R46788c. x 4. 
Fic. 2. Cross-sections (slide). R46788a. x 4. 

Fic. 3. Cross-section (slide). R46788a. x 9. 

Fic. 4. Longitudinal section (slide). R46788b. x 4. 


Rio Suripa section; Silurian, Ludlow. 


Acanthohalysites sp. 
Fic. 5. Longitudinal section (slide). R46780f. x 4. 
Fic. 6. Cross-sections (slide). R46789a. x 4. 
Rio Suripa section; Silurian, Ludlow. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 5 


PLATE 5 


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| THE EARLIEST GOATS AND OTHER 


ary RAL 


ANTELOPES FROM THE SAMOS 
HIPPARION FAUNA 


A. W. GENTRY 


BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 
GEOLOGY Vol. 20 No. 6 
LONDON : 1971 


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THE EARLIEST GOATS AND OTHER ANTELOPES' ) 


FROM THE SAMOS HIPPARION FAUNA \ 


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BY 


ALAN WILLIAM GENTRY 


Pp. 229-296; 6 Plates, 16 Text-figures 


BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 
GEOLOGY Vol. 20 No. 6 
LONDON : 1971 


THE BULLETIN OF THE BRITISH MUSEUM 
(NATURAL HISTORY), istituted in 1949, 1s 
issued in five series corresponding to the Departments 
of the Museum, and an Historical series. 

Parts will appear at irregular intervals as they become 
veady. Volumes will contain about three or four 
hundred pages, and will not necessarily be completed 
within one calendar year. 

In 1965 a separate supplementary series of longer 
papers was instituted, numbered serially for each 
Department. 

This paper 1s Vol. 20, No. 6 of the Geological 
(Palaeontological) series. The abbreviated titles of 
periodicals cited follow those of the World List of 
Scientific Periodicals. 


World List abbreviation 
Bull. Br. Mus. nat. Hist. (Geol.) 


© Trustees of the British Museum (Natural History), 1971 


TRUSTEES OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 


Issued 15 July, 1971 Price £3 


iE HAs | GOATS AND OTHER ANTELOPES 
FROM THE SAMOS HIPPARION FAUNA 


By A. W. GENTRY 


CONTENTS 
Page 
I. INTRODUCTION : c : - . . : : : 231 
II. Systematics or Palaeoryx, Protoryx anp Pachytragus . : 5 233 
III. SySTEMATICS OF THE SPIRAL HORNED ANTELOPES : : 3 259 
IV. TRIBAL CLASSIFICATION . ; : : é ; 0 : 275 
V. CONCLUSIONS : ; ; 3 : : é ; é 292 
VI. ACKNOWLEDGEMENTS : ; : : : 5 3 : 292 
VII. SUMMARY : : ; 5 : : F : : : 293 
VIII. REFERENCES . : : : 3 : : : : : 293 
SYNOPSIS 


Lower Pliocene antelopes belonging to Palaeoryx, Protoryx and Pachytvagus and hitherto 
taken as Hippotragini, are revised and placed in the Caprinae. The species of Protragelaphus, 
Prostrepsiceros and Palaeoreas are likewise revised; the last two genera have normally been 
classified as Tragelaphini, but Pvostrepsiceyos should join Protragelaphus in the Antilopini 
and Palaeoreas is in the Ovibovini. Hippotragini and Tragelaphini are almost totally African, 
Caprinae and Ovibovini almost all Eurasian, and those Antilopini to which Pvrostvepsiceros 
and Protvagelaphus are related are also Eurasian. Thus the Samos fossil fauna contains no 
antelopes related to living African species; it is more properly seen as a stage in the evolution 
of Eurasian bovid faunas. 


I. INTRODUCTION 


Towarps the end of the nineteenth century Major (1888, 1891a, 1891b, 1894) 
collected fossil mammals on the Aegean island of Samos very close to the mainland 
of Turkey, and recognized a later Tertiary fauna similar to that already known 
from Pikermi in Attica. Much of his collection passed to the Geology Department 
of Lausanne University, some was purchased by the British Museum (Natural His- 
tory) in 1889 and 1890, and more pieces went to other museums. Before the First 
World War collectors provided material for geological institutes in Munich, Miinster 
in Westphalia and Stuttgart, and for the museum in Vienna, and in 1924 Brown 
collected for the American Museum of Natural History, New York. His field 
notebook contains meagre details of the quarries which he excavated, and their 


232 THE EARLIEST GOATS AND OTHER ANTELOPES 


positions were shown on a small map in Brown (1927 : Ig). Quarry I was in the 
Adriano district on land owned by the Soufoulis family; this quarry was near 
former German excavations and about 13 miles north of Mytlini; quarry 2 was 
in the Potamies district on land owned by Trifon Balidakis; quarry 3 was in the 
Megalosvrakos district on land owned by Trifon Balidakis, but no Bovidae are known 
from this quarry; quarry 4 was in the Potamies district on land owned by Dr 
Gliarmis; quarry 5 was in the Limitzis district on land owned by the widow Soumena; 
quarry 6 was in the Tholoramo or Vigles district on waste land. 

Despite all this collecting, there is little information on the geology of the fossili- 
ferous deposits. Stefani (im Stefani, Major and Barbey, 1892) acknowledged 
accounts of some earlier travellers, and noted two basins of Tertiary lacustrine or 
marshy deposits, that of Mytilini occupying a large part of the island east of Ambelos, 
and that of Karlovassi farther west. Brown (1927) gave a summary of the deposits. 
Schlosser (1904 : 112) noted from the matrix on the fossils that different associations 
of bovid species occurred in different compositions of the sediments. Abel (1922 : 
143) considered that the Samos fauna had been catastrophically annihilated in 
volcanic eruptions, but that the absence of associations of the skeletal parts indicated 
postmortem stream transport. 

J. A. Van Couvering (pers. comm.) writes as follows. “Tertiary sediments of the 
Mytilini district consist of well-bedded volcanic sediments—siltstones, sandstones, 
and volcanic pebble breccias—interlayered with freshwater algal limestones and 
marble cobble conglomerates (Van Couvering & Miller, 1970). The only authigenic 
minerals within the sequence are calcite (in the limestones and locally as cement 
in the sediments) and silica, which appears only in a thin-layered cherty limestone 
formation near the top of the sequence. No soil horizons appear to have been 
developed in the sequence, and no angular unconformities can be detected, indicating 
that deposition was more or less continuous. The sequence is one which seems most 
likely to have developed in a slowly subsiding intermontane basin surrounded by 
upfaulted marble basement and traversed by low-gradient streams carrying mostly 
fine-grained volcanic detritus from the nearby active Cappadocian pyroclastic 
province to the east (Westerveld 1957). The basin floor was periodically submerged 
in shallow lakes, probably after activity on the faults to the west and northeast 
which now show downthrow towards the basin, and the water in the lakes and in the 
subsurface was high in dissolved carbonate from the basement. The zeolites and 
authigenic feldspar which might have formed in a more arid, alkaline environment 
from the volcanic detritus (Hay 1966) are absent, which suggests that the steppe 
climate of the Samos fauna was more like that of the temperate zone grasslands 
than the African savannah. The fossils occur in a variety of volcanic sediment 
types (Schlosser 1904) in the main horizon at Adriandé (Soufoulis farm), but not in 
association with primary ash falls accounting for the deaths of the animals. Sug- 
gestions that the algal limestones formed in a Pontian “‘Aegan lake’’ (Spratt 1846) 
or that the alluvial beds are part of the valley fill in an ancient course of the Maeander 
or Menderes River (Brown 1927) are unsupported by the geological evidence.’ 

A group of antelopes which is more abundant at Samos than at any other site is 


FROM THE SAMOS HIPPARION FAUNA 238 


that of Palaeoryx and Pachytragus, and I shall here reconsider their classification. 
A second group in the Samos fauna which will be similarly treated contains the 
spiral-horned Protragelaphus, Prostrepsiceros and Palaeoreas. Two other lower 
Pliocene sites broadly contemporaneous with Samos will be referred to, those of 
Maragha in northern Persia (see Pohlig 1886 and Mecquenem 1908) and Pikermi 
in Greece (Woodward r1gor). Pikermi has material of Pvotoryx, a relative of 
Palaeoryx and Pachytragus, and Maragha has a diversity of spiral-horned antelopes. 
However, it is the presence of so many complete skulls, crania and dentitions of 
bovids and the large number of species in the Samos deposits, which give that fauna 
its decisive importance. Adequate discussion of these antelopes involves referring 
to other fossil genera, and necessitates giving opinions about their classification. 
Nevertheless my revision covers only species of the above six genera occurring at 
Samos, Pikermi and Maragha. During this study I have had access to previously 
published material in European museums and to unpublished material in New 
York. The initials BM(NH) indicate material in the British Museum (Natural 
History) in London, and AMNH in the American Museum of Natural History, 
New York. Measurements are always expressed in millimetres. 


Il. SYSTEMATICS OF PALAEORYX, PROTORYX AND PACHYTRAGUS 


The first of the Palaeoryx group to be discovered was the large Antilope pallasi 
Wagner (1857 : 149) from Pikermi, of which the type specimen is still in Munich. 
Gaudry founded the generic name Palaeoryx for this species although he actually 
intended the name as a subgenus. He likened the fossil particularly to Oryx among 
living antelopes and since then it has always been considered a member of the 
Hippotragini. Schlosser (1904 : 38 and 43) added two more species from Samos, 
P. majon and P. ingens, the latter based only on teeth, and Andree (1926 : 161) 
added P. laticeps. Some other species formerly supposed to belong to Palacoryx, 
particularly the fine later Pliocene skulls of ‘“Palaeoryx’ boodon and ‘Palaeoryx’ 
cordtert in Paris have been placed in a separate boselaphine or bovine genus Parabos 
by Arambourg and Piveteau (1929a : 144), and others may belong to Leptobos 
(Pilgrim and Hopwood 1928 : 74). 

Major (1891a : 608-609) founded the genus Protoryx for some antelopes from 
Samos similar to Palaeoryx, but having more compressed horn cores and sometimes 
a longer cranium. He considered Pyotoryx to have more striking resemblances to 
Hippotragini than did Palaeoryx. He referred to the new genus a Pikermi cranium 
figured but not named by Gaudry (1865 : 289, pl. 52 fig. 1 ‘Antilope d’espéce 
indéterminée’) and a skull from Maragha, BM(NH) M.3841 which was not figured. 
Four species were named as occurring at Samos, P. carolinae, P. longiceps, P. gaudryt 
and P. Mippolyte, none of which were given diagnoses or figures. P. carolinae is 
the only one he cited as occurring at Pikermi, and for this reason Pilgrim and 
Hopwood (1928) later selected P. carolinae as the name for Gaudry’s illustrated 
cranium, 


234 THE EARLIEST GOATS AND OTHER ANTELOPES 


Schlosser (1904 : 45) corrected the generic diagnosis in which Major had mistakenly 
referred to the braincase being very little angled on the face, referred three Samos 
skulls to P. carolinae Major (Schlosser 1904 : 45, pl. 9 figs 1, 4, 8) and a frontlet 
to P. cf. carolinae, founded a second species P. hentscheli on teeth only, and sug- 
gested that another new genus and species of his, Pseuwdotragus capricornis, might 
include material of Major’s nomina nuda Protoryx gaudryi and P. ippolyte. He 
founded a new genus and species Pachytragus crassicornis differing from Protoryx by 
having an anterior keel on the horn cores, rather divergent horn cores in anterior 
view, the braincase still more strongly angled on the face axis, and wide orbital 
rims. He also (1904: 87) established a subfamily Pseudotraginae to include 
Protoryx, Pseudotragus and Pachytragus along with Eotragus (=Eocerus), 
Protragocerus, Miotragocerus! and Neotragocerus. His definition of the new sub- 
family (1904 : 85) included the characters of strongly compressed goat-like horns 
and a long narrow face, and Palaeoryx remained a hippotragine. 

Andree (1926) referred new material to Protoryx carolinae, founded a new species 
P. crassicorms, a new variety laticeps of P. carolinae, and a new variety tenuicornis of 
P. hentschelt Schlosser. He founded a new species of Pachytvagus—P. schlosseri, 
referred a skull to Pseudotragus capricornis Schlosser, and founded a new species 
longicornis of Pseudotragus. Finally he referred one fossil skull to Hippotragus as 
the new species H. kopassi. He followed Schlosser’s consignment of the genera 
into Pseudotraginae and Hippotraginae. 

Pilgrim & Hopwood (1928 : 27, 30) selected P. carolinae as the type species 
of Protoryx with Gaudry’s skull in Paris as holotype. They added to P. carolinae 
two Pikermi skulls, BM(NH) M.10839 and M.11415, and one from Samos, M.4108, 
as well as two Lausanne skulls, 298 and 362, which Major (1894 : 28, 30) had labelled 
‘P. gaudryi’. They reduced P. crassicornis Andree to a variety of P. carolinae, but 
raised his variety /aticeps of P. carolinae to species level, assigning to it Lausanne 
skulls 28 and 201 and the maxilla 580 and Schlosser’s (1904 : 48) frontlet of P. cf. 
carolinae. They considered that Schlosser’s and Andree’s records of P. carolinae 
were not conspecific with Gaudry’s type skull or the other material they had just 
assigned themselves to this species, and used for it Major’s name P. longiceps with 
the Lausanne skull 22 as holotype and the Maragha skull BM(NH) M.3841 as para- 
type. Finally they took a skull in Lausanne, 30, labelled P. Mippolyte as the type 
of a new variety of Schlosser’s Pseudotragus capricorms. 

Bohlin (1936 : 17, 18) transferred the two London skulls M.10839 and M.11415 
from Protoryx carolinae to the related genus Palaeoryx, suggested confining the specific 
name carolinae to the actual Paris specimen and using P. gaudryi as the name for 


1] thank Q. B. Hendey for telling me of a paper by Kretzoi (1968) in which it is pointed out that the 
familiar generic names Tvagoceyus Gaudry 1861 and Microtvagus Andree 1926 for fossil antelopes are 
definitely preoccupied by beetles. Kretzoi proposed the new name Sporadotragus in place of Microtvagus. 
For Tvagocerus the next available name seems to be Miotyvagocervus Stromer. This name was published 
in 1928; Graecoryx, which I believe could have been applied to the same genus, was published 
by Pilgrim and Hopwood at some date close to 28th June 1928. This was the date at which the copy 
of their book in the Palaeontology Library of the British Museum (Natural History) was accessioned. 
In this paper I shall use Miotvagocerus in place of the junior homonym Tvagocerus. 


FROM THE SAMOS AHIPPARION FAUNA 235 


Samos ‘P. carolinae’, i.e. the Lausanne skulls 298 and 362. He thought the London 
Samos skull M.4198 was not a Protoryx, but he assigned to Protoryx many specimens 
previously put elsewhere: Andree’s specimens of Schlosser’s Pseudotragus capri- 
cornis, of Pseudotragus longicornis, Pachytragus schlossert and Hippotragus kopasst, 
and Pilgrim and Hopwood’s Pseudotragus capricornis var. hippolyte. There was 
no skull from Pikermi which agreed with any of the Samos Protoryx, and this 
threatened a nomenclatorial revision since the type cranium of Protoryx carolinae 
was a Pikermi fossil. None the less he continued to use the genus Protoryx for 
Samos specimens, although he considered that they represented a group which, 
like Chilother1um Ringstrom and Samotherium Major, never spread as far as Pikermi. 
He attempted no revision at the species level, but did propose that Palaeoryx 
could not be in a separate family (=tribe of Simpson’s 1945 classification) from 
Protoryx. From this it seemed to follow that they would all pass into the Hippo- 
tragini, and that the group ‘Pseudotraginae’ in which they were wrongly linked 
with Eotragus, Protragocerus, Miotragocerus and Neotragocerus would be abolished. 
Already in his work on Chinese lower Pliocene Bovidae Bohlin (1935c : 119) had 
doubtfully referred the two genera, with some related Chinese forms, to Hippotragini. 
Neither Pilgrim (1939 : 26-27) nor Gentry (1967 : 266) challenged this view, but 
Sokolov (im Orlov 1968 : 537) had doubts. It is now the purpose of this paper 
to interpret Pachytragus and possibly Protoryx as members of the tribe Caprini, 
and Palaeoryx as an ovibovine. Although I do not place all three genera in one 
tribe, there is no doubt that in the lower Pliocene time level they were closely 
related. 


Palaeoryx, Protoryx and Pachytragus differ from the contemporaneous and 
commonly fossilized boselaphine Miotvagocerus by not having a stepped anterior 
keel, by having horn cores less strongly compressed medio-laterally, a braincase 
more strongly angled on the face axis and without temporal ridges on its dorsal 
surface, a higher infraorbital foramen, a wider mastoid exposure of the periotic, 
and smaller foramina ovalia. 


Skull characters shared by Palaeoryx, Protoryx and Pachytragus are horn cores 
without transverse ridges or torsion; the postcornual fossa, lying postero-laterally 
to the horn core base, is shallow or altogether absent ; the braincase top is at an angle 
to the line of the face axis; the parieto-frontals suture has only a slight anteriorly 
directed indentation centrally or none at all; temporal lines are not developed as 
strong ridges and do not approach one another very closely; the supraorbital pits 
are small; the preorbital fossa is large and shallow and sometimes has an upper 
rim; the back edge of the infraorbital foramen is fairly high over P2-3 or P3; the 
median indentation at the back of the palate is level with the lateral ones or passes 
slightly anterior to them; the mastoid exposure of the periotic has a moderate or 
large area; posteriorly the ventral edge of the auditory bulla may pass downwards 
where it meets the front of the paraoccipital process; there are no goat folds (anterior 
transverse flanges) on the lower molars; the lateral lobes of the lower molars are 
not drawn out transversely. These characters could be considered for inclusion 
in the definition of any tribe or subfamily to which the three genera belong. 


2360 THE EARLIEST GOATS AND OTHER ANTELOPES 


Genus PALAEORYX Gaudry 


1861a Palaeorvyx Gaudry : 241. 
1861b Palaeoryx Gaudry : 393. 


TYPE SPECIES. Antilope pallasi Wagner, 1857 : 149, pl. 9, fig. 21. 
GENERIC DIAGNOSIS. As for the species. 


Palaeorysx pallasi (Wagner) 


1857 Antilope pallasi Wagner : 149, pl. 9 fig. 21. 

1861a Palaeoryx pallast Gaudry : 241. 

1861b Palaeoryx speciosus Gaudry : 393, pl. 9 figs 1-3. 

1865 Palaeoryx pallasi Gaudry : 271, pl. 47 figs 1-5. 

1894 Palaeoryx votundicornis [nom. nud.) Major : 24. 

1904 Palaeoryx major Schlosser : 38, pl. 7 figs 1-5. 

1926 Palaeoryx laticeps Andree : 161, pl. 13 figs 4, 4a, 6. 

1928 Palaeoryx woodwardi Pilgrim & Hopwood : 77, pl. 6 fig. r. 
1928 Palaeoryx woodwardi var. columnatus Pilgrim & Hopwood : 78. 


Lectotype. The cranium at Munich figured by Wagner, and designated by 
Pilgrim & Hopwood (1928 : 75). It has survived the Second World War. 


Locatitigs. Pikermi, Samos. 
AGE. Lower Pliocene. 


Diacnosis. Moderate to large sized antelopes with a low and wide skull; horn 
cores are of short to moderate length, little compressed medio-laterally, without 
keels, set fairly obliquely in side view and widely apart, moderately divergent in 
anterior view, tips reapproaching slightly; braincase is short and wide; orbital rims 
are moderately projecting; frontals between the horn bases are a little higher than 
the orbital rims; mid-frontals suture is not raised; mid-frontals and parieto-frontals 
sutures are not usually complicated; sides of braincase are generally parallel, but 
sometimes widening anteriorly or posteriorly; supraorbital pits are set widely 
apart; ethmoidal fissure is present; zygomatic arch is deep at its anterior end where 
it passes beneath the orbit; back edge of tooth row is slightly anterior to the level 
of the front of the orbit. 

Occipital surface faces almost unitormly backwards; the median vertical occipital 
ridge is well marked and the hollows on either side of it moderately so; the anterior 
tuberosities of the basioccipital are set rather widely apart; basioccipital usually 
has some indication of a central longitudinal groove; foramina ovalia are moderately 
sized; auditory bulla is small to moderate sized and moderately inflated. 

Brachyodont cheek teeth; enamel may be somewhat rugose; basal (or accessory) 
pillars are moderate-sized to small on lower molars and small to absent on uppers; 
there are indentations into the back edge of the rear central cavities of the upper 
molars; the rear of the front medial lobe and the front of the rear medial lobe on 
the upper molars fuse only relatively late in wear; styles are not very prominent 


FROM THE SAMOS AIPPARION FAUNA 237 


on upper molars or premolars; ribs between parastyle and mesostyle of upper molars 
are sometimes strong; premolar row is long with scarcely reduced front premolars. 

REMARKS. Previously named specimens. The horn cores of the lectotype 
diverge rather less than is normal in the species, and this was partly the reason 
for founding some of the synonymous species names. However some other fossils 
have previously been referred to Palaeoryx pallasi. These are a skull from Pikermi 
now in Paris which was figured by Gaudry (1865 : 271, pl. 47 fig. 1); a Lausanne 
specimen, 198, from Samos with part of its left horn core and most of the braincase ; 
a Miinster skull referred to by Andree (1926 : 160, pl. 15 fig. 7) with rather a narrow 
cranium and small horn cores, probably a female; a cranium from Pikermi in the 
Vienna museum labelled P. pallast; and a Pikermi skull and cranium, BM(NH) 
M. 10831 and M.11426, referred to P. pallasi by Pilgrim & Hopwood (1928 : 76). 
M.11426 has its horn core perhaps badly stuck on but certainly curving strongly 
backwards, and it is M.10831 which indicates the presence of an ethmoidal fissure 
in this species. The skull of P. pallasi from Maragha (Mecquenem 1924 : 31, 
pl. 4 fig. 1) is really a Miotragocerus as noticed by Bohlin (1936 : 14), and there is no 
other convincing evidence of Palaeoryx pallasi from Maragha. I have not seen the 
two Stuttgart skulls mentioned by Andree (1926 : 160, pl. 12 fig. 8) as possibly 
females of P. pallast. 


The Lausanne skull, 200, of Palaeoryx rotundicornis Major has already been 
referred by Pilgrim & Hopwood (1928 : 75) to P. pallasi. A Lausanne cranium 
with horn core bases, 29, was also taken as P. votuwndicornis by Major (1894 : 18), 
but is also P. pallasi. The anterior tuberosities of the basioccipital of 29 are rather 
wider apart than in 200. 

The cranium of P. majori Schlosser (1904, pl. 7 figs 5, 5a, 5b) in Munich has fairly 
straight, very divergent horn cores which show considerable inward curvature at 
the tips. According to the diagnosis the orbits are situated entirely beneath the 
horn cores, but this character is difficult to use in bovids with such obliquely inserted 
horns, and I could not see that any difference existed between this species and the 
lectotype of P. pallast. The horn core characters, larger braincase, rounded orbits, 
and supposedly smaller primitive teeth do not justify a separate specific name. 
Andree (1926 : 161) placed a Samos cranium in Vienna, IgII.v.g, in P. majori, and 
this too can be taken as P. pallast. Schlosser (1904 : 43, pl. 8 figs 3-5) also founded 
a species Palaeoryx ingens on teeth, but I would not be certain that they even belong 
to Palaeoryx (see also p. 239). The holotype of Andree’s P. laticeps is a cranium 
with a low wide braincase, horn cores rather strongly curved backwards, thick and 
robust. These, and other linked characters given in his diagnosis essentially 
amount to a wide skull and backward horn core curvature, and are insufficient to 
carry the specimen beyond a likely range of variation for P. pallasv. 

P. woodward, BM(NH) M.10832, was alleged by Pilgrim & Hopwood to differ 
from P. pallasi in its more divergent and narrower horn cores, which with the frontals 
are smaller relative to the rest of the skull. The horn cores certainly are small but 
all that this and other invoked characters demonstrate is a less robust skull which is 
possibly of a female. It is true that there are no basal pillars on the upper molars, 


238 THE EARLIEST GOATS AND OTHER ANTELOPES 


but teeth assigned by Schlosser (1904, pl. 7 fig. 1) to P. majort have a small basal 
pillar only on M2. The greater divergence of the horn cores in this species agrees 
with those called laticeps and majori, but there is not the inward curvature of the 
tips. The variety columnatus of P. woodwardi was based on a Lausanne skull 199 
and a London palate M.11416. The palate was noted to be too wide for Protoryx 
cavolinae {but was mistakenly assigned to that species on another page (Pilgrim & 
Hopwood 1928 : 30)]._ Basal pillars are present on all molars, as in most upper 
molars of Palaeoryx pallasi, and the supposed hypsodonty and weak development 
of mesostyles are insufficient to separate it from P. pallasi. The preserved right 
horn core of 199 is very narrow, widely divergent with little inward curving at the 
tip, and set obliquely. 

Palaeoryx pallast is not represented by skulls, crania or frontlets in the Samos 
collection of the American Museum of Natural History. 


Infraspectfic variation 


I have not found differences between the Samos and Pikermi representatives of 
this species, but there is a fair amount of individual variation. Thus the Vienna 
specimen from Samos shows a flattening of the lateral surface of the horn cores. 
The mid-frontals sutures are complicated in the London and Vienna skulls from 
Pikermi but less so in Lausanne skulls 29 and 200 from Samos; the frontals-parietal 
suture has almost no central indentation in the Lausanne skulls but more in others. 
The braincase widens anteriorly in the Munich skull from Samos and in BM(NH) 
M.10831 from Pikermi, but in Lausanne 200 and the Miinster specimen figured by 
Andree (1926, pl. 13 figs 4, 6) it widens slightly posteriorly, and in BM(NH) M.10832 
and both Vienna skulls its sides are nearly parallel. The back edge of the infra- 
orbital foramen is high over the middle or back of P? in M.10831 and Lausanne 
skulls 199 and 200, but over the P2-3 junction in the Paris example. The Minster 
specimen shown in Andree (1926, pl. 15 fig. 7) has the median indentation at the 
back of the palate behind the level of the lateral ones. The occipital median ridge 
and flanking hollows are quite strongly developed in Lausanne skull 198. In 29 the 
strong median ridge gives the appearance of the occipital surface facing two ways. 
The basioccipital has a central longitudinal groove in most pieces but not in Lausanne 
29 (Pl. 1 fig. 2) and 200. Moderately sized foramina ovalia may be seen in Lausanne 
198 and BM(NH) M.10831, and larger ones in the Minster skull figured by Andree 
(1926, pl. 13 figs 4, 6). The downturning of the lower edge of the auditory bulla 
into the paraoccipital process is seen in Lausanne 29 (PI. 1 fig. 1) and in the Minster 
skull figured by Andree (1926, pl. 13 figs 4, 6). Both specimens have quite small 
auditory bullae, that of 29 perhaps more inflated than in the Minster specimen. 
The bulla of the other Minster skull (Andree 1926, pl. 15 fig. 7) is slightly larger 
and the back does not pass down into the paraoccipital process. 

Some mean skull measurements of Palaeoryx pallasi, together with ranges, 
standard deviations and coefficients of variation are shown on Table 2 p. 258. 
With individuals coming from both Pikermi and Samos and with the possibility 
of female animals having been included, there are high coefficients of variation. 


FROM THE SAMOS HIPPARION FAUNA 239 


Tooth characters 


The upper teeth of Palaeoryx pallasi are known from the London skulls M.10831 
and M.10832, the Paris skull illustrated by Gaudry (1865, pl. 47 fig. 1), the Lausanne 
skulls 199 and 200, and from the skull in Minster illustrated by Andree (1926, 
pl. 15 fig. 7). They are distinguished from teeth of the similarly sized Samos 
ovibovine Criotherium argalioides Major by the latter’s rounded medial lobes of the 
upper molars and premolars, massive P2, relatively long and narrow upper molars, 
lower premolars with transversely-running rather than diagonal front and back 
edges, the somewhat rounded outline of worn lateral lobes of the lower molars, 
not very outbowed medial walls of the lower molars, their straighter central cavities, 
and the small basal pillars set away from the main body of the tooth. 

They are more difficult to distinguish from Mzotragocerus. Even their great 
size is not decisive, since a larger species of Miotvagocerus than M. amalthea is known 
from Samos and Maragha (p. 243 below). This animal, which is quite definitely 
not a Palaeoryx by the lack of bending of its braincase, its temporal ridges, its horn 
cores being medio-laterally compressed at least in their higher parts, fails to show 
even the distinctive large P? of the smaller Miotvagocerus species. 


Individual dentitions 


Even complete upper or lower dentitions are very difficult to identify unless they 
are attached to complete skulls or associated with horn cores. The palate which 
Roth & Wagner (1855 : 452, pl. 14 fig. 1) described as Antilope speciosa may belong 
to P. pallasi or to some other species. It is not identifiable from the illustration, 
although Gaudry (1861a : 240; 1861b : 393) took it as the same species as P. pallast. 

In the Munich collection the upper dentition figured by Schlosser (1904, pl. 7 
fig. 1) as Palaeoryx majori can perhaps be assigned to P. pallasi. The late joining 
up of the back of the front lobe of M2 can be seen, and the incipient bilobing of P3 is 
slightly less than it appears on the drawing. By the relative sizes of individual 
premolars this is slightly more likely to be Palaeoryx than a large Miotragocerus. 
The deciduous premolars and lower molar shown in pl. 7 figs 2 and 3 could be P. 
pallasi, but I would not identify them thus with certainty. The lower dentition of 
pl. 7 figs 4, 4a is more likely to belong to a Mzotragocerus by the large size of its Pz and 
the shallowness of the ramus. The Munich teeth assigned by Schlosser (1904, 
pl. 8 figs 3, 4, 5) to Palaeoryx ingens, supposedly differed from P. pallasi by their 
large size and molars with more angular crescents. The generic attribution is 
doubtful, but if it were correct there would be no reason to separate the teeth from 
P. pallasi. The basal pillars on the lower molars stand clear of the body of the tooth. 

A large palate from Pikermi in London, BM(NH) M.11416, was figured by Pilgrim 
& Hopwood (1928, pl. 5 fig. 1, 1a) as Palaeoryx woodwardi var. columnatus, and is 
very large, as much so as AMNH 20587. As with the above specimens there is 
the difficulty of deciding whether it might be referable to a large Miotragocerus 
species. 

A possible specimen of Palaeoryx pallasi teeth in New York is AMNH 20587 
from quarry 5. It is a large palate in which the permanent premolars are just 


240 THE EARLIEST GOATS AND OTHER ANTELOPES 


coming into wear. The molars have strong ribs between their parastyles and 
mesostyles such as exist in the Palaeoryx pallast skull BM(NH) M.10831 and tapered 
and pointed medial lobes, the premolars are narrower than in Criotherium, there 
are no basal pillars, there are indentations into the rear central cavities of the M2s; 
in no molars are the medial lobes joined to one another or to the lateral side of the 
tooth in its centre, and the infraorbital foramen is above the back of P3. The 
P4s are somewhat twisted in their sockets, a distortion also seen in the next palate 
below. The brachyodonty can be assessed from the measurements: height of 
mesostyle on little worn M3 from the base of the enamel = 20-3 and length = 26-4 at 
the occlusal surface and 29-7 as the maximum at a lower level. 

AMNH 20751 is another palate from quarry 4, with rather more worn teeth than 
the above. The left P2 is absent (present in life), the left P4 is twisted in its socket, 
and some molars are damaged. It is a smaller palate than 20587, P2 may be rela- 
tively smaller and P3 is certainly smaller than in 20587. Other characters are narrow 
and pointed medial lobes, no basal pillars, strong ribs between parastyle and meso- 
style, no spurs into central cavities (at this stage of wear), mesostyles less marked 
(again at this state of wear), infraorbital foramen above back of P3. 

AMNH 20643 from quarry I is a very damaged palate; all teeth except the right 
P2 have survived but only the left P2 and mnght M3 are undamaged. The teeth 
are well worn although the molars still have their central cavities. The basal 
pillars are small, and the left M2 shows what was probably a strong rib between 
parastyle and mesostyle. 

AMNH 86627 from quarry I is a palate in middle wear with all its teeth except 
the left P?, but slight damage to some teeth. It is a little smaller than the pre- 
viously mentioned fossils, and does not have strong ribs between parastyle and 
mesostyle. There are very small basal pillars on M? and M3. 

AMNH 86465 a left P3-M3 and 86570 a left upper molar from quarry 1 could also 
belong to Palaeoryx pallasi. 

A number of fossils in Lausanne may belong to P. pallasi: a right rather worn 
maxilla, 519, a worn left mandible 411 with P,—P, and the anterior part of the 
medial wall of Py closed, a left mandible 888 with P3-Mj, a left mandible fragment 
1095 with a broken M; and M2 + Msz, and a right mandible fragment 1264 with 
Mz and Ms. However the identity of the mandibles is not certain, and lower tooth 
characters were not included in the diagnosis of Palaeoryx pallast. 

There are also dentitions in the Miinster collection which could belong to P. 
pallast. 


CoMPARISONS. Bohlin (1935c : 138, text-figs 119-126) refers to Palaeoryx 
sinensis and Palaeoryx sp. from the Chinese lower Pliocene. He wrote that P. 
sinensis was so close to P. majori (here included in P. pallast) that it could be the 
same species. The same would probably apply to Palaeoryx longicephalus Sokolov 
(1955 : 219, fig. 2) from the upper Miocene or lower Pliocene of Novocherkassk. 
We may conclude that the single species P. pallasi or a superspecies of which it was 
part was widespread in the lower Pliocene. Sinoryx bombifrons Teilhard de Chardin 
& Trassaert (1938, pl. I fig. 5, text-figs 37, 38) could also belong here; the pictures 


FROM THE SAMOS HIPPARION FAUNA 241 


of it much resemble a crushed cranium of Palaeoryx pallasi, 1122, in Lausanne, 
except that its tooth row may be placed too posteriorly. Palaeoryx athanasim 
Simionescu (1922 : 452; 1930 : I2I, 145, text-figs 60-66, pl. 4 figs 2, 3, pl. 5 fig. 1) 
from the Romanian site of Malusteni of Plaisancian age is later than other Palaeoryx. 
Its tooth row is also rather too posterior for it to be satisfactory as Palacoryx, 
although its small central incisors support the idea of it as some kind of caprine. 


Genus PROTORYX Major 


1891a Protoryx Major : 609. 
1892 Protoryx Major in Stefani, Major & Barbey : 94. 


TYPE SPECIES. Protoryx carolinae Major, 1891a : 608. 


GENERIC DIAGNOSIS. The type species is the only one here included in the genus. 
It is known only from Pikermi. 


Protoryx carolinae Major 


1865 Antilope d’espéce indéterminée. Gaudry : 289, pl. 52 fig. 1. 
1891a Protoryx carolinae Major : 608. 
1928 Pyrotovyx carolinae Major. Pilgrim & Hopwood : 30, pl. 3 figs I, 3. 


Hototyre. The cranium from Pikermi in Paris figured by Gaudry. 
LocaLity. Pikermi. 
AGE. Lower Pliocene. 


Diacnosis. Differs from Palaeoryx pallasi in its slightly smaller size. The skull 
is high and narrow rather than low and wide; horn cores are long, somewhat com- 
pressed in the medio-lateral plane, with a tendency to a flattened lateral surface, 
widest posteriorly, without keels, more uprightly inserted in side view than in 
Palaeoryx pallasi and appearing to insert less posteriorly, set closer together 
at their bases, not very divergent in anterior view, strongly curving backwards, 
horn core tips scarcely reapproach; sides of the braincase are more or less parallel; 
the braincase is narrow in dorsal view; orbital rims project moderately; the frontals 
are a little higher between the horn bases than are the orbital rims; the mid-frontals 
suture is not very raised; the mid-frontals and parieto-frontals sutures are not very 
complicated; supraorbital pits are set widely apart; the large ethmoidal fissure is 
not narrow (BM(NH) M.11415); zygomatic arch is deep anteriorly (BM(NH) 
M.11415); tooth row may be less anteriorly placed than in Palaeoryx pallasi; each 
half of the occipital surface tends to face partly laterally as well as backwards; 
basioccipital is narrow perhaps with a less clear central longitudinal groove than in 
Palaeoryx pallasi; moderately large auditory bulla. Tooth characters as in Palaeoryx 
pallast. 


242 THE EARLIEST GOATS AND OTHER ANTELOPES 


REMARKS. The differences of Protoryx carolinae from Palaeoryx pallasi very 
largely amount to a narrower skull (Text-fig. 1) and associated features such as 
narrower, more uprightly inserted and backwardly curved horn cores. Otherwise, 
and particularly in its tooth characters, there is very little difference. The holotype 
cranium and left horn core in Paris and two skulls in London are all from Pikermi. 
The Paris specimen shows clearly that the frontals, including the horn pedicel, are 
hollowed, and is not preserved sufficiently far anteriorly to show the supraorbital 
pits. 

Pilgrim & Hopwood (1928 : 32) provisionally assigned to P. carolinae a Samos 
skull with mandibles, atlas and axis vertebrae, BM(NH) M.4198. Bohlin (1936 : 3) 
rejected this identification, and I follow him. The braincase of this skull is hardly 


80 100 120 


er 2° |. BRAINCASE LENGTH 


2.WIDTH ACROSS HORN BASES 


3. ANT.- POST. DIAMETER OF HORN CORE 


4. LENGTH M! -m3> 


A. Palaeoryx pallasi C. Pachytragus laticeps 
B. Pachytragus crassicornis D. Protoryx carolinae 


Fic. 1. Percentage diagram of the means of four measurements on skulls belonging to 
the Palaeoryx-Pachytragus group of antelopes. Palaeoryx pallasi has been used for the 
standard line at 100%; the mean readings for other species are expressed as percentages 
of the mean reading in P. pallasi. Both Pikermi and Samos specimens contribute to the 
readings for P. pallasi, and tooth measurements were taken only from identified skulls. 
The maximum numbers of readings for each species were: P. pallasi 11, Protoryx cavolinae 
3, Pachytragus laticeps 25, P. crassicoynis 13, but the full number of readings was not 
available for every measurement. Horizontal lines show the extent of the standard 
deviations for P. laticeps. Note the slightly smaller size and narrow skull of Protoryx 
cavolinae compared with Palaeoryx pallasi, the rather large horns in Pachytragus laticeps 
compared with Protoryx carolinae, and that the teeth of Pachytvagus crassicornis are 
only a little smaller than in P. laticeps. 


FROM THE SAMOS HIPPARION FAUNA 243 


at all angled on the face axis, and I believe that it belongs to the Boselaphini. 
Along with a number of other skulls in various collections from Samos and Maragha, 
it is likely to be a species related to Miotragocerus amalthea but somewhat larger. 
Prodamaliscus gracilidens Schlosser (1904 : 29, pl. 4 fig. 6, pl. 6 fig. 4) may also 
have been this species, but the specimen was probably destroyed during the Second 
World War. Pilgrim & Hopwood (1928 : 30) had P. carolinae at Samos on the basis 
of Lausanne skulls 298 and 362, but Bohlin (1936 : 4) has already pointed out that 
362 is a Miotragocerus, and I accept neither skull as P. carolinae (see p. 250 below). 
The Pikermi mandibles in London referred by Pilgrim & Hopwood (1928 : 32) to 
P. carolinae could well be of that species, but I would not be certain of the identi- 
fication. 


CoMPARISONS. It is interesting that Protoryx carolinae shows some similarities 
to ?Protoryx planifrons from the Chinese lower Pliocene of Kansu described by 
Bohlin (1935c : 119, text-figs 88—-g1, pl. 15 fig. 5). It is not likely, so far as I can 
see, that ?P. shansiensis Bohlin (1935c : 123, text-figs 92-94) or ?Protoryx sp. 
(Bohlin 1935c : 125, text-figs 95, 96) are distinct species from ?P. planifrons. This 
Chinese species agrees with Palaeoryx pallasi and with Protoryx carolinae in being 
a large antelope, its supraorbital pits set widely apart, the parieto-frontals and 
mid-frontals sutures not very complicated, possibly a deep zygomatic arch anteriorly, 
the molar teeth not very hypsodont, with basal pillars and long premolar rows. 
In addition it resembles P. carolinae in the fairly upright horn core insertions, the 
relative height of the skull, and in the greatest width of the horn core section lying 
posteriorly, but a central longitudinal groove on the basioccipital and perhaps the 
divergence of the horn cores take it closer to Palaeoryx. With its especially massive 
horn cores and notably small supraorbital pits it must represent an East Asian 
development of the Protoryx stock unparalleled at more western sites. The skull 
M.1295 in Uppsala of ?Protoryx shansiensis has a thick parietal bone and an ex- 
tremely small and narrow ethmoidal fissure. 

There is no reason to suppose that the antelopes referred in the same paper to 
Prosinotragus and Sinotragus (Bohlin 1935c : 130, 133) are other than a more 
extreme development from the same ancestry as Protoryx planifrons. Their horn 
cores have become very short and thick, compressed with an anterior keel above, 
with a clockwise torsion in the right horn core, a short braincase much angled on the 
face, wide nasals, a quadrangular basioccipital, small foramina ovalia, and small 
to moderately inflated auditory bullae, but still a large preorbital fossa and rather 
unadvanced teeth. It is interesting that clockwise torsion in the right horn core 
has developed in this stock as well as in the smaller Ozoceros. Protoryx carolinae 
could be an ancestor or a western ancestral-like member of this group. In this case 
the ultimate nomenclatorial procedure would be to extend the name Protoryx to 
the whole Chinese group, and not to sink a monospecific Protoryx carolinae in 
Palaeoryx. 

Paraprotoryx founded by Bohlin (1935c : 126, figs 97-104) for other Chinese 
specimens with a fairly well rounded horn core section, is probably related to 
Protoryx. 


244 THE EARLIEST GOATS AND OTHER ANTELOPES 


Genus PACHYTRAGUS Schlosser 
1904 Pachytragus Schlosser : 56. 
TYPE SPECIES. Pachytragus crassicornis Schlosser, 1904 : 56. 


GENERIC D1aGnosis. Smaller than Palaeoryx or Protoryx; skulls are fairly 
narrow; horn cores are moderately long to long, medio-laterally compressed, more 
uprightly inserted even than in Protoryx and appearing to rise more directly above 
the orbits than in Palaeoryx, set closer together, little divergent, the widest part 
of their transverse section lying mid-way along their antero-posterior diameter, 
hollowed close to their bases; frontals are higher between the horn bases than in 
Palaeoryx or Protoryx ; mid-frontals suture is rather raised ; mid-frontals and parieto- 
frontals sutures are quite complicated; braincase has parallel sides or widens 
anteriorly; supraorbital pits are less small and less widely spaced than in Protoryx 
carolinae; nasals are long, domed and have a narrowly drawn out back suture; 
ethmoidal fissure is long and narrow; zygomatic arch has not deepened anteriorly; 
occipital surface is in two planes with each half facing partly laterally as well as 
backwards; basioccipital is narrow; foramina ovalia are small to moderate; auditory 
bullae are moderate to large; the ventral edge of the bulla may pass downwards 
posteriorly on to the front edge of the paraoccipital process, instead of rising to make 
the join. 

The teeth are more hypsodont than in Palaeoryx pallasi or Protoryx carolinae; 
their enamel is only slightly rugose; basal pillars are very small or absent on upper 
molars and small on lower molars; there is no late joining of the medial lobes of the 
upper molars; the upper molars have a strong mesostyle with a tendency for the 
lateral wall behind to acquire a concave section; the rib between parastyle and 
mesostyle is not strong; medial walls of lower molars are little outbowed between 
the stylids; premolar row is short; styles are fairly strong on upper premolars; 
hypoconid of Py, is quite pointed so that the lateral wall in front of it appears 
indented; metaconid of Py, is rather bulbous in middle wear; paraconid of Py is 
not joined with the metaconid to close the anterior part of the medial wall; P? 
smaller than in Palaeoryx pallast and Protoryx carolinae. 


Contained species: Pachytragus crassicornis Schlosser, the type species. 
Pachytragus laticeps (Andree). 


REMARKS. The most important difference of Pachytragus from the antelopes 
previously considered, and the one which principally justifies its generic rank 
and indicates the origin of a new adaptive zone (definition of Simpson 1953 : 201) is 
its advanced teeth. The diagnostic features of these teeth are illustrated in Text- 
fig. 5. A more stable support for the horn cores of Pachytragus is perhaps indicated 
by the decline of the anteriorly deepened zygomatic arch. Pachytvagus as con- 
ceived here contains many specimens formerly placed in Protoryx. 


Pachytragus laticeps (Andree) 


1891a Pyrotoryx carvolinae (in part) Major : 608. 
1891a Protoryx longiceps [nom, nud.} Major : 608. 


FROM THE SAMOS HIPPARION FAUNA 245 


1891a Protoryx gaudvyi {nom. nud.] Major : 608. 

1891a Protoryx hippolyte [nom. nud.] Major : 608. 

1904 Protorvyx cavolinae Major. Schlosser : 45, pl. 9 fig. 8. 

1904 Protoryx cf. cavolinae Schlosser : 48. 

1924 Protoryx cavolinae Mecquenem : 33, pl. 5 figs 3, 4. 

1926 Protoryx cavolinae Andree : 151, pl. 12 figs 3, 3a, 4. 

1926 Protoryx carolinae var. laticeps Andree : 153, pl. 12 figs 5, 9. 

1926 Protorvyx hentscheli Schlosser. Andree : 154, pl. 12 fig. 2, pl. 13 fig. 9. 
1926 Protoryx hentscheli var. tenuicornis Andree : 155, pl. 12 fig. 6, pl. 13 fig. 2. 
1926 Protovyx crassicovnis Andree : 156, pl. 12 fig. 1, pl. 13 fig. 8. 

1926 Hippotragus kopassi Andree : 158, pl. 15 figs 8, ro. 

1928 Protoryx longiceps Pilgrim & Hopwood : 34, pl. 3 figs 2, 2a, pl. 5 figs 2, 2a. 
1928 Protoryx carolinae var. crassicovnis Andree. Pilgrim & Hopwood : 33. 
1928 Pseudotyvagus capricornis var. hippolyte Pilgrim & Hopwood : 4o. 

1928 Protoryx laticeps Andree. Pilgrim & Hopwood : 36, pl. 4 figs 1-3. 


Hototyre. The skull in Minster figured by Andree (1926, pl. 12 figs 5, 9). 
Localities. Samos, Maragha. 
AGE. Lower Pliocene. 


Diacnosis. Horn cores are relatively larger than in Protoryx carolinae, moderately 
long, compressed’ medio-laterally, without keels, strongly curved backwards, 
sometimes more strongly bent back at the tips than lower down; orbital rims are 
narrow to moderately wide; braincase is sometimes long; median occipital ridge and 
its flanking hollows are frequently only poorly marked; the basioccipital has a 
central longitudinal groove. 


Remarks. The smaller size and_ relatively larger horn cores of Pachytragus 
laticeps than Protoryx carolinae can be seen in Text-fig. 1. The increased horn size 
must be linked with other differences from Palaeoryx and Protoryx, for instance 
that the horn cores have acquired more upright insertions and a more curved 
course in profile, thereby distributing their increased weight equally over each side 
of the occipital condyle-atlas pivot. 

The illustrated paratype of this species is the Maragha skull BM(NH) M.3841. 
The Paris skull of Pachytragus from Maragha (Mecquenem 1924 : 33, pl. 5 figs 3, 4) 
also belongs here; its horn cores diverge about as much as in the holotype but are 
shorter. The back of the nasals is narrow, there is a long and narrow ethmoidal 
fissure, and the preorbital fossa lacks an upper rim. 


Long-brained and short-brained varieties 


In some examples, for which Pilgrim & Hopwood (1928 : 34) used Major’s name 
Protoryx longiceps, the horn cores are larger, more medio-laterally compressed, less 
divergent and with tips which do not reapproach, the width across the top of the 
skull in the region of the horn bases is smaller, the braincase longer, the occipital 
surface higher and the median occipital ridge and its flanking hollows less marked. 
This is a more extreme change from the putative Palaeoryx or Protoryx-like ancestors. 
In the graphs of Text-figs 2-4 I have indicated by a separate symbol the specimens 
assigned by Pilgrim & Hopwood to the name longiceps as well as others which 


246 THE EARLIEST GOATS AND OTHER ANTELOPES 


seemed to fit the criteria just mentioned. It can be seen that there is only imperfect 
separation from other Pachytragus laticebs in horn core compression, braincase 
length and relative narrowness across supraorbital pits and horn bases. It is 
probable that temporally or geographically separate natural populations have 
contributed to the P. laticeps material as it exists in museum collections today. 


60 mm 


Transverse 
diameter 


Ant-posterior diameter 


Fic. 2. Graph of horn core compression. The readings were taken at the base of the horn 
cores immediately above the pedicel. Palaeoryx pallasi has large and little compressed 
horn cores, those of other species are more medio-laterally compressed, and in Pachytragus 
cyassicovnis they are also smaller. + = Palaeoryx pallasi, c = Protovyx carolinae, 
- = Pachytragus laticeps, o = longer crania of P. laticeps, x = P. cvassicornis, h = two 


Lausanne specimens of ‘Pyotoryx ’hippolyte. 


FROM THE SAMOS HIPPARION FAUNA 247 


It is impossible to sort out the members of these original populations, and it would 
be unwise to assume that only two such populations have been sampled, one for 
each extreme of the range of variation. For this reason I shall not use the trivial 
name longiceps as a trinomial. 

The means of some skull measurements, and their ranges, standard deviations 
and coefficients of variation for Pachytragus laticeps are shown in Table 2 on p. 258. 
Despite the inclusion of the long-brained individuals of this species, the coefficients 
of variation are generally less high than in the smaller sample of Pachytragus 
crassicornis. 

The cranium with horn cores at Lausanne, 22, was that which Pilgrim & Hopwood 
(1928 : 28) believed Major had intended to be the holotype of Protoryx longiceps. 
The tips of its horn cores are not sharply bent backwards, the frontals above the 
left orbit are hollowed, the mid-frontals suture is not raised, the sides of the braincase 
are parallel or even widening anteriorly, the large mastoids are visible, the anterior 
tuberosities of the basioccipital are not large and flank a central longitudinal groove 


100 
Braincase length 


Skull width at mastoids 


Fic. 3. Graph of braincase length against skull width across the mastoids. This graph 
indicates the size and relative narrowness of the cranium. Braincase length is measured 
from the mid-dorsal point of the parieto-frontals suture to the top of the occipital surface. 
Symbols as in Text-fig. 2. 


248 THE EARLIEST GOATS AND OTHER ANTELOPES 


(Pl. 2 figs 1, 2). The median vertical ridge on the occipital is not marked, but the 
left and right sides of the bone face partly laterally. The Lausanne cranium 26 is 
very similar except for the more localized raising of its frontals between the horn 
bases. 

Protoryx carolinae of Schlosser (1904 : 45) is a long-brained Pachytragus laticeps. 
The braincase is parallel sided and there is a large mastoid. The face fragment 
used in his pl. g fig. 8 cannot be fitted to the cranium; in fact a part of the posterior 
end of the face is not shown in the illustration. 

Examples of long-brained P. laticeps in the American Museum of Natural History 
are as follows. 20612 from quarry I is a cranium with lower parts of the horn cores 
in which the apparent length of the braincase may have been increased by the use 
of plaster. 20621 also from quarry I is a cranium with lower part of the right and 
almost complete left horn core; it is the only New York specimen with an auditory 
bulla and the bulla shows the downward connection to the front of the para- 
occipital process. It also has small to moderate-sized foramina ovalia. 20645 from 
quarry I is acranium with horn cores. 20649 from quarry I is a frontlet with lower 
parts of horn cores. 20690 from quarry I is a cranium with well preserved horn 
cores showing abrupt bending back of the tips. 22783 from block H in quarry I is 
a cranium with the right horn core and part of the left; the left one was sectioned 
approximately 20 mm above the pedicel top and showed spongy central parts 
(Pl. 2 fig. 4). 23037 from quarry 4 is a cranium with complete horn cores, bent 


Width across _ 
supraorbital foramina 


+ 
Tals 
+ 
+ 

a ae 


60 


40 


Width across horn bases 


80 100 120 140 160 


Fic. 4. Width across supraorbital foramina compared with width across narrowest part 
of lateral walls of horn pedicels. Symbols as in Text-fig. 2. Among Pachytragus it 
is P. cvassicoynis which has the widest separation of supraorbital foramina, and is closest 
to later goats. 


FROM THE SAMOS HIPPARION FAUNA 249 


back at their tips. 23038 from quarry I is a cranium with the lower parts of its 
horn cores. The right one was sectioned at about 10 mm above the pedicel top 
and showed a clear central hollowing (PI. 2 fig. 3). 

The Lausanne cranium 20453 has rather a long braincase, and also has a hollowing 
at the base of its left horn core. 

Andree’s Hippotragus kopassi in Minster is also rather long-brained. It has a 
narrow ethmoidal fissure, parallel sides of its braincase, small foramina ovalia, the 
ventral edge of its auditory bulla rises posteriorly where it meets the paraoccipital 
process, and it has preserved its dentition and rather high face. Andree (1926 : 158, 
159) used this skull to show the closeness of Hippotragus to his Protoryx group of 
the Pseudotraginae (=Pachytragus as used in this paper). The narrow and high 
face, strong bending of the braincase on the face, and the high insertions of the 
large transversely compressed horn cores impressed him as distinctive characters, 
but it did not appear to me that any substantial difference existed between this 
skull and other Pachytragus laticeps. 

The holotype cranium of Pachytragus laticeps does not have a particularly long 
braincase. It has parallel sides of its braincase, and the ventral edge of the left 
auditory bulla descends to meet the front edge of the paraoccipital process. 

A well preserved P. laticeps skull on public exhibition in the Natural History 
Museum in Basle is an excellent example of the shorter-brained form of this species. 
Its horn cores approach having an anterior keel in the middle of their course. 
Although the M's have already lost their central cavities, there are indications of 
transverse ridges across the dentine of the molars’ occlusal surfaces, which suggests 
use of the cheek teeth in a way similar to goats and sheep. 

The shorter-brained Lausanne cranium 201 (Pilgrim & Hopwood 1928, pl. 4 
figs I, Ia) is a P. laticeps, but the lack of a central longitudinal groove on its basioc- 
cipital makes it more like the species to be described next. Its occipital surface is 
lower and wider than in the long-brained Lausanne cranium 22, and the sides of 
its braincase are parallel. A Lausanne frontlet 28 (Pilgrim & Hopwood 1928, 
pl. 4 fig. 2) has no anterior keels and rather diverging horn cores, and is probably 
from a shorter-brained P. laticeps. 

I have not seen the material of Protoryx cf. carolinae of Schlosser (1904 : 48), but 
I include it with the shorter-brained Pachytragus laticeps, following his description 
and Pilgrim & Hopwood’s (1928 : 36) placing. 

The shorter-brained Miinster skull which Andree (1926 : 156, pl. 12 fig. 1, pl. 13 
fig. 8) called Protoryx crassicornis shows quite compressed horn cores with large 
bases, a high face, a braincase widening slightly anteriorly, moderate-sized foramina 
ovalia, and a moderately-developed median occipital ridge and flanking hollows. 
The illustration in front view shows reapproaching horn core tips, now lost. The 
differences which Andree noted from other skulls here included in Pachytragus 
laticeps, valid as they may be between individuals, do not carry the skull beyond 
the morphological range within which it could be considered conspecific. There 
was certainly no reason for Pilgrim & Hopwood (1928 : 33) to link this skull with 
Protoryx carolinae which they had principally built around Pikermi specimens, for 


250 THE EARLIEST GOATS AND OTHER ANTELOPES 


this skull is smaller, its horn cores insert more uprightly, and the teeth are like those 
of other Samos skulls. Andree’s own text (1926 : 156) emphasizes this point 
about the teeth. 

Shorter-brained Pachytragus laticeps in the American Museum of Natural History 
are the following. As with the long-brained variety, none come from quarry 5. 
20674 from quarry I is a cranium with left horn core strongly bent back at its tip 
and with the lower part of the right horn core. 20691 from quarry I is a cranium 
with the lower parts of both horn cores. 20707 from block E in quarry I is a partly 
cleaned skull without the front of its face. Both its horn cores are broken at the 
level of the top of the pedicel and hollowed internally. The long narrow ethmoidal 
fissures and back part of the nasals are visible. 20770 from 100 yards west of 
Mytilini village is a cranium with horn core bases. 20777 from 100 yards west of 
the same village is a rather small left horn core with an inwardly deflected tip. 
22857 from quarry 4 is a cranium with horn cores. 86580 is a frontlet with horn 
cores, and it is labelled ‘block Y’ but without a quarry number. 86583 of unknown 
quarry is a damaged cranium with horn cores broken at their bases and clearly 
hollowed. 

I have not been able to assign all P. Jaticeps to the shorter or longer brained 
varieties. Doubtful specimens in New York are 20609 from quarry I which is a 
face without premaxillae or the right nasal but showing the lachrymal and jugal 
sutures, 20598 from quarry I a cranium with horn core bases, 20673 from quarry I 
the base of a right horn core and a left horn core with skull fragments, 20778 and 
20779 two frontlets with horn core bases from 100 yards west of Mytilini, and 
86450 a frontlet with horn cores. The Lausanne frontlet 27 is another doubtful 
specimen. 


Other skulls and crania 


The Lausanne cranium 298 is interesting; it was labelled as Protoryx gaudryi by 
Major and referred to P. carolinae by Pilgrim & Hopwood (1928 : 30). It is con- 
siderably damaged and has been repaired with glue and plaster; it agrees with the 
species to be described next in its keels and diverging horn cores, but is rather 
large and has a wide shallow longitudinal groove on its basioccipital. No measure- 
ments could be taken because of the damage. 

The other Lausanne cranium, 362, which they also referred to P. carolinae belongs 
to Miotragocerus as shown by its temporal ridges with rugose surface in between, 
the occipital surface in one plane only, the horizontal top edge of the occipital in 
rear view, rather narrow mastoids, and large foramina ovalia. 

The most difficult specimen to assess at Lausanne is the cranium, 30, of ‘Protoryx 
hippolyte’ (Pl. 3 figs 1, 2), referred to as a variety of Schlosser’s Pseudotragus capri- 
cornis by Pilgrim & Hopwood (1928 : 40). However it is too large to belong to that 
species, does not show the relatively very large horn cores of the presumed male 
skull, and the supraorbital pits are set closer together. At first sight it appears 
that the braincase is little bent on the face axis but this is probably due to dis- 


FROM THE SAMOS HIPPARION FAUNA 251 


tortion, the back of the braincase having been pushed forwards against the horn 
bases. There is strong medio-lateral compression of the horn cores, their divergence 
increases evenly towards the tips, and they appear rather uprightly inserted in side 
view. Their appearance of having been short and having had an anterior keel may 
result from damage caused by weathering. The Pachytragus skull in Basle shows 
that the angle of the parietal to the occipital surface here is not too small for P. 
laticeps. The occipital surface is low and wide as in most P. Jaticeps, and it has 
a weak median ridge without hollows on either side. The front of the basioccipital 
is missing but there was a well marked central longitudinal groove. From these 
characters and its size this specimen can be provisionally included in P. laticeps. 

Another Lausanne specimen, the frontlet 31, much resembles the cranium just 
discussed. 

Protoryx hentscheli was founded by Schlosser (1904 : 49) on teeth of Pachytragus. 
The syntypes in Munich were supposed to differ from teeth of ‘Protoryx carolinae’ 
(=Pachytragus laticeps as used here) by weaker styles and ribs on the molars, smaller 
premolars, the anterior position of the vertical indentation on the lateral side of 
P3 and Py, the weaker indentation on the medial lobes of P2 and P8, and the weaker 
development of medial cusps on Pz and Py. These, and other differences mentioned 
by Pilgrim & Hopwood (1928 : 38) seem valid only between individuals. It is 
impossible to assign the teeth specifically; that they belong to Pachytragus is all 
I would be prepared to say. The name Protoryx hentscheli was subsequently 
extended by Andree to a nearly complete skull, and the name P. hentscheli var. 
tenuicorms to a cranium, both in Munster. The nearly complete skull is very 
interesting in that it shows some characters divergent from other Pachytragus: 
frontals only a little raised between horn bases, rather a low face, the tooth row set 
rather anteriorly; all this recalls Palaeoryx pallasi. Otherwise it appears to be 
an example of the normal fairly short brained P. Jaticeps with horn cores diverging 
in the middle of their course and reapproaching towards the tips. The cranium of 
var. tenuicormis agrees with the above skull in what characters are available, and 
its broken left horn core shows a hollowed pedicel. Although these skulls are an 
apparently primitive variation of Pachytragus laticeps, I do not consider them worth 
naming, and certainly there is no case for applying to them Schlosser’s specific 
name hentscheli, based on indeterminate teeth. They illustrate what an early 
form of Pachytragus could have been like. I have retained these two pieces within 
P. laticeps, and have not supposed that they belong to an actual ancestral species. 
They suggest that Pachytragus could derive from Palaeoryx or a Palaeoryx-like 
ancestor, perhaps some antelope not dissimilar to Protoryx carolinae. 

A skull from Salonica assigned to Protoryx carolinae by Arambourg & Piveteau 
(1929b : 105, pl. 7 fig. 6, 6a) probably belongs to this species. Its closely inserted 
horn cores are without keels, the brain widens anteriorly in dorsal view, temporal 
lines are wide posteriorly, the nasals are narrowly drawn out posteriorly and have 
no lateral flanges anteriorly, and large premaxillae rise with even width to a definite 
contact with the nasals. These characters at the front of the face are probably 
common to the whole genus Pachytragus, if not to Palaeoryx and Protoryx as well. 


252 THE EARLIEST GOATS AND OTHER ANTELOPES 


A’ female skull 


_ In the New York collection is a Pachytragus skull with small horn cores, 20687 
from quarry I (PI. 3, fig. 3). It is presumably a female. It is complete except for 
premaxillae, most of the nasals, a part of. the left postorbital bar, and the right 
postorbital bar and zygomatic arch. The horn cores are of very small basal diameter 
(30:2 x 22-0, right), somewhat medio-laterally compressed, set rather obliquely 
and with a concave front edge in profile, inserted close together and diverging little 
in anterior view. Connected with the smallness of the horn cores is the strong 
slope of the orbital rims. The preorbital fossa is only shallow (they are normally 
smaller in females), neither supraorbital pits nor infraorbital foramina are visible, 
the frontals between the horn bases are hardly higher than the orbital rims, the 
maxilla is deep above the tooth row, and the occipital surface is clearly in two planes. 
The skull’s provenance in quarry I would seem to rule out its assignation to P. 
crassicornis. An awkward question is why there are no other female skulls in any 
Samos collections. A left horn core AMNH 20777 is very like a horn core of P. 
laticeps and is an alternative candidate for representing females among the fossils. 
Its basal diameters are about 49 x 38 mm. 


Tooth characters and individual dentitions 


The teeth of Pachytragus laticebs may easily be told from those of Palaeoryx 
pallast and Protoryx carolinae by their smaller size and advanced morphology. 
Smaller size distinguishes them from the unnamed large Miotragocerus represented 
by AMNH 23036, BM(NH) M.4198 and other specimens, and their advanced 
characters from all Miotragocerus. Teeth of Miotvagocerus are less hypsodont, 
they retain larger basal pillars (a) and a later joining together of the medial lobes 
of the upper molars (b), the mesostyle on the upper molars is less marked (c), the 
medial walls of the lower molars are more outbowed between the stylids (d), the 
premolar row is longer and anterior premolars larger, hypoconid of P, is not pointed 
(e), metaconid of Py, is less bulbous but has a large backwardly turned medial 
flange (f), and the paraconid of Py, is larger relative to the parastylid (g). The 
characters indicated by letters (a) to (g) are illustrated in Text-fig. 5, and a Pachy- 
tragus palate is photographed in PI. 4 fig. 2. 

Very many upper and lower dentitions of Pachytrvagus are known, and I will 
comment only on previously misidentified specimens. The teeth shown by 
Schlosser (1904, pl. 9) may all be taken as belonging to either this species or the next. 
The teeth of pl. 9 figs 2, 3, 5, 6 and 7 had been used to establish the species Protoryx 
hentscheli, supposedly having weaker ribs and styles, rounded inner lobes, a large 
metastyle on M3, a triangular rear lobe of Ms, and rugose enamel. These characters, 
in so far as they are detectable at all, are inadequate to remove the teeth from 
assignation to Pachytragus laticeps or to the next species. Since it is doubtful 
which of the two they belong to, I have not listed P. hentscheli as of Schlosser (1904) 
among the synonyms of P. laticepbs. Skulls which Andree later assigned to P. 
hentscheli have been included in P. laticeps. 


FROM THE SAMOS HIPPARION FAUNA 253 


The right upper dentition 578 in Lausanne, listed by Major (1894 : 35) as ‘Protoryx 
sp.’ is really a Miotragocerus. 


Pachytragus crassicornis Schlosser 


1904 Pachytragus crassicornis Schlosser : 56, pl. 11 fig. 11. 

1926 Palaeoryx cf. stiitzeli Andree : 162, pl. 14 figs 1-3. 

1926 Pseudotragus longicorvnis Andree : 147, pl. 10 figs 2, 3. 

1926 Pseudotvagus capricornis Schlosser. Andree : pl. 13 fig. 7. 
1926 Pachytragus schlossevi Andree : 148, pl. 12 fig. 7, pl. 13 fig. 3. 


Lectotype. The frontlet described and figured by Schlosser (1904 : 56, pl. 11 
fig. 11) was designated by Pilgrim & Hopwood (1928 : 43). Pachytragus crassicornis 
is the type species of its genus. 


Locality. Samos. 
AGE. Lower Pliocene. 


M2 M3 Ey 
pee e., ie g 
= 
oui ZR sy, MIOTRAGOCERUS 
i g 10mm 


LS, PACHY TRAGUS 


\ 


CAPRA 


cS 
as iS 
i eA CeO) HIPPOTRAGUS 


Fic. 5. Occlusal views of cheek teeth of the right side, their anterior edges being towards 
the right. Explanation in text, p. 252, and h = goat fold. 


254 THE EARLIEST GOATS AND OTHER ANTELOPES 


Diacnosis. Smaller than Pachytragus laticeps; horn cores are slightly smaller 
and shorter, often more medio-laterally compressed, with an anterior keel, insertions 
less upright than in P. laticeps but more than in Protoryx carolinae, divergence 
greater and increasing toward the tips instead of tending to reapproach at the tips, 
less curved backwards in side view; orbital rims are rather wide; braincase top is 
fairly long and set at a steeper angle to the occipital surface; tooth row set more 
posteriorly than in Palaeoryx pallasi; median occipital ridge is often prominent 
and with deeper flanking hollows; basioccipital has fairly localized anterior tubero- 
sities and thus little development of a central longitudinal groove; teeth are no smaller 
than in P. laticeps despite the overall size reduction. 

REMARKS. By its smaller overall skull size unaccompanied by any substantial 
diminution of tooth size P. crassicorynis is evidently adapted to a harsher environ- 
ment than P. laticeps. It differs additionally from that species by its shorter less 
backwardly curved horn cores with anterior keels, and the tooth row is now de- 
finitely placed rather posteriorly. Profile views of this species in comparison with 
others are shown in Text-fig. 6, anterior views of horn cores in Text-fig. 7, and sections 
across horn cores in Text-fig. 8. 


PACHY TRAGUS 
CRASSICORNIS 


PACHY TRAGUS 
LATICEPS 


. PROTORYX 


CAROLINAE 


Fic. 6. Reconstructions of side views of skulls of Palaeoryx, Protoryx and Pachytragus. 
The figures are in scale with one another. Notice the inclination and curvature of the 
horn cores and deep anterior part of the zygomatic bars in Palaeoryx pallasi and Protoryx 
cavolinae; the anterior positioning of the tooth row in Palaeoryx pallasi; that the teeth of 
Pachytrvagus crassicoynis have not diminished below the size of those of P. laticeps; and 
the differing inclinations and curvatures of their horn cores. 


FROM THE SAMOS HIPPARION FAUNA 255 


The lectotype of Pachytragus crassicornis Schlosser (1904 : 56, pl. 11 fig. I1) 
shows strong bending of the braincase on the face axis (the appearance of this being 
exaggerated by distortion), the orbital rims would have been wide when complete, 
and the upper parts of the right horn core are sufficiently preserved to show the 
anterior keel. 


Individual skulls and crania 


The following specimens in the American Museum of Natural History are all 
from Brown’s quarry 5 with one exception. 20567 is part of a skull with braincase, 
right horn core, part of the right side of the face, the right P3 to M3 and the left 
P4 to M3, 20568 is a more or less complete skull lacking only the front of its face; 
it has the left P2 to M3 and the right P to M3, and a long and thin ethmoidal fissure. 
20569 (Pl. 4 fig. I) is most of a skull lacking parts of the right orbit, nasals, pre- 
maxillae and parts of the basioccipital; it has the right P? to M3 and left P? to M3. 
20579 is another more or less complete skull, lacking only nasals and premaxillae ; 
it is probably the best preserved skull of the species in existence. The ethmoidal 
fissures are long and thin, and the teeth present are the right P? to M3 and the left 
M1! to M3. 20708 is from quarry I but agrees better with P. crassicornis than with 
P. laticeps; it is a cranium without the right horn core or parts of the lower occipital 
surface. 22938 is a cranium with both horn cores intact. 22939 is a cranium with 
both horn cores. 22940 and 22943 are frontlets with most of the right horn core 
and part of the left. 22948 is a damaged cranium with a somewhat distorted right 


Fic. 7. Anterior view of the horn cores of (A) Pachytragus laticeps, (B) long-brained 
variety of P. laticeps, (C) P. crvassicovnis. The figures are in scale with one another. 
Notice in (6) compared with (A) that the horn cores are larger, less divergent, and with 
tips which do not reapproach. PP. cvassicornis has anterior keels. 


256 THE EARLIEST GOATS AND OTHER ANTELOPES 


horn core and part of the left one. 22949 is a cranium with horn cores on which 
part of the left preorbital fossa is visible. 

A number of other named specimens in European museums can best be placed 
in this species, although their inclusion widens the tange of variation within the 
species. As with the long-brained examples of P. laticeps, no conception of what 
was happening to the species in time can be hoped for without more geological 
knowledge of the Samos deposits. The first of these specimens is the skull of Pseudo- 
tragus capricornis in Minster described by Andree (1926 : 146, pl. 13 fig. 7) but not 
conspecific with the skull for which Schlosser (1904 : 51, pl. Io figs 7, 8) had first 
used the name. Andree’s specimen shows short medio-laterally compressed horn 
cores diverging from one another and with anterior keels, the braincase probably 
widening anteriorly, but the basioccipital not clearly with less developed longitudinal 
ridges behind the anterior tuberosities than in Pachytragus laticeps. There is a 
slight tendency towards transverse wear ridges across the dentine of the upper 
molars as in goats and sheep. I have not seen the Stuttgart skull fragment which 
Andree refers to (1926 : 146) under this name, but the Minster one differs from 
Pseudotragus capricornis by its greater size, anterior keel, and relatively larger teeth 
and face. 

The almost complete skull of Pachytragus schlosseri Andree (1926 : 148, pl. 13 
fig. 3) is in Vienna and is certainly rather small. It has been much restored with 


A e MEDIAL 


2com | —— ANTERIOR 


a Ce 


Fic. 8. Sections of right horn cores taken at a distance above the pedicel top equal to 
half the antero-posterior diameter at the base of the horn core. A = Palaeoryx pallasi 
from Samos figured by Schlosser (1904, pl. 7 fig. 5); B = Megalovis latifvons, a left horn 
core (Se 1483) in Basle reversed for this drawing; C = Protoryx cavolinae BM(NH) 
M.11415; D = Pachytragus laticeps, a skull in Basle; E = P. cvassicovnis AMNH 22938 
reversed for this drawing; F = the long brained variety of P. laticepbs AMNH 23037. 


FROM THE SAMOS HIPPARION FAUNA 257 


plaster on the alisphenoid flanges, the right zygomatic bar, the top of the postorbital 
bars, and the top of the occipital surface. It is the restoration of the top of the 
postorbital bars which has given a wrong impression of narrow orbital rims. Also 
in the dentition picture (Andree 1926, pl. 14 fig. 4) the large metastyle of M2 should 
have been shown as the parastyle of M8. The horn cores are somewhat compressed, 
their triangular cross section as shown by Andree does not extend much above 
their base, they are quite strongly divergent in anterior view, there is a small 
ethmoidal fissure, the small and shallow preorbital fossa has a trace of an upper rim, 
the infraorbital foramen is high above the front of P® on the left and the back of 
P3 on the right, and the median indentation at the back of the palate is behind the 
level of the lateral ones. The skull is probably closer to this species than to P. 
laticeps by its rather small size, latero-medial compression of horn cores without 
reapproach of the tips, and the quite strong divergence of the horn cores. But the 
horn cores lack keels, and the condition of the occipital surface cannot be clearly 
seen. 

The cranium in Minster assigned to P. schlossert by Andree (1926, pl. 12 fig. 7) is 
similarly difficult to assign. It has no anterior keel on the horn cores, but it does 
have divergent short horn cores, and the frontals between the horn cores are well 
raised. The braincase probably widened anteriorly. 

Pseudotragus longicornis of Andree (1926, pl. 10 figs 2, 3) is in Vienna. The 
lateral surface of its horn cores is somewhat flattened, the back of the nasals is just 
a little in front of the level of the front of the orbits, the moderate sized preorbital 
fossa has a slight upper rim, the infraorbital foramen is above the front of P’. Itis 
like Pachytragus crassicornis in its small size, strong medio-lateral compression 
higher up its horn cores with which is linked the tendency to an anterior keel, and 
the shape of the anterior tuberosities of the basioccipital with barely any central 
longitudinal groove. The lesser divergence of the horn cores, and their backward 


TABLE I 
Minimum Width 
Antero- Latero- aes across 
posterior medial iteval lateral Length Length 
i i 13 2_p4 
poe hae of diameter of Gitine ce edges of M1-M P2_-p 
orn core horn core ee supraorbital 
pedicels foramina 
Pseudotragus capyicornis 
(Andree pl. 13 fig. 7) 52-6 337 — 39°8 551 — 
Pachytragus schlosseri 
(Andree pl. 13 fig. 3) 47°3 42°0 1OI-4 49°7 56-6 39°3 
Pachytvagus schlossert 
(Andree pl. 12 fig. 7) 56:8 43°9 98:3 46:4 oe _ 
Pseudotvagus longicornis 
(Andree pl. ro figs 2, 3) 52°7 45°2 97:0 C.46°5 53°5 38-1 


Palaeoryx cf. stiitzeli 
(Andree pl. 14 figs 1, 3) 5505 43°0 97°3 C.44°3 = = 


258 THE EARLIEST GOATS AND OTHER ANTELOPES 


curvature are more like P. laticeps, but in the width of its orbital rims and the 
hollowings of the occipital surface the Vienna animal is intermediate. 

The frontlet in Vienna which Andree assigned to Palaeoryx cf. stiitzeli agrees well 
with his specimens of ‘Pseudotragus longicornis’ and ‘Pachytragus schlossen’. It is 
not conspecific with the example of Palaeoryx stiitzeli Schlosser (1904, pl. 8 fig. 6) in 
Munich which is a Sporadotragus; this specimen is of a larger animal, it lacks the 
anterior surface on its horn cores and has less extreme bending down of the face 
on the braincase. The orbital rims are moderately to strongly projecting, the lateral 
surface of the horn cores is a little flattened, and there is possibly an approach to 
having a keel highe# up on the right, but it is too damaged to be certain. 

Those skulls described by Andree which I believe to be Pachytragus crassicornis 
have the following measurements shown in Table 1 on p. 257, which I made myself 
and used in the Text-figures. 

Some skull measurements for Pachytragus crassicornis are shown in Table 2 
below. Coefficients of variation are rather high in comparison with the low numbers 
of measured individuals; this is because of the difficult skulls just discussed. 


TABLE 2 
Number Standard Cogficient 
Mean Range Beale of 
measured deviation eft 
variation 
Antero-posterior diameter of horn 10 62:3 54:2-68:7 4:08 6°55 
core at base 23 62:9 57:0-68:9 2-99 4°75 
13 541 ADS 58-7, 3°34 6-17 
Latero-medial diameter of horn 10 51-6 45°3-57°9 4°90 7°55 
core at base 24 44°5 35°4-49°8 3°34 7°52 
13 38-7 33°5-45°2 AnOz EG 8) 
Minimum width across lateral Il 133°5 108-2-152-0 1-33 8-49 
surfaces of horn pedicels 21 105°6 94:4-123°6 6:71 6-36 
Io 97°7 82:2-102°5 5°95 6:09 
Width across lateral edges of 10 68-1 58:-6-75°9 5°23 7:68 
supraorbital pits 21 43:0 36:°5-49:0 3°73 8-77 
13 456 38:6-49'8 3°56 780 
Braincase length from back of 10 69°5 59:2-82°8 Fug 10:26 
frontals to top of occipital 17 75°5 65°3-91°2 5°89 7°81 
6 66°8 60°1-75°3 5°13 7°69 
Skull width across mastoids 6 11473 105:0-119°8 5°72 5-01 
behind auditory meatus 22 95°4 85:8-106°8 5:60 5°87 
5 93°5 85:7—100°3 6:10 6:52 
Length M1—M3 6 67:6 61:9-69'9 3:00 4°44 
18 57:6 54°4-61-:0 1°84 3°19 
15 56:8 53°5-00°6 BU 3°74 
Length P2—pP4 4 50°1 46:2-52°6 — 5:62 
9 38-0 35°I-41-9 218 5-60 
9 37°2 34°0=39°3 1-60 4°29 


For each measurement the top line shows the readings for Palaeorvyx pallasi, the middle 
line for Pachytragus laticeps, and the last line for P. crassicornis. 


FROM THE SAMOS HIPPARION FAUNA 259 


Fic. 9. Graph of the length of the upper premolar row plotted against length of upper 
molar row. Symbols as in Text-fig. 2 except that no separate symbol is used for the long 
brained Pachytragus laticeps, e = Hippotragus equinus, n = H. niger, s = Capra sibirica, 
a= C. aegagyus, and m = Megalovis latifrons. Tooth measurements were taken on 
identified skulls, and in addition one Pachytvagus dentition from Brown’s quarry 5 in 
New York was taken as P. cvassicornis and four from quarries 1 and 4 as P. laticeps. 
Notice that the two Pachytragus species have the same size and proportions despite the 
smaller overall size of P. crvassicornis. Megalovis latifyons has a slightly shorter premolar 
row than does Palaeoryx pallast. 


260 THE EARLIEST GOATS AND OTHER ANTELOPES 


80 100 120 140 


A. Palaeoryx pallasi 
y Ser 4 B. Pachytragus crassicornis 
oe ae C. Capra aegagrus 
4 ee J MeN”, ‘*.. D. Hippotragus equinus 
L \ t ri ‘ : 
C B A f E. Hippotragus niger 


F. Megalovis latifrons 


Fic. 10. Percentage diagram to compare some mean skull measurements of Palaeoryx' 
pallasi (the standard line at 100%) and Pachytragus crassicoynis with males of some} 
living Bovidae: Capra aegagrus (10 individuals), Hippotvagus equinus (10), and H.; 
nigey (12). Three measurements of Megalovis latifyons from Senéze are also shown, 
based on only one reading for separation of horn cores and two for the other two measure- 
ments. The measurements numbered 1 to 4 on the left of the diagram are the same as in 
Text-fig. 1. Capra aegagrus may differ from Pachytragus crassicornis by its more closely 
inserted but large horn cores, and has small teeth. The two Hippotvagus species are 
rather more different from Pachytvagus crassicornis, H. nigey being slightly smaller but 
with larger horn cores. 


Dentitions 


The teeth which Schlosser (1904, pl. 11 figs 2, 4, 5) put in Pachytragus crassicornis 
may be taken as Pachytragus of some species although those of figs 2 and 5 are rather 
scrappy, but the teeth of pl. 11 figs 1 and 3 which he also placed in P. crassicornis are 
more likely to be of Muotragocerus. The teeth of pl. 8 figs 1 and 2 assigned to 
Palaeoryx stiitzeli are also of Mtotvagocerus. 

Comparisons. Teilhard de Chardin and Trassaert (1938 : 41) described from the 
lower or perhaps later Pliocene of China an antelope called ?Protoryx yushensis 
which from the figures appears to match Pachytragus crassicornts in its short brain- 
case widening anteriorly in dorsal view, and keels on the horn cores. The horn 
cores are rather short (as in Lausanne skull remains 30 and 31). In anterior view 
the horn cores diverge more than in the Samos skulls. The Chinese skull may well 
be a closely related species. 

Of the two Samos species of Pachytragus it is P. laticeps which must be the more 
primitive on the basis of horn cores without anterior keels, the orbital rims being 
only moderately wide alongside the horn core insertions, and the less developed 
median occipital ridge and its poorer flanking hollows. 


FROM THE SAMOS HIPPARION FAUNA 261 
Ili, SYSTEMATICS OF SPIRAL HORNED ANTELOPES 


Clearly spiralled horns occur among living antelopes as follows. 


Tragelaphini all species Africa horns in males only, except in 
Taurotragus and one species of 
Tragelaphus 
Hippotragini Addax Sahara desert horns in both sexes 
nasomaculatus 
Antilopini Antilope India horns in males only 
cervicapra 
Caprini Capra caucasica Caucasus horns in both sexes 
C. falconert India horns in both sexes 
Ammotragus North Africa horns in both sexes 
lervia 
Pseudois nayaur Central Asia horns in both sexes 
Ovis ammon Eurasia horns sometimes in males only, 


but many populations with 
horned females as well 
O. canadensis Siberia, horns in both sexes 
N. America 


It is apparent that several independent evolutions of spiralled horns have taken 
. place. 

The first fossil antelope with spiral horn cores to be described was Antilope 
lindermayert from Pikermi by Wagner (1848 : 367), later transferred by Gaudry 
(1865 : 290) to Palaeoreas. Wagner (1857 : 154) described another spiral horned 
antelope from Pikermi, Antilope rothi, which Gaillard (1902 : 93) took as the type 
species for his genus Ozoceros. Pikermi had two more spiral horned antelopes to 
yield, both of them already present in Gaudry’s material assigned to Palaeoreas 
lindermayert. These were Protragelaphus skouzest Dames (1883 : 97) and Helicoceras 
votundicornis Weithofer (1888 : 288) the latter’s generic name subsequently becoming 
Helicotragus. 

As the only species of its genus, Palaeoreas lindermayeri has had a simple history. 
Gaudry (1861) named the genus in accordance with his belief that it was an early 
tragelaphine, and since then it has not been moved from that tribe. Pyrostrepsiceros 
has had a more complicated history. Major (1891a : 609) took as his genotype 
the species Tvagelaphus? houtumschindleri then newly described by Rodler & 
Weithofer (1890 : 768) from Maragha. He referred Samos specimens to a new species 
P. woodwardi and to Prostrepsiceros? sp. Schlosser (1904 : 31) named a similar 
specimen from Samos Protragelaphus zitteli, considering it closely related to Dames’s 
P. skouzesi. Pilgrim & Hopwood (1928 : 84, 89, 91) regarded Major’s Prostrepsiceros 
woodwardi as a nomen nudum and themselves assigned to it a holotype. They added 


262 THE EARLIEST GOATS AND OTHER ANTELOPES 


a third species, P. mecquenem, to the genus for Mecquenem’s (1924 : 37) Maragha 
material in Paris, which he had assigned to P. houtumschindlert. They assigned 
Protragelaphus zitteli Schlosser to a new genus, Hemistrepsiceros, and in this species 
they also placed Major’s Prostrepsiceros? sp. 

Ozansoy (1965) referred some Turkish fossils to new species of Palaeoreas and 
Helicotragus, but they come from later Plaisancian deposits than other species of 
those genera, and it is difficult to relate them convincingly to the older species. 

Prostrepsiceros and Hemustrepsiceros have been regarded as members of the 
Tragelaphini, but Pilgrim & Hopwood (1928 : 20) assigned Helicotragus to the 
Antilopini, and Pilgrim (1939 : 129, 135) thought that Pyrotragelaphus skouzesi 
should go there as well. The purpose of the second part of this paper is to transfer 
Prostrepsiceros to the Antilopini and Palaeoreas to the Ovibovini, and to revise 
the Samos, Pikermi and Maragha species of these genera. I shall also discuss 
Protragelaphus skouzest which I accept as an antilopine. I have already briefly 
referred to these questions (Gentry 1968 : 874). 

The two genera Prostrepsiceros and Protragelaphus share the following skull 
characters, which can be taken as a kernel for defining any suprageneric grouping 
to which they and their relatives may belong. They have an open spiralling of the 
horn core or a twisting of its axis which is anticlockwise from the base upwards 
on the right side, no transverse ridges on the horn cores nor a flattened lateral 
surface, little divergence of the horn cores, complicated mid-frontals and parieto- 
frontal sutures, temporal lines wide apart on the top of the braincase, braincase 
sides parallel or widening slightly posteriorly in dorsal view, a preorbital fossa, a 
moderate area of exposure of the mastoid, the ventral edge of the auditory bulla 
not descending posteriorly to meet the front of the paraoccipital process, fairly 
hypsodont cheek teeth, and quite short premolar rows. 

Although both genera are known at Pikermi and Samos, it is the more complete 
remains in the Paris collection from Maragha which are the most important for their 
interpretation. 


Genus PROSTREPSICEROS Major 


1891a Prostrepsiceryos Major : 609. 
1903 Helicotvagus Palmer : 873. 
1928 Hemiustrepsiceros Pilgrim & Hopwood : 94. 


Type species. Tvagelaphus? houtumschindlert Rodler & Weithofer. 


GENERIC DIAGNOSIS. Small to moderate sized antelopes; horn cores are moder- 
ately long, with keels or traces of keels, no deep longitudinal grooving, inserted 
above the orbits and rather obliquely in side view, moderately wide apart at their 
insertions in anterior view and rather openly spiralled; postcornual groove is fairly 
shallow or moderately deep; frontals are not hollowed internally. 

Orbital rims project; frontals between horn bases are only marginally higher 
than orbital rims; supraorbital pits are moderate-sized ; preorbital fossa is moderate 
to large. 


FROM THE SAMOS HIPPARION FAUNA 263 


Nuchal crests are poor to moderate; median vertical occipital ridge and flanking 
hollows are poor to moderate; anterior tuberosities on the basioccipital are moder- 
ately sized with some development of longitudinal ridges behind them; anterior 
tuberosities are close together, hence a central longitudinal groove is seen anteriorly ; 
auditory bulla is large and inflated. 

Teeth are known from only one of the two contained species. 


Prostrepsiceros houtumschindleri (Rodler & Weithofer) 


1890 Tvagelaphus? houtum-schindleri Rodler & Weithofer : 768, pl. 6 fig. 2. 

1891a Pyrostrepsicevos woodwardi {nom. nud.) Major : 608. 

1891a Pyrostrepsiceros sp. Major : 608. 

1904 Protvagelaphus zitteli Schlosser : 31, pl. 6 figs 2, 3, 5, 12. 

1924 Tvagelaphus houtum schindleri Mecquenem : 37, pl. 5 figs 5, 7; pl. 6 figs 5, 7. 
1928 Prostrepsiceros woodward: Pilgrim & Hopwood : 91, pl. 7 figs 1, Ia, 1b. 

1928 Pyrostrepsiceros mecquenemi Pilgrim & Hopwood : 92. 

1928 Hemistrepsiceros zitteli (Schlosser). Pilgrim & Hopwood : 94. 


Hototyre. A frontlet from Maragha in the Natural History Museum, Vienna, 
numbered 1886.X XVIII.6. 


LocaLiTies. Samos and Maragha. 
AGE. Lower Pliocene. 


Diacnosis. Horn cores are robust, with some latero-medial compression, medial 
surface less convex than lateral one (Maragha), strong posterior keel descending 
to a postero-lateral insertion or posterior keel absent, another keel descending 
to an anterior or antero-medial insertion and strong in those without a posterior 
keel, and poor to moderate divergence; braincase is strongly angled on the face. 

The remaining characters are known in Maragha specimens only: nasals are fairly 
long with transverse doming and small lateral and central flanges anteriorly; 
ethmoidal fissure is moderate-sized and narrow; premaxillae rise with even width 
and have a short contact on the nasals. 

Teeth are fairly hypsodont; basal pillars are absent on upper molars but sometimes 
present on lowers; there are no indentations into back edges of rear central cavities 
of upper molars; medial lobes of upper molars do not join to one another and to 
lateral side of tooth until quite late after eruption; styles and ribs on upper molars 
are poor; lower molars have goat folds; P4 has a medial opening between paraconid 
and metaconid; metaconid of Py, is directed backwards; lateral wall of P4 is indented 
in front of the hypoconid. 

ReMARKS. Material from Maragha. P. houtumschindlert is represented in 
Vienna by the damaged type frontlet with left horn core, a left horn core 
1886.X XVIII.9, and two other horn cores, 1886.XXVIII.8, from Maragha. There 
are many Maragha specimens in Paris including the skull figured by Mecquenem 
(1925, pl. 5 fig. 5 for its teeth and pl. 6 fig. 7) which lacks the distal parts of its horn 
cores and the braincase, a second skull also lacking its braincase (Pl. 5 fig. I), a 


264 THE EARLIEST GOATS AND OTHER ANTELOPES 


skull with M2 and M3 on both sides but lacking the left side and back of the braincase 
and the face above the tooth row, a cranium with right horn core on which the 
front of the basioccipital is missing, and many other dentitions and horn cores. 

The original illustration of this species by Rodler and Weithofer (1890, pl. 6 
fig. 2) was probably constructed from both the type frontlet and the better pre- 
served left horn core, 1886.XXVIII.9. The divergence of the horn cores on the 
holotype exceeds that on most of the Paris examples, although the Paris specimen 
with the most completely preserved cranium does have a similarly pronounced 
divergence. 


A second variety from Samos 


From Samos there is a skull BM(NH) M.4192 (Pl. 5 fig. 3), a frontlet with left horn 
core, M.4210, and part of a right horn core, M.4213; a frontlet with horn cores from 
Brown’s quarry 6, AMNH 20575 and a left horn core from quarry 5, AMNH 20576; 
a frontlet figured by Schlosser (1904, pl. 6 fig. 5) in Munich; and a frontlet, 1911 
Samos V 130, in Vienna. Schlosser’s specimen does not have so compressed a section 
in its upper parts as the others, and shows that any tendency to a posterior keel 
is confined to near the horn core tip. In these Samos examples which have hitherto 
been placed in the species woodwardi and zitteli, the horn cores have an anterior 
keel but no posterior keel. They are a distinct variety from the Maragha specimens, 
but I take them as conspecific by their robust, little divergent, keeled horn cores 
and by the braincase top being so angled on the face axis. 


Dentitions 


The two mandibles figured as P. houtumschindlert by Mecquenem (1924, pl. 5 
fig. 7 and pl. 6 fig. 5) agree in size with the upper dentitions attached to skulls. 
They show small back lobes on the Mgs, very small or absent basal pillars on the 
molars of one and moderate to small basal pillars on the other, goat folds on the 
molars, the anterior part of the medial wall of P,4 is not closed, metaconid of Py, is 
directed backwards, the lateral wall of P4 is indented just in front of the hypoconid, 
and the horizontal ramus is not very deep. Large numbers of lower partial dentitions 
of this size are present in the Maragha collections in Paris, and even though some 
may belong to other species it is very likely that many belong to the same species 
as the most numerous horn core type. The most likely alternative identity for some 
of these mandibles is Ozoceros rothi, which is present at Maragha but less numerous 
than Prostrepsiceros houtumschindlen.. The only indication of the size of the teeth 
in this species is provided by the skull of Mecquenem (1924, pl. 7 fig. 7). It is not 
certain that this skull is of O. vothi, but by its basioccipital morphology it is certainly 
not a Prostrepsiceros. Its tooth row (Mecquenem pl. 6 fig. 4) is slightly smaller 
than those of the skulls of P. houtwmschindleri, but suggests that there would be a 
considerable size overlap between dentitions of the two species. There is no per- 
ceptible morphological variation among the mandibles of this size range as they are 
preserved, and it would not be surprising if O. vothi had very similar teeth to P. 
houtumschindlert. 


FROM THE SAMOS HIPPARION FAUNA 205 


The supposed P. rotundicornis mandible from Maragha (Mecquenem 1924, pl. 7 
fig. 5) is smaller than the mandibles among which some may be accepted as P. 
houtumschindler, its molars have no goat folds, the basal pillars range in size from 
moderate on M, and Mg to slightly smaller on Ms, and the back lobe of Msg is quite 
large and possesses a central cavity. This and other similar mandibles are not 
P. houtumschindleri, but they might belong to the species which Mecquenem (1924 : 
30) called Gazella deperdita (see p. 284 footnote and Gentry 1970 : 273). 

The specific name of this species was wrongly spelled by Pilgrim & Hopwood 
(1928) as houtum-schlindleri with two ‘l’s. 


Prostrepsiceros rotundicornis (Weithofer) 


1865 Palaeoreas lindeymayert (in part) Gaudry : 292, pl. 52 fig. 5. 
1888 Helicoceras votundicorne Weithofer : 288, pl. 18 figs 1-4. 
1889 Helicophorva votundicornis (Weit.). Weithofer : 79. 

1903 Helicotragus votundicornis (Weit.). Palmer : 873. 

1908 Antidorcas? gaudvyi Mecquenem : 52. 

1924 Helicophora votundicornis Mecquenem : 39, pl. 7 fig. I. 
1926 Helicoceras fvaasii Andree : 163, pl. 11 fig. 4; pl. 15 fig. 1. 
1928 Helicotrvagus fraasii (Andree). Pilgrim & Hopwood : 23. 


LectotypPe. The Pikermi specimen figured by Weithofer (1888, pl. 18 figs 1, 2) 
in the Natural History Museum at Vienna was chosen by Pilgrim & Hopwood 
(1928 : 21). 

Loca.ities. Pikermi, Samos, Maragha. 

Acer. Lower Pliocene. 


Diacnosis. Horn cores are less massive than in Maragha examples of P. 
houtumschindlert, with some degree of antero-posterior compression; posterior keel 


2cm 
—— 
—— medial anterior 
Fic. 11. Sections of left horn cores from Maragha taken at a distance above the pedicel 
top equal to half the antero-posterior diameter at the base of the horn core. A = 
Protragelaphus skouzesi (Mecquenem 1924, pl. 6 fig. 6); B = Prostrepsiceros houtum- 


schindleri (Mecquenem 1924, pl. 6 fig. 7); C =P. votundicornis (Mecquenem 1924, 
pl. 7 fig. 1); D = Antilope cervicapra, BM(NH) 32.12.11.8. 


266 THE EARLIEST GOATS AND OTHER ANTELOPES 


is absent; a trace of an anterior keel is present and descends to an antero-medial 
or medial insertion; braincase is not strongly angled on the axis of the face. 
RemarKS. The Pikermi variety. The last species existed in two well marked 
varieties at Maragha and Samos but was absent from Pikermi; this one also exists 
in two clear varieties, but one occurs at both Maragha and Samos, and the other at 
Pikermi. P. votundicornis is less completely preserved than P. houtumschindleri but 
the following specimens are known. In London there is the Pikermi material listed 
by Pilgrim & Hopwood (1928 : 23), among which the incomplete skull M.11437 was 
figured by them (pl. 1 figs 2, 2a). There are also horn cores from Pikermi in Paris. 
The Pikermi material shows not very great divergence of the horn cores, not exceed- 
ing that of most of the P. houtumschindleri material, the horn cores are inserted 
rather obliquely at the base, and the basal part of the horn core before any outward 
swing begins is short. The skull M.11437 has a trace of a posterior keel at its base. 


A second variety from Maragha and Samos 


Maragha examples of this species are represented possibly by two single horn 
cores numbered 1886.X XVIII.8 in Vienna and by many specimens in Paris among 
which the more important are the frontlet figured by Mecquenem (1924, pl. 7 fig. 1), 
a cranium with the left horn core and part of the left preorbital fossa (Pl. 5 fig. 2), 
two further frontlets, and a frontlet possessing only the left horn core. The Maragha 
specimens of this species have horn cores inserted more uprightly, and a long basal 
part followed by a strong outward swing. It is interesting that there is a cranium 
with horn cores from Samos which agrees with the Maragha variety of P. votundicorms. 


Microtragus parvidens ye) oxo xx0 X XX 
Protragelaphus skouzesi 0 00 “To 
M. 13007 x 
Prostrepsiceros xo x KOX xX 

houtumschindleri 0 = uppers 

x =/owers 

Palaeoreas E O) ) 0) @ 3 XK Yen IK 

lindermayeri 


>< 


40 45 50 mm 


Fic. 12. Lengths of upper and lower molar rows of some antelopes. The uppers are 
from identified skulls only; the lowers of Palaeoveas lindeymayeri and Protvagelaphus 
skouzesi are fairly easily recognizable; the Spovadotvagus (—Microtragus) parvidens is 
only doubtfully identified. The Prostvepsiceros houtumschindleri is from Maragha only, 
and the Palaeoveas linderymayeri from Pikermi only. 


FROM THE SAMOS HIPPARION FAUNA 267 


It was figured by Andree (1926, pl. 11 fig. 4 and pl. 15 fig. 1), and I have seen at 
Minster a cast of the original specimen kept at Stuttgart. The horn core on the 
left side is sufficiently near complete to show that its divergence as a whole does 
not exceed that in other Prostrepsiceros despite the outward swing above the basal 
part. The braincase of this specimen appears to be angled on the face rather more 
than in the Pikermi M.11437 or in the Maragha specimen figured here, but it is less 
angled than in P. houtumschindlert. 

Major (1894 : 25) listed two Samos horn cores in Lausanne, 204 and 205, as 
Helicophora rotundicorms, but I believe that they are more likely to belong to 
Oioceros wegnert Andree (1926 : 170, pl. 15 figs 3, 6). 

The Pikermi examples of this species are the ones which have been called rotundt- 
cornis in the past, while the Maragha ones and the Samos example have been called 
fraast. 


Transverse 
diameter 6 
a 
40 + 
ro) a 
a a 
a ¢ + 
ca] + a 
° = + 
Ul oO * pe 
fo) x 
O- o X 4 
Xe) °” see 
30 see: x" 
’ ro 0’ x 
X’ ie Z 4 > 4 
: x 
; Antero-posterior diameter 
30 40 50 mm 


Fic. 13. Graph of horn core compression. x = Prostrepsiceyos houtumschindleri from 
Maragha, x’ = P. houtumschindleri from Samos, 0 = P. votundicorvnis from Maragha, 
0’ = P. rotundicorvnis from Pikermi, -++ = Protvagelaphus skouzesi, a = Palaeorveas 
lindermayert (including a the Samos specimen in Lausanne), - = Antilope cervicapra. 
o and + are the casts in Miinster of Prostvepsiceros votundicornis and Protragelaphus 

skouzest from Samos. The Samos Prostvepsiceyos houtumschindleri and the Pikermi 

P. rotundicornis are closest to Antilope but the Maragha P. votundicornis is rather larger. 

Protragelaphus skouzesi and Maragha Prostrepsiceros houtumschindleri are more medio- 


laterally compressed than the others. 


268 THE EARLIEST GOATS AND OTHER ANTELOPES 


Both varieties of P. rotundicornis differ from P. houtumschindleri by less massively 
built horn cores, keels absent or nearly absent, an ‘anterior’ keel in so far as one is 
ever present perhaps descends to a medial rather than to an antero-medial insertion, 
the horn cores are not more compressed higher up than lower down, the braincase 
is less angled on the face axis (Pl. 5 fig. 2), and the supraorbital pits are perhaps 
smaller. 

On the percentage diagram (Text-fig. 14) Pyrostrepsiceros rotundicornis from 
both Pikermi and Maragha has horn cores more like those of Antilope cervicapra 
than has the Maragha P. houtwmschindleri; the horn cores of the Pikermi P. rotundi- 
cornts are also small enough to approach the size of those of Antilope cervicapra. 


Dentitions 


The only example of a mandible I have been able to find which might belong to 
this species is BM(NH) M.13007, a left mandible from Pikermi with P3 to M3 in an 
early stage of wear (Pl. 6 fig. 2). It had been assigned to Palaeoreas lindermayeri 
(Pilgrim & Hopwood 1928 : 87). There is a small back lobe of M3; basal pillars 
are of small to moderate size on My, small on Mg and absent on M3; there are goat 
folds on the molars; the metaconid of P, is directed backwards and there is quite a 
deep indentation on the lateral wall in front of the hypoconid. All these characters 
cause M.13007 to resemble the slightly smaller Pvostrepsiceros houtumschindleri 
mandibles from Maragha, but the ramus may be slightly deeper below the tooth 
row. The teeth are slightly larger than in a number of Palaeoreas lindermayert 
mandibles from Pikermi, the molars have larger goat folds, and P3 is relatively 


80 100 120 140 160 


| Ant=post. diameter at horn core base 


2 Latero-medial diameter at h.core base 


3 Width across horn bases ; Biases 


- 


4 Width across supraorbital pits Ee: 4 
_—_ 


Fic. 14. Percentage diagram for some skull measurements of spiral-horned antelopes, 
based on Table 3 in the text. The standard line at 100% is the mean of 20 male Antilope 
cervicapra, and means of the other species are expressed as percentages of their values in 
A. cervicapra. Horizontal lines show the extent of standard deviations in A. cervicapra. 
The capital letters, A to G, indicate the species concerned as on Table 3, p. 274. 


FROM THE SAMOS AHIPPARION FAUNA 269 


smaller. The complete premolar row would have been relatively longer than in 
Protragelaphus skouzesi, which in any case has larger teeth. M.13007 is not small 
enough to belong to a gazelle or probably to Ozoceros rothi (see discussion on p. 264), 
but it would be the right size for Sporadotragus parvidens. Other mandibles which 
I have tentatively assigned to S. parvidens in my notes, e.g. BM(NH) M.130009, 
M.13011 and M.4184; AMNH 22778 and 86415, differ only in less or no development 
of goat folds, so M.13007 cannot be definitely taken as Prostrepsiceros rotundicornis. 
My expectation would have been to find a smaller tooth row in this last species. 
The right M; and Mz of an immature Samos antelope illustrated by Schlosser (1904, 
pl. 13 fig. 12), agree with M.13007. 


Genus PROTRAGELAPHUS Dames 
1883 Protvagelaphus Dames : 97. 
TYPE SPECIES. Protragelaphus skouzesi Dames. 
GENERIC DIAGNosIS. As for the species, which is the only one in the genus. 


Protragelaphus skouzesi Dames 
1857 Antilope lindermayeni (in part) Wagner : 155, pl. 7 fig. 18. 


1865 Palaeoveas lindermayeri (in part) Gaudry : 291, pl. 53 fig. 4. 
1883 Protragelaphus skouzesi Dames : 97. 


60 80 100 120 140 160 


5 Braincase length 
6 Skull width across mastoids 


7 Occipital height 


8 Width ant tubs basioccipital eS | 


\ \ 
AY No it 
9 Width post. tubs. basioccipital : Se 


ee 
10 Length mi -m3 A mee i 
Il Length pP2-p4 : eee ere 


Fic. 15. Percentage diagram for further skull measurements of spiral-horned antelopes. 
Explanation under Text-fig. 14. The braincase length was measured from the mid- 
frontals’ suture at the level of the supraorbital pits to the occipital top. Standard 
deviations for Antilope cervicapra could not be shown on this diagram, and have been 
listed after Table 3 in the text, p. 275. 


270 THE EARLIEST GOATS AND OTHER ANTELOPES 


Hototyre. The Berlin frontlet described but not figured by Dames. Pilgrim 
& Hopwood (1928 : 88) take Wagner’s figure as being of the paratype. Gaudry’s 
figure is a right mandible which is the size of this species, and was so taken by 
Pilgrim & Hopwood. 


Locarities. Pikermi, Samos and Maragha. 
AGE. Lower Pliocene. 


DiacGnosis. Moderate sized antelopes (larger than Prostrepsiceros); skull is 
fairly low and wide; horn cores are long, not medio-laterally compressed but the 
posterior keel adds to the antero-posterior diameter, with a strong posterior keel 
descending to a postero-lateral insertion but no anterior keel, inserted a little behind 
the orbits and rather obliquely in side view, inserted moderately wide apart in 
anterior view, moderately diverging, and the axis itself is twisted and lacks the open 
spiralling of Prostrepsiceros; postcornual fossa is usually moderate or large sized; 
frontals are hollowed; orbital rims slope rather than project strongly; braincase 
top is short and strongly angled on face axis; frontals are slightly higher between 
the horn bases than the level of the orbital rims; frontals surface is convex in front 
of the horn bases; mid-frontals suture may be raised; parieto-frontals suture is 
indented; supraorbital pits are smaller than in Prostrepsiceros and moderately 
wide apart; nasals are fairly long; suture at back ot nasals is narrowly drawn out as 
a V-shape; preorbital fossa is moderate to large sized; infraorbital foramen is above 
the front half of P§; premaxillae may rise with an even width to a short contact 
with the nasals; median palatal indentation is level with or behind lateral ones; 
nuchal crests are poor to moderate; occipital surface is more nearly in one plane 
facing backwards than in Prostrepsiceros; median occipital ridge and flanking 
hollows are poorly marked; anterior tuberosities of the basioccipital are wider apart 
than in Prostrepsiceros; anterior tuberosities are small with poor longitudinal ridges 
behind. 

Teeth are fairly hypsodont; the enamel is only slightly rugose; basal pillars 
are very small on upper molars and small to moderate on the lowers, decreasing 
backwards; rear central cavities of upper molars have indented back edges; medial 
lobes of upper molars remain unfused to one another fairly late in wear; styles and 
ribs are poor; goat folds on lower molars are poor or non-existent; premolar row is 
short; metaconid of P4, may join the paraconid and close the anterior part of the 
medial wall; the lateral wall of P4 is indented in front of the hypoconid; Ps is shorter 
relative to P, than in Palaeoreas. 


REMARKS. The more important fossils of Protragelaphus skouzest which I have 
seen are the paratype skull from Pikermi in Munich, two skulls in Paris from Maragha 
one of which was figured by Mecquenem (1924, pl. 6 fig. 6 and pl. 5 fig. 2), a cranium 
in London, M.10840, from Pikermi, a frontlet from Samos in Stuttgart, and a 
fontlet from Maragha in Vienna. There are other Maragha horn cores in Paris. 
I have not seen the holotype, nor the cranium in Gottingen figured by Weithofer 
(1888, pl. 17 figs 4-6). 

The Stuttgart specimen figured by Andree (1926, pl. 15 figs 4, 5) is the only 


FROM THE SAMOS HIPPARION FAUNA 271 


decisive evidence for this species from Samos; I did not see the original but was able 
to see a plaster cast in Miinster. The twisting of the keels on this Samos specimen 
is rather tight and the keel stronger than in other specimens; at its base the keel 
connects by a ridge with the back of the orbit. The London cranium has the back 
part of the braincase stuck to the front, and it is possible that the braincase appears 
to slope too little on the face axis on this specimen. 

There is a palate from Maragha in Paris which seems to belong to this species, 
and in addition I would assign to it these dentitions and teeth: mandibular pieces 
BM(NH) M.13021 and M.13022 (Pl. 6 fig. 2) from Pikermi, AMNH 86478 from 
Samos, 618 and 661 from Samos in Lausanne, and the Paris mandible figured by 
Mecquenem (1924, pl. 6 fig. 1) from Maragha. These pieces show that the teeth 
of this species are large among the smaller antelopes of lower Pliocene times but 
smaller than the common Samos genus Pachytragus. 

CoMPARISONS. Protragelaphus skouzesi differs from Prostvepsiceros as a whole 
by its greater size; more posterior horn insertions; a twisting of the horn core axis 
rather than an open spiralling; the combination of strong posterior keel on the 
horn cores and no anterior keel is not found in any known Prostrepsiceros population 
(Text-fig. 11); higher frontals between the horn bases; hollowed frontals with a 
convex surface in front of the horn bases; orbital rims projecting little; smaller 
supraorbital pits; occipital surface more definitely in one backwardly-facing plane; 
and wider anterior tuberosities on the basioccipital with less of a longitudinal 
central groove between them. 

It differs additionally from P. houtumschindleri in not having any medio-lateral 
compression of its horn cores (Text-fig. 13); a narrowly drawn out suture at the back 
of its nasals; upper molars with spurs often projecting into the back edges of the 
rear central cavities; no goat folds on its lower molars; and a tendency for paraconid- 
metaconid fusion to close the anterior part of the medial wall of Py. The Maragha 
mandible figured by Mecquenem (1924, pl. 6 fig. 1) has a completely fused paraconid 
and metaconid on its Py. It differs additionally from P. rotundicornis by its brain- 
case being more strongly angled on the facial axis, and by the horn cores being more 
obliquely inserted than in Maragha and Samos specimens. 

On the percentage diagram (Text-figs 14 and 15) Protragelaphus skouzesi is quite 
similar to the smaller Prostvepsiceros houtumschindlen, the latter having relatively 
narrower anterior tuberosities of its basioccipital. One can visualize the common 
ancestor of this pair not too far in the past. 


Genus PALAEOREAS Gaudry 


1861a Palaeoveas Gaudry : 299. 
1861b Palaeoveas Gaudry : 395. 


TYPE SPECIES. Antilope lindermayert Wagner. 


GENERIC DIAGNOsIS. There is only one species within the genus, so the generic 
diagnosis is as for that species. 


272 THE EARLIEST GOATS AND OTHER ANLELOPRES 


Palaeoreas lindermayeri (Wagner) 


1848 Antilope lindermayerr Wagner : 367, pl. 12 fig. 5. 

1861a Palaeoreas lindermayert Gaudry : 299. 

1861b Palaeoreas lindermayert Gaudry : 395. 

1865 Palaeoreas indermayert Gaudry : 290, pl. 52 fig. 4; pl. 53 figs 1-3; pl. 54; pl. 55. 


Ho.otyPe. Base of a right horn core in the Palaeontological Institute, Munich, 
no. 530. The antero-posterior diameter at the base of this horn core is 42-1 and 
the latero-medial diameter 40-2 mm. 


LocatiTies. Pikermi and Samos. 
AGE. Lower Pliocene. 


DraGnosis. Small to moderate sized antelopes; horn cores are moderately long 
and massive (more massive than in Pvostrepsiceros houtumschindlert), not medio- 
laterally compressed, often with deep fairly irregular longitudinal grooving, with 
a posterior keel which is sometimes strong and a weaker anterior keel, the posterior 
keel descending to a postero-lateral position, horn cores inserted above the orbits, 
set fairly obliquely in side view, close together in anterior view and poorly divergent, 
and the axis itself twisted anticlockwise from the base up on the right side but 
without open spiralling; there is an elongated very deep postcornual fossa. Orbital 
rims project moderately; mid-frontals and parieto-frontals sutures are not visible; 
temporal lines on braincase roof probably do not approach closely posteriorly ; 
braincase may widen posteriorly; large supraorbital pits; mid-frontals suture is 
raised as an incipient ridge in front of the horn bases; there is another localized 
raising of the mid-frontals suture behind the horn bases; the ethmoidal fissure is 
long and narrow; preorbital fossa is extensive and moderately deep; face is low in 
side view; infraorbital foramen is above the back part of P2; the premaxillae rise 
with an even width to a short contact on the nasals. 

Occipital surface is low and its dorsal edge is not evenly rounded; the median 
vertical occipital ridge is strong with large shallow flanking hollows; mastoids 
are moderate to large; basioccipital is long with a central longitudinal groove weaker 
in the centre than at either end; nuchal crests are moderately strong; auditory 
bulla is inflated and moderate to large, and its ventral edge does not descend poster- 
iorly to meet the front of the paraoccipital process. 

The teeth are fairly hypsodont (but perhaps less than in Prostrepsiceros and 
Protragelaphus); basal pillars are small or absent on the upper molars and slightly 
larger on the lowers; there are not usually indentations in the back edge of the rear 
central cavities on the upper molars; medial lobes of the upper molars remain 
unfused with one another until fairly late in wear; styles on upper molars are moder- 
ate sized and a rib between parastyle and mesostyle is often fairly strong; there is 
a tendency to goat folds on the lower molars; front and back edges of P3 and Py, are 
set transversely: anterior medial wall of Pg is not closed; the metaconid on Py is 
not directed backwards; there is no valley in front ot the hypoconid on the lateral 
wall of P4; Ps has a strong entostylid behind the entoconid; and P3 is fairly large 
in relation to P4. 


FROM THE SAMOS HIPPARION FAUNA 273 


REMARKS. There is a face with horn cores M.10843, several frontlets, and many 
horn cores of this species in London, all Pikermi. There are three skulls, and many 
other horn cores from Pikermi in the Paris collection. Three frontlets, 23, 24 
and 25 (Pl. 6 fig. 1) in Lausanne are the only known occurrence of the species from 
Samos. In the London collection I assign the following mandibular pieces to this 
species: the four numbered M.11505, M.13008, M.13012, M.15828 (Pl. 6 fig. 2) 
and M.15829. Pilgrim & Hopwood (1928 : 23, 70) had assigned M.11505 and 
M.13012 differently, but they did have M.13008 as P. lindermayert. Of the other 
dentitions which they assigned to P. lindermayert, I believe M.13007 has a P3 too 
small in relation to P4 for assignation to Palaeoreas lindermayeri (see p. 268), and 
the others I would not care to identify. 

In the Paris collection from Pikermi is a fine small palate with M1-M3 measuring 
39:4 mm long, M2 13-9 mm, and P2-P4 28-3 mm long. The rear median indentation 
passes further forwards than the lateral ones, ribs are strong between parastyle 
and mesostyle on the molars, M1 alone has a very small basal pillar, and the medial 
lobes of the molars are still not joined to the lateral sides of the teeth. I have 
taken this as P. lindermayert, as it agrees with other dentitions on the Paris and 
London skulls in its strong ribs. 

The species is thus very common at Pikermi, but rare at Samos. It has been 
recorded from other sites, but I would not accept most of these records based as 
they are on doubtful dentitions. However Schlosser (1921 : 44) recorded a horn 
core from Veles in Macedonia. It is principally from the London skull and the 
series of more or less complete ones in Paris that the diagnosis has been constructed. 
It is unfortunate that some weathering or rolling has taken place on these skulls, 
so that the details of structure are often missing. On one of the two Paris skulls 
in which they are present the nasals are transversely domed and on the other they 
are not. Nor could I be certain about the level of the median indentation at the 
back of the palate. 

The Samos skull in Miinster which was named Ozoceros wegnert by Andree (1926 : 
170, pl. 15 figs 3, 6) has many resemblances to Palaeorveas lindermayeri, for example 
no horn core compression, deep longitudinal grooving on the horn cores, the great 
height of the frontals between the horn bases, a localized raising of the mid-frontals 
suture anterior to the horn bases, and a long narrow ethmoidal fissure. Such 
similarities are surprising when it is realized that the torsion of the horn cores is 
in the reverse direction from P. lindermayeri. The only other clear differences 
of O. wegnert from P. lindermayeri are that the torsion is stronger, the spiralling 
more open, the keel descends to a lateral insertion, and the braincase is shorter 
with a more steeply inclined roof. I have considered Ozoceros as quite unrelated 
to Palaeoreas, Protragelaphus or Prostrepsiceros. 


CoMPARISONS. Palaeoreas lindermayeri is the most distinctive of the lower 
Pliocene spiral horned antelopes. It differs from Prostrepsiceros and Protragelaphus 
by its more massive horn cores, horn cores sometimes with deep irregular longitudinal 
grooving, a stronger posterior keel than in all except the Maragha P. houtumschindlert, 
horn cores not very compressed antero-posteriorly or medio-laterally (Text-fig. 13), 


274 THE EARLIEST GOATS AND OTHER ANTELOPES 


a deeper postcornual fossa, braincase more strongly bent on the face axis, frontals 
higher between the horn bases, the mid-frontals and parieto-frontals sutures not 
visible, larger supraorbital pits closer together, perhaps a larger ethmoidal fissure, 
stronger median vertical occipital ridge and thus more of a tendency for the occipital 
surface to face partly laterally as well as posteriorly, perhaps a slightly larger 
mastoid, basioccipital larger, basioccipital with less localized anterior tuberosities 
and as large a central longitudinal groove as the strongest ones in P. houtumschindler, 
and probably a stronger rib between parastyle and mesostyle on the upper molars. 


TABLE 3 
B Cc D E F G 
Antero-posterior diameter at 413 28:3 28:6 335 45°4 42°7 27°3 
base of horn core (11) (3) (3) (5) (5) (7) (20) 


Latero-medial diameter at base 303 27°8 30°5 34°5 371 37°53 28:3 
( ( 


of horn core (11) (2) (3) 5) (5 5) (20) 
Minimum width across lateral g2:2 82-9 82-7 87:9 103°7 86°5 74°4 
edges of horn pedicels (9) (3) (3) (3) (5) (5) (20) 
Width across lateral edges of 40°2 40°3 40°4 39°4 41°7 34:0 476 
supraorbital pits (8) (2) (2) (3) (4) (Sli, (ae) 
Braincase length from level of 89:9 _- — — 109°4 93°5 1024 
supraorbital pits to occiput (1) (1) (4) (20) 
Skull width across mastoids 69:0 -- -—— — 79°8 73°3 81:7 
behind exterior auditory meatus (1) (2) (4) (17) 
Occipital height from top of 27°1 — —— Biles 28:7 30°5 26:9 
foramen magnum (1) (1) 2) (6) (19) 
Width across anterior tuberosities 15:5 — — 19:2 22°8 222 22 
of basioccipital (1) (1) (3) (4) (17) 
Width across posterior tuberosities 23:8 — — 27°8 29'7 28:9 29:0 
of basioccipital (1) (1) (2) (4) (15) 
Length M1—M8 42:0 -- --- — 47°3 38-3 43°6 

(2) (2) (4) (16) 
Length P2—P4 27°2 — — = Beez 25:2 20°6 


Prostrepsiceros houtumschindlevi from Maragha only. 
from Samos only. 
votundicornis from Pikermi only. 
; from Maragha only. 
Protvagelaphus skouzesi from Pikermi and Maragha. 
Palaeoreas lindermayeri from Pikermi only. 
Antilope cervicapra, males of the living blackbuck. 


QpVACOnS 
tid dt dea 


FROM THE SAMOS HIPPARION FAUNA 275 


It differs additionally from Prostrepsiceros by its horn cores with a twisted axis 
instead of more open spiralling and perhaps by smaller auditory bullae, and from 
P. houtumschindlert by less strong goat folds on its lower molars, transversely set 
front and back edges of Ps and Pa, the metaconid on Py, is not directed backwards, 
no indentation on the lateral wall of P4 in front of the hypoconid, a larger Ps and 
P3 with a strong entostylid. It differs additionally from Protragelaphus skouzesi by 
less divergent horn cores, more projecting orbital rims, the back of the nasals less 
narrowly drawn out, the transverse front and back edges of Pg and Pa, no closing 
of the anterior part of the medial wall of Py, no indentation on the lateral wall of 
Py, anterior to the hypoconid, the large size and strong entostylid of P3. 

On the percentage diagram (Text-figs 14 and 15) Palaeoreas lindermayeri has 
large horn cores and a fairly large back part of the skull (characters 5—9 inclusive) 
compared with the size of the tooth row; the massiveness of the back of the skull 
presumably being linked with the size of the horn cores. 

Table 3 shows the means of some skull measurements of spiral horned antelopes 
used in Text-figs. 14 and 15 and the figures in brackets are the size of the sample. 
Standard deviations for the sample of Antilope cervicapra, listed in the same order 
asuthe measurements, ate: 1-78, 2:21, 4-14, 3°27, 3°46, 3-85, 2:20, 1-82, 1-67, 2:26 
and 1°34. 


IV. TRIBAL CLASSIFICATION 
The Palaeoryx, Protoryx and Pachytragus group 


Comparison with Hippotragint 


The tribe Hippotragini includes the following living species: 
Hippotragus equinus (Desmarest 1804) the roan, 
Hippotragus mger (Harris 1838) the sable antelope, 

Oryx gazella (Linnaeus 1758) the gemsbok and beisa, 
Oryx dammah (Cretzschmar 1826) the scimitar oryx, 
Oryx leucoryx (Pallas 1777) the Arabian oryx, 
Addax nasomaculatus (Blainville 1816) the addax. 


They are medium to large-sized stocky antelopes with large horn cores in both 
sexes, hypsodont cheek teeth with basal pillars on the molars, and little reduction 
of premolars. Hippotragus has a long braincase and medio-laterally compressed 
horn cores strongly curved backwards, Ovyx has a shorter braincase and little- 
compressed straight horn cores, and Addax has a shorter braincase and spiralled 
horn cores. 

The older authors gave but few reasons why they regarded Palaeoryx, Protoryx 
and Pachytragus as Hippotragini. Gaudry (1861a : 241; 186r1b : 394) in writing 
of Palaeoryx mentions the form, proportions and insertion of the horn cores, position 
of the supraorbital pits and lack of wide orbital rims as resembling modern Oryx, 
although its teeth were certainly very different. Major (1891a : 608) in founding 


276 THE EARLIEST GOATS AND OTHER ANTELOPES 


Protoryx writes of a more decided hippotragine aspect than even Palaeoryx possessed 
—horn cores bigger relative to skull size, brachyodont teeth, and in some species 
a short parietal. The reference to brachyodonty as a resemblance is puzzling. 
Apart from that, it seems that the little compressed and obliquely inserted horn 
cores of Palaeoryx cause it to resemble Ovyx, and that Protoryx with its more com- 
pressed and uprightly inserted horn cores can be regarded as not unlike Hippotragus. 

So far this is not very convincing, and the only other resemblances of the fossils 
to Hippotragini lie in characters which can reasonably be supposed to be primitive. 
Thus the fossils have no keels on the horn cores (except in Pachytragus crassicornis), 
the extent to which the frontals are raised between the horn bases is about the same, 
there are no transverse ridges on the front of the horn cores, the horns are inserted 
above the back of the orbits, the horn cores of Protoryx cavolinae and Pachytragus 
laticeps diverge about as much as in Hippotvagus, the horn cores have a simple 
course without torsion, postcornual fossae are small or absent, the orbital rims 
have about the same width, the supraorbital pits are small, an ethmoidal fissure is 
present, the infraorbital foramen above the tooth row is in about the same position, 
the palatal foramina are at about the same antero-posterior level, the mastoids 
are large, the anterior tuberosities of the basioccipital are set about as widely apart, 
and the degree of hypsodonty in Pachytragus approaches that of Hippotragini. 

Two other possible resemblances to the Hippotragini need further discussion; 
these are the solid horn cores of the fossils and the dimensions of their braincases. 
The fossil horn cores are mostly solid, but traces of a basal hollowing have been 
found (see p. 248). Hippotragini also have solid horn cores, but in them the central 
lowest parts are at most only slightly spongy in texture, and I have found no sign 
of the development of hollowing. A collection in Cape Town of the large extinct 
Hippotragus gigas Leakey from the Elandsfontein Pleistocene site confirms this. 
Hollowing of the frontals extends to the top of the horn pedicels, above which the 
horn core itself is not hollowed. A very large East African frontlet of the same species 
in Nairobi (figured by Leakey 1965, pls 89, 90) has the frontal hollowing extending 
about 35 mm above the external indication of the pedicel top, but this hollowing is 
clearly demarcated from the horn core substance above. A male roan antelope 
in the National Museum, Nairobi was sectioned 20 mm above the top of its horn 
pedicel and at that level it was solid. So the hollowing in the fossil AMNH 23038 
(see p. 249) already exceeds that in Hippotragus, and even the extreme sponginess 
of AMNH 22783 would not be expected in Hippotvagus. It is therefore difficult 
to derive the totally solid condition of living Hippotragus from that of the fossils 
in which hollowing has already been initiated. 

Braincase lengths of the fossils can be matched with one or other of the Hippo- 
tragini. Thus Palaeoryx pallasi agrees with Oryx, Protoryx carolinae and longer- 
brained Pachytragus with Hippotragus equinus, and other Pachytragus with Hippo- 
tragus niger. This is in line with the supposed connection of Palaeoryx with Oryx, 
and of Protoryx and Pachytragus with Hippotragus. However the resemblance 
ends here. The bending down of the braincase on the facial axis is less in either 
species of Hippotragus than in Protoryx and Pachytragus, and braincases of Hippo- 


FROM THE SAMOS HIPPARION FAUNA 277 


tragus are wider than in the fossils. With the differences in inclination and pro- 
portion, it is difficult to see that the length of the braincases can indicate any real 
connection of the fossils with Hippotragini. 

Turning to the differences of the fossils from Hippotragini, we find that the most 
important ones concern the teeth. Hippotragini retain basal pillars on their molars, 
and have strong outbowed labial ribs between the styles on their upper molars. 
Hippotragus itself has evolved large basal pillars, complicated central cavities on 
its upper molars, goat folds on its lower molars, and relatively large premolars 
(Text-fig. 5). It is obvious that the teeth of the two Pachytragus species are not 
evolving in this direction. Even if one could discuss a possible hippotragine re- 
lationship for Palaeoryx or Protoryx, one could certainly not do so for Pachytragus. 

Finally in comparing the Samos fossils with modern Hippotragini, one should 
mention that there are two fossil hippotragines from the Pinjor stage of the Siwalik 
Hills in India and Pakistan (perhaps of early Pleistocene age) which are substantially 
different from living Hippotragini but do not suggest a derivation from Protoryx 
or Pachytragus. These two fossils are Sivatragus bohlini (Pilgrim 1939 : 80, pl. 2 
figs 3-6, text-fig. 6) and Sivoryx sivalensis (= Antilope sivalensis of Lydekker 1878 : 
154, pl. 25 figs 1, 2) which I take to include S. cautleyz (Pilgrim 1939 : 74); both are 
represented in the British Museum (Natural History). Neither have the frontals 
between the horn bases raised above the level of the orbital rims; Sivatragus bohlim 
shows boselaphine-like characters in the braincase being little angled on the line 
of the (absent) face and in its fairly marked temporal lines behind the horn bases, 
and is further unlike the Samos and Pikermi antelopes in its braincase being 
definitely wider posteriorly than anteriorly; Sivoryx sivalensis has rather a low and 
wide skull and its upper molar teeth have basal pillars and are without such marked 
mesostyles as Pachytragus. Derivation of S. sivalensis from Palaeoryx pallasi 
could not be ruled out on morphological grounds, but P. pallasi is too large to be a 
likely ancestor. 

I conclude from all the above evidence that Palaeoryx, Protoryx and Pachytragus 
cannot be placed in the Hippotragini. 


Comparison with the Caprini 


Most of the primitive skull characters in which the fossils resemble Hippotragini 
are also resemblances to Caprini, and particularly to goats (Capra Linnaeus 1758) 
within the Caprini. Caprini are wholly Palaearctic except only for Capra walie 
Rueppell 1835 which has reached a part of the Ethiopian highlands and Ovis 
canadensis Shaw 1804 which has spread into America.2 If the Samos antelopes 
should turn out to be caprines, the supposed African affinities of that fauna would 
be much diminished. It is therefore of interest to look for further caprine resem- 
blances in the fossils. 

The delimitation of the species of goats and their very near relatives (Capra, 


2 Oveamnos americanus (Blainville 1816), the Rocky Mountain goat, is also in North America, but 
Simpson (1945 : 162) places Oveamnos in the tribe Rupicaprini of the subfamily Caprinae. 


278 THE EARLIEST GOATS AND OTHER ANTELOPES 


Hemitragus, Ammotragus, Pseudots) adopted by Ellerman and Morrison-Scott (1951 : 
403-410) and the arrangements of more recent authors are clearly unsatisfactory 
in their various ways. Many of the named forms can interbreed to produce fertile 
offspring (Gray 1954 : 70), and striking differences of male horns probably have little 
taxonomic value. This has been Payne’s (1968) point of view, and although I do 
not follow him to all his conclusions, it seems unlikely that we could find separate 
ancestors for most or all of the ‘species’ of Capra very far back in the geological 
record. In this paper I shall use the specific names of Ellerman and Morrison-Scott 
within the genera Hemitragus, Ammotragus and Pseudois, and within Capra the 
following names: C. aegagrus Erxleben 1777 for goats with an anterior keel on their 
horn cores, C. 7bex Linnaeus 1758 for the European ibex, C. sibivica (Pallas 1776) for 
Siberian ibexes, C. caucasica Gildenstaedt & Pallas 1783 for the Caucasian turs, 
and C. falconert (Wagner 1839) for the spirally horned markhors. 

There are a number of characters in which the Samos fossils, especially Pachytragus, 
are similar to goats, and taken together these characters indicate convincingly a 
relationship of the fossils to goats. These characters are as follows. 

An anterior keel exists on the horn cores of Pachytragus crassicornis, the most 
advanced of the fossils, and on those of Capra and Hemitragus. In AMNH 22938 
and AMNH 229309 the keel descends to an antero-medial insertion; this would allow 
for the later development of an antero-lateral longitudinal swelling such as can be 
seen in many Capra aegagrus. The beginning of such a swelling may be present 
in AMNH 20708. This swelling could so easily develop into the broad anterior 
surface of ibex horn cores, that one doubts whether ibexes necessarily had different 
ancestors from C. aegagrus as far back as the lower Pliocene. 

The cranium AMNH 23037 of Pachytragus laticebs has horn cores completely 
preserved to their tips, and in profile their course is not an even arc with a large 
radius of curvature like Hippotragus but they become more sharply curved towards 
their tips; such a curvature resembles that in the male horns of living goats and 
ibexes. Other examples of Pachytragus fail to show this so well, but it does occur 
in the Pachytragus laticeps cranium 201 in Lausanne, and in AMNH 20674 and 
20690. 

Extensively hollowed horn cores are characteristic of the living Bovini and 
Caprini, but in other bovid tribes hollowing is confined to the frontals and horn 
pedicels. Traces of hollowing near the bases of the horn cores have been noted in 
Pachytragus (page 248), and this would be appropriate in ancestors or relatives of 
later Caprini. 

The bending down of the braincase on the axis of the face in Protoryx and Pachy- 
tvagus is a character also found in goats. 

In some Pachytragus (and Palaeoryx) individuals a tendency exists for the widest 
part of the braincase to lie anteriorly. It appears in the Lausanne skull 30 which is 
probably a Pachytragus laticeps, in the Minster skull of P. cvassicornis figured by 
Andree (1926, pl. 13 fig. 7), in a number of the New York Pachytragus skulls, and 
in the Pachytragus skull from Salonica figured by Arambourg & Piveteau (1929, 
pl. 7 figs 6, 6a). It can also be seen in the Palaeoryx pallasi skull BM(NH) M.10831 


FROM THE SAMOS HIPPARION FAUNA 279 


and in the Munich example of the same species from Samos, but two other P. pallast 
braincases widen posteriorly. In Hippotragini the sides of the braincase are either 
parallel or widen posteriorly, but in living Caprini they are parallel or widen anter- 
iorly. 

On Text-fig. 4 it can be seen that the supraorbital foramina have become wider 
apart, relative to the distance across the horn bases, in Pachytragus crassicornis 
than in P. lJaticeps, and this character would link P. crassicornis more closely with 
Capra. 

The ethmoidal fissure is not only present in both species of Pachytragus, but is 
also long and narrow as in Capra, Hemitragus and Ammotragus; it is less wide than 
in Hippotragini. 

The Pachytragus face of AMNH 20609 has a jugal which is not unlike that of 
Capra, but is without the two unequally-sized lobes of a Hippotragus. It does 
not show any antero-ventral expansion and smoothly rounded overall course of the 
front suture like many individuals of caprine species. 

The foramina ovalia are small to moderately sized in the fossils as in Caprini 
instead of moderate to large as in Hippotragini. 

In the type skull and in the cranium AMNH 20621 of Pachytragus laticeps and in 
the Lausanne cranium 29 (Pl. x fig. 1) and Miinster cranium (Andree 1926, pl. 13 
figs 4, 6) of Palaeoryx pallasi, the auditory bullae have survived, and it can be seen 
that the posterior part of their ventral edges turn downwards to meet the front of 
the paraoccipital processes as in the caprines Hemitragus, Pseudois, Ammotragus 
and many Capra. I took this to be a resemblance of the fossils to Caprini (Gentry 
1968 : 874), and although this was correct I have since found that the character 
occurs frequently in the sable antelope. 

The diminution of basal pillars on the cheek teeth of Pachytragus laticebs and 
P. crassicormis foreshadows their almost total absence in the teeth of living Caprini; 
the central cavities of the upper molars have an uncomplicated outline; in P. 
laticeps and crassicornis the mesostyle is frequently prominent on the upper molars 
and is followed by a concave lateral wall behind as in Caprini. Finally the short 
premolar row (Text-fig. 9, already shorter in P. laticeps and P. crassicornis than 
in Hippotragus) and somewhat reduced P2 in the fossils foreshadow later Caprini. 
Such teeth can convincingly be seen as an intermediate stage in the evolution of 
modern caprine teeth from the fairly generalized original condition of bovid teeth 
such as is seen in Palaeoryx pallast and Protoryx carolinae. 

An extremely interesting character to know would be the size of the central 
incisor teeth in Palaeoryx, Protoryx and Pachytragus, for they are small in all Caprini 
(as in most Eurasiatic antelopes) but larger in Hippotragini (as in most African 
antelopes). The mandible AMNH 23073 had hs perhaps only slightly bigger than 
the more lateral incisors and canine like Caprini, but clear evidence from an unworn 
dentition is required. A mandibular symphysis in Minster of an unknown Samos 
antelope of the size of Pachytragus has rather small Is. 

Text-fig. 10 shows the relative proportions of some skull measurements in the 
fossils and living antelopes. The sable antelope has larger horn cores than the roan 


280 THE EARLIEST GOATS AND OTHER ANTELOPES 


and both have rather long braincases, the last character being exaggerated on the 
diagram because of the relative shortness of the braincase in Palaeoryx pallasi, here 
used as a standard. Capva and Pachytragus crassicornis have similar proportions 
of the cranium, but Capra has very large horn cores and small teeth. 

It is difficult to interpret the evolutionary history of Pachytragus, not least 
because of the lack of precise details about the vertical distribution of its species. 
It is known only that P. crassicornis in the New York collection is confined to 
Brown’s quarry 5, while quarries 1 and 4 contain the less advanced P. laticeps. The 
supposition that quarry 5 might be later than the other quarries depends on the 
morphological interpretation of the two species of Pachytragus; Sondaar (1968 : 68) 
has mentioned a time difference between the quarries but without specifying whether 
quarry 5 was the later. Except for the relative smallness of the teeth in Capra, 
there seems no reason why Pachytragus crassicornis should not be the actual ancestor 
of goats. A more detailed knowledge of later Pliocene faunas is desirable before 
asserting this more definitely. 

Tossunnoria pseudibex Bohlin (1937 : 37, pl. 4 fig. 3, pl. 5 figs 1-3, text-figs 66-68, 
70b, 71-74), a caprine from the lower Pliocene of north eastern Tibet, has been 
linked with the ancestry of goats. It has large very strongly compressed horn 
cores inserted at a high angle to one another so that their bases diverge backwards. 
Its braincase widens posteriorly. I am prepared to relate it to Pachytragus among 
its contemporaries, and very tentatively to Hemitragus among its successors. Its 
horn cores are more advanced or specialized than in Pachytragus. 


Differences of the Samos fossils from living Caprint 


A number of advanced characters of later Caprini are absent in the lower Pliocene 
fossils: the extreme enlarging of male horn cores and the linked raising of the level 
of the frontals between the horn bases, the frequently posterior setting of the 
palatal foramina, and the very wide anterior tuberosities of the basioccipital. The 
primitive state of these characters in the fossils were previously noted as similarities 
to Hippotragini; such resemblances may simply result from the acquisition of some 
specializations in Caprini later than the earlier Pliocene. Other later caprine 
characters not met with in these fossils are the very wide projection of the lower 
rim of the orbits (less pronounced in Ovis ammon and Ammotragus lervia than in 
other living Caprini), the tendency to antero-ventral expansion of the jugal and an 
evenly curved course of its front suture which is most apparent in Pseudois, Ammo- 
tragus and Hemitragus, the small angle of the lower jaw, the fusion of the metaconid 
and paraconid on P,, the presence of goat folds on lower molars, and high transverse 
crests across little worn and unworn upper molars. The crests across the upper 
molars are detectable on dentine as well as enamel and must result from rigidly 
fixed transverse occlusal movements. Possible initial traces of such wear are visible 
on the Pachytragus laticeps and P. crassicorynis specimens in Minster figured by 
Andree (1926, pl. 12 fig. 2 and pl. 13 fig. 7). 

Among these characters by which modern goats differ from Pachytragus, the 
large horn cores with extensive hollowings, raised frontals, and wide basioccipital 


FROM THE SAMOS HIPPARION FAUNA 281 


suggest that the method of intraspecific fighting used by Capra (see Schaffer 1968) 
had not yet evolved. It may be mentioned that although the sparse and inade- 
quately identified antelope limb bones from Samos have not been studied in this 
paper, there are no extremely shortened goat-like metapodials in any museum 
collection to suggest that even Pachytragus crassicornis had entered areas of pre- 
cipitous rocky slopes. 

If we consider other skull characters than those in which the fossils are less ad- 
vanced than all living genera of Caprini, we find that Pachytragus is still not very 
close to Ovis, the latter genus differing strongly in its broad-fronted divergent 
curled horn cores and no ethmoidal fissure.? Pseudois differs by its non-compressed 
divergent horn cores often with deep longitudinal grooving in mature animals, 
the short braincase very strongly angled on the face, the generally advanced outline 
of the jugal, no preorbital fossa or ethmoidal fissure, and small mastoid. Ammo- 
tragus differs by its non-compressed divergent horn cores, the generally advanced 
outline of its jugal, no preorbital fossa and no ethmoidal fissure. Hemuitragus 
differs by its short horn cores, long dorsal parts of its orbital rims, often an expanded 
jugal, and no preorbital fossa. Capra aegagrus differs in the absence of a preorbital 
fossa, and it is this form from which Pachytragus, especially P. crassicornts, is least 
remote; Capra falconeri has a large posterior keel and strongly twisted horn cores, 
most ibexes have broad-fronted horn cores (the prominent knobs on the sheaths 
are not present on the cores), and Capra caucasica has horn cores rather more 
reminiscent of Ammotragus or Pseudots. 


The position of Palaeoryx pallasi 


The similarities noted between the Samos fossils and living goats have principally 
concerned Pachytvagus and especially P. crassicornis. Little positive sign of a 
connection between Palaeoryx pallasi and goats can be seen. Although P. fallasi 
cannot satisfactorily be taken as in the Caprini, it does have some similarities to 
later members of other tribes of Caprinae, for example the living East Asian Capri- 
corms Ogilby. The resemblance to Capricornis is at least as great as to the hippo- 
tragine Ovyx. More interesting are its similarities to Megalovis latifrons from 
the Villafranchian of Senéze, France (Schaub 1923 : 2092, fig. 5; 1943 : 281, figs 5 
and 6). Some fossils assigned to Pliotragus (=Deperetia) ardeus are very probably 
conspecific with M. latifrons, e.g. the cranium illustrated by Schaub (1923, fig. 3) 
and the skull from the Villafranchian of Olténie in Romania illustrated by Bolomey 
(1965, figs 1-3). It is even possible that this species includes the original maxilla 
of Antilope ardea Depéret (1884, pl. 8 fig. 3) in which case nomenclatorial alteration 


3 It may be more difficult in the future to determine the ancestry of sheep than of goats. Sivacapra 
Pilgrim (1939 : 49) from the Pinjor stage of the Siwaliks has torsion of its horn cores which is clockwise 
on the right side and it is a possible relative of sheep. It has resemblances both to Sinotvagus mentioned 
on p. 243 above and to Samotragus crassicoynis Sickenberg (1936) from Samos, which in its turn is like 
Oioceros wegnevi Andree (1926: 170, pl. 15 figs 3, 6). Yet it is impossible to link Sinotvagus with 
Otocevos if the former’s relationship to Pyvotoryx and Palaeorvyx (p. 243) is accepted, so one is faced with 
two caprine stocks having clockwise torsion of their horn cores. The assignation of individual fossils 
becomes difficult, and we also have to find out whether sheep descend from either stock or from some other 
form such as Spovadotragus (see p. 283 below). 


282 THE EARLIEST GOATS AND OTHER ANTELOPES 


of M. latifrons to M. ardea would be needed. Villalta & Crusafont Pairo’s (1955 : 
431, figs 1-3) Hesperoceras merlae from Villaroya must be at least a close relative 
of M. latifrons. Bolomey’s skull in particular suggests a connection with Palaeoryx 
pallasi, with which it shares or from which it could easily have derived the following 
characters: large size (both species are large among their contemporaries), short to 
moderately long horn cores, little compression of the horn cores (Text-fig. 8), horn 
cores strongly divergent and inserted behind the level of the orbits, braincase angled 
on the axis of the face, short braincase, small supraorbital pits set widely apart, 
and the back of the tooth row lying just anteriorly to the level of the front of the 
orbits. Text-fig. 10 shows that a couple of measurable Megalovis latifrons have 
rather larger horn cores and tooth rows than in Palaeoryx pallasi. Other Villa- 
franchian skull pieces I examined in Paris and Basle show further characters in 
common with Palaeoryx pallasi: not very complicated mid-frontals and parieto- 
frontals sutures, a large mastoid, and a wide basioccipital. However, the teeth 
of these Pleistocene fossils are more advanced than in P. pallasi, and the relative 
length of the premolar row a little reduced (Text-fig. 9). 

Accepting Pachytragus as a definite member of the Caprini, one can either place 
Palaeoryx and Protoryx with it as close relatives or separate them, placing Palaeoryx 
in the same tribe as Megalovis. The correct tribal position for Megalovis has been 
a problem, some authors relating it to sheep and others to the Ovibovini (Guérin 
1965 : 12). Unlike Schaub (1923) I take it as an ovibovine. It agrees with the 
Ovibovini (discussed further on page 289) or at least with the living Ovibos and 
Budorcas in its large size, dorso-ventral compression of the horn cores, their insertion 
behind the orbits and very wide divergence, presence of a ridge from the base of the 
horn core to the top back of the orbit, short braincase, well projecting orbital rims, 
not a complicated mid-frontals suture, small supraorbital pits which are set widely 
apart, infraorbital foramen placed as far posteriorly as above the back of P3, an 
indication of concavities postero-laterally to the anterior tuberosities of the basi- 
occipital, small auditory bulla, absence of basal pillars on the molar teeth, upper 
molars rather long relative to width, upper molars with fairly strong styles and 
rounded medial lobes, P? remaining large, mandible not markedly deep below the 
molars, and paraconid of P, fused to the metaconid. In addition the quite sharp 
upstanding ridges on the posterior tuberosities of the basioccipital and the central 
longitudinal groove constricted between the anterior tuberosities are like Budorcas. 
There seems to be no reason to link Megalovis with sheep which have horn cores 
inserted above the orbits, emerging without much divergence, and with a marked 
spiral course. I suggest that Megalovis is an ovibovine and that Palaeoryx too be 
placed in that tribe. This opinion is tentative, and I have not seen the Megalovis 
skull from Olténie, but I believe it is better to have a definite and possibly interim 
classification than one with an unworkable proportion of queried assignations. In 
the same manner I shall take Protoryx and its Asian relatives as Caprini, although 
there is hardly any balance of probabilities taking them closer to that tribe than 
to Ovibovini. With Palaeoryx no longer related to Oryx, the evidence for rather 
dry steppe conditions at Pikermi, if not also at Samos, is diminished. An ancestor 


FROM THE SAMOS HIPPARION FAUNA 283 


of Oryx could be visualized with a tendency to inhabit the rather dry areas favoured 
by the living species, but we do not know what habitats might have held an ancestor 
of Megalovis latifrons. 


Other related lower Pliocene fossils 


The foregoing revision has been concerned only with species of Palaeoryx, 
Protoryx and Pachytragus occurring at Samos, Pikermi and Maragha. Paraprotoryx, 
Prosinotragus, Sinotragus and Sinoryx have been mentioned in the comparisons, 
and there are other Eurasian Pliocene bovids which should probably be removed 
from the Hippotragini, namely Pseudotragus, Leptotragus, Olonbulukia and Sporado- 
tragus. 

Pseudotragus capricornis founded by Schlosser (1904 : 51) on Samos material is 
represented by the type skull in Munich (Schlosser 1904, pl. ro fig. 7) by a poorly 
preserved skull in New York (AMNH 20577), by the London skull BM(NH) M.4193, 
and by some dentitions in Munich (Schlosser 1904, pl. Io figs 1-3, 5, 6). The 
Munich examples are in a different matrix from the other bovids (Schlosser 1904 : 
I12-113), hence there is a good likelihood that the teeth are correctly referred; the 
New York specimen is from Brown’s quarry 6 in which, like quarry 2, Pachytragus is 
not represented. Leptotragus was founded by Bohlin (1936 : 8, figs 2, 3) for a second 
smaller skull referred by Schlosser (1904 : 51, pl. 10 fig. 8) to Pseudotragus capn- 
cornis, the supposed generic difference being based on its straighter and narrower 
horn cores, larger orbits situated more anteriorly, horn cores set more obliquely 
and having an anterior keel. It seems unlikely that Leptotragus pseudotragoides can 
be separated specifically from Pseudotragus capricornis, but I was not able to check 
the specimen in Munich which was probably destroyed in the Second World War. 
Pseudotragus in Schlosser’s original sense is smaller than Pachytragus, and has 
relatively very large, strongly compressed horn cores, well projecting orbital rims, 
a long premolar row and a relatively large P?. It resembles Caprini in the rather 
small size of the face relative to the cranium and in the braincase being strongly 
angled on the face. 

Olonbulukia tsaidamensis Bohlin (1937 : 30, pl. 2 figs 10, 11, pl. 3 fig. 1) is based 
on a cranium from the supposed lower Pliocene of Tsaidam in China. It is about 
the size of Pachytragus or Pseudotragus, has horn cores strongly compressed latero- 
medially, with an anterior keel, little divergent and curved backwards in side view. 
There is a postcornual fossa and the braincase would have been somewhat angled 
on the missing face. Olonbulukia shows no clear sign of tribal affinities in itself, 
but it can continue to be tentatively taken as an Asian relative of Pachytragus and 
Protoryx. 

Sporadotragus Kretzoi (1968) is the corrected name for Muicrotvagus Andree 
(see p. 234). It is again smaller than Protoryx. It differs from Pseudotragus by 
having less compressed horn cores, frontals very strongly raised between the horn 
bases, horn cores frequently with an anterior surface, and narrower orbital rims. 
The middle two of the preceding characters, along with the rather small face 
(Pikermi) and widening of the anterior parts of the braincase (Pikermi) are decidedly 


284 THE EARLIEST GOATS AND OTHER ANTELOPES 


caprine-like and the clear upper and lower rims of the preorbital fossa recall sheep 
in particular. 

I suggest that Pseudotragus (including Leptotragus) and Sporadotragus be trans- 
ferred to the Caprini, while Olonbulukia be regarded as ?Caprini. 

The skull of Tvagoreas oryxoides Schlosser (1904 : 34, pl. 6 figs 1 and g) is from 
a small antelope with strongly compressed and obliquely inserted horn cores, frontals 
less raised between the horn bases than in Pseudotragus, no upraised mid-frontals 
suture, a preorbital fossa without an upper rim, a fairly large P?2, and an apparently 
undistorted brain top which is scarcely angled on the face axis. It could be related 
to Miotragocerus on the basis of these characters, although smaller than the smallest 
species of that genus, M. valenciennesi Gaudry (1865 : 288). No feature of its 
morphology suggests membership of the Hippotragini, but only the strongly com- 
pressed horn core would go against such an assignation. Doubtful placing in the 
Boselaphini seems a better solution to the problem, since it would not be satisfactory 
to use this unique and puzzling specimen as the only basis for the presence of 
Hippotragini at Samos.4 


Ancestors for the Palaeoryx group 


Nothing certain is known of the ancestors of Palaeoryx, Protoryx or Pachytragus. 
Earlier representatives of the boselaphine genus Muiotragocerus than the Samos, 
Pikermi and Maragha species are known from the Sarmatian of the Vienna Basin 
(Thenius 1959 : 87) and the Chinji of India and Pakistan, and the related genera 
Protragocerus and Eotyvagus also occur at such early time levels. But the record 
for pre-Pannonian Caprini includes only Ozoceros from Tung Gur, Fort Ternan and 
Prebreza, ?Pseudotragus potwaricus (Pilgrim) from the Siwaliks and Fort Ternan 
and its possible relative ?Gazella stehlint from Europe. (See Gentry (1970) for dis- 
cussion and references to these occurrences.) The only bovid which is a possible 
candidate for ancestry of Palaeoryx, Protoryx or Pachytragus is Damalavus boroccot, 
known as a cranium and other horn cores and teeth from the Miocene of Oued 
Hammam (Bou Hanifia) in Algeria. It was described by Arambourg (1959 : 120, 


4 Bohlin (1935c : 107, pl. 13 figs 7-14, pl. 14 figs 1-6) described two fine skulls of Tvagoveas lagreli 
from the Chinese lower Pliocene which he later suggested should be renamed T. altidens (Bohlin 1941 : 
107). They had somewhat compressed horn cores set very closely together, very deep postcornual 
fossae, the front of the braincase at a high level relative to the face, but the back part bent downwards. 
Should Tvagoveas become unavailable as a generic assignation for this species, it could be referred to 
Pseudotragus or to Doycadoryx Teilhard de Chardin & Trassaert (1938 : 32), possibly as a separate 
species from their D. tviquetricornis. A number of horn cores in the Paris collection from Maragha 
may be close to ‘Tvagoreas’ altidens; they are short and thick, there is a very deep postcornual fossa, 
wide orbital rims, and a braincase much angled on the face. A frontlet has been illustrated (Mecquenem 
1924, pl. 3 fig. 3), and all of the Maragha specimens are larger than the Gazella deperdita from the type 
locality, Mount Léberon, to which they were referred. (Another Maragha frontlet of this supposed 
gazelle in Vienna had previously been named by Rodler & Weithofer (1890 : 767, pl. 5 fig. 1 and pl. 6 
fig. 1) as Gazella capricornis, changed to G. vodlevi by Pilgrim & Hopwood (1928 : 16), and later said by 
Pilgrim (1939 : 45) to be possibly an Ozoceros. In the absence of well marked torsion of its horn cores 
there is no reason to assign it to Oiocevos.) A frontlet from the Nagri stage of the Siwalik Hills in Pakistan 
which Pilgrim (1939 : 86, pl. 2 figs 1, 2) called gen. indet. (cf. Tvagoreas) potwaricus and the same species 
from the Fort Ternan upper Miocene in Kenya are unlikely to be linked with Tvagoreas ovyxoides or 
with ‘Tvagoreas’ altidens; I have written elsewhere that a relationship to Pseudotragus is just possible 
(Gentry 1970 : 288). 


FROM THE SAMOS HIPPARION FAUNA 285 


pl. 18 figs 4, 4a) as an alcelaphine, and the type specimen does resemble a Damaliscus, 
but with a long braincase and short more obliquely inserted horn cores. It is 
alternatively possible that this ancient antelope could be an ancestor of Palaeoryx 
(this may have been Arambourg’s (1954 : 297) first opinion of it when he wrote of a 
Palaeoryx at the site). It is large for its geological age but smaller than P. pallasi, 
the horn cores are only moderately long, slightly curved backwards and obliquely 
inserted in side view, without keels and with perhaps a slight lessening of divergence 
towards their tips. The cranium has been transversely crushed, as Arambourg 
noted; its horn cores may have been slightly more divergent in anterior view, and 
their insertions a little wider than actually appears. There is a shallow postcornual 
fossa, small supraorbital pits, the frontals between the horn bases are hardly higher 
than the orbital rims, the braincase is moderately long and not very strongly bent 
on the face axis (this is a difference from Palaeoryx, but one which is probable in its 
putative ancestor), mid-frontals and fronto-parietal sutures are fairly complicated, 
and there are no temporal ridges—only temporal lines which do not approach very 
closely posteriorly. This absence of temporal ridges might remove it from candida- 
ture for boselaphine ancestry. Measurements on this specimen, comparable with 
those taken on Palaeoryx and Protoryx are: antero-posterior and transverse diameter 
of horn core 40-2 and 32:8 mm. 

A left Mg which Monsieur Arambourg showed me in Paris appeared to be a com- 
panion piece to the right Mg assigned to Tvagocerus (now Mtotragocerus) and shown 
in pl. 17 figs 4, 4a of his work and was of a size to go with Damalavus. It was 
22:0 mm long at its occlusal surface, and the height of its medial wall between front 
and central lobes was 10:2 mm. 

As to the age of Oued Hammam, Arambourg (1959 : 10) thought it was Tortonian. 
Cooke (1968 : 249) believed it could be later, and I agree (Gentry 1970 : 312). It 
would be of much zoogeographical interest if the affinities of Damalavus could be 
definitely decided, but I was unable to do this when I saw the material in Paris. 


Spiral horned antelopes 


Comparison with Tragelaphini 


Prostrepsiceros and Palaeoreas have always been taken as Tragelaphini although 
Pilgrim (1939 : 129, 135) moved Protragelaphus to the Antilopini. The living 
Tragelaphini are a fairly homogeneous group of browsing African antelopes found 
in habitats ranging from montane moorlands to forest but generally where there 
is at least some bush. They are mostly large sized. Their skulls have keeled and 
spiralled horn cores with anticlockwise torsion on the right side, which is their 
major resemblance to the Eurasian Pliocene fossils. Otherwise they show quite 
a distinctive pattern of skull characters which is not at all foreshadowed in the fossils. 
These are that a postcornual fossa is absent, horn cores tend to insert behind the 
orbits, the dorsal part of the orbital rims slopes from the horn bases and projects 
very little, the frontals between the horn bases are a little raised above the level 


286 THE EARLIEST GOATS AND OTHER ANTELOPES 


of the orbital rims, the mid-frontals and parieto-frontal sutures disappear in adult 
males, the braincase sometimes widens posteriorly, a perforation in the side of the 
braincase is often seen behind the postorbital bar, the orbital surface of the lachrymal 
is at a wide angle to its facial surface, the supraorbital foramina are in lengthened 
narrow pits, a preorbital fossa is absent, the infraorbital foramen is placed anteriorly 
and rather low, the premaxillae narrow anteriorly to a blunt point, the occipital 
surface has a flat top edge and straight sides, the mastoids are small, the basioccipital 
is long with anterior tuberosities in front of the foramina ovalia and it has a 
transverse constriction centrally, and P, often has a fused paraconid and metaconid. 

Tragelaphini retain as probably primitive characters a braincase which is little 
angled on the face axis, long nasals, an ethmoidal fissure, brachyodont cheek teeth, 
medial lobes of the upper molars which do not fuse with one another until late in 
wear, lower molars without goat folds, and long premolar rows with large front 
premolars. The extinct Tvagelaphus nakuae Arambourg (1941 : 343; 1947 : 418) 
from Omo in southern Ethiopia is appreciably more primitive than living tragela- 
phines in its projecting orbital rims, supraorbital pits not elongated antero-posteriorly, 
and an occipital surface which is perhaps less squared in outline. 

The resemblances of Prostrepsiceros, Protragelaphus and Palaeoreas to Tragela- 
phini lie almost entirely in primitive characters, and none of them are evolving 
towards the sort of morphology seen in living tragelaphines. Sometimes they may 
show resemblances, as for example in the long basioccipital of Palaeoreas lindermayert, 
but such resemblances are few and apparently fortuitous. In the past Tragelaphini 
have been linked with the Boselaphini and Bovini, which is a position I support 
(Gentry 1970 : 316), and it would certainly be awkward to accommodate in the 
same overall group the small spiral horned genera from Samos. 


Comparison with the Indian blackbuck 


I would rather put Prostrepsiceros and Protragelaphus into the same group as the 
living Indian blackbuck, Antilope cervicapra (Linnaeus 1758). Whereas Tragela- 
phini tend to be larger antelopes, the blackbuck is a fairly small bovid like most of 
the fossils. This and its lack of the specialized features of Tragelaphini make it 
quite a strong contender for relationship to the fossils. Its fairly long horn cores, 
their spiralling with anticlockwise torsion on the right side, their inclination in side 
view, width across the insertions and the amount of divergence are all about the 
same as in Prostrepsiceros and Protragelaphus. 

It agrees with both the Pvostrepsiceros species in its horn cores being inserted 
above the orbits, frontals not being raised between the level of the horn bases, and 
in the moderate projection of the orbital rims, but these characters amount only 
to a lack of the more specialized conditions found in Protragelaphus. Going down 
to species level, one finds that some facial and dental characters of P. houtum- 
schindleri agree with A. cervicapra. The small central and lateral flanges anteriorly 
on the nasals (Pl. 5 fig. 1) and the premaxillae rising with even width to a contact 
on the nasals give P. houtumschindleri quite a striking resemblance to the blackbuck. 
The near absence of basal pillars on the molars (complete absence in the blackbuck), 


FROM THE SAMOS HIPPARION FAUNA 287 


poor styles and ribs on the upper molars, lower molars with goat folds (slightly less 
marked in the blackbuck), no paraconid-metaconid fusion on Pq, and the indented 
lateral wall of P4 in front of the hypoconid are additional resemblances. It is quite 
possible that such resemblances would also be found in the unknown face and 
dentition of P. rotundicorms. With P. rotundicornis in particular the blackbuck 
agrees in the absence of keels, no medio-lateral compression of its horn cores, and 
the poor degree of bending of the braincase on the face axis. 

Antilope cervicapra is practically devoid of keels and this obviously gives it more 
resemblance to P. votundicornis than to any other of the fossil species. There are 
occasional examples of A. cervicapra in which a vestige of an anterior keel exists, 
e.g. BM(NH) 27.2.14.41, 27.2.14.50 and 32.12.11.8, and this keel descends to a 
medial rather than to an antero-medial insertion, which is also like P. votundicornis. 
Finally, although the horn cores of P. votundicornis are neither so slender nor spiralled 
so closely to the central axis as in A. cervicapra, they are less massive than in the 
other fossils (Text-figs 11, 13, 14) and thus approach the living form more closely. 
These characters all make P. votundicornis the best choice as the species to which 
A. cervicapra could be related. However the more important conclusion is that the 
group of Prostrepsiceros and Protragelaphus as a whole is related to the blackbuck 
and not to tragelaphines. 

A. cervicapra differs from Prostrepsiceros by its very large supraorbital pits, smaller 
preorbital fossa, wide anterior tuberosities of the basioccipital (Text-fig. 15), and 
very large mastoid. Face and dental characters differing from P. houtumschindlert 
are the shorter and wider nasals, very small or absent ethmoidal fissure, more hypso- 
dont teeth, occasional presence of indentations into the back edge of the rear central 
cavities on the upper molars, earlier fusion of the medial lobes of the upper molars, 
less backwardly inclined metaconid of P4, and absent Pz. The percentage diagrams 
(Text-figs 14 and 15) show that A. cervicapra has supraorbital pits fairly wide apart, 
a relatively wide and low braincase, and a short premolar row. There is no reason 
to suppose that any of these characters are primitive and could preclude the black- 
buck from descent from or relationship to the fossil genus. However they are 
ptobably sufficient to retain Prostrepsiceros as a separate genus from Antilope. 

A. cervicapra differs rather more from the larger Protragelaphus skouzest. Apart 
from characters in which it is advanced, it has a less low and wide skull, horn cores 
less massive at the base, no posterior keel on the horn cores and less open spiralling, 
horn cores not inserted so posteriorly, more strongly projecting orbital rims, brain- 
case less angled on the face axis, frontals not hollowed, flatter nasals, the median 
indentation at the back of the palate passing forward of the lateral ones, palatine 
foramina close together, goat folds on the lower molars, and no paraconid-metaconid 
fusion on Py. It can scarcely have descended from P. skouzest. 

A. cervicapra differs still more strongly from Palaeoreas lindermayert, which 
accords with my conclusion that the latter can best be classified as a small ovibovine. 
The differences are less massive horn cores at the base, no deep irregular longitudinal 
grooving, horn cores less thick, no posterior keel nor a weak anterior one, some spiral- 
ling of the horn cores rather than a mere twisting of their axis, not such a deep 


288 THE EARLIEST GOATS AND OTHER ANTELOPES 


post cornual groove, orbital rims strongly projecting, braincase not strongly angled, 
longer braincase, frontals low between the horn bases, no raising of the mid-frontals 
suture, infraorbital foramen high over P%, a less strong median ridge on the occiput, 
poor styles and ribs on the upper molars, the lateral wall of P, indented in front of 
the hypoconid, P3 relatively smaller, and the front and back edges of P3 and Py, not 
set transversely. 


Phylogeny of spiral horned Antilopim 

On the question of phylogeny, not a lot can be said, particularly in the absence 
of detailed time correlations of the sites where the varieties of horn core types occur. 
It is possible to conceive that the Maragha and Samos forms of P. votundicornis are 
later than that in Pikermi, in so far as they are more gracile and therefore remote 
from P. houtumschindlert. However this conclusion is the more doubtful by the 
fact that the Pikermi form of Spovadotragus appears more advanced than at Samos. 
Bearing in mind the possibility of a time span at Samos, it is as well to follow the 
speculation no further. On the whole P. votundicornis shows more signs of ancestry 
to A. cervicapra than any other of the Pliocene species, and it is a pity that it is less 
completely known than P. houtumschindlent or Protragelaphus skouzest. 


ANTILOPINI | OVIBOVINI | CAPRINI 
Antilope | Ovibos and | Capra . 
| Budorcas | Hemitragus 
. | 
Gazellospira Megalovis | 
Spirocerus | Moxapanis 
| or ] 
? | pain fin | Sinotragus 
| | Protoryx 
Protragelaphus Pachytraqus 
( Criotherium ) ¢rassicornis 
Prostrepsiceros Palaeoryx Fa 
houtumschindleri \ i, Pachy traqus Tossunnoria 
Prostrepsiceros \ / laticeps 
rotundicornis  \ Palaeoreas Yi 
\ yf fp poredbecat 
Pseudotragus 


Set 


Fic. 16. Possible relationships of bovids mentioned in this paper. Names of species 
and genera which have been dealt with at length are underlined. The middle horizontal 
band contains forms known from Samos and other sites of broadly the same age. The 
upper band is for later forms, and the lower one is for a pre-Samos time level. Precise 
origins are not shown for Spivocerus, Ovibos and Tossunnoria. 


FROM THE SAMOS HIPPARION FAUNA 289 


It is certainly possible and very plausible to link Protragelaphus skouzesi with the 
similar European Villafranchian Gazellospira torticornis (Aymard), which Pilgrim 
& Schaub (1939) have already classified as an antilopine. 

It would be interesting, were the material accessible, to assess the relationships 
of these European and West Asian spiral-horned antelopes with those of the Pliocene 
and Pleistocene of China. It is likely that there is a Pliocene species in China, 
Antilospiva licenti, succeeded by the Pleistocene Spivocerus wongi (see Teilhard de 
Chardin & Piveteau (1930), Teilhard de Chardin & Young (1931), and Teilhard de 
Chardin & Trassaert (1938) for these Chinese antelopes, remembering that many 
of their specific names are likely to be synonyms. Sfirocerus wongi dates from 
1930, but is itself quite likely to be a synonym of the Russian S. kiakhtensis (Pavlow) 
1910). It is tempting to see S. wongi as an eastern form of the same species or 
superspecies as Gazellospiva torticornis, but S. wongi possesses an anterior keel and 
sometimes a weaker posterior one whereas G. forticornis, in common with the earlier 
Protragelaphus skouzesi, has a strong posterior keel and no anterior one. One 
wonders if S. wongi descends from the earlier Antilospiva licenti and if that in its 
turn is related to Prostrepsiceros houtumschindleri or to Protragelaphus skouzest, but 
I can write nothing useful about this. 

A possible ancestor of the Pliocene spiral-horned antelopes is Sivoreas eremita 
(Pilgrim 1939 : 131, pl. 4 figs 1, 1a) from the Chinji stage of the Siwalik Hills (Gentry 
1970 : 259). It has horn cores more medio-laterally compressed than in the lower 
Pliocene antelopes; anterior and posterior keels on the horn cores, the anterior 
one descending to an anterior rather than to an antero-medial or medial insertion ; 
torsion of the horn cores and a narrow transverse ridge across the frontals between 
the horn bases. Much doubt surrounds the rather inadequate remains. 

The living blackbuck is almost exclusively a grazer, and has some physiological 
adaptation to scarcity of water. In its undisturbed state it was an animal of flat 
plains and open woodlands, moving in big herds over areas of short grass. Its 
ecology was similar to that of a gazelle, although competition with Gazella bennetti 
was avoided. One can probably assume that Pvostrepsiceros showed a tendency 
to inhabit the harsher environments, but this may not have applied to Protragelaphus. 


The position of Palaeoreas lindermayernt 


I had earlier written (Gentry 1968 : 874) that Palaeoreas lindermayeri should be 
placed in the Antilopini, along with Prostrepsiceros and Protragelaphus. However 
the comparisons on p. 273 have shown that it is very distinct from those Antilopini. 
I now think that although it is less phenetically remote from them than is any other 
ovibovine, there is a slight preference for assigning it to the Ovibovini because of 
characters it shares with the much larger Criotherium argalioides. 

Besides the living muskox, Ovibos moschatus (Zimmermann), and takin, Budorcas 
taxicoloy Hodgson, and their immediate Pleistocene relatives such as the fossil 
muskoxen of Europe, the early Chinese muskox Boopsis sinensis Teilhard de Chardin, 
and the early takin Lyvocerus satan Teilhard de Chardin & Trassaert, this tribe 
contains a number of other extinct genera and species. These are: 


290 THE EARLIEST GOATS AND OTHER ANTELOPES 


Urmiatherium polaki Rodler 1889 from Maragha, 

Urmiatherium intermedium Schlosser 1903 from the Chinese lower Pliocene, 

Plesiaddax depereti Schlosser 1903 from the Chinese lower Pliocene; (Bohlin 
(1935c) first assigned skulls to Schlosser’s names for the last two species, 
which had been based on teeth), 

Tsaidamotherium hedini Bohlin 1935a from the lower Pliocene of Tsaidam in 
western China, 

Parurmiatherium rugosifrons Sickenberg 1933 from Samos, 

Criotherium argalioides Major 1891a, 1892 from Samos. 


In addition I have already referred the European Villafranchian Megalovis 
latifrons and its synonyms or relatives to the Ovibovini (see p. 282), and I also 
believe that the extinct Makapania broom Wells & Cooke 1956 from the Transvaal 
is related to Megalovis latifrons (Gentry, in press). I shall not here enter into the 
complicated questions of a revision of this whole group. The Maragha and Chinese 
species of Urmiatherium appear to be very close to Plestaddax depereti and the smaller 
Parurmiatherium rugosifrons, and all have specialized horn cores, a condition carried 
still further in Tsaidamotherium. All the Villafranchian and later ovibovines have 
a rather less extreme horn core morphology, and, as I have noted above, some of 
them may descend from Palaeoryx pallast. Crnotherium, known only from Samos, 
stands by itself with spiralled horn cores, but I am not ready to dispute Schlosser’s 
(1904 : 27) and Bohlin’s (1935b) opinions of its ovibovine affinities, chiefly because 
of dental similarities and its basioccipital morphology with strong paired longitudinal 
ridges and the trace of an enlargement of the posterior tuberosities. However 
it should be noted that the teeth of Cviotherium are less advanced than those of 
Urmiatherium in retaining basal pillars on the lower molars, less rounded lateral 
lobes on the lower molars, and a longer premolar row. Also Criotherium’s horn 
cores, fairly large preorbital fossa, fairly unenlarged occipital condyles, and basioc- 
cipital morphology are definitely less extremely specialized than in Urmiatherium. 
It is to Criotherium that I would now relate Palaeoreas. 

It must be admitted that Palaeoreas lindermayeni differs from Ovibovini in many 
characters. It has its own specializations of a very deep postcornual groove, large 
supraorbital pits, and a long basioccipital. It also lacks quite a number of the 
specializations of later Ovibovini. It does not have a long face with anteriorly 
placed upper tooth row, the ethmoidal fissure is still present, the preorbital fossa is 
rather large, the infraorbital foramen is in a forward position instead of above 
P3 or further back, the nasals are not parallel or almost parallel with the upper 
tooth row, the occipital condyles are not unusually massive nor are the posterior 
tuberosities of the basioccipital enlarged, the upper molars do not have rounded 
medial lobes, the lower molars do not have rounded and transversely narrow lateral 
lobes, they also do not have little outbowed medial walls or straight central cavities, 
and the cervical vertebrae lack enlarged centra. Some of these specializations, 
particularly those of the cervical vertebrae, condyles and basioccipital could be 
unnecessary in P. lindermayert because of its smaller size. 

In comparison with Criotherium argalioides the horn cores of P. lindermayeri are 


FROM THE SAMOS HIPPARION FAUNA 291 


inserted less far behind the orbits, the braincase is longer and less angled on the 
face axis, basal pillars are slightly larger on its lower molars and sometimes present 
on its uppers, and there is sometimes a strong rib between parastyle and mesostyle 
on the upper molars. In all these characters the smaller form lacks the specializa- 
tions of the larger, which is a frequent situation between related pairs of species of 
differing size. 

In fact Palaeoreas lindermayert can be regarded as a small and less specialized 
version of Criotherium argalioides. It shows the following strong agreements with 
that species: 

The horn cores have a strong postero-lateral keel and a weaker anterior one. 

There is deep irregular longitudinal grooving on some horn cores. 

The axis of the horn cores is twisted, and twisted in the same direction as in 
Criotherium, and there is no open spiralling. 

There is a localized raising of the mid-frontals suture forward of the horn bases 
and just behind the nasals. (This elevated suture is also to be seen in Sforvadotragus.) 

The central cavities of the upper molars remain joined to one another until fairly 
late in wear. 

The left mandible BM(NH) M.15828 assigned to Palaeoreas lindermayert has 
its Ps and P, with transverse front and back edges (PI. 6 fig. 2). 

There is no valley in the lateral wall of P, in front of the hypoconid. 

P3 is fairly large in M.15828 in relation to Py. 

Some of the differences of Palaeoreas lindermayeri from all or various of the other 
spiral-horned antelopes considered in this paper also cause it to approach C7o- 
therium argalioides. Such features are: 

The rather massive horn cores of Palaeoreas. Their massiveness gives them an 
appearance of relative shortness. 

The small divergence of the horn cores in anterior view. 

The stronger angling of the braincase on the face axis. 

The higher level of the frontals between the horn bases. 

The usual disappearance of signs of the mid-frontals and parieto-frontals suture in 
adults. 

The smaller separation of the supraorbital pits from one another. 

A central longitudinal groove on the basioccipital. 

The metaconid of P, not being directed backwards. 

For these reasons it seems marginally better to place Palaeoreas in the Ovibovini 
than in the Antilopini, the resemblances to Criotherium being sufficiently strong 
to suggest not too remote a common ancestry. A count of skull character dif- 
ferences gave the result that Palaeoreas lindermayert had 22 differences from 
Protragelaphus skouzesi, 15 from Pyostrepsiceros houtumschindlert and 17 from 
Cniotherium argalioides; this quantifies the problem and is an indication of how 
marginal the classification of Palaeoveas lindermayeri must be. 

If it is accepted that Palaeoreas is an ovibovine, then it and Criotherium are 
the only members of the tribe with spiralled horn cores of any length. However 
this is probably not a severe isolating feature, because vestiges of spiralling remain 


292 THE EARLIEST GOATS AND OTHER ANTELOPES 


in Parurmiathertum, and Budorcas and Ovibos have at least slight torsion. I don’t 
think it would be advantageous to split them from other Ovibovini. 


V. CONCLUSIONS 


In a previous paper (Gentry 1970) I have described how the antelopes of the 
Fort Ternan upper Miocene site in Kenya, dated to 14 million years B.P., were 
closely related to Eurasian antelopes of the Vindobonian and equivalent time levels. 
They could be satisfactorily included in the tribes Boselaphini and Caprini, tribes 
which later became largely Eurasian in their distribution. It was just possible that 
some signs of ancestry to later African antelopes could be seen at Fort Ternan, 
but this was rather tentative, and the origin and development of African antelopes 
remains more undocumented than that of Eurasian ones. It is clear that some 
antelope groups confined to Africa by the historical period were also in northern 
India during the Quaternary and at least the later Tertiary. Work on such im- 
portant African sites as Baringo, Kanapoi and Lothagam (Kenya) and Langebaanweg 
(Cape Province, South Africa) may throw more light on the history of African 
antelopes. This present paper on Samos has been intended to remove one source 
for confusion in deciphering this history. Palaeoryx, Protoryx and Pachytragus are 
not hippotragines and Prostrepsiceros and Palaeoreas are not tragelaphines. The 
only Samos antelope which at present looks as if it could be even remotely con- 
nected with the ancestry of any later African form is the unique skull of Tvagoreas 
oryxoides (see above p. 284). In fact there are no firm grounds for detecting any 
African affinities among the Samos antelopes. They are more properly seen as an 
earlier stage in the evolution of Eurasian bovid faunas, and date from a time younger 
than the Fort Ternan fauna when regional differentiation must have been becoming 
more marked. I have discussed the historical zoogeography of antelopes at greater 
length in my Fort Ternan paper (Gentry 1970 : 310-317). 


VI. ACKNOWLEDGEMENTS 


Dr L. S. B. Leakey of Nairobi suggested this work on Samos bovids, took steps 
to get it started, and has maintained interest init. Dr John Van Couvering kindly 
provided a concise statement of some important geological information about 
Samos. Monsieur Jean Guex of Lausanne and Dr Giles T. MacIntyre of New York 
gave considerable help with photography. I was allowed the use of a room for 
several months at the American Museum of Natural History, New York, and the 
use of a desk computer at Bedford College, London. Iam grateful for the assistance 
of the staffs of the Natural History Museums and Palaeontological Institutes in 
Paris, Vienna, Lausanne, Munich, Minster in Westphalia, Basle, New York and 
London. 

I received travelling grants from the Royal Society and from the Percy Sladen 
Fund of the Linnaean Society of London. A grant from the Wenner-Gren Foun- 
dation for Anthropological Research has been a great help. 


FROM THE SAMOS HIPPARION FAUNA 293 
VII. SUMMARY 


This paper considers the classification, phylogeny and aspects of the zoogeography 
of two groups of antelopes prominent in the lower Pliocene fauna of Samos, and also 
known from the rich sites of Pikermi in Greece and Maragha in Iran. 

Antelopes hitherto referred to a number of species of Palaeoryx, Protoryx and 
Pachytragus can be arranged in the following species: 

Palaeoryx pallasi (Wagner) from Samos and Pikermi, 

Protoryx carolinae Major from Pikermi, 

Pachytragus laticeps (Andree) from Samos and Maragha, 

Pachytragus crassicornis Schlosser from Samos. 
Both Pachytragus species, and particularly the more advanced P. crassicornis, have 
affinities with the living goats (Caprini, Capra). Protoryx carolinae and Palaeoryx 
pallasi are related to Pachytragus, and none of these species belong to the African 
tribe Hippotragini, which is where they have been placed in Simpson’s (1945) and 
other classifications of mammals, following work in the years between the two 
World Wars. Protoryx carolinae can be linked with Chinese lower Pliocene fossils 
and tentatively placed in the Caprini, while Palaeoryx pallasi could well be related 
to the Villafranchian ovibovine Megalovis latifrons. I suggest that Palaeoryx itself 
be placed in the Ovibovini. 

Spiral-horned antelopes with anticlockwise torsion on the right side can be 
arranged in four species: 

Prostrepsiceros houtumschindlent (Rodler & Weithofer) from Maragha and Samos, 
Prostrepsiceros votundicornis (Weithofer) from all three sites, 

Protragelaphus skouzesi Dames from all three sites, 

Palaeoreas lindermayert (Wagner) from Pikermi and Samos. 

Prostrepsiceros and Protragelaphus can both be taken as Antilopini, and are 
related more or less closely to the Indian blackbuck, Antilope cervicapra. Palaeoreas 
lindermayert is best classified as a small and primitive ovibovine related to Cvo- 
therium argalioides of the Samos fauna. None of the spiral-horned antelopes from 
Pikermi, Samos or Maragha can be placed in the African tribe Tragelaphini. Bovids 
from these three sites can be seen as a stage in the evolution of those occurring later 
in Eurasia, and show no signs of relationship with African antelopes. 


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A. W. Gentry, B.A., D.Phil. 

Dept. of Zoology 

British MusEuM (NATURAL History) 
CROMWELL Roap 

Lonpon, S.W.7 


= 


PAGE ax: 
Palaeorysx pallasi 
(Scales represent 20 mm) 


Fic. 1. Lateral view of Lausanne cranium, 29, to show the ventral edge of the auditory 
bulla descending posteriorly to the front of the paraoccipital process. This is indicated by the 
arrow. 


Fic. 2. Ventral view of the same cranium. The anterior tuberosities of the basioccipital 
are localized and without longitudinal ridges to the rear. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 6 BBA Ear 


PLATE 2 
Pachytragus laticeps 
(Scale represents 10 mm) 
Fic. 1. Posterior view of Lausanne cranium, 22, to show the shape of the occipital surface, 
the median vertical ridge and the large mastoids. 


Fic. 2. Ventral view ofthesamecranium. The basioccipital has longitudinal ridges flanking 
a central groove. 


Fic. 3. Section across right horn core, AMNH 23038, about 1o mm above the top of the 
pedicel. This view is looking towards the tip of the horn core from below, with the anterior 
edge towards the top of the page and the lateral side to the left. 


Fic. 4. Section across left horn core, AMNH 22783, about 20 mm above the top of the 
pedicel. The horn core is oriented as in fig. 3, except that the lateral side is to the right. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 6 PLATE 


PLATE 3 
Pachytragus laticeps 
(Scales represent 50 mm) 


Fic. 1. Anterior view of Lausanne cranium, 30. 
Fic. 2. Lateral view of the same cranium. 


Fic. 3. Lateral view of the female skull, AMNH 20687, from quarry 1, Samos. 


PLATE 3 


Bull. By. Mus. nat. Hist. (Geol.) 20, 6 


PLATE 4 
Pachytragus crassicornis 
(Scales represent 50 mm) 


Fic. 1. Lateral view of skull, AMNH 20569, from quarry 5, Samos. 


Fic. 2. Palate, AMNH 22981, from quarry 5. It is definitely of Pachytragus, and by its 
provenance is assumed to belong to P. crvassicornis. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 6 


PLATE 5 
(Scales represent 20 mm) 


Fic. 1. Anterior view of a previously unfigured skull of Prostrepsiceros houtumschindleri 
from Maragha and now in Paris. Notice the anterior keel and divergence of the horn cores, 
and the small central and lateral flanges at the front of the nasals. 

Fic. 2. Lateral view of a cranium of P. rotundicornis from Maragha and now in Paris. 


Fic. 3. Lateral view of a skull of P. houtumschindleri, BM(NH) M.4192, from Samos. 
Notice the inclination of the braincase roof and of the horn core insertions in comparison with 
the cranium in fig. 2. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 6 PLATE 5 


f a] 
<9 
Bs 


PLATE 6 
(Scales represent 20 mm) 


Fic. 1. Anterior view of Lausanne frontlet, 25, Palaeoreas lindermayeri from Samos. 


Fic. 2. Three lower dentitions from Pikermi. From above they are BM(NH) M.15828, 
left, of Palaeoreas lindermayeri; M.13022, right, of Protragelaphus skouzesi; M.13007, 
left, thought to be of Prostrepsiceros rotundicornis. 


PLATE 6 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 6 


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3. Davey, R. J., Downin, C., SARGEANT, W. A. S. & WILLIAMS 
Mesozoic and Cainozoic Dinoflagellate ea Pe 248; 28 Plat 
figures. 10966. £7. - : . 

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7966). Sope 
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STRATIGRAPHY OF THE 
_ JURASSIC AND LOWER CRETACEOUS 
ROCKS AND JURASSIC AMMONITES 
- FROM NORTHERN AREAS OF 
TLL WEST PAKISTAN 


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A. N. FATMI 


BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 
_ GEOLOGY | Vol. 20 No. 7 
/ LONDON: 1972 


SERGE RAPEHY “OF THE JURASSIC AND 
TOWER CRETACEOUS ROCKS AND JURASSIC 
AMMONITES FROM NORTHERN AREAS OF 
WEST PAKISTAN 


FAR M ] 


ALI NASIR FATMI 


Geological Survey of Pakistan, Quetta, West Pakistan 


Pp. 297-380, 11 Plates; 6 Text-figures 


BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 
GEOLOGY Vole20" No. 7 
LONDON : 1972 


THE BULLETIN OF THE BRITISH MUSEUM 
(NATURAL HISTORY), instituted in 1949, is 
issued in five series corresponding to the Departments 
of the Museum, and an Historical series. 


Parts will appear at wrregular intervals as they become 
veady. Volumes will contain about three or four 
hundred pages, and will not necessarily be completed 
within one calendar year. 

In 1965 a separate supplementary series of longer 
papers was instituted, numbered serially for each 
Depariment. 

This paper is Vol. 20, No. 7, of the Geological 
(Palaeontological) series. The abbreviated titles of 
periodicals cited follow those of the World List of 
Scientific Periodicals. 


World List abbreviation : 
Bull. Br. Mus. nat. Hist. (Geol.) 


© Trustees of the British Museum (Natural History), 1972 


TRUSTEES OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 


Issued 28 January, 1972 Price £4°25 


SERATIGRAPHY OF IME JURASSIC AND LOWER 
CRETACEOUS ROCKS AND JURASSIC 
AMMONITES FROM NORTHERN AREAS 
OF WEST PAKISTAN 


By A. N. FATMI 


CONTENTS 
Page 
I. INTRODUCTION : : : P : : : 302 
Il. History OF PREVIOUS RESEARCH : < : : é ; 305 
Ill. GENERAL SEQUENCE é 310 
IV. STRATIGRAPHY OF THE Jurassic AND Lower CxeTAGHoUS: ROCKS 
OF THE AREA . : : : ‘ : } : 3 : 312 
Datta Formation . . : : : : : ° 312 
Samana Suk Limestone . : 5 5 ; : : 315 
Chichali Formation . é j i : j : : 318 
Lumshiwal Formation . : c : : : : 323 
. FOSSIL LOCALITIES . : : : ; : : : : 326 
VI. SYSTEMATIC DESCRIPTIONS : 3 6 : 6 328 
Family PH YLLOCERA TIDAE Zittel 5 : : . 328 
Subfamily Calliphylloceratinae Spath . : é : 328 
Genus Holcophyllocervas Spath . : ‘ : 328 
Holcophylloceras silesiacum (Oppel) ; : 328 
Genus Ptychophylloceras Spath : : 328 
Ptychophylloceras ptychoicum (Quenstedt 0 328 
Family LYTOCERATIDAE Neumayr : : 329 
Subfamily Lytoceratinae Neumayr ° 2 5 ; 329 
Genus Ptevolytoceras Spath . ; : ‘ ° 329 
Pterolytoceas exoticum (Oppel) : : : 329 
Pterolytoceras sp.indet. . : é : 330 
Family HILDOCERATIDAE Hyatt . ; : 3 3 330 
Subfamily Bouleiceratinae Arkell. : i : 6 330 
Genus Bouleicevas Thevenin . : c : : 330 
Bouleicevas nitescens Thevenin . 2 : 330 
Bouleicevas Chakdallaense sp. nov. : 6 331 
Bouleiceras sp. indet. . : : > : 332 
Family HAPLOCERATIDAE Zittel . : F 6 332 
Genus Hildoglochiceras Spath é 5 : - 332 
Hildoglochiceyvas sp. indet. . é . 6 332 
Family MA YAITIDAE Spath . 5 ‘ : 2 - 333 
Genus Mayaites Spath é ; 6 é 333 
Mayaites ci. waagent (Uhlig) : : c 333 
Family REINECKETIDAE Hyatt . : ; : c 334 
Genus Reineckeia Bayle : . F : 334 
Reineckeia anceps Gzemeeke) c : : 334 
Reineckeia cf. tovulosus (Spath) . . . 334 


Reineckeia sp. indet. 0 F a : 335 


300 JURASSIC AND LOWER CRETACEOUS ROCKS 


Family PERISPHINCTIDAE Steinmann . 
Subfamily Proplanulitinae Buckman 
Genus Obtusicostites Buckman 
Obtusicostites buckmani Spath 
Obtusicostites sp. indet. 
Genus Hubertocervas Spath 
Hubertoceras sp. indet. 
Subfamily Pseudoperisphinctinae Sonindeaolt 
Genus Choffatia Sieniradzki . 
Choffatia sp. indet. 
Subfamily Perisphinctinae Steinmann . 
Genus Prasosphinctes Schindewolf . 
Prososphinctes virguloides Waagen 
Genus Perisphinctes Waagen . 
Perisphinctes sp. indet. 
Subgenus Kvanaosphinctes Buckaani 
P. (Kvanaosphinctes) sp. indet. . 
Subgenus Avisphinctes Buckman 
P. (Arisphinctes) orientalis Siomaders 
Subgenus Dichotomosphinctes Buckman 
(Dichotomosphinctes) cf. votoides 
Ronchadze : 
P. (?Dichotomosphinctes) a idee 
Subfamily Virgatosphinctinae Spath : 
Genus Katrolicevas Spath . 
Katroliceras cf. pottingeri UJ. de C. Sowerby) 
Katroliceras sp. indet. 
Genus Pachysphinctes Dietrich 
Pachysphinctes vobustus Spath 
Genus Aulacosphinctoides Spath é 
Aulacosphinctoides hazavaensis sp. nov. . 
Aulacosphinctoides uhligt Spath 
Aulacosphinctoides sp. indet. 
Genus Virgatosphinctes Uhlig 
Virgatosphinctes denseplicatus fwaseea) 
Virgatosphinctes frequens (Oppel) . 
Virgatosphinctes sp. indet. : 
Family ASPIDOCERATIDAE Zittel. 
Subfamily Aspidoceratinae Zittel . 
Genus Euaspidoceras Spath . 
Euaspidoceras cf. wagurense (Spath) 
Genus Aspidoceras Zittel 
Subgenus Aspidoceras Zittel 
A. (Aspidoceras) sp. indet. 
Subgenus Pseudowaagenia Spath : 
A. (Pseudowaagenia) sp. indet. . 
Genus Physodoceras Hyatt : 5 
Subgenus TE ge Spath 
P. (Simaspidoceras) sp. indet. 
Subfamily Simoceratinae Spath ; 
Genus Hybonoticeras Breistreffer 
Hybonoticeras sp. indet. 
Family OLCOSTEPHANIDAE Haug 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 301 
Subfamily Spiticeratinae Spath 350 
Genus Proniceras Burckhardt 350 
Proniceras indicum Spath 350 
Genus Spiticevas Uhlig . 350 
Spiticeras multiforme Dyapelidee 350 
Spiticeras sp. indet. 351 
Subfamily Provalanginitinae nov. 351 
Genus Provalanginites nov. 351 
Provalangimtes rvhodest sp. nov. 352 
Provalangimites howarthi sp. nov. 353 
Family BERRIASELLIDAE Spath . 353 
Subfamily Berriassellinae Spath . 353 
Genus Blanfordicevas Cossman ; 353 
Blanfordiceras cf. wallicht (Gray) . 353 
Blanfordiceras cf. latidomus (Uhlig) 354 
Blanfordiceras sp. indet. : 354 
Genus Protacanthodiscus Spath j : 355 
Protacanthodiscus cf. michaelis (Uhlig) . 355 
Protacanthodiscus sp. indet. . 356 
Subfamily Himalayitinae Spath . 357 
Genus Himalayites Uhlig in Boehm 357 
Himalayites cf. depressus Uhlig 357 
Himalayites middlenisst (Uhlig) 357 
Himalayites sp. indet.. . 358 
Himalayites cf. hyphaisis (Blanford) 358 
Genus Aulacosphinctes Uhlig. 359 
Aulacosphinctes spitiensis (Uhlig) 359 
APTYCHI : é é 359 
Laevaptychus 359 
VII. CoRRELATIONS 360 
(a) Jurassic and Gcteeenns SEES in aorta West Bene 360 
(b) Correlation within Pakistan 362 
(i) Baluchistan 362 
(c) Correlation with areas outside Pakieen 363 
(i) Cutch 363 
(ii) Spiti ‘ : : 365 
(i) Persia (Elburz Mountain) . 307 
(iv) Saudi Arabia (Jebel fe 367 
(v) Iraq (Kurdistan) 367 
(vi) Madagascar 368 
(vii) Tanganyika 369 
(viii) Jubaland 370 
(ix) Somaliland : j ; : j : 370 
(x) Southern France (Borders of the Massif central) 370 
VIII. REFERENCES . 373 


ABSTRACT 


The stratigraphy of the Jurassic and Lower Cretaceous formations and Jurassic ammonites 
from Hazara, Kala Chitta, Nizampur, Western Kohat (Samana Range) and the Trans Indus 
Ranges in Northern Pakistan are described. 

A provisional zonal scheme is proposed and correlation is suggested with Spiti, Cutch, Mada- 


302 JURASSIC AND LOWER CRETACEOUS ROCKS 


gascar, Mediterranean Province, Middle East, and East Africa. Failure to recognize certain 
ammonite zones in the area may be explained by non-deposition, slow deposition, unfavourable 
facies, failure of collection or some combination of these factors. 

Middle Callovian, Upper Oxfordian and Lower Kimmeridgian ammonites from the Trans 
Indus Range, Upper Oxfordian—Tithonian ammonites from Nizampur, Lower Toarcian 
ammonites from Kala Chitta and Lower Tithonian ammonites from northern areas of Hazara 
are recorded and described for the first time. In addition, a definite Aptian ammonite fauna 
is recognized in parts of Western Kohat and the Kala Chitta Range. 

The faunal studies indicate that the Jurassic passes into the Cretaceous without a break in 
most areas of northern West Pakistan. The major stratigraphical breaks are Pre-Toarcian, Intra- 
Jurassic (pre-Upper Oxfordian, pre-Kimmeridgian or pre-Tithonian) and intra-Cretaceous 
(post-Lower—Middle Albian). 


I. INTRODUCTION 


ExIsTING knowledge of the Jurassic-Cretaceous biostratigraphy in general, and of 
the ammonite faunas in particular, of the northern areas of Pakistan (fig. 1 ) is very 
imperfect. In the majority of cases the faunal descriptions are based on collections 
which lack adequate biostratigraphical control. The geological information avail- 
able in more recent published literature (Davies 1930; Cotter 1933; Spath 1930, 
1934, 1939; Arkell 1956; Pascoe 1959; Krishnan 1960), though it gives the impression 
of the presence in the area of various Jurassic—Cretaceous stages, does not clearly 
relate them to the rock succession and little attempt has been made to correlate them 
in different parts of the country. 

This state of confusion may be judged by the following remarks of Arkell (1956: 
393) on the Jurassic rocks of the Salt Range, “Very little palaeontological classifica- 
tion of these (Jurassic) rocks is yet possible, though ammonites occur. Callovian is 
indicated by Golden Oolite .... It was also found in working the fauna of the 
condensed and transgressive Valanginian beds that they contain a number of derived 
Upper Jurassic ammonite fragments which indicate the former presence of Middle 
Spiti Shales. Old records by Oppel of ammonites . . . suggest the presence of 
Upper Oxfordian also’”’. Spath similarly (1939; 131, 152) recognized Callovian and 
Tithonian ammonite fragments from the Salt Range and its Trans Indus extension, 
but considered the Tithonian fauna to be derived, and doubtfully pointed out the 
Callovian ammonites to have come from the limestone below the “‘Belemnite Beds”. 

Encouraged by the known occurrences of ammonites in the area, a detailed study 
of selected Jurassic and Lower Cretaceous sections in northern Pakistan (figs I, 3) 
was carried out during 1963-1966. In this paper the biostratigraphy of the Jurassic 
and Lower Cretaceous rocks and the systematic descriptions of Jurassic ammonites 
from Hazara, Kala Chitta, Nizampur, Samana Range (Western Kohat) and Trans 
Indus Ranges are presented. A tentative correlation of the various Jurassic and 
Cretaceous formations of northern West Pakistan is also offered. This work forms 
part of a Ph.D. thesis submitted to the University of Walesin 1968. The ammonites 
of Lower Cretaceous age will be described in a separate publication. 

The Mesozoic rocks of northern West Pakistan (figs 2, 3) are exposed in the hill 
ranges bordering the Kohat district to the north (Samana and adjoining ranges) and 
extending eastward into Nizampur and the Kala Chitta Range. Further east of 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 


393 


Kala Chitta the outcrops take a north easterly swing and are exposed in Hazara 
Ranges (Margala and Murree Hills) lying between Abbottabad and Islamabad. 
These northerly placed Mesozoic out-crops are separated by a belt of Tertiary and 
Quarternary deposits from the southern outcrops of Western Salt Range and Trans 
Indus Ranges (Surghar, Maidan and Khisor Ranges including Shaikh Budin Hills). 
In the eastern and north-eastern limits the Mesozoic rocks of northern areas are 
separated from that of Himalaya (Spiti) by a belt of Tertiary and Quarternary 


INDEX 
AREA INVESTIGATED 
1. HAZARA 
2. KALACHITTA 
3. NIZAMPUR 
4. KOHAT 
5. TRANS INDUS SALT RANGE 
6. SHAIKH BUDIN HILLS 


ei 66% 


QUETTA 
° 


al 


ABBOT 


TABAD 
1 


2 


s Hongu 
74 
Thal 5 
LZ 


ol SARG 
° 


i /PESHAWAR 8 
oe 1: r 
‘| 4 Kohat gy 7oCampbelipur 
ie Br ® 17s, © RAWALPINDI 


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FIG. 1. 


e HYDERABAD 


Index map of West Pakistan showing areas investigated. 


304 JURASSIC AND LOWER CRETACEOUS ROCKS 


deposits while in the western limits the Tertiary and Quarternary deposits of D.I. 
Khan district separate it from the Mesozoics of Sulaiman Range and its northerly 
extension is Waziristan and Kurram Agency. 

The area investigated falls between Lat. 32° N and 34° 30’N and Long. 71° E 
and 73°30’E. Bordering it in the north are the high Karakoram-Hindukash 
mountain ranges with a complex geological history and with rocks belonging to a 
complex igneous and metamorphic suite of doubtful Precambrian to Tertiary age. 
On the southern boundary of the area, the Salt Range and Trans Indus Ranges with 
Precambrian to Tertiary rocks give place to the alluvial plain of River Indus through 
which protrudes near Chiniot and Shahkot (Kerana Hills), the reminiscent of the 
Precambrian metamorphic rocks of the Indian Shield. 

The majority of the ammonites are preserved as internal moulds in a ferruginous, 
phosphatic, glauconitic, sandy, calcareous matrix, and much less commonly they 
have recrystallised or original shell matter preserved. The Callovian and Lower 
Jurassic ammonites are preserved in limestone. The Lower Jurassic (Toarcian) 
ammonites have abundant comminuted molluscan debris, are often fragmentary, 
and are unevenly distributed along the outcrop. The Callovian ammonites are 
better preserved and more complete. 


Tertiary and Quaternary 
deposits 


Mesozoic sediments 


Paleozoic and Pre- Cambrian 
sedimentary, metamorphic and 
igneous rocks 


25 50 Miles 


vi PESHAWAR 


2 Pt 


JAMMU AND KASHMIR 


SARGODHA 
. 


Orawn by'—Inayat Ali 


Fic. 2. Geological map of parts of West Pakistan showing Mesozoic outcrops. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 305 


The Upper Oxfordian ammonites occur in condensed sandy, glauconitic, nodular 
marls (less than a foot in thickness) at the base of the Chichali Formation. They are 
commonly fragmentary and worn, though abundant, in certain parts of the outcrop, 
but irregular in their distribution. The specimens from the Trans Indus Ranges 
show a better preservation than those from the Kala Chitta and Nizampur (Mazar 
Tang). The ammonites are associated with bivalves, gastropods, brachiopods and 
belemnites. 

The Lower Kimmeridgian ammonites are preserved in calcareous, ferruginous, 
phosphatic nodules and are not very common. They are located in the lower 10 to 
15 feet of the Chichali Formation (“‘Belemnite beds’’) in the Trans Indus Ranges and 
in the basal 2 to 3 feet of the Chichali Formation (= “‘Spiti Shales’) in parts of 
Hazara and Kala Chitta. 

The Tithonian ammonites are more commonly distributed in the succeeding beds 
of the lower member of the Chichali Formation in the Trans Indus Ranges. In parts 
of Hazara they occur in the basal part of the Lumshiwal Formation (=“‘Giumal 
sandstone’) and show better preservation than that of the Trans Indus Ranges. 
Associated with ammonites are abundant belemnites, less commonly bivalves 
(Trigonia sp., Gryphaea sp.), brachiopods and reptilian remains. 

This paper presents the results of the research work on Mesozoic Stratigraphy and 
Palaeontology of northern areas of West Pakistan carried out for a Ph.D. thesis at 
the University College, Swansea, University of Wales during 1967-68. Many 
colleagues and friends in and outside Pakistan have been of great assistance in 
providing helpful suggestions and criticisms. I am particularly indebted to Prof. 
F. H. T. Rhodes and Dr. J. C. W. Cope of University College, Swansea for their 
supervision, guidance and critical review of the work. For this paper I am deeply 
indebted to Dr M. K. Howarth who guided me in its presentation and has critically 
reviewed the fauna. Assistance of Dr. M. K. Howarth and the staff of the British 
Museum in reorganizing some of the illustrations and re-photographing the specimens 
for presentation in this paper is gratefully acknowledged. Special thanks are due 
to Dr J. H. Callomon of University College, London for his helpful criticism of the 
research work. Dr R. Casey, Mr N. J. Morris and Prof. D. V. Ager are thanked 
for their guidance and identification of some ammonites, bivalves and brachiopods 
respectively. 

Financial assistance to carry out the research at the University College of Swansea 
from the Government of Pakistan and the Senate of the University College, Swansea 
is gratefully acknowledged. 

The systematic descriptions mostly carry the standard morphological terms as 
defined in the Treatise on Invertebrate Palaeontology (1957: (L) Mollusca-4). The 
standard dimensions (diameter, whorl height, whorl thickness, umbilical diameter) 
are given in millimeters and as percentage of diameter. The measurements were 
made over the ornamentation unless specified in the text. 


II. HISTORY OF PREVIOUS RESEARCH 


The presence of Jurassic and Cretaceous rocks in northern West Pakistan was first 
recognized in the late 19th century (Waagen 1875; Wynne 1878; 1880, Griesbach 


306 JURASSIC AND LOWER CRETACEOUS ROCKS 


1891; Middlemiss 1896), but it was many years later that a more detailed Mesozoic 
succession was established by the field studies of Davies (1930) in the Samana Range, 
Cotter (1933) in the Kala Chitta Range, Spath (1939) and Gee (1945) in the Salt 
Range and its Trans Indus extension (Trans Indus Ranges). 

The ammonite collections of Gee, Cotter, Davies and such other workers as Wynne 
and Fleming were described by Spath in a series of monographs (1930, 1934, 1939). 

Spath based his palaeontological conclusions on the stratigraphical information 
provided by other workers. His interpretation of the fauna, though fairly accurate, 
lacks in many instances a proper biostratigraphical control. Four of his observa- 
tions, mentioned below, have been found to require reassessment in the light of the 
present work. 

I. Spath and others (Arkell, Pascoe, Krishnan) suggested a break in sedimenta- 
tion at the Jurassic-Cretaceous boundary. Although Spath mentioned Upper 
Jurassic ammonites in the basal ““Belemnite Beds’’, he considered them to be 
derived. The present study shows that there is no break of sedimentation at the 
Jurassic—Cretaceous boundary. 

2. Spath (1930 : 65-66) suggested the absence of Aptian transgression (which 
reached Persia and Cutch) from most of the areas of northern West Pakistan. The 
present discovery of Aptian ammonites in Kohat-Nizampur area indicates sea 
connections with Cutch and Persia via Baluchistan in at least the western half of 
the area examined. 

3. Spath (1939 : 132) believed the lowermost Neocomian (Berriasian and Lower 
Valanginian) to be absent in the main Salt Range (implying the western part) and the 
Tithonian and rest of the Upper Jurassic down to Callovain to be absent from the 
Trans Indus Ranges. In the present study, it was found that Berriasian and Lower 
Valanginian ammonites occur in the western Salt Range and that a definite Upper 
Oxfordian—Lower Kimmeridgian—Tithonian and Berriasian succession is present in 
the Trans Indus Ranges. 

4. Spath (1939 : 131) postulated the continuity of ‘‘Spiti Shale” facies of Spiti, 
Himalaya in the Hazara, Kala Chitta, Waziristan and Baluchistan regions and the 
subsequent denudation and erosion of the Upper Jurassic sediments prior to Berri- 
asian transgression. The present study indicates that the Upper Oxfordian—Lower 
Kimmeridgian transgression connected Cutch with Spiti through parts of the area 
under discussion. The major transgression, however, took place in the Tithonian 
and effected all the area extending to Baluchistan in the west. 

The more important contributions to the Mesozoic stratigraphy and palaeontology 
of individual areas may be summarized as follows: 

Hazara. Rather fragmentary information exists in literature on the area (Waagen 
and Wynne 1872; Middlemiss 1896; Wadia 1926; Arkell 1956; Pascoe 1959; 
Krishnan 1960). Waagen and Wynne and later Middlemiss recognized the following 
Himalayan (Spiti) succession: 


3. “Giumal Sandstone”’ Cretaceous 
2. spiti Shales” Jurassic 
I. “‘Kioto Limestone”’ Mainly Triassic 


The ‘“‘Kioto Limestone’ of Hazara is the most confusing unit being relatively 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 307 


poor in ammonites and other well-preserved fossils. It has been referred to the 
Upper Triassic by Middlemiss (1896), Wadia (1926 : 155), Pascoe (1959 : 897) and 
to the Upper Triassic-Lower Jurassic by Cotter (1933), Arkell (1956) and Krishnan 
(1960). The Upper Triassic age was suggested on the reported occurrence of frag- 
mentary mollusca, identified as Megalodon, Dicerocardium, Chemnitzia (Pascoe: 898). 
More recently Davies and Gardezi (1965) recorded Bouleiceras (identified by Dr 
Howarth of the British Museum) of Lower Jurassic age (Lower Toarcian) from the 
lower part of the “Kioto Limestone” in parts of Hazara (Bagnotar). 

The “‘Spiti Shales’ in Hazara are reported to contain Belemnopsis gerard: (Oppel) 
and Virgatosphinctes frequens (Oppel). 

Spath (1933 : 804) recorded the Berriasian ammonites Neocosmocarms octagonides 
(Uhlig) and Neocosmoceras subradiatus (Uhlig) from Murree Hills in Hazara and 
correctly thought them to have come from below the Albian ammonite beds and 
above the Virgatosphinctes frequens (Oppel) horizon in the Guimal Sandstone 
(Pascoe 1959 : 1186) near Kathwal. A similar Lower Tithonian ammonite fauna 
from this area is described here. 

From the upper part of the “Giumal Sandstone’”’ Spath (1930) described Middle 
Albian ammonites such as Lyelliceras lyelli (d’Orbigny), Douvilleiceras aff. monile 
(J. Sowerby), and Oxytropidoceras aff. roissyanum (d’Orbigny). He correlated the 
Hazara Albian ammonite bed with that of Kala Chitta and Kohat (Samana Range) 
and pointed out the abundance of Lyelliceras in Hazara and that of Douvilleiceras 
in the Samana Range. 

Middlemiss (1896) and Wadia (1926) compared the Jurassic rocks of northern 
Hazara with the “‘Spiti Shales” of Himalaya (Spiti) and the more arenaceous facies 
of southern Hazara with the Jurassic of the Salt Range. It is, however, not evident 
which arenaceous rocks they implied in the correlation. 

Kala Chitta Range. Cotter (1933) carried out the first detailed survey of the Kala 
Chitta Range. His fossil collections were studied and monographed by Spath 
(1934—Cephalopoda), Cox (1935—Bivalves and Gastropoda) and Muir Wood 
(1937—Brachiopoda). Cotter recognized the following Mesozoic succession. 


“Shales north of Kawaghar’’. ‘ é : A : (uncertain age ? 
Palaeocene) 
Giumal limestone, sandstone bun Fperen tinted Upper Oxfordian 
and sandy limestone to Albian 
“Kiota Limestone”. ; : 2 ; : : Upper Triassic 
to Liassic. 


Cox (1935) identified Indopecten sp. of Upper Triassic age and Lima gigantea 
(Sowerby), Eopecten velata (Goldfuss), Plicatula spinosa (Schloth) of Lower Jurassic 
age from the “Kioto Limestone, but no precise stratigraphic position of these fossils 
was given. He further identified the Middle Jurassic bivalves Corbula lyrata 
(Sowerby), Protocardia grandidieri (Newton), Eomiodon indicus Cox from the gray 
rubbly limestone, and placed them doubtfully in the upper part of the “‘Kioto 
Limestone’. Cox compared the fauna with the Kuar Bet Beds of Cutch and 
regarded it as Bajocian, but with the reassessment of the fauna of Kuar Bet Beds 
the age of the beds was changed to Upper Bathonian (Arkell 1956 : 391, 400). 


308 JURASSIC AND LOWER CRETACEOUS ROCKS 


Spath (1933 : 803) briefly mentioned some Lower Triassic ammonites submitted 
to him in Wynne’s Punjab collections from “Central Kala Chitta Pahar’ (Kala 
Chitta Range), but without any precise location or stratigraphic position. In the 
present work the stratigraphy of the “‘Kioto Limestone”’ is redefined on the basis of 
newly found fossil horizons and changes in lithology. The limestone is divided into 
five distinct formations. The lower three Triassic formations are separated with a 
marked disconformity from the overlying Lower and Middle Jurassic formations. 

From the ammonite collections of Cotter marked “basal Giumal’’, Spath (1934) 
identified a typical Upper Oxfordian (Transverserium Zone) and Tithonian assem- 
blage including species of Perisphinctes, Mayatites polyphemus (Waagen), Blanfordi- 
ceras, Aulacosphinctes, Himalayites etc. Cox (1935) identified Exoygra fourtaui 
Stefanini, Gryphaea balli (Stefanini) and Ctenostreon proboscideum (J. Sowerby). 
Although he assigned an Upper Oxfordian age to the assemblage, he mentioned 
rightly that Gryphaea balli is abundantly distributed in the basal Kimmeridgian of 
British Somaliland, and the present study shows that this species occurs in beds of 
Lower Kimmeridgian and younger age. 

From the upper part of “Giumal’”’ Spath identified Oxytropidoceras and Cox 
Neithea attockensis Cox, Exogyra arduennensis (d’Orbigny) and assigned a Middle 
Albian age. Cox also identified Tvigonia ventricosa Krauss from the “Giumal 
Sandstone”’ and assigned a Neocomian age. 

Summarizing the geological information on the Attock district (Kala Chitta 
Range), Arkell (1956 : 400) stated “‘the Spiti Shales in turn are overlapped by Giumal 
Sandstone, which takes on a shelly facies and incorporates at the base, or rests on 
condensed representatives of, certain Oxfordian horizons which belong low down in 
the Spiti Shales’. Similar views were expressed by Cotter (1933) who contended 
that the “Spiti Shales’’ may not have been deposited in the area. The present study 
indicates that the “‘Spiti Shales’ and the ““Giumal Sandstone”’ renamed in accordance 
with the Stratigraphic Code of Pakistan as the Chichali and Lumshiwal Formations 
respectively are distinct and recognizable units which show lateral variations in 
lithology and thickness, but are persistent in the area investigated. 

Nizampur. Excepting for some general remarks regarding the presence of Jurassic 
and Cretaceous rocks (Griesbach 1891; Pascoe 1959 : 1314, 1169) there is no 
published information on the fauna of this area. 

Kohat district. LL.M. Davies (1930) was the first to define the Mesozoic succession 
in the Samana Range and assign more precise ages based on his own observations 
and identification of the fossils by Cox (1930—gastropods and bivalves), Muir-Wood 
(1930—brachiopods), Currie (1930—echinoids) and Spath (1930—ammonites). 
Davies established the following sequence in the Samana Range. 

7. “Upper Lithographic Limestone” | 


6. “Variegated Series” > Upper Cretaceous 

5. ‘Lower Lithographic Limestone” 

4. “‘Main Sandstone Series” Lower Cretaceous 

3. “Belemnite Bed” Neocomian 

2. Samana Suk Limestone Uppet Jurassic 

1. “Lowest Samana Beds” Lower-Middle Jurassic 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 309 


From the upper part of Unit 1 Muir-Wood identified Rhynchonelloidea arcuta 
(Quenstedt) and the horizon was assigned a probable Upper Bathonian and possible 
Lower Callovian age. 

From the upper part ot the Samana Suk Limestone (Unit 2) Davies recorded 
traces of ammonites, belemnites and fragmentary crinoids (Pentacrinus sp.) and 
considered the age to be Upper Jurassic. 

From Unit 3 (““Belemnite Bed’’) Davies reported abundant belemnites, but no 
ammonites from the Samana Range. He did collect one ammonite from the 
Khadimakh hill (Kadamak of Davies), which was identified by Spath as Olco- 
stephanus (O.) aff. astierianus (d’Orbigny) and assigned a Lower Hauterivian age. 
It is from this formation that a fairly representative Berriasian—Valanginian 
ammonite fauna was collected during the present survey. 

From the uppermost bed of Unit 4 (‘“Main Sandstone Series’’) poorly preserved 
gastropods, bivalves, echinoids, brachiopods and ammonites have been mono- 
graphed. Amongst the ammonites Spath described Douvilleiceras mammuillatum 
(Schlotheim), Cleoniceras daviest Spath and Brancoceras indicum Spath etc. A 
Middle Albian age was assigned to the formation. 

No fossils were recorded from Units 5 to 7. The present work indicates that the 
Unit 6 (“Variegated Series’’ of Davies) is not present in the area and the Upper and 
Lower Lithographic Limestone units follow each other conformably and are dis- 
tinguishable as members of a formation. The limestone contains abundant small 
Foraminifera (Globotruncana sp.) and rarely ammonites (in the basal part). 

Trans Indus Salt Ranges. ‘Waagen (1875) compared the Jurassic rocks of the Salt 
Range with that of Cutch, and Wynne (1880) further pointed out the similarity of 
the “Golden Oolite’’ (Callovian) of Khera Hill of Cutch with similar rocks on either 
side of the River Indus. The strata that Wynne referred to as “Golden Oolite’’, a 
name also quoted in later literature (Arkell 1956 : 393), occur in a sandy, ferruginous 
formation (Pascoe 1959 : 1158), the “‘Variegated Series’’ of Gee (1945). Their 
stratigraphic position is much below the presently established Callovian beds in the 
uppermost part of the overlying ‘“‘Baroch Limestone’’. 

The most substantial contribution to the geology of the Salt Range and its Trans 
Indus extension could be attributed to E. R. Gee (1945) who divided the Jurassic 
and Cretaceous rocks as follows: 


4. ““Lumshiwal Sandstone” Cretaceous 

3. ““Belemnite Beds” Lower Cretaceous- Jurassic 
2. “Baroch Limestone”’ Jurassic 

in Variegated"Stage”’ Jurassic 


No precise ammonite horizons were reported from either the “‘Variegated Stage”’ 
or the ““Baroch Limestone”, but Spath (1933 : 802) recorded Subkossmatia flemingi 
(Fleming’s collections) from the ‘‘Calcareous strata below the coal shales with 
belemnites”’ near Kalabagh. Spath also identified some fragmentary ammonites 
as Hubertoceras sp., Obtusicostites sp. and Kinkeliniceras sp. marked by the collectors 
“from the Belemnite Beds of Miranwal nala, Makerwal’”’. He (1939 : 121) correctly 
thought their position to be below the ““Belemnite Beds” in the Jurassic limestone. 
Spath (1933 : 802) mentioned some unlabelled ammonites housed in the British 


310 JURASSIC AND LOWER CRETACEOUS ROCKS 


Museum, which he considered to have come from the Chichali Hills in the Trans 
Indus Salt Ranges. He identified them as Indocephalites transitotious Spath, 
Pleurocephalites habyensis Spath and Kamptokephalites magnumbilicatus (Waagen). 
Because of their golden matrix. Spath first thought them to have come from Cutch. 
Krishnan (1960 : 419) placed the above mentioned ammonites in the limestone 
above the “‘Variegated Series’ without reference to their locality. If the occurrence 
of the Lower Callovian ammonites from the Chichali Hills is correctly reported, they 
must be very rare as no such ammonites were detected in the Chichali Hills during 
the present survey. 

A confusing account of some Upper Jurassic ammonites and belemnites (considered 
derived) is represented in the literature (Arkell 1956 : 393; Pascoe 1959 : 1159-1160; 
Spath 1933 : 802; 1939 : 162). These ammonites are believed to have come from 
the ‘““Belemnite Beds’? of Neocomian age. Pascoe (1959) reviewing the Jurassic 
rocks of the Salt Range and the Trans Indus Ranges, pointed out correctly the 
presence in these areas of Bathonian, Callovian and Tithonian (mentioned only from 
Sokun in the Main Salt Range). He, however, contended that several ammonite 
found in the overlying Cretaceous beds (““Belemnite Beds’’) appeared to have been 
derived from the Spiti Shales. Arkell (1956 : 393) similarly pointed out the over- 
stepping of the Neocomian “Belemnite Beds’ on the underlying Jurassic. The 
views expressed by Arkell, Pascoe and Krishnan are presumably based on Spath’s 
analysis of the faunas who contended (1939 : 132) “‘there is no evidence that the 
Infra-Valanginian (Berriasian) and Lower Valanginian were ever represented in the 
Salt Range proper where the Middle and Upper Valanginian may rest upon the 
Tithonian. Conversely the Lower Valanginian must have been comparatively well 
developed in the west (Trans Indus Ranges) where, however, the Tithonian is com- 
pletely absent in addition to the rest of the Upper Jurassic down to Callovian”’. 

An Upper Oxfordian—Kimmeridgian—Tithonian—Berriasian—Valanginian ammonite 
sequence has been established in the “‘Belemnite Beds” by the present field investi- 
gations. These beds rest disconformably on the Middle Callovian ammonite bed 
of the “Baroch Limestone”. The Jurassic-Cretaceous boundary is transitional 
and not disconformable as previously thought. 

Shaikh Budin Hills. Lower Jurassic ammonites (Bouleiceras sp.) and Callovian 
brachiopods have been reported from this area (Pascoe 1959 : 1160-61). From a 
green glauconitic sandstone (possibly ‘“‘Belemnite Beds’’) Sahani (1939) identified 
Oxfordian and Kimmeridgian brachiopods (Zelleria sp., Kingena sp.). Spath (1939 : 
136) recorded Hibolithes subfusiformis (Raspail), Cymatoceras sp. and crioceratid 
fragments and concluded the presence of “Belemnite Beds’ in the area. C. W. 
Wright (unpublished oil company report) identified Blanfordiceras acuticostatum 
(Uhlig) and Virgatosphinctes communis Spath from the basal part of the “black 
zone” (‘“Belemnite Beds’’). Similar Tithonian ammonites were collected and are 
described here. 


Ill. GENERAL SEQUENCE 


The Mesozoic rocks of the area comprise of the following formations. The oldest 
is underlain disconformably (Para-conformity of Teichert and Kummel, 1966) by 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 311 


Permian Chhiddru Formation and the youngest overlain disconformably by Palae- 
ocene Hangu Formation or Dhak Pass Formation. 


8. Kawaghar Formation Upper Cretaceous 
Disconformity 
7. Lumshiwal Formation Upper Jurassic to mainly Lower 
Cretaceous 
6. Chichali Formation Upper Jurassic to Lower Cretaceous 
5. Samana Suk Limestone Middle Jurassic 
Disconformity 
4. Datta Formation Lower Jurassic 
Disconformity 
3. Kaingriali Formation ? Upper Triassic 
2. Tredian Formation/ ? Middle Triassic 
Chak Jabbi Limestone 
1. Mianwali Formation Lower Triassic 


Mianwali Formation: The name Mianwali was used by Gee (in Pascoe, 1959 : 852) 
and formalized by Kummel (1966 « 373-374) as a formation for rocks referred to 
previously (Waagen 1875; Wynne 1878) as “‘Ceratite Limestone’, ““Ceratite Marls’’, 
“Ceratite Sandstone” and “‘Bivalve Beds”. The formation is marine consisting 
of limestone, marls, with subordinate sandstone and dolomite. Kummel (1966) 
divided the formation into three members (Kathwai, Mittiwali and Narmia). The 
formation is 350-600 feet thick in the Salt Range and Trans Indus Ranges and 130 
feet thick (base not exposed) in the Kala Chitta Range. 

Tredian Formation|Chak Jabbi Limestone: The name Tedian was introduced by 
Gee (written communication to the Stratigraphic Committee of Pakistan) tor rocks 
referred to earlier by him (1945) as Kingriali Sandstone in Salt Range and Trans 
Indus Ranges. It consists of shale (lower part) and sandstone (upper part). The 
thickness is 130-207 teet. In Kala Chitta the equivalent rocks which immediately 
overlie the Mianwali Formation are sublithographic, medium bedded, unfossiliferous 
limestone named here as Chak Jabbi Limestone. The thickness is 110 feet. No 
Tredian Formation lithology is developed in Kala Chitta. 

Kingriali Formation: Overlying the Tredian Formation of the Salt Range and 
Trans Indus Ranges and the Chak Jabbi Limestone of Kala Chitta are the massive 
to thick bedded dolomite and dolomitic limestone ot the Kingriali Formation, (the 
“Kingriali dolomite” of Gee, 1945). The unit is 300-350 feet thick and is probably 
present in Hazara and parts of Kohat. 

Jurassic and Lower Cretaceous Formations: These comprise of clastic and carbonate 
rocks of marine to non-marine origin and are overlain and underlain disconformably 
by Upper Cretaceous and Triassic formations respectively. A disconformity 
between the Middle and Upper Jurassic is also present (Chapter IV). 

Kawaghar Formation: The name Kawaghar is here adopted (after Day of Attock 
Oil Company) tor rocks referred to previously as “Lithographic Limestone”’ in un- 
published Geological Survey of Pakistan and Oil Companies reports. The formation 
is typically a lithographic to sublithographic grey limestone with subordinate marls 
and shale in Western Kohat and Hazara. In Eastern Kohat, Nizampur and northern 


312 JURASSIC AND LOWER CRETACEOUS ROCKS 


Kala Chitta, the lithologyis mainly dark marls and calcareous shale with subordinate 
limestone. The thickness varies from 147 to 420 feet. The formation is missing in 
southern Kala Chitta, Salt Range and Trans Indus Ranges. 


IV. STRATIGRAPHY OF THE JURASSIC AND LOWER CRETACEOUS 
ROCKS OF THE AREA 


The ammonites described in this publication were collected from the following 
four formations which are over and underlain disconformably by Upper Cretaceous 
and Triassic rocks (fig. 4). 


4. Lumshiwal Formation 32-687 ft Upper Jurassic to mainly 
Lower Cretaceous 
3. Chichali Formation 30-213 ft Upper Jurassic to 
Neocomian 
Disconformuty 
2. Samana Suk Limestone 220-1087 ft Middle Jurassic 
1. Datta Formation 60-1300 + ft Lower to Middle Jurassic 


These formations have large aerial extent. They show significant lateral facies 
changes and, in most areas, the lithological boundaries transgress time planes 


(fig. 5). 
Datta Formation 


The name Datta Formation was introduced by Danilchik (1961) from the Datta 
nala in the Trans Indus Salt Ranges for the “‘Variegated Stage” of Gee (1945). The 
name is here adopted for similar rocks (fig. 4) in western Kohat (“Lower Samana 
Beds” of Davies 1930), Kala Chitta Range (‘‘Ferruginous Beds in the Kioto Lime- 
stone” of Cotter 1933, ‘““Red Clay Zone” and “‘Sumbal Panni Clay” of Oil Company 
Geologists), and Hazara (“‘Maira Formation” of R. G. Davies and Gardezi 1965). 


Trans Indus Ranges 


This area forms the type locality of the Datta Formation. The lithology consists 
of variegated sandstone and shale with some argillaceous limestone interbeds in the 
upper part, and coaly, carbonaceous, ferruginous and fireclay beds in the lower part. 
It rests with a disconformity on the ?Upper Triassic Kingriali Formation and is 
transitional with the overlying Samana Suk Limestone. 

The thickness ranges from 500 feet in Nammal Gorge to 700 feet in Datta nala 
(Danilchik and Shah (1967) and over 1300 feet in the Shaikh Budin Hills (Gee 1945; 
Habib Abbas and Bhuyan 1966, unpublished report). It thins out east of Nammal 
Gorge and is thick towards the west and south west in the Trans Indus Ranges. 

Fauna and Age: Pascoe (1959 : 1160) has recorded Bouwleiceras sp. from Shaikh 
Budin Hills (without any stratigraphic position or locality). Spath (1933 : 802) 
identified Indocephalites aff. transitorious Spath and Kamtokephalites cf. magnumbili- 
catus (Waagen) which he thought to have come from the Chichali hills in the Surghar 
Range. 

Commenting on this fauna Spath (1933 : 802) said “‘on account of their matrix 
I have up to now taken them to be from Kachh (India). The preservation in 


Ace)|| MOWENCUATURE USED pBsOLETE MAWES: 


zl 


ne 


KAWAGHAH FORMATION. 


E15) ovanpass FORMATION | HANGU FORMATION | OHAK FESS BEOS 
ss Rong ond Sevinern | (onal) HANGU SANDSTONE 
SectiON-7 E18 | eres 
soir Bl: eal 
saat eta fale oy ee 
: gece 
‘gue Tavacany ronvavion | Besusiltes ue 
[sre 


ee 


| oupreniwesrone 


CRETACEOUS: 


[Cowen [UPPER 


LUNSHIWAL FORMATION 


CHICHAL! FORMATION 
Gincontarmily 


(GUUAL SANDSTONE 
MHADIUAKH FORMATION 
WAIN SANOSTONE SERIES: 
BELEUNITE BEDS 
SPIT] SHALE 


JDRASSIC 


5 AWANA Sux LIMESTONE 


DATTA FORMATICH 


ROCH LIMESTONE 

RIOTO LIMESTONE 
FIGTO LIMESTONE 
VARIEGSTED SERIES 
LOWEST SAMANA BEDS 


Discontormity 
WINGRIAL! FORMATION 


RINGRIALI DOLOMITE! 
KIGTO LIMESTONE 


TOWER] MIDOLE JUPPER|LOWER| MOOLE 


4 1g |smconn renucrion |xacacinva) aineniatt sawosrove 
siesiecte 18 |essestanenindant [SIONS 
S Meeteata tie aire) : genrontinénl [ptiele mest! 
SN, Minsssate Seta z oT ae 

SECTION: Wanwau! Formarion eae 

engin gance [Is ctnavife a€0s seen 
ae af \ SECTION-S INDE TO LIPROSTRATIGHAPHEC UNITS FOR HAZARS ALACHT TA, MEAMPUR; ari netsene arate) 

2 aosoorecess mniaueue 


KOHAT, TRANS-ROUS SALT RANGE.ANO SHEm BUDIN HALLS 
on 


[WUCH KHWAR-GANDAB) 


/ Luusirwa FORMATION ater x 
wzAueua 
stcriono! [WAZARI-TANG! SECTIONS 
Hs TRANS INOUS SALT RANGE \ SECTON-< HAZARA ae 
secrowie 2 Tena Az) rae e EicTON (souTn OF J BBRIANI 
sereiventate FE Vi (gone MV Serre tchy 
eel) \ < Courosire Va 


AWAGARH FORMATION 
BS sribaunases 


u} 


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Se ‘Gmreot|pocceas 
| canramres 
=| COM SHIWAL FORMATION 


Aeitnea AY ceewme (6) 


One 


=rereel ||P tortsat set") 


‘wocemcceeas 
portent 


7 4 niemecwect Soyer lel fechaLi Forwarion Tacoiureaniswnecs fee Peseta) feruaL FORMATION. —Poeey_ jeacrerectns el} sei ownerce Setar (Cl remris S 
ssc contenu Seager els Re SCT ee beeen Soin es Geacre masons E “i 
NRercrnas spin Sa RSEAnUS a TIPTREE TAT AITAELEA Se DRT OTTO 


Fl Neiromer sit canes (4 Y/BeTHEE at Teneearale \suoraasncs te a qd TINO rays Gee A) 
een eee ya” |) ae raamanesie aout 
= Tae acral 
aa = 
ES ees! z = 
SAMANA SUK LWESTONE |™) = 
= Ee 
= Seat = 
— Sutin furs ene Chuan sux iesToke 
Al seman 
=e 
oa . 
Bees eee 


l 


Con 


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SRAECenas Cussoaaleac v2 


Hn 


Fengeon 


i 


Preiprcte 


ia 


i 


foes DATTA FORMATION 


ABROANT 
common 
BARE 


KINGRIAL FORMATION 


DETTA FORUATION 


won 


wares 


300 


100 


100 


Fic. 3, Lithological sections of the ‘Mesozoic rocks of Hazant, Kala Chitta, ‘Nizampur, 
Kohat, Trans Indus Ranges including Shaikh Budin Hills, West Pakistan. 


TE EE EEE  —8“8rLLL Se __..___ ee 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 313 


the characteristic yellow and crimson matrix of the ferruginous ‘macrocephalus’ 
beds is identical with that of certain undoubted Kachh examples’. The same 
fauna has been listed by Krishnan (1960 : 410) and Pascoe (1959 : 1160) from the 
limestone which overlie the “Variegated stage’ in the Trans Indus Ranges. Spath 
(1933) further pointed out the similarity of “golden oolite” of Cutch with the “golden 
oolite’” referred by Wynne (1878 : 101; 1880 : 46-47) from the Salt Range and the 
Trans Indus Extension. Wynne’s so-called “‘golden oolite’” occurs in the upper part 
of the Datta Formation (Pascoe 1959: 1158). If the Bowleiceras and other 
ammonites are correctly reported the Datta Formation in this area is Lower to 
Middle Jurassic in age and may be correlated with Western Kohat. 

In the present Survey, no Lower Callovian ammonites were found in the Chichali 
hills (mentioned by Spath 1933), and this occurrence may still be regarded doubtful 
until their correct stratigraphic position or occurrence is established by future work. 

Kala Chitta—Nizampur area: In the Kala Chitta Range a rather confused name 
of “Kioto Limestone” was used by Cotter (1933) for the limestone below the “‘Giumal 
and Spiti” sequence. An Upper Triassic to Liassic age was assigned by Cotter. 
The upper age limit was later extended to Upper Bathonian on the basis of the 
similarity of bivalves with the Kaur Bet Beds of Cutch (Arkell) 1956 : 400. During 
the present study it was found that the “Kioto Limestone” of Cotter consists of 
five distinct formations, and the Triassic—Jurassic contact is disconformable. The 
five divisions are as follows (fig. 4: Section 4). 


5. Samana Suk Limestone 620 ft Middle Jurassic 

4. Datta Formation 61 ft Lower Jurassic 
Disconformity 

3. Kingriali Formation, dolomite, 300 ft ? Upper Triassic 


dolomitic limestone, massive, thick 
bedded, brown to greyish brown 
2. Chak Jabbi Limestone, grey, medium 110 ft ? Middle Triassic 
bedded, lithographic to sublithographic 
limestone, unfossiliferous, slightly 
dolomitized in beds and equivalent to 
Tredian Formation (‘‘Kingriali 
Sandstone’’) of the Salt Range. 
1. Mianwali Formation, thin bedded 130+ ft Lower Triassic 
limestone, calcareous shale and marls, (base not exposed) 
green, grey, argillaceous with 
abundant ammonites 
The Triassic sequence: The Lower Triassic Mianwali Formation is exposed in the 
faulted outcrops north of Chak Jabbi Rest House (43 C/6) and in the core of the 
anticline one mile east south east of Bagh (43 C/I). 
The ammonites (to be studied and described) include Owemnites, Anokashmirites, 
Subvishnuites, Xenoceltites, Xenodiscoides, Koninckites, Kymatites and Paranorites. 


314 JURASSIC AND LOWER CRETACEOUS ROCKS 


The ammonites are typically Scythian and represent a mixed Himalayan and Salt 
Range assemblage. 

The Mianwali Formation is overlian by Chak Jabbi Limestone in Kala Chitta 
which stratigraphically hold the same position as the Tredian Formation in Salt 
Range and Trans Indus Ranges. The formation is well exposed in Bagh and Chak 
Jabbi outcrops. It is overlain by the thick cliff-forming, brown weathering Kin- 
griali Formation. 

Overlying the Triassic Kingriali Formation with a marked disconformity (best 
seen in the Chakdalla section) is the Datta Formation of Kala Chitta Range. Ina 
measured section near Chakdalla (43 C/6), the Datta Formation is 61 feet thick and 
can be divided into three members. The upper member (1g ft) 1s red clays and 
thin bedded limestone. The middle member (22 ft) is grey, nodular marly limestone 
with Bouleiceras and other fossils. The lower member consists of red and white 
quartzose and hematitic sandstone with (locally) fire clay horizons. As compared 
to the Salt Range, Trans Indus Ranges and Western Kohat, the thickness is much 
reduced in the Kala Chitta Range. 

Fauna and Age: The fauna from the middle member consists of Bouleiceras 
mitescens Thevenin, Bouleiceras chakdallaense sp. nov., Spiriferina sp. Vela ta 
velata (Goldfuss), Pecten sp. (similar to Indopectan sp. figured by Cox 1935 from this 
area), Lima (Plagiostoma) gigantea J. Sowerby and indeterminate corals and gastro- 
pods. The age of the middle member is Lower Toarcian and the age of the formation 
in the Kala Chitta area is Lower Jurassic (mainly Toarcian). 


Western Kohat (Samana Range) 


The Datta Formation in Western Kohat shows a significant facies change, and 
consists of thin to medium bedded, grey to brownish grey limestone with interbedded 
sandstone, calcareous sandstone, sandy, oolitic limestone and shale. In a measured 
section north east of Shinawari, on the western end of the Samana Range, the 
thickness is over 1300 feet, the base being faulted against Tertiary shale. The upper 
contact is gradational with the overlying Samana Suk Limestone (fig. 4, section 7). 

The Datta Formation is not exposed in the Khadimakh section, but north of 
Darsamand 500 to 600 feet crops out in the core of an anticline. In the Tribal Hills 
north and east of the Samana Range and Shinawari a greater thickness seems to be 
developed, but due to inaccessibility of this area it has not yet been studied. As 
correctly pointed out by Davies (1930) the possibility of Triassic rocks in the Tribal 
Hills to the north and east of the Samana Range cannot be ruled out. 

The Datta Formation of Western Kohat is of shallow-water marine origin as 
contrasted to the mixed marine (upper) and continental (lower) type in the Salt 
Range Trans Indus Ranges, Kala Chitta and Hazara. The lithology is more closely 
comparable with rocks of Lower and Middle Jurassic age of the Sulaiman province 
(Baluchistan and Kurram). 

Fauna and Age: In the upper part, rhynchonellid brachiopods occur which were 
also recorded by Davies (1930) and identified by Muir Wood (1930 : 26) as Rhyn- 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 315 


chonelloidea arenata (Quenstedt) of Upper Bathonian or Lower Callovian age. The 
presence of Sfiriferina sp., Velata sp. and indeterminate ammonite fragments 
(oxyconic with complicated suture) in the lower beds indicates a Lower Jurassic age 
similar to the bivalves and brachiopods of the Toarcian beds of the Kala Chitta 
Range. The age of the Datta Formation in Western Kohat may, therefore, be 
considered like that of the Trans Indus Ranges as Lower to Middle Jurassic (Pre 
Callovian). 


Hazara 


The present investigation does not cover a detailed stratigraphic study of the 
Datta Formation in Hazara. In one measured section, north of Kalapani, of the 
“Kioto Limestone”’ (treated here under Samana Suk Limestone), the Datta Forma- 
tion lithology is not developed, partly due to intensive folding and faulting, and 
partly due to non-deposition (fig. 6). In the Galdanian area, north west of Kalapani 
(43 F/7) Calkins and Matin (1968 : 15) recorded “Red Beds”’ with hematitic shale, 
sandstone and limestone (‘“Galdanian formation’’) underlying conformably their 
“Daulatmar limestone” (Samana Suk Limestone) and overlying a dolomitic limestone 
unit (“Abbottabad formation’). These “‘Red Beds” are considered Lower Jurassic 
in age and possibly represent the Datta Formation (similar to the Red Beds of Kala 
Chitta). The underlying dolomitic limestone is similar to the Kingriali Formation 
of ?Upper Triassic age. These correlations are tentative, based on the present study 
of the Kala Chitta Range and the similarity of the so-called “Kioto Limestone”’ of 
Hazara with that of Kala Chitta (Cotter 1933). 

Davies and Gardezi (1965) found Bowleiceras sp. in a section near Bagnotar (43 
F/8), Hazara, in the middle part of the “‘Maira formation”, (=Datta Formation) 
which overlies ‘““Hazara slates’ disconformably and underlie their “Jurassic lime- 
stone’ (=Samana Suk Limestone). The thickness varies from 100 to 120 feet 
(1965 : 25). The lithology shows a strong similarity with that of Kala Chitta Range. 

Fauna and Age: The presence of Bouleiceras in the Bagnotar area of Hazara and 
the strong similarity of this section with Kala Chitta indicate a Lower Jurassic 
(mainly Toarcian) age of the formation which rest disconformably on Precambrian, 
Paleozoic or Triassic rocks (figs 4, 5), and is not developed in parts of Hazara (e.g. 
Kalapani section). 


Samana Suk Limestone 


The name Samana Suk was introduced by L. M. Davies (1930) from the peak of 
this name in the Samana Range, Western Kohat. The name is here adopted for 
similar limestones of the Kala Chitta Range (part of ‘‘Kioto Limestone” of Cotter 
1933), the Salt and Trans Indus Ranges (““Baroch Limestone” of Gee 1945) and 
Hazara (part of “Kioto limestone” of Middlemiss 1896; ‘“‘Jurassic limestone” of 
Davies and Gardezi 1965; ‘“‘Daulatmar limestone” of Calkins and Matin 1968). 


316 JURASSIC AND LOWER CRETACEOUS ROCKS 


Western Kohat (Samana Range) 


In the type area the Samana Suk consists of grey, medium grey to dark grey, 
thick to medium bedded limestone with oolitic, calcareous shale and marl interbeds. 

The thickness varies from 615 feet in the Samana Range (western outcrops near 
Shinawari) to 562 feet in the Darsamand section. 

The formation is gradational with the underlying Datta Formation, and is over- 
lain disconformably by the Chichali Formation. 

Fauna and Age: The fossils are mostly comminuted shells (bivalves, gastropods 
and brachiopods). About 3 feet below the top belemnites (Belemnopsis cf. grantana) 
were obtained from a shale parting on the south flank of the Samana anticline. The 
top uneven surface of the limestone, which weathers rusty brown, has sectioned 
belemnites, molluscan casts and crinoidal remains. On the basis of Belemnopsis 
granata (d’Orbigny), which is similar to the figured specimen of Spath (1924, pl. III, 
fig. 3) from Cutch, the upper age limit of the formation is dated as Middle Callovian, 
and the formation may range in age from Middle to Lower Callovian. 


Trans Indus Ranges 


The Samana Suk Limestone is similar in lithology to the type locality, except the 
bedding is thinner and the colour is lighter grey. The formation is 220 feet in the 
Chichali section. It thins out towards the east in the Salt Range, but thickens to 
450 feet in Baroch nala towards the west. Further south, in the Shaikh Budin Hills, 
Krishnan (1960 : 419) recorded 800 feet of the limestone. 

The uppermost 2 to 3 feet of the formation is richly fossiliferous in ammonites, 
particularly in the area west of Chichali Pass (Datta, Punnu, Lunda, Mallakhel, 
Makerwal), and has yielded the Middle Callovian ammonites described in the present 
work. In the sections east of the Chichali Pass no ammonites were detected in this 
horizon, but Spath (1928 : 205) has recorded Subkossmatia flemingi from north of 
Kalabagh. 

Fauna and Age: The ammonites include Reimeckera anceps (Reincecke), R. sp. 
indet. R. cf. torulosus (Spath), Choffatia sp. indet., Hubertoceras sp. indet., Obtusico- 
stites buckmami Spath and Obstuicostites sp. indet. 

Among the non-ammonite fauna, rhynchonellid and terebratulid brachiopods, 
bivalves and gastropods occur quite commonly. The Bivalves include Homomya cf. 
gibbosa Sowerby, Pecten sp., Arctostrea sp. and Tellurimya tellaris (Lamarck). 
Among the rhynchonellids Somalirhynchia nobelis (J. De C. Sowerby) is the most 
abundant species in some sections. 

The upper age limit of the formation is Middle Callovian and the formation may 
extend in age from Middle to Lower Callovian (Middle Jurassic). 


Kala Citta Nizampur area 


The Samana Suk Limestone in this area (upper part of the “Kioto Limestone” of 
Cotter 1933) consists of thin to medium bedded limestone with thicker interbeds. 


Sum Ora) Ove Lae 2 IS. 1S Vv ae DISSVIYL 


CrREprANC EO WS 


c 


JURREATSES 


STAGES 
and 
SUBSTAGES 


TURONIAN 


Upper 
Middle 


BARREMIAN 
HAUTERVIAN 


Upper 
VALANGINIAN 
Lower 


BERRIASIAN 


ALBIAN 


NEOCOMIAN 


TiTHONIAN UPPEr 
Lower 


LOWER 
KIMERIDGIAN 


OXFORDIAN /PP er 


ower 

Upper 

CALLOVIAN Middle 

Lower 
BATHONIAN 


CHARACTERISTIC 
FAUNA 


TTRANS INDUS 


WESTERN KOHAT 


NTRAL AND 
SOUTHERN KALACHITTA 


E 
HAZARA (South) 


E 


Lyelliceras tyelli 


Douvelliceras_mammilatum_ 


Caspianites 
Ammoniticeras 


Olcostephanus salinarius 


asreaniie is 


Subthurmannia fermor/ 


Blonfordiceras, Himolayites 
Aulacosphinctoiaes 
tepsiahactes® 


Ht ; | SALT RANGE 


|LUMSHIWAL FORMATION |= 
=| ammonitoceras. Oufrenoyia 


-NQ EVIDENCE __  __ 
Z|CHICHALI FORMATION 


Kilianella. Neocomites 
|_thurmanniceras. 


Subthurmannia 
Neocosmoceras 


(commen) 


d 
= 
ey 
are 
Zz 
it 
4 
x 
(ta 
pe 
En) 
i= 
= 
<n 
NW 
ze 
— ===... | 
+ +| KAWAGHAR FORMATION 
Sl —Tiabotruncana veniricosa 
—-—---—---=- =! at 
[Sp = ee Sh 
| 
lll 
! 
| 


I} HAZARA (North) 


| 
i- 
| 
Sfpcocsoces 
| 
== 
| 


J] ouvelliceras_ 


|NO_ EVIDENCE __ 


Ticostephanus 


Subthurmannia 
Spiticeras 


| Protoacanthod/scus 


Provalanginites, Hikioglocheeras| 


Pachysphinctes, Katroliceras 
4 (Pseudowoagenia } 


Aslemogpsis gerard) __ _ 


Perisphincles . Euaspidoceras 


R (Reineckela) anceps 


Orytropideceras 
LUMSHIWAL FORMATION 


“E] Cospianites 


= =e ee eee 4: 


Trigonlo_ventricosa 


lis 


aaa 
Fike 


2Non Sequence 


2Non sequel 


? Neocosmoceras sp 


“13 > Non sequence 


CHICHALI FORMATION 
8 gerardi 


T 
Wee ating 


3 ?Non sequence Unfossiliferous 


B gerardi, Pachysphinctes 


Perisphinctes. Euospidoceras 


{| _Perisphinctes: 


Lyelliceros, Douveiliceras 


NO EVIOENCE 


Aulacosphincto/des 
Virgatosphinctes 


SAMANA SUK 


MESTONE Belemmopsis grantona 
atites 


Corbula . Eomidon, Protecardia 


Corbula, Eomidon, Protocardia 


= 


BAJOCIAN 


MIDOLE|/]U PPER 


TOARCIAN 


PLIENBACHIAN 


SINEMURIAN 


LOWER [ 


HETTANGIAN 


Bouleiceras nitiscens 
Bouelceras _chakdallensis_ 


ISAMANA SUK LIMESTONE 


Spiriferina, Pecten 


DATTA FORMATION 


KINGRIALI FORMATION 


KALACHITTA LIMESTONE 


Fe] MIANWAL! FORMATION. 


Biostratigraphical correlation 


of the Mesozoic formations of northern West 
Pakistan. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 317 


The limestone weathers to grey-brown and has subordinate nodular marl and 
calcareous shale intercalations. The succession is gradational to the underlying 
Datta Formation and is disconformably overlain by the Chichali Formation. 

Nearly 10 feet above the basal shelly limestone occurs a distinct yellow brown to 
dark rusty brown ferruginous coarse oolitic bed of 2 to 5 feet in thickness. This 
ferruginous oolite bed is developed in the western half of Kala Chitta (West of Chak 
Jabbi), while in the eastern section, it is represented by calcareous oolites only. 

The upper 1 or 2 feet of the Samana Suk Limestone are nodular, marly and have 
yielded bivalves. 

The thickness in a measured section near Chakdalla is 620 feet. In the Gandab 
section of Nizampur, the thickness increases to 800 feet. 

Fauna and Age: The bivalves in the top bed of the formation include Protocardia 
grandidient (Newton), Eomiodon indicus Cox and Corbula lyrata J. de C. Sowerby. 
The bivalves are the same as described by Cox (1935) from the “Kioto Limestone” 
of this area. They are also similar to the one occurring in the Kuar Bet Beds of 
Cutch, which have been assigned an Upper Bathonian age (Arkell 1956 : 391, 400). 

The upper age limit of the Samana Suk Limestone in Kala Chitta is Upper 
Bathonian, and as the formation overlies the known Toarcian Datta Formation of 
this area conformably, the lower age limit may extend to Bajocian. 

It is worth mentioning that nearly 60 to 70 miles further west in the Samana 
Range, and 50 to 60 miles south west in the Trans Indus Ranges, the Samana Suk 
Limestone is Callovian. 


Hazara 


In the Hazara area the formation was studied only in one section, situated 14 
miles north of Kalapani (43 F/8). The lithology comprises thick to medium bedded 
(with thin beds) grey, brownish grey limestone, poorly fossiliferous, with interbeds 
of oolitic dolomitized limestone, nodular marl and calcareous shale. It is discon- 
formably overlain by dark shale of the Chichali Formation (‘‘Spiti Shales’), and 
disconformably underlain by quartzites and slates of doubtful Palaeozoic age. The 
basal 3 feet of the limestone is conglomeratic with quartz pebbles. 

The thickness is 1087 feet in the section north of Kalapani. 

From the Bagnotar area to the south R. G. Davies and Gardezi (1965 : 25) 
reported over 1200 feet of similar limestone overlying their “Maira Formation” 
(=Datta Formation with Bouwleiceras), Calkins and Matin (1968) from the Gal- 
danian area recorded thick, grey limestone (‘‘Daulatmar Limestone’’) overlying 
their “Galdanian formation” (=Datta Formation). This limestone probably 
represents the Samana Suk Limestone. 

Fauna and Age: The Samana Suk Limestone of Hazara is poor in identifiable 
fossils. No ammonites occur. Its stratigraphic position above the Lower Jurassic 
Bouleiceras-bearing Datta Formation, lithological similarity with that of the Kala 
Chitta area and its disconformable contact with the overlying Upper Jurassic 
Chichali Formation, suggest a Middle Jurassic age similar to the Kala Chitta Range. 


318 JURASSIC AND LOWER CRETACEOUS ROCKS 


Chichali Formation 


The name Chichali Formation was introduced by Danilchik (1961) and Danilchik 
and Shah (1967) from the Chichali pass in the Trans Indus Ranges for rocks pre- 
viously described as “‘Belemnite Beds’ (Spath 1939; Gee 1945). The name is 
here adopted (fig. 4) for similar rocks which disconformably overlie the Samana Suk 
Limestone in Kala Chitta (‘‘Spiti Shales’”’ of Middlemiss 1896) and Shaikh Budin 
Hills (“Black Zone”’ of oil company geologists). 


Trans Indus Ranges 


The lithology in the Trans Indus Ranges, which includesthetype locality, consists of 
dark green, greenish brown, dark bluish grey (lower part), soft glauconitic sandstone 
and sandy shale, with subordinate nodular, calcareous, phosphatic strata. Some 
portions of the formation (the Middle member in Makerwal area and the Upper 
member in Chichali-Kalabagh area) are sufficiently rich in glauconite and/or 
chamosite to provide low grade iron ore. 

The thickness ranges from 150 feet in the eastern section of Kalabagh to 180 feet 
in the Chichali Pass and 185 feet in the western sections of Makerwal and Baroch 
Nala. From the Shaikh Budin Hills, Abbas and Bhuyan reported (unpublished) 
a maximum thickness of 159 feet. 

The formation is divisible into three members. The basal bed of the lower 
member (less than a foot in thickness) is calcareous, glauconitic and sandy, with 
Upper Oxfordian ammonites and belemnites. These are succeeded by dark grey 
silty, sandy, glauconitic shale (10-15 ft), which contains some calcareous, phos- 
phatic, or ferruginous nodules with Lower Kimmeridgian ammonites and abundant 
belemnites (including Belemnopsis gerardi). The shale becomes gradually more 
sandy and greenish in colour in the succeeding 20 to 30 feet and has yielded Lower 
Tithonian ammonites and abundant Hibolithes but no Belemnopsis. The rest of 
the lower member passes into a dark green, glauconitic sandstone weathering into 
soft sands with Upper Tithonian ammonites. In the uppermost 2 to 3 feet the first 
basal Cretaceous ammonites (Subthurmannia) appear, and it is this part which is 
considered transitional from the Jurassic to the Cretaceous. The thickness of the 
lower member ranges from 70 to 75 feet in the Makerwal-Lunda—Punnu Mines 
sections, to 110 feet to the east in Chichali Pass and Kalabagh sections. 

The middle member is a massive, calcareous, glauconitic sandstone, weathering 
rusty brown to greenish brown (dark green when fresh). It has abundant belemnites 
and common ammonites. The lower 3 to 4 feet of the member has Berriasian 
ammonites and the rest Valanginian. In the uppermost 2 to 3 feet Upper Valan- 
ginian ammonites (Olcostebhanus) are commonly distributed. The thickness ranges 
from 35 to 45 feet in the Makerwal-Punnu Lunda Mines sections to 25 to 30 feet in 
the Kalabagh and Chichali Pass sections. The middle member thins towards the 
east, and in the Shaikh Budin Hills a maximum of 40 feet has been reported. 

The upper member consists of greenish or reddish brown, massive, sandy shale 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 319 


and sandstone which are glauconitic and chamositic but are devoid of ammonites. 
In the Chichali Pass and western sections about 3 to 5 feet below the top contact 
with the Lumshiwal Formation some Hibolithes and Gryphaea occur. In the rest 
of the member even belemnites, which are abundantly distributed in the lower and 
middle members, are absent. The upper contact with the Lumshiwal Formation 
in the sections west of the Chichali Pass appears to be transitional. In the sections 
at and east of the Chichali Pass, the upper contact with the Lumshiwal Formation 
is marked by a red ferruginous sandstone bed and is sharp. The thickness of the 
upper member is 10 feet in Kalabagh, 40 feet in the Chichali Pass, 60 feet in the 
Makerwal-Lunda—Punnu Mines and 80 feet in the Shaikh Budin Hills. The upper 
member shows a marked thinning towards the east (Main Salt Range). 

Fauna and Age: The Upper Oxfordian fauna includes P. (Kranaosphinctes) sp. 
indet., P. (Dichotomosphinctes) cf. rotoides Ronchadze, P. (?Dichotomosphinctes) sp. 
indet., Mayaites cf. waagent (Uhlig), and Belemnopsis gerardi (Oppel). 

The Lower Kimmeridgian is represented by Aspidoceras (Aspidoceras) sp. indet., 
A. (Pseudowaagenia) sp. indet., Physodoceras (Simaspidoceras) sp. indet., Laevapty- 
chus, Ptychophylloceras ptychoicum (Quenstedt), Katroliceras cf. pottingert (J. de C. 
Sowerby), Pachysphinctes robustus Spath, Hibolithes sp., Belemnopsis gerard: and 
Hybonoticeras sp. indet. The non-cephalopod fauna consists of Gryphaea sp., some 
rhynchonellid and terebratulid brachiopods. 

The Lower Tithonian is represented by Aulacosphinctoides sp., Virgatosphinctes 
sp., Hildoglochioceras sp. indet., Proniceras indicum Spath, Provalanginites rhodest 
gen. nov. sp. nov., Provalangimites howarthi sp. nov., Holcophylloceras silesiacum 
(Oppel). The Upper Tithonian fauna includes Blanfordiceras cf. wallicht (Grey), 
Himalayites cf. hyphaisis (Blanford), Himalayites sp. indet., Pterolytoceras exoticum 
(Oppel), Spiticeras multiforme Djanelidze, Ptroacanthodiscus cf. muchaelis (Uhlig), 
Protacanthodiscus sp. indet., and Aulacosphinctes spitiensis (Uhlig). 

This Upper Oxfordian to Tithonian fauna occurs in the lower member of the 
Chichali Formation. In the upper 2 feet, however, Subthurmannia appears, and 
extends into the basal 3 to 4 feet of the middle member. The Jurassic—Cretaceous 
boundary is placed at the first appearance of the genus Subthurmannia. 

The Berriasian is represented by Protacanthodiscus sp., Subthurmanma fermort 
Spath (abundant), S. /issonioides Spath and other Subthurmannia spp., Neocosmoceras 
subradiatus (Uhlig), Neocosmoceras cf. spitiensis (Uhlig), and Spiticeras (Negreliceras) 
aff. subnegreli Djanelidze. 

The Lower Valanginian (Middle member of the Chichali Formation) is represented 
by Thurmanniceras sp., Sarasinella uhligi Spath, Sarasinella spinosa (Uhlig), Neo- 
comites (Neocomites) sp. nov., N. (Neocomites) cf. teschensis (Uhlig), N. (Neocomites) 
pycnoptychus (Uhlig), N. (Calliptychoceras) spp. nov., N. (Parandiceras) cf. rota 
(Spath), N. (Parandiceras) theodori1, (Oppel), N. (Parandiceras) aff. indicus (Uhlig), 
N. (Odontodiscoceras) similis Spath, and its subspecies, Uhligites sp. indet. Kilianella 
asistica Spath, K. besaivei Spath, Kilianella sp. nov., Neohoploceras (Neohoploceras) 
sp. indet. and Neohoploceras baumbergert Spath. 

The Upper Valanginian is represented in the uppermost 2 to 3 feet of the middle 
member by Olcostephanus (Olcostephanus) salinarius and its 5 subspecies (most 


320 JURASSIC AND LOWER CRETACEOUS ROCKS 


common), O. (O.) sakavalensis (Besairie), O. (O.) cf. filosa (Baumberger), O. (0.) 
sublaevis Spath, O. (O.) fascigerus Spath, O. (O.) sp. nov., O. (O.) aff. geet Spath, O. 
(Rogersites) schenki (Oppel), O. (R.) sp. nov., Leopoldia sp., Distoloceras sp. and Lytico- 
ceras Sp. NOV. 

No ammonites occur in the upper member excepting for some poorly preserved 
Gryphaea and Hibolithes in the upper part. 

The ammonite fauna indicates an Upper Oxfordian to Valanginian age of the 
lower and middle members. The upper Member may represent the rest of the 
Neocomian (Hauterivian—Barremian). 


Western Kohat (Samana—Darsamand—Khadimakh sections) 


The lithology is very similar to the type section of the Trans Indus Ranges except 
that the thickness is much attenuated (50-60 ft). Inthe Samana—Darsamand area, 
the formation is divisible into three members, but in the Khadimakh section only 
two fold division (corresponding to lower and middle members of the Samana 
section) is possible. The upper member in Khadimakh is not separable from the 
overlying Lumshiwal Formation of similar lithology (fig. 4). 

The formation rests disconformably on the Samana Suk Limestone, and is followed 
by the glauconitic (in Khadimakh) or quartzose sandstone of the Lumshiwal 
Formation. 

Fauna and Age (fig. 5): The ammonites in the lower member include ?Protacantho- 
discus sp., Berriasella sp., Spiticeras (Spiticeras) aff. greisbachi (Uhlig), S. (S.) cf. 
mojsvart (Uhlig), Neocosmoceras octagonum (Blanford) and Subthurmanma aft. 
boissieri (Pictet). These are followed in the basal part of the middle member by 
Subthurmannia fermori Spath, S. aff. pseudopunctata Spath, S. ssonioides Spath, 
Pterolytoceras aff. exoticum (Oppel), Pterolytoceras sp. indet., Thurmanniceras sp. and 
Neolissoceras grasianum (d’Orbigny). Succeeding these faunas in the middle member 
are Neocomites sp., Kilianella sp. nov. and Kuilianella leptosma (Uhlig). This is 
followed, in the upper 2 to 3 feet of the middle member by O. (O.) salinarius Spath, 
O. (0.) radiatus Spath, O. (O.) cf. sublaevis Spath, O. (O.) sp. nov., O. (O.) pachycyclus 
Spath and Lyticoceras sp. indet. 

The upper member is barren of fossils. The age of the Chichali Formation is 
Upper Tithonian to Neocomian. 


Kala Chitta—Nizampur area 


The Chichali Formation of this area is broadly comparable in lithology with the 
Trans Indus Ranges and the Samana Range, but it also shows some peculiarities 
which require separate treatment. 

In the outcrops of Western Kala Chitta (Bagh, Sujhanda sections) and south east 
of Nizampur (Wuch Khawr and Gandab sections) the formation is 80 to go feet thick 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 321 


and consists of two members. The Upper Member is a dark pyritic silty shale, 
and is not developed in the outcrops of central Kala Chitta (Chakdalla—Jhallar 
sections) where the formation is 30 to 40 feet thick and consists of dark green or grey 
glauconitic sandstone and sandy shale with a nodular calcareous bed at the base. 

In the sections north—north west of Jhallar, central Kala Chitta Range, the forma- 
tion consists of the following: 

Upper part Greenish sandy shale, glauconitic with Hibolithes sp., Gryphaea sp. 
annelids, overlain by light brown calcareous sandstone of the Lum- 
shiwal Formation 20 to 15 feet. 

Lower part Dark green, glauconitic, soft sandstone, with phosphatic and 
calcareous nodules, containing the following fossil horizons: 20 to 
15 feet 

d. near the top, Neocosmoceras subradiatus (Uhlig) and Gryphaea aff. 
balla (Stefanini). 

c. major portion of the unit; abundant Hzbolithes sp., Gryphaea cf. 
balli (Stefanini), and less commonly Himalayites sp., and Blanfordi- 
ceras sp. towards the base. 

b. belemnite shingle (up to 1 ft) consisting of nodular (calcareous, 
ferruginous) glauconitic silty sands, with abundant Belemnopsis 
gerardt (Oppel) and Hibolithes sp.,and some gastropods and bivalves. 

a. sandy glauconitic, calcareous, rubbly bed (up to 14 ft), with abundant 
poorly preserved perisphinctid ammonites, brachiopods, bivalves, 
gastropods, belemnites; overlies disconformably the Samana Suk 
Limestone. 

Fauna and Age (fig. 5): The lithology and fossil beds indicate that, though the 
formation ranges in age from Upper Oxfordian to Lower Neocomian, it is much 
condensed and is full of non-sequences. 

The Upper Oxfordian fauna (unit a) includes Prosophinctes (?) virguloides Waagen, 
P. (P.) sp. indet., P. (Avisphinctes) orientalis Siemiradzki, P. (? Dichotomosphinctes) 
sp. indet. Euaspidoceras cf. wagurense (Spath), Euaspidoceras sp. indet., and the 
bivalves and gastropods include Ctenostreon proboscideum (J. Sowerby) and Pleuro- 
tomaria sp. 

There is no evidence from the ammonites of the presence of Lower Tithonian, but 
the abundance of Belemnopsis gerard, rare fragmentary perisphinctid ammonites 
and Gryphaea cf. balli (Stefanini) in the condensed horizon (unit b), indicate the 
presence of Lower Kimmeridgian. The Lower Tithonian is probably missing 
because of non-sequences in Kala Chitta. The Upper Tithonian is represented by 
Himalayites ci. depressus Uhlig, Blanfordiceras sp. indet and Aulacosphinites sp. 
indet. and Gryphaea cf. balli (Stefanini). Gryphaea is also commonly distributed in 
the glauconitic sands (unit c) in beds which overlie Blanfordiceras. It may be 
pointed out that the Blanfordiceras specimens are limonitic and occur towards the 
base of unit c. 

The Berriasian is indicated by the presence of fragmentary specimens of Neocosmo- 
ceras cf. subradiatus (Uhlig). 

Because of the presence of Tvigonia ventricosa (Krauss) in the basal beds of the 


322 JURASSIC AND LOWER CRETACEOUS ROCKS 


overlying Lumshiwal Formation, which in Cutch and South Africa (Arkell 1956 : 
387) is found in the Valanginian, the upper age limit of the Chichali Formation in 
Kala Chitta may be Lower Valanginian. 


Hazara 


In Hazara the Chichali Formation shows a distinct facies change from the dark 
““Spiti shales’ type exposed in the outcrops north of Haro River (investigated west 
of Jabrian and in Kathwal—Kalapani sections) to the Kala Chitta type dark green 
glauconitic sandstone facies exposed south of Haro River (investigated north of 
Jabrian Rest House and extending to the south west in the Margala Hills). 

The “‘Spiti Shales” facies is represented by black or dark grey shale with some 
ferruginous, sandy and silty concretions. The shales are unfossiliferous, except in 
the lowermost part where some belemnites (Belemnopsis sp.) and fragmentary peri- 
sphinctid ammonites occur. The formation rests disconformably on the Samana 
Suk Limestone (‘‘Kioto limestone’’), and is followed without any apparent break, 
but with change of lithology, by the Lumshiwal Formation (‘“Giumal sandstone’’). 

The thickness in the section north northwest of Kalapani is 213 feet and thins out 
to 134 feet to the south in a roadside section near Jhamiri village. 

The green glauconitic sandy facies of the Chichali Formation is 110 feet thick in a 
measured section north of Jabrian Rest House on the Haro River (north bank). 

Fauna and Age: The formation is poor in ammonites and other fossils. The 
occurrence of Belemnopsis gerardi (Oppel) and poorly preserved, phosphatized 
fragmentary perisphinctid (?Pachysphinctes sp.) ammonites in the basal part indicate 
a Lower Kimmeridgian age for the base. It appears that the condensed Upper 
Oxfordian bed developed in Kala Chitta and the Trans Indus Ranges is missing from 
this area. Belemnopsis gerardi (Oppel) occurs both in the Upper Oxfordian and 
Lower Kimmeridgian beds of the Trans Indus and Kala Chitta Ranges. Unless 
more definite evidence of Upper Oxfordian age (based on ammonites) is obtained by 
future investigations of other outcrops, a Lower Kimmeridgian age is favoured here 
for the base of the formation. 

The upper age limit of the Chichali Formation in Hazara is still less definite, 
mainly because of the paucity of fossils. In the Kalapani-Kathwal sections Lower 
Tithonian ammonites occur in the basal part of the overlying Lumshiwal Formation 
(“Giumal Sandstone’’) indicating mainly a Lower Kimmeridgian age of the Chichali 
Formation in these sections. 

In the sections of Haro River, no fossil evidence could be obtained from the upper 
part of the formation, but Spath (1933) and Pascoe (1959) have reported Neocosmo- 
cervas subradiatus (Uhlig) and Neocosmoceras octagonides (Uhlig) from the overlying 
“Giumal sandstone” in outcrops Io to 15 miles north east of the examined localities 
(Murree—Abbottabad Road). This suggests that the upper age limit of the Chichali 
Formation in the Haro River sections (Jabrian) may be Tithonian and the formation 
may extend from Lower Kimmeridgian to Tithonian. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 323 


Lumshiwal Formation 


The name Lumshiwal was introduced by E. R. Gee (1945) for a white or light 
coloured sandstone overlying the Chichali Formation (‘““‘Belemnite Beds’’) and over- 
lain disconformably by the Lower Tertiary coal beds in the Trans Indus Ranges. 
The name Lumshiwal Formation is here adopted for similar rocks previously called 
the “Main Sandstone Series’ (Davies 1930) in the Samana Range, and “‘Giumal 
sandstone” in Kala Chitta (Cotter 1933) and Hazara (Middlemiss 1806). 

The formation exhibits a great variability of lithology and thickness in different 
parts of the area investigated (fig. 4). It is mainly quartzose sandstone in the Trans 
Indus Ranges, quartzose, and glauconitic sandstone in western Kohat and parts of 
Hazara and a mixed quartzose, glauconitic or calcareous sandstone and limestone in 
Nizampur, Kala Chitta, and southern Hazara. 

The thickness is 330 feet in the Trans Indus Ranges, but it thins out eastward and 
is absent in the main Salt Range. It is 670 feet in western Kohat, 220 feet in 
Nizampur, 180 feet north of the Haro River and 32 feet in the Kalapani-Kathwal 
sections of northern Hazara. 

The upper age limit of the formation is Lower—Middle Albian in Kohat, Kala 
Chitta, Hazara and doubtfully so in the Trans Indus Ranges. The lower age limit 
is more variable. It is regarded doubtfully Aptian in Trans Indus Ranges and more 
definitely in Western Kohat, Upper Neocomian in Nizampur and Kala Chitta, 
doubtfully Lower Neocomian in the Haro River sections and Lower Tithonian in 
Kathwal—Kalapani sections of Hazara (fig. 5). 

The formation is overlain disconformably by the Kawaghar Formation of Upper 
Cretaceous age in Kohat, Nizampur, northern half of Kala Chitta and Hazara. In 
the Trans Indus Ranges and southern half of Kala Chitta, no Upper Cretaceous rocks 
are developed, for Lower Tertiary sandy marls and limestone le disconformably on 
the Lumshiwal Formation. 


Trans Indus Ranges 


The lithology consists of fine to medium and some times coarse, light grey or white, 
quartzose sandstone. The sandstone is massive and current bedded, cliff-forming 
and in the upper part commonly includes carbonaceous matter. The basal 5 to 10 
feet is silty glauconitic shale or siltstone, and contains poorly preserved Gryphaea sp. 
and Hibolithes sp.in Baroch Nala outcrops. In the eastern sections of Chichali and 
Kalabagh no such fauna occurs. The lower contact with the Chichali Formation in 
the sections west of Chichali Pass is transitional, while towards the east, it is sharp. 
The upper contact with the Lower Tertiary coal beds is disconformable. 

The thickness is 330 feet in the Makerwal area, 125 feet in the Chichali Pass and is 
practically missing in the Kalabagh section. 

Age and Fauna: The formation is unfossiliferous except for some Gryphaea in the 
western sections of the Trans Indus Ranges. Its transiticnal contact with the under- 
lying Neocomian beds and lithological similarity with the Kohat sections suggest an 
?Aptian to Mid-Albian age. 


324 JURASSIC AND LOWER CRETACEOUS ROCKS 


Western Kohat 


In the Samana Range section, the formation (641 ft)is divisible into three members. 
The upper member is a green to reddish brown glauconitic and ferruginous sandstone 
with a hard (2-6 ft) calcareous sandstone containing abundant fossils including 
ammonites near the top. The middle member (187 ft) is a light coloured coarse to 
medium grained current-bedded, massive, quartzose sandstone. The lower member 
(250 ft) is a thin to medium-bedded, quartzose sandstone with decomposed pyrite 
and some silty clay partings in the middle part. 

In the Darsamand section, the lithology is similar to that of the Samana Range 
except the thickness is reduced to 550 feet. In Khadimak section no quartzose 
sandstone is developed. The formation (thickness 670 ft) is represented by dark 
green to greenish grey glauconitic sandstone and sandy shale with some calcareous 
and phosphatic interbeds. 

Fauna and Age: The topmost hard, dark rusty weathering, calcareous sandstone 
bed in the Samana and Darsamand sections contains ammonites and other fossil 
casts. The most common ammonite is Douvilleiceras mammillatum (Schlotheim). 
Other ammonites genera include Oxytropidoceras, Desmoceras, Cleoniceras, Branco- 
ceras, and Lemuroceras. In addition, poorly preserved brachiopods, bivalves and 
echinoids occur, which have been figured by Muir Wood, Cox and Currie (1930). 
The upper age limit in Western Kohat is Lower Albian (Mammillatum Zone). From 
the Khadimakh section nearly 200 feet below the Mammillatum zone, Aptian 
ammonites were located. These include Caspianites sp. nov. cf. C. wassillewsky 
(Renngarten), “Ammonitoceras” sp. cf. pavlowi (Vassillievsky), Pseudosaynellid 
(2? Azloceras), Deshayesitids (?Gen. nov. aff. Dufrenoyia) (identified by Dr R. Casey 
of the Institute of Geological Sciences, London). 

As no ammonites and other fossils occur in the lower most part, no positive age 
assignment is possible. From the stratigraphic position above the known Neo- 
comian ammonite—bearing rocks of the Chichali Formation, the lower age limit is 
very probably Aptian and may extend in some sections (Khadimakh) to Upper 
Neocomian. 


Kala Chitta Nizampur area 


When compared with Western Kohat and the Trans Indus Ranges, the Lum- 
shiwal Formation in this area shows a significant facies change and consists of lime- 
stone and marl in the upper part and glauconitic and quartzose sandstone in the 
lower part (fig. 4). The thickness is 155 feet in Wuch khawr section of Nizampur, 
1go feet in Western Kala Chitta (south of Sujhanda) and 172 feet in Central Kala 
Chitta (north northwest of Jhaffar). 

The lithology in Wuchkhawr section is as tollows: 

d. limestone and nodular marls, medium bedded with comminuted 

shells (bivalves, gastropods) and with a 2 feet hard, nodular, 
brownish, phosphatic, glauconitic, limestone bed near the top, 
echinoids and some ammonites (Oxytorpidoceras sp.) in the lower 
part. 40 feet 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 325 


c. grey to green marly limestone, nodular, thin bedded with echin- 

oids ammonite; Douvilleiceralids and nautiloids in the middle part. 52 feet 
b. grey to green, fine silty sandstone, thin bedded, glauconitic, 

phosphatic, of calcareous towards the top. 36 feet 
a. a-3 Coarse glauconitic sandstone 

a-2 limestone, sandy, glauconitic with bivalves (Tvigonia sp.) 

a-I light grey to grey, quartzose sandstone, glauconitic in the 

upper part with Tvigonza sp. 


Fauna and Age: The lowermost unit (a) in all the sections has yielded Tvigonia 
spp., including Tvigonia ventricosa (Krauss). The uppermost unit (d) is generally 
poor in recognizable fossils but contain Oxytropidoceras sp. and Neithea attockensis 
Cox. Unit c contain Large Douvilleiceralids (Gen. nov.). 

The age of the formation may, therefore, range from Upper Neocomian to Lower 
?Middle Albian. 


Hazara 


In Hazara, the Lumshiwal Formation, like the Chichali Formation, shows a 
significant facies change in the sections lying north and south of the Haro River. 
In the Jabrian section on the north bank of the Haro River (near Forest Rest House) 
the lithology is mixed sandstone and limestone similar to the Kala Chitta Range, 
while in the section further north the formation is mainly sandstone comparable 
with the “Giumal sandstone” of Spiti. The thickness is 32 feet in Kathwal and 
177 feet in the section north of Jabrian Rest House. In the Kathwal-Kalapani 
sections the formation is mainly quartzose and ferruginous glauconitic sandstone 
with Lower—Middle Albian fossils in the top calcareous rusty beds and Lower 
Tithonian fossils from the lowest 6 to 7 feet of the formation. 

Fauna and Age: The uppermost 2 to 4 feet of the Lumshiwal Formation in the 
Kathwal and north of Haro River sections (Jabrian) has yielded Lower—Middle 
Albian ammonites and other poorly preserved bivalves and gastropods. The 
ammonites include Lyelliceras (abundant), Oxytropidoceras, Mojsisoviczia, Dipolo- 
cevas, Hamites and Douvilleiceras. 

From the basal 6 to 7 feet of the highly condensed sequence of the Lumshiwal 
Formation in Kathwal—Kalapani sections Lower Tithonian ammonites (fig. 5) 
occur which are described in the present work. These include Aulacosphinctiodes 
hazaraensis sp. nov., Aulacosphinctoides uhligt Spath, Aulacosphinctiodes sp. indet., 
Virgatosphinctes densiplicatus (Waagen) Virgatosphinctes frequens (Oppel). The 
bivalves include Tvigonia sp. (small form). 

The age of the Lumshiwal Formation is from Lower Tithonian to Lower—Middle 
Albian in the northern sections (Kathwal—Kalapani) and probably Berriasian to 
Middle Albian in the Haro River sections. The Berriasian age in the latter areas is 
considered likely because in the adjoining sections of Murree-Abbottabad Road 
Neocosmoceras has been reported (Pascoe 1959; Spath 1933) to occur in the ““Giumal 
sandstone” (Lumshiwal Formation). The formation in this area appears to be full 
of non-sequences and represents a highly condensed deposit. 


326 JURASSIC AND LOWER CRETACEOUS ROCKS 


V. FOSSIL LOCALITIES (Text-figs 1-2) 
1. Hazara 


Lower Tithonian and Albian ammonites and other fossils occur in the basal and 
upper most beds of the Lumshiwal Formation respectively in the Kathwal (lat. 
34° 11’ 45”; long. 73° 19’) and Kalapani (lat. 34° 13’; long. 73° 10’ 30”) sections of 
northern Hazara (fig. 2; 1-2). The underlying Chichali Formation in this area 
has a few belemnites (Belemnopsis sp.) in the basal 2 to 3 feet. 

In the section north of Jabrian (lat. 33° 54’ 30”; long. 73° 10’ 30") in southern 
Hazara (fig. 2; 3-4), Albian ammonites are commonly distributed in the uppermost 
5 feet of the Lumshiwal Formation. One mile south of Jabrian (fig. 2; 5), some 
Upper Jurassic fragmentary perisphinctid ammonites and belemnites (Belemnopsis 
sp.) occur in the basal 2 to 3 feet of the Chichali Formation. 


2. Kala Chitta Range 


Lower Triassic ammonites are found } a mile north of Chak Jabbi Rest House in 
central Kala Chitta and 14 miles east of Bagh (lat. 33° 45’ 30”; long. 72° 13’) in 
Western Kala Chitta (fig. 2, 8). 

Lower Jurassic (Toarcian) ammonites occur in the middle part of Datta Formation 
north of Chak Dalla village (lat. 33° 38’ 50”; long. 72° 23’ 25”) in central Kala 
Chitta (fig. 2; 6). 

Upper Bathonian bivalves in the uppermost beds of Samana Suk Limestone and 
Upper Jurassic ammonites, belemnites and other fossils in the basal 2 to 3 feet of 
the Chichali Formation occur in the outcrops of central and Western Kala Chitta 
Range (fig. 2; 6). The best exposures are found north northwest of Jhallar (lat. 
33° 38’ 45”; long. 72° 19’ 15”). 


3. Nizampur 

In the Wuch Khawr section (lat. 33° 46’; long. 72° 2’ 30”), 2 miles south east of 
Nizampur (fig. 2; 9), Albian and Aptian ammonites and other fossils occur in the 
upper and middle part and Neocomian bivalves in the basal 10 to 15 feet of the 
Lumshiwal Formation. In the Mazari Tang section (fig. 2; 10) southwest of 
Nizampur (lat. 33° 44’; long. 71° 57’ 30”) Upper Jurassic ammonites are distributed 
in the basal 2 to 3 feet of the Chichali Formation. 


4. Kohat 


The Albian ammonites and other fossils are commonly distributed in the upper 
4 to 6 feet of the Lumshiwal Formation in the Samana Range (fig. 2; 11-14), north 
of Darsamand (fig. 2; 15-17) and north of Thal (fig. 2; 18-18) in Khadimakh Hill. 
In the Khadimakh section Aptian ammonites and other fossils occur 200 feet below 
the top Albian fossiliferous bed of the Lumshiwal Formation, while the upper dark 
rusty brown sandstone members of the Chichali Formation in this section has yielded 
Berriasian to Valanginian ammonites. In the section west northwest of Darsamand 
village, rare Upper Cretaceous ammonites occur in the basal 3 feet of the Kawaghar 
Formation. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 327 


5. Trans Indus Ranges 

The bulk of the ammonites described in the paper comes from the Surghar and 
Maidan Ranges located between Kalabagh (lat. 32°59’; long. 71° 32’ 30") and 
Makerwal (‘at. 32° 56’ 30”; long. 71° 9’) in Mianwali district (fig. 2; 21-27). The 
Middle Callovian ammonites occur in the outcrops of Samana Suk Limestone 
(upper bed) between west of Chichali Pass and Makerwal (Datta, Lunda and Punnu 
mines sections; Baroch nala section). The Upper Jurassic and Neocomian ammon- 
ites are distributed in the lower and middle members of Chichali Formation exposed 
in Maidan and Surghar Ranges and extend eastward in western Salt Range and 
southward in Shaikh—Budin Hills. 


6. Shaikh Budin Hills 

The Tithonian ammonites were collected from the lower member of Chichali 
Formation, 2 miles east and west of Shaikh Budin Village (lat. 32° 18’; long. 
70° 49’ 45") in Dera Ismail Khan district (fig. 2; 28-30). 


Afrid|i and Husankhel : w 
‘Tribal Hills 3 
pam Compbelipur 
no Selecta | A ; 7x x6 
G Darsamand 
x 71615 
Khadimakh |8xx% 
Sy 


ul Kalachittg 
14x | 


Fic. 5. Fossil locality map of Hazara, Kala Chitta, Kohat, Trans Indus Ranges including 
Shaikh Budin Hills, West Pakistan. 


328 JURASSIC AND LOWER CRETACEOUS ROCKS 


VI. SYSTEMATIC DESCRIPTIONS 


Class CEPHALOPODA 
Sub-class AMMONOIDEA 
Order PHYLLOCERATIDA 
Superfamily PHYLLOCERATACEAE 
Family PHYLLOCERATIDAE Zittel 1884 
Sub-family CALLIPHYLLOCERATINAE Spath 1927 
Genus HOLCOPHYLLOCERAS Spath 1927 
Holcopyhlloceras silesiacum (Oppel) 
(Plate 1) 


1865 Ammonites silesiacus Oppel: 550 
1868 Phylloceras silesiacum (Oppel) Zittel: 62, pl. 5, figs 1-7 


MATERIAL. One specimen, C.76546. 
Horizon. 20 feet above the base of Chichali Formation, Lower Tithonian. 


DEscRIPTION. The specimen is a wholly septate internal mould, 280 mm in 
diameter. The whorl section is elliptical, much higher than wide, and the umbilicus 
is very narrow. There are Io to 12 constrictions per whorl on the internal mould, 
which are conspicuous near the venter, but weak towards the umbilicus. They are 
prorsiradiate on the lower half of the whorl side, then bend backwards to become 
rursiradiate on the upper part of the whorl. 

DIMENSIONS. C.76546-280: 165 (59), 95 (34), 30 (11). 

REMARKS. The specimen is comparable with Spath’s figure (1927; pl. VI, fig. 2b) 
of H. aff. polyolcum (Benecke) from the Kimmeridgian beds of Cutch, but the style 
of constrictions and suture line are different. Spath’s figured specimen has a less 
elevated whorl section. 


Locatity. Chichali Pass, Trans Indus Ranges. 


Genus PTYCHOPHYLLOCERAS Spath 1927 
Ptychophylloceras ptychoicum (Quenstedt) 
(Plate 2, figs Ia, b) 


1847 Ammonites ptychoicus Quenstedt: 219, pl. 17, fig. 12. 
1875 Phylloceras ptychoicum (Quenstedt) Waagen: 30, pl. VII, figs 2a—c. 
1927 Ptychophylloceras ptychoicum (Quenstedt); Spath: 46 (see for synonymy). 


MATERIAL. One specimen, C.76547. 


Horizon. Lower part of lower member (about 10 feet above the base) of the 
Chichali Formation, Lower Kimmeridgian. 


DeEscrRIPTION. The specimen is involute, inflated, wholly septate and about 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 329 


66 mm in diameter. The whorl section has sub-parallel whorl sides and a broadly 

_arched venter, and the umbilicus is very narrow. There are 6 labial ridges per half 
whorl at 66 mm diameter, which are well developed on the venter and ventral 
shoulder, but fade out on the whorl sides, and are not seen on the inner whorl. 

DIMENSIONS. C.76547-66: 38 (58), 32 (48), —. 

REMARKS. This specimen is very similar to Waagen’s figure from the Katrol 
Beds of Cutch; from P. tithonicum Spath (1927, : 48, pl. V, fig. 9) it is distinguished 
by its more compressed whorl section. 

Locatity. Punnu Mines, Trans Indus Ranges. 


Order LYTOCERATIDA 
Superfamily LYTOCERATACEAE 
Family LYTOCERATIDAE Neumayr 1875 
Sub-family LYTOCERATINAE Neumayr 1875 
Genus PTEROLYTOCERAS Spath 1927 
Pterolytoceras exoticum (Oppel) 


(Plate 2, figs 2a, b) 
1863 Ammonites exoticus Oppel: 278, pl.76, figs 5a—c. 
1903 Lytoceras exoticum (Oppel) Uhlig: 114, pl. I, figs 3a—-d, 4a—c (see also for synonymy). 
1939 Ptevolytoceras exoticum (Oppel); Spath: 7 (see for discussion). 


MATERIAL. One specimen and two doubtful fragments C.76548-50. 


Horizon. Near the base of the middle and upper part of the lower member of 
the Chichali Formation, Upper Tithonian—Berriasian. 

DESCRIPTION. The complete specimen is very evolute, the outer whorl hardly 
touching the inner one, and is 9 mm in diameter. Nearly half of the outer whorl 
is body-chamber. The whorl section is sub-circular, wider than high. The orna- 
mentation consists of very fine, ridge-like, crinkled costae, which are distant on 
septate whorls, but closer on the body-chamber; they are rectiradiate or gently 
prorsiradiate on the whorl side and venter. Between them are finer and denser ribs 
or lirae. The shell is thin and internal moulds are smooth. 


DIMENSIONS. C.76548—90: 32 (36), 34 (38), 40 (44). 
C.70548-64: 22 (34), 25 (39), 28:5 (45). 

REMARKS. These specimens resemble closely in ornamentation and dimensions 
Uhlig’s figure from Chidamu, Spiti area, but they have slightly more inflated shells 
with a greater whorl height and whorl thickness at comparative diameters. 

The two poorly preserved fragmentary specimens from the Samana Range are 
wholly septate. 

Localities. Chichali Pass (C.76548), Trans Indus Ranges, and south of Fort 
Lockhart, Samana Range (C.76549-50). 


330 JURASSIC AND LOWER CRETACEOUS ROCKS 


Pterolytoceras sp. indet. 
(Plate 2, figs 3a, b) 


MaTERIAL. Three specimens, C.76551-3. 

Horizon. Basal part of the middle member and upper part of the lower member 
of the Chichali Formation, one fragment from the lower part of the rusty brown 
sandstone member of the Chichali Formation at Khadimakh; Upper Tithonian— 
Berriasian. 

DeEscrIpTION. The figured specimen is a smooth, wholly septate internal mould 
of approximately 180 mm in diameter. The whorl section is sub-oval near the 
aperture, higher than wide, but half a whorl before it is sub-circular, slightly wider 
than high. The umbilicus is wide, the umbilical wall is steep and the umbilical edge 
is rounded. 


DIMENSIONS. C.76551—-180: 64 (35), 60 (33), 80 (44) (all approx.). 


REMARKS. One of these specimens occurs in the same bed as P. exoticum (Oppel) 
described above. The overall whorl shape and suture line compare favourably with 
P. exoticum (Oppel), which on Uhlig’s figured specimen from the Spiti area (1910: 
pl. I, fig. 3a, b) has a complete body chamber with dorsal extensions at the apertural 
end at about 80-0 mm diameter, and occupies nearly half of the outer whorl. 

In its large size, the figured specimen may be compared with Hemilytoceras rex 
(Waagen) (1875 : 36, pl. VII, fig. 1). Waagen’s species has similar whorl propor- 
tions (at 660 mm: 220 (36), 200 (33), 230 (39)), but shows different ornamentation. 
The whorl section, however, is very similar. 


LocaLiTieEs. South west of Malla Khel, Trans Indus Ranges; South of Fort 
Lockhart, Samana Range; Khadimakh. 


Order AMMONITIDA 
Superfamily HILDOCERATACEAE 
Family HILDOCERATIDAE Hyatt 1867 
Subfamily BOULEICERATINAE Arkell 1950 
Genus BOULEICERAS Thevenin 1906 
Bouleiceras nitescens Thevenin 
(Plate 3, figs 1a, b, 3a, b) 


1906 Bouleicevas nitescens Thevenin: 171, figs 1-3. 
1908 Bouleicevas nitescens Thevenin: 13, pl. 11, figs 6 (lectotype designated by Arkell 1952), 11. 
1952 Bouleicevas nitescens Thevenin; Arkell, p. 261. 

MaTERIAL. Three specimens, C.76554-6. 

Horizon. Middle member of Datta Formation, Lower Toarcian. 


DESCRIPTION. The larger fragmentary septate specimen (C.76555) is smooth, 
and has a rectangular whorl section which is much higher (75 mm) than wide (51 mm). 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 331 


The whorl sides are flat and parallel. The venter is unicarinate and fairly broad. 
The suture line includes a three to four pronged asymmetrical, fairly deep, first 
lateral lobe. 

The smaller specimen (C.76554) is more typical of the species. It is evolute, of 
roughly 58 mm diameter, and has a sub-rectangular whorl section, higher (21 mm) 
than wide (?18 mm). The whorl sides are sub-parallel, and gradually convergent 
towards a rather broad unicarinate-bisulcate venter. The inner whorl (up to a 
diameter of approximately 43 mm) has two rows of strong, sharp spine-like tubercles 
on the ventral and umbilical shoulders. The outer whorl has rounded, smooth 
rursiradiate ribs which curve forwards obliquely and are weakly tuberculate at the 
umbilical edge. Some ribs bifurcate at the umbilical edge. 


REMARKS. The larger septate fragment has a similar suture-line to Arkell’s 
figured specimen of B. sp. indet.from Jebel Tuwaigq (1952 : 263, fig. 5 (I); pl. xv, fig. 1). 
In its large size and partly in suture it is comparable with Thevenin’s (1908: pl. 1, 
fig. 11) of B. mitescens. The smaller specimen is very similar to the lectotype 
designated by Arkell (Thevenin 1908 : pl. II, fig. 6). 

The specimen figured by Arkell (1952: 260, fig. 4) from Jebel Tuwaiq, Arabia, as 
B. nitescens has a more compressed and comparatively much higher than wide whorl 
section, which is convergent to a narrow, keeled venter. The ventral shoulders are 
not as distinct as in the lectotype or the Kala Chitta specimen. It appears that 
Arabian forms are closer in whorl section to Thevenin’s (1908) pl. ii, figs 8 and Io, 
which Arkell (1952) designated as B. elegans Arkell (with weaker tubercles). 


Locauity. Chakdalla, Kala Chitta Range. 


Bouleiceras chakdallaense sp. nov. 
(Plate 3, figs 2a, b, 4) 
DiaGnosis. Evolute, whorl section sub-rectangular, slightly wider than high on 


inner whorl, and higher than wide on outer whorl. Venter unicarinate-bisulcate. 
Shell with two rows of thick bullate tubercles. 


HoLoTyPe. C.76557. 
MATERIAL. Two septate fragmentary specimens, C.76557-8. 
Horizon. Middle member of Datta Formation, Lower Toarcian. 


DESCRIPTION. Both specimens are wholly septate, and up to 92 mm in diameter. 
The whorl section is sub-rectangular with sub-parallel whorl sides and a unicarinate- 
bisulcate venter. There are two rows of prominent bullae at the umbilical and 
ventral shoulders which become thick and blunt on the outer whorl. The suture 
line consists of two or three pronged first lateral lobes and rounded saddles. 


Dimensions. C.76557-92: 30 (33), 30 (33), 44( 48). 
C.76557-64: 19 (30), 22 (34), 30 (47). 


332 JURASSIC AND LOWER CRETACEOUS ROCKS 


REMARKS. The strong tumid tubercles of this species are comparable with those 
of B. tumidum Arkell (1952 : 261; also Thevenin 1908 : pl. II, fig. 9, lectotype), but 
it differs distinctly in whorl section, evolution and the persistence of two rows or 
tubercles at a larger diameter. 


Locatity. Chakdalla, Kala Chitta Range. 


Bouleiceras sp. indet. 


MATERIAL. Three specimens, C.76559-61. 
Horizon. Middle member of Datta Formation, Lower Toarcian. 
DEscRIPTION. The larger fragmentary specimen (C.76561) has a smooth, septate, 


fairly compressed and involute shell. The whorl section is much higher than wide. 
The whorl sides are convergent towards a rather narrow unicarinate venter. 


REMARKS. The specimen resembles, in side view and suture line, Arkell’s figure 
of B. nitescens Thevenin from Jebel Tuwaiq (Arkell 1952 : 260, fig. 4). In its tall 
compressed whorl section, the specimen may also be compared with B. elegans 
Arkell (Thevenin : 1890, pl. II, figs 8 and 10). It is also comparable with B. aff. 
nitescens Thevenin from Hazara (Davies and Gardezi 1965). 


Locatity. Chakdalla, Kala Chitta Range. 


Superfamily HAPLOCERATACEAE 
Family HAPLOCERATIDAE Zittal 1884 
Genus HILDOGLOCHICERAS Spath 1924 
Hildoglochiceras sp. indet. 
(Plate 3, fig. 5) 


MATERIAL. One specimen, C.76562. 
Horizon. 20 feet above the base of Chichali Formation, Lower Tithonian. 


DESCRIPTION. The whorl section is much compressed with whorl sides converging 
towards a bluntly keeled venter. There is a spiral furrow at the middle of whorl 
side which first appears at about 18 mm diameter and becomes distinct and fairly 
deep at diameters greater than 28-5 mm. In cross section the ventral side of the 
furrow is shallow, but the umbilical side is deep and steeply inclined. The inner 
whorls are smooth, but at 22 mm diameter weak, crescent-shaped rursiradiate ribs 
appear on the ventral side of the spiral furrow. 


DIMENSIONS. C.76562—28:5: 12 (42), 6 (21), 8:5 (30). 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 333 


REMARKS, The specimen differs from Hildoglochiceras latistrigatum (Uhlig) 
(1903 : 27, pl. II, fig. 4; pl. III, fig. 5) in being more compressed, having a higher 
whorl section, showing earlier appearance of crescent-shaped costae, and lacking a 
distinct spiral furrow on the earlier whorls. In the earlier appearance of costae and 
the later appearance of the spiral furrow it is more like specimens of Hildoglochiceras 
kobelli (Oppel) figured by Uhlig (1903 : 25, pl. LVII, figs 3a—b, 4a-d) and Waagen 
(1875 : 72, pl. XIII, figs 11-12) from middle Katrol sandstone of Cutch. It differs, 
however, in being more compressed and in having a shallower spiral furrow. Spath 
(1939 : 124, pl. XVIII, figs 8a, b) figured a specimen from the Trans Indus Ranges 
as Hildoglochiceras sp. indet. (group of H. propinoum Waagen) but considered it to 
be worn and probably derived. The present form differs from Spath’s species in 
whorl shape and ornamentation. The external mould is attached to the whorl side 
of an Aulacosphinctoides (group of A. whligi Spath) and suggests a close association 
of the two genera. 


Locatity. West of Makerwal, Trans Indus Ranges. 


Superfamily STEPHANOCERATACEAE 
Family MAYAITIDAE Spath 1928 
Genus MAYAITES Spath 1924 
Mayaites cf. waageni (Uhlig) sp. indet. 
(Plate 3, figs 6a, b, 7a, b) 


1910 Macrocephalites waageni Uhlig: 270, pl. LX XVII, figs 1-3. 
1933 Mayaites waageni (Uhlig); Spath: p. 804. 


MATERIAL. Two specimens, C.76563-4. 
Horizon. Basal 3 inches of Chichali Formation, Upper Oxfordian. 


DEscrRIPTION. The specimens are involute, septate, and 30 and 51 mmin maximum 
diameter respectively. The whorl section is subcircular, slightly wider than high on 
the inner whorls, but higher than wide at larger diameters. The umbilicus is narrow 
and deep. The ribs are strong and gently sinuous, and three secondary ribs intervene 
between each primary rib. There are 16 to 17 primary ribs at 30 mm diameter on 
C.76563 and 18 to 19 at 24 mm diameter on C.76564. 


DIMENSIONS. C.76563-30:15 (50), 15°5 (52), 7°5 (25); 
C.76563-24: Ir (46),12 (50), 6 (25). 
C.76564-51: 20°5 (40), 20 (39), 215-5 (30); 
C.76564-24: 11 (46), 11-5 (48), 7 (29). 


Remarks. In size, ornamentation and involution the specimen compares 
favourably with M. waageni (Uhlig) and is less close to M. kitcheni (Uhlig) from the 
Upper Oxfordian of Spiti. It differs in being less inflated, more evolute and in 
having a narrower, less elevated whorl section. 


Locality. Punnu Mines, Trans Indus Salt Ranges. 


334 JURASSIC AND LOWER CRETACEOUS ROCKS 


Superfamily PERISPHINCTACEAE 
Family REINECKEIIDAE Hyatt 1900 
Genus REINECKEIA Bayle 1878 
Reineckeia anceps (Reinecke) 
(Plate 4, figs Ia, b, 2a, b, 3a, b) 


1818 Nautilus anceps Reinecke: 82, pl. VII, fig. 61. 

1846 Ammonites anceps (Reinecke); d’Orbigny: 462, pl. 166. 

1876 Reineckeia anceps (Reinecke); Bayle: pl. LVI, figs 1?, 2, 3. 

1881 Reineckeia anceps (Reinecke); Steinmann: 284 

1928 Reineckeia anceps (Reinecke); Spath: 255, pl. XLIV, fig. 6a—c (see for discussion). 


MATERIAL. Seven specimens, C.76565-71. 
Horizon. Upper one foot of Samana Suk Limestone, Middle Callovian. 


DEscRIPTION. The specimen C.76565 is evolute, septate and 50 mm in diameter. 
The whorl section is cadiconic, much depressed, with a broadly arched venter and 
a mid-ventral groove. The umbilicus is wide and shallow, and the umbilical wall 
is rounded. There are two to three oblique, deep constrictions on all visible whorls. 
Weak primary ribs on the umbilical wall terminate at strong conical tubercles on 
the side of the whorl. Three or four secondary ribs issue from each tubercle and 
cross the venter with interruption at the shallow mid-ventral sulcus. Occasional 
ribs are intercalated and not joined to tubercles. The rib preceding a constriction 
is weakly tuberculate, while the rib following the constriction on the apertural side 
is non-tuberculate. 

There are 14 or 15 tubercules on the outer whorl of C.76565. Specimen C.76568 
differs in being less evolute, having four constrictions on its last whorl, a narrow 
ventral groove and greater number of tubercles at a comparative diameter. 

DIMENSIONS. C.76565-48: 13 (27), 22 (46), 24 (50). 

C.76568-60: 16 (27), 24 (40), 22 (37). 

REMARKS. The specimen C.76565 compares very closely in ornamentation and 
depressed whorl section, to the inner whorls of the specimens figured by d’Orbigny 
and Bayle. It is similar in whorl shape and ornamentation to the small septate 
specimen figured by Spath (1928) from Neidlingen, Wurttemburg. 


Locatities. Lunda Mines (C.76565-69) and Punnu Mines (C.76570-71), Trans 
Indus Ranges. 


Reineckeia cf. torulosus (Spath) 
(Plate 4, figs 4a, b) 
1933 Reineckeites tovulosus Spath: 679, pl. CX XVII, figs 5, 6, 11; pl. CX XVIII, figs 1, 8. 


MATERIAL. Four specimens C.76572-5. 
Horizon. Upper one foot of Samana Suk Limestone, Middle Callovian. 


DescripTION. The shell is evolute, septate and approximately 113 mm diameter. 
The whorl section is oval, higher than wide, with subtabulate, grooved venter. The 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 335 


umbilicus is wide and the umbilical wall is steeply inclined. Weak ribs on the 
umbilical wall are surmounted by radially elongate tubercles on the lower third of 
whorl side. Three or four straight, prorsiradiate ribs issue from each tubercle and 
are interrupted along the mid-venter. 

DIMENSIONS. C.76572-?113: 44°5 (39), 26 (32), 44 (39). 

REMARKS. The species was described by Spath (1933) from the Anceps Beds of 
Cutch. It is placed here in Reineckeia because of its prominent lateral tubercles 
and bundles of 3 or 4 secondary ribs. 

Locatities. West of Makerwal (C.76572), and Lunda Mines (C.76573-5), Trans 
Indus Ranges. 


Reineckeia sp. indet. 

MATERIAL. Five specimens, C.76576-80. 

Horizon. Upper 2 feet of Samana Suk Limestone, Middle Callovian. 

DescriPTION. The specimen C.76576 is worn, evolute and approximately 
I20 mm in diameter. The worl section is rounded with equal height and thickness. 
The umbilicus is wide and the umbilical wall is steep. Some constrictions are 
present. 

Distant, rectiradiate ribs are surmounted by tubercles on the lower third of the 
whorl side. 4 or 5 rectiradiate to slightly prorsiradiate ribs issue from each tubercle 
and are interrupted at the mid-venter. 

REMARKS. In its smooth venter, evolute shell, and rounded whorl section, 
C.76576 is comparable with Reinecketa brancoi Steinmann (1881: 285, text- 
figure 4), but differs in ornamentation. In R. brancoi there are frequently non- 
tuberculate trifurcating and bifurcating ribs along with tuberculate bundled ribs. 
The specimen C.76578 has coarse ribs which resemble R. avthnitica (J. de C. Sowerby) 
as figured by Spath (1928, pl : XX XIII, figs 2a—b) from Cutch. 

Locatities. Lunda Mines (C.76576-7), and south of Malla Khel (C.76578-80), 
Trans Indus Ranges. 


Family PERISPHINCTIDAE Steinmann 1890 
Sub-family PROPLANULITINAE Buckman 1921 
Genus OBTUSICOSTITES Buckman 1921 
Obtusicostites buckmani Spath 
(Plate 4, figs. 5a, b; Plate 5, figs 1a, b, 2a, b) 


1875 Perisphinctes obtusicostata Waagen: 147, pl. XX XVIII, figs 3a, b only. 
1931 Obtusicostites buckmam Spath: 300, pl. LIII, figs 3a—b (paratype); pl. LXII, fig. 8 (see for 
synonymy). 
MATERIAL. Four specimens, C.76581-—4. 


Horizon. Uppermost 14 feet of Samana Suk Limestone, Middle Callovian. 


336 JURASSIC AND LOWER CRETACEOUS ROCKS 


DEscripTIonN. The specimen C.76584 may be a microconch for it shows the 
beginning of body chamber and uncoiling of the last whorl at the apertural end at 
75 mm diameter. The other two specimens are septate, and C.76583, of 135 mm 
diameter, appears may be a macroconch. The whorl section is rounded and slightly 
wider than high. The umbilical wall is smooth and almost vertical, and the 
umbilical edge is rounded. The ribs are strong, rectiradiate to gently prorsiradiate, 
and bifurcate or trifurcate at about the middle of the whorl side. The rib counts 
are as follows: 

C.7658I—15 primary ribs at 66 mm diameter. 
C.76583—23 primary ribs at 135 mm diameter, 20 at 98 mm. 
C.76584—15 or 16 primary ribs at 75 mm diameter. 
DIMENSIONS. C.76581— 52: 20 (38), 24 (46), I9 (37). 
C.76583-120: 46 (38), 42 (35), 42 (35). 
C.76584- 73: 27 (37), 29 (40), 27 (37). 

REMARKS. C.76581 closely resembles the holotype figured by Waagen (1875, 
pl. XXXVIII, fig. 3). The specimen C.76583 resembles, in ornamentation and 
dimensions, Spath’s paratype (1931 : pl. LIII, figs 3a—b) from Upper Anceps—Lower 
Athleta Beds of Cutch. The species differs from O. obtusicosta (Waagen) in having 
longer and less strong and blunt, nontuberculate primary ribs and the persistence 
of strong secondary ribs on the body chamber. 


Locatity. Punnu Mines, Trans Indus Ranges. 


Obtusicostites sp. indet. 


MATERIAL. Seven specimens, C.76585-o1. 
Horizon. Upper 2 feet of Samana Suk Limestone, Middle Callovian. 


Remarks. The fragments C.76585-6 and C.76588 show coarse primary ribs 
branching into two to four secondary ribs low on the whorl side. In ribbing and 
whorl section, C.76585-6 are like O. buckmani Spath and O. ushas Spath (1931: 
pl. LIII, fig. ra—b; pl. LVI, fig. 1). C.76588 also resembles O. buckmamt Spath, but 
its blunt primary ribs splitting into 3 to 4 secondary ribs are like those of O. obtusi- 
costa (Waagen) (1875 : pl. XX XVIII, figs ta—b). C.76591 is crushed but shows 
coarse primary ribs (19 to 20 per whorl at 94 mm diameter) dividing into 3 secondary 
ribs near the middle of whorl side. The approximate dimensions are: 94 mm: 
39 (41), 27 (29), 30 (32). This specimen may also belong to O. buckmant Spath 
though the straight secondary ribs resemble O. devi Spath (1931: pl. LIV, figs 1a—b) 
and O. waageni Spath (1931: pl. LIII, figs 2a—b) from Cutch. 


Locatities. Lunda Mines (C.76585-90), and Datta Mines (C.76591), Trans 
Indus Ranges. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 337 


Genus HUBERTOCERAS Spath 1930 
Hubertoceras sp. indet. 
(Plate 5, figs 3, 4a, b, 5a, b, 6) 


MATERIAL. Three incomplete body chamber specimens and to fragments, 
C.76592-C.76604. 
Horizon. Upper 2 feet of Samana Suk Limestone, Middle Callovian. 


DescripTIon. The four figured specimens and most of the fragments are body 
chambers, and C.76597 shows a lateral lappet. Moderately strong rectiradiate to 
gently prorsiradiate primary ribs bifurcate or rarely trifurcate in the upper third of 
the whorl side. Occasionally the secondary ribs are intercalatory and the primary 
ribs simple. The whorl section is oval and higher than wide, with a rounded venter. 
The umbilicus is rather narrow and the umbilical wall is steep. 

DIMENSIONS. C.76592—41: 16:5 (40), 14 (34), 12°5 (30). 

C.70595-42: 16 (38), 14 (33), 15 (30). 
C.70597-57: 22 (39), 14 (25), 20°5 (30). 

REMARKS. Spath (1931) described and figured a number of Hubertoceras species 
and their variants from Lower Athleta and Anceps Beds of Cutch. In view of the 
poor preservation and fragmentary nature of the Trans Indus specimens, it is not 
possible to assign them to any of the species of Waagen and Spath from Cutch. The 
Trans Indus species show some variations in ribbing, whorl thickness and involution 
but are generally more involute and smaller in size than the Cutch forms. They 
are from one locality and horizon. 

The figured specimen C.76595 (Plate 5, figs 5a, b) can be compared in whorl 
section and ornamentation with H. dhosaense (Waagen) (Spath 1931: 319), but 
differs in having additional intercalatory ribs and in being more involute. The 
specimen C.76597 (Plate 5, fig. 6) compares favourably in compressed whorl section 
with H. mutanus (Waagen) (Spath 1931: 318), but differs in details of ornamentation. 


LocaLity. Lunda Mines, Trans Indus Ranges. 


Sub-family PSEUDOPERISPHINCTINAE Schindewolf 1925 
Genus CHOFFATIA Siemiradzki 1898 
Choffatia sp. indet. 
MATERIAL. Three fragments, C.76605-7. 
Horizon. Upper 2 feet of Samana Suk Limestone, Middle Callovian. 


DESCRIPTION. The specimen C.76605 is evolute and wholly septate, with a whorl 
height of 33 mm and whorl thickness of 27 mm. The primary ribs are long, recti- 
radiate or gently prorsiradiate, and bifurcate near the ventral shoulder. Occasion- 
ally there is one short intercalatory rib between the bifurcating ribs. The secondary 
ribs are weak and interupted on the mid-venter. (C.76607 has more convex whorl 
sides and coarser, distant primary ribs. 


338 JURASSIC AND LOWER CRETACEOUS ROCKS 


REMARKS. The poor preservation does not allow close comparison with any 
species of the genus. C.76605 1s comparable in ornamentation and whorl section 
with C. sakuntla Spath (1931: 351, pl. LXIII figs 4a—b), but has a more evolute shell. 
C.76607 show some resemblance in coarse, blunt primary ribs with C. cobra (Waagen). 


LocaLity. South south west of Malla Khel (Baroch nala), Trans Indus Ranges. 


Sub-family PERISPHINCTINAE Steinmann 1890 
Genus PHOSOSPHINCTES Schindewolf 1925 
Prosophinctes (?) virguloides (Waagen) 
(Plate 6, figs I, 2a, b) 


1875 Perisphinctes virguloides Waagen: 203, pl. XLIX, figs ta—b. 
1925 Perisphinctes virguloides Waagen; Spath: 122. 
1931 Prososphintes virguloides (Waagen); Spath: 441, pl. LXX, fig. 3; pl. XC, fig. 4 (see for 
synonymy). 
1932 Perisphinctes virguloides Waagen; Lanquine: 635. 
1934 Prososphinctes virguloides (Waagen); Spath: 12, pl. I, figs 3, 4a—b, 6 (holotype); pl. II, 
figs 3, 4a—b; pl. IV, figs 5a—b; pl. V, fig. 7. 
MATERIAL. Twelve specimens, C.76608-109. 
Horizon. Basal one foot of Chichali Formation, Upper Oxfordian. 


DESCRIPTION. The specimens are wholly septate and up to 88 mm in diameter. 
The whorl section is oval, with flat sides. Shallow constrictions parallel to the rib 
direction can be seen on the 88 mm diameter specimen but are absent on the other 
specimens. Long primary ribs bifurcate at the ventro-lateral shoulder; there are 
28 primary ribs per half whorl at 88 mm diameter on C.76609, and 53 or 54 on C.76608 
at 81 mm diameter. 


Dimensions. C.76608-81: 25 (31), —, 39 (48). 
C.76609-88 : 28 (32), 24°5 (28), 36°5 (41). 

ReMARKS. This species was placed in the genus Perisphinctes by Spath (1925), 
Dietrich (1925 : 19) and Lanquine (1932 : 635). Later, Spath (1931 : 441; 1934: 
12) put it into Prososphinctes and assigned to it an Upper Oxfordian to Lower 
Kimmeridgian age in Cutch, and an Upper Oxfordian, Transversarium Zone, age in 
Kala Chitta. Spath (1934: pl. I, fig. 6) refigured Waagen’s holotype, which shows 
strong and sharp prorsiradiate ribs with pronounced forward projection on venter. 
The specimen figured here is Pl. 6, fig. 1, from Mazari Tang, Nizampur, is very 
similar in ornamentation and dimensions to the holotype. 

Spath (1934 : pl. II, fig. 4) figured another specimen from Kala Chitta which is 
more involute, and considered it to be the best example of the species. The incom- 
plete specimen figured here in PI. 6, fig. 2, also from Mazari Tang, is similar, and 
differs from the holotype in being more involute and in having a greater whorl 
height. 

P. virguloides is doubtfully referred to the genus Prososphinctes, for it shows strong 
sharp ribbing, has weak or no constrictions, and occurs in the Upper Oxfordian, 


AND JURASSIC AMMONITES FROM WEST PAKISTAN « 339 


Transversarius Zone of Kala Chitta and Mazari Tang. Prososphinctes is regarded 
by Arkell (1957) as Lower Oxfordian in age, and the type species, Pevisphinctes 
mazuricus Bukowski, 1887, has weak, dense ribs, prominent constrictions and less 
distinct bifurcation. Arkell (1937 : 1) also did not agree with Spath’s inclusion of 
P. virguloides in Prososphinctes. 


Locatity. Mazari Tang, Nizampur, and north north-west of Jhallar, Kala 
Chitta. 


Genus PERISPHINCTES Waagen 1869 
Perisphinctes sp. indet. 
(Plate 6, figs 3a, b) 
MATERIAL. Two specimens C.76622-3, from Mazari Tang and two, C.76620-1 
from Trans Indus Ranges. 
Horizon. Basal bed of Chichali Formation, Upper Oxfordian. 


DEscriIpTION. The inner whorls of specimen C.76622 from Mazari Tang are 
similar to those of C.76620 from Trans Indus Ranges. The whorls are depressed and 
the dense prorsiradiate ribs bifurcate on the upper part of the whorl then cross the 
venter with slight forward arching. Some ribs are simple. Distinct constrictions 
are present. The outer whorl of C.76622 has distant coarse ribs. 

DIMENSIONS. C.76620-35: 9:5 (27), II (31), I1°3 (32). 

Remarks. In the dense prorsiradiate ribbing and presence of constrictions, the 
Mazari Tang specimen, C.76622, compares favourably with the holotype of Peri- 
sphinctes jelskiw (Siemiradzki) (Spath, 1934: 6, pl. V, figs 6a—b) and with other 
specimens from the Transversarium Zone of the Attock district figured by Spath 
(1934: 6, pl. IV, figs 2-4). 

Locauitigs. Mazari Tang, Nizampur (C.76622-3); north of Kalabagh, Trans 
Indus Ranges (C.76620-1). 


Subgenus KRANAOSPHINCTES Buckman 1921 
Perisphinctes (Kranaosphinctes) sp. indet. 
(Plate 6, figs 4a, b) 
MATERIAL. Four specimens, C.76624-27. 
Horizon. Basal bed of Chichali Formation, Upper Oxfordian. 


Description. The figured specimen, C.76624, is very evolute, wholly septate 
and 100 mm diameter. The whorl section is rounded, slightly wider than high, and 


340 JURASSIC AND LOWER CRETACEOUS ROCKS 


the whorl sides are nearly flat. Two constrictions (one deep) are seen on the outer 
whorl. The strong, straight, prorsiradiate ribs are moderately distant, and bifurcate 
high on the whorl side near the ventral shoulder. There are a few intercalated 
secondary ribs on the final third of the last whorl and a very few ribs remain simple 
throughout. The ribs are much reduced, or almost effaced, at the middle of the 
venter. C.76624 has about 48 primary ribs at Ioo mm diameter. 


DIMENSIONS. (C.76624-100: 24, 25, 59. 


REMARKS. The species is similar in its evolute whorls, ornamentation and rib 
density to the inner whorl of P. (K.) cymatophorous (Buckman) figured by Arkell 
(1939: pl. XXXVII, figs 3a-b), but differs in dimensions. In dimensions, rib 
density and whorl section it also compares with P. (K.) trifidus (J. Sowerby) as 
figured by Arkell (1939 : pl. XX XVI, fig. 2a—b), but shows more irregular trifurcation 
of the ribs. 


Locatities. Chichali Pass (C.76624), north of Kalabagh (C.76625), Trans Indus 
Ranges; north north west of Jhallar (C.76626-7), Kala Chitta Range. 


Subgenus ARISPHINCTES Buckman 1924 
Perisphinctes (Arisphinctes) orientalis Siemiradzki 


1875 Perisphinctes plicatilis (J. Sowerby); Waagen: 189, pl. LI, figs 2a—b; pl. LII, fig. 3 

1891 Pevisphinctes orientalis Siemiradzki: 289. 

1931 Perisphinctes orientalis Siemiradzki; Spath: 416, pl. LXIX, fig. 1; pl. LXXII, fig. 2; 
pl. LXXIV, figs 3a—b (see for synonymy). 

1934 Pevisphinctes orientalis Siemiradzki; Spath: 4, pl. IV, figs ra—b. 


MATERIAL. One specimen, C.76627. 
Horizon. Basal one foot of Chichali Formation, Upper Oxfordian. 


DEscripTIon. The shell is evolute, wholly septate and 190 mm diameter. The 
whorl section is rounded quadrate, higher than wide, but depressed on the inner 
whorls. The ribs are moderately dense on the inner whorls, becoming gradually 
more distant and coarse on the outer whorl. They are prorsiradiate, bifurcate near 
the ventral shoulder and are gently arched forwards on the venter. There are 
occasional short intercalatory ribs. Near the aperture, the ribs fade out on the mid- 
venter and many are simple. There are about 47 ribs at I90 mm diameter. Some 
shallow constrictions occur especially on the inner whorls. 


DIMENSIONS. 190: 52 (27), ?46 (24), 102 (54). 


REMARKS. This is a worn incomplete specimen, very similar in ornamentation, 
rib density and whorl section to the Kala Chitta and Cutch specimens figured by 
Spath, but differs in dimensions and in having a higher than wide whorl section at 
comparative diameters. 


Locatity. Mazari Tang, Nizampur. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 341 


Subgenus DICHOTOMOSPHINCTES Buckman 1926 
Perisphinctes (Dichotomosphinctes) cf. rotoides Ronchadze 
(Plate 7, figs ra, b, 2) 


1917 Pevisphinctes votoides Ronchadze: 11, pl. I, fig. 8. 
1938 Perisphinctes (Dichotomosphinctes) votoides Ronchadze; Arkell: 90, pl. XVI, figs 1-7. 


MaTERIAL. Five fragments, C.76629-33. 
Horizon. Basal 4 inches of Chichali Formation, Upper Oxfordian. 


DeEscriPTIOn. These are septate fragments with evolute, quadrate whorls, the 
whorl section being higher (20:5 mm) than thick (18-5 mm). Strong rectiradiate or 
slightly prorsiradiate ribs are separated by wider interspaces. They bifurcate high 
on the whorl side near the ventral shoulder and are straight or slightly arched 
forwards across the venter. Occasional simple ribs occur. There are prominent 
deep constrictions parallel to the ribs. 

ReMARKS. These Trans Indus fragmentary specimens compare well in ornamen- 
tation, whorl section, evolute shell and in the presence of deep constriction with 
Arkell’s figures of P. (D.) rotoides from the Plicatilus Zone of England. They also 
compare with P. (D.) antecedens Salfield as figured by Arkell (1938 : pl. XVI, fig. 8). 


Loca.tity. Chichali Pass, Trans Indus Ranges. 


Perisphinctes (? Dichotomosphinctes) sp. indet. 
(Plate 7, fig. 3a, b) 


MATERIAL. Two fragments, C.76634-35, from Trans Indus Ranges, and C.76636 
from the Kala Chitta Range. 


Horizon. Basal 3 inches (Trans Indus Ranges) or basal one foot of Chichali 
Formation Upper Oxfordian. 


REMARKS. These fragmentary specimens indicate the presence of one or more 
species of Dichotomosphinctes in the collections. They have dense, prorsiradiate ribs 
which bifurcate high on whorl side close to the ventral shoulder, and cross the 
venter with slight forward arching. At small diameters, the whorl height is less than 
whorl thickness, but the outer whorl is more compressed. Spath (1934: 11, pl. III, 
figs 5a—b; pl. VI, figs 3a-c) figured specimens from Kala Chitta similar to C. 76636 
as P. (Dicholomosphinctes) aff. grossouvrer (Siemiradzki). The Trans Indus speci- 
mens are somewhat different, and resemble P. (D.) Jacki Spath (1931: pl. LX XIII, 
fig. 6) and P. (D.) subhelenae Spath (1931: pl. CI, figs 2, 4a—b) in ribbing and whorl 
section. 


LocatitiEs. Chichali Pass, C.76634, and Punnu Mines, C.76635, Trans Indus 
Range; north north west of Jhallar, C.76636, Kala Chitta Range. 


342 JURASSIC AND LOWER CRETACEOUS ROCKS 


Sub-family VIRGATOSPHINCTINAE Spath 1923 
Genus KATROLICERAS Spath 1924 
Katroliceras cf. pottingeri (J. de C. Sowerby) 
(Plate 7, figs 4a, b) 
1840 Ammonites pottingert J. de C. Sowerby: 719, pl. LXI, fig. 10. 
1931 Katroliceras pottungert (J. de C. Sowerby); Spath: 505, pl. LX XXIII, fig. 4; pl. XCV, 
figs 6, 7; pl. XCVIII, fig. 4; pl. CII, figs 5a—d (see for synonymy). 

MATERIAL. One fragment, C.76637. 

Horizon. 6 to 7 feet above the base of Chichali Formation, Lower Kimmeridgian. 

DESCRIPTION. The specimen is septate, and has a sub-coronate whorl section, 
with a broad, gently arched venter. The whorl height is 44 mm, the thickness 
approximately 60 mm. Distant, massive ribs are separated by broad interspaces. 
They branch near the umbilical shoulder into about three ribs which cross the venter 
with forward arching. There is a swelling at the point of branching. Occasionally 
one of the ventral ribs is intercalated. 

REMARKS. This specimen closely resembles, in ribbing and whorl section the 
example K. pottingerit (J. de C. Sowerby), from the Middle Katrol beds of Cutch, 
figured by Spath (pl. CII, figs 5a—b; pl. LXXXIII, fig. 4). It also resembles the 
very closely allied species, K. pingue Spath (1933: pl. LX XXII, figs ta—b) from a 
similar horizon in Cutch. 


Locatity. Punnu Mines, Trans Indus Ranges. 


Katroliceras sp. indet. 


MATERIAL. Three specimens, C.76638—40. 

Horizon. 5 to 7 feet above the base of Chichali Formation, Lower Kimmeridgian. 

REMARKS. The specimens are small and septate with the following dimensions: 

C.76639-25: 8-5 (34), 12 (48), 12°5 (50). 
C.76638-20°5: 7 (34), 10 (49), 9 (44). 

They may represent the inner whorls of forms like K. depresswm Spath (1931: 515, 
pl. LXXXIX, figs 4a—b) or K. zittela Spath (1931: 513, pl. LXX XVII, figs 6a-b). 
It is possible that the species is the inner whorls of Pachysphinctes which also has a 
depressed whorl section and similar ornamentation at a comparative diameter. 


Locatities. Datta Mines (C.76638) and north of Kalabagh (C.76639—40), Trans 
Indus Ranges. 
Genus PACHYSPHINCTES Dietrich 1925 
Pachysphinctes robustus Spath 
(Plate 7, figs 5a, b) 
1931 Pachysphinctes vobustus Spath: 491, pl. LXXXIV, fig. 5; pl. XCIII, figs 1roa—b. 


MATERIAL. Three specimens, C.76641-3. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 343 


Horizon. 5 to 7 feet above the base of Chichali Formation, Lower Kimmeridgian. 


DeEscriPTION. These are evolute, septate fragments up to 135 mm diameter. 
The whorl section is sub-quadrate, wider than high, with greatest thickness on the 
lower third of the whorl side. The strong, rectiradiate or gently prorsiradiate ribs 
- are separated by deep interspaces two to three times as wide on the outer whorl, but 
inner whorls are more densely ribbed. They bifurcate high on the whorl side at a 
small blunt tubercle. Occasionally ribs remain simple (about 2 per half whorl), 
and a few indistinct trifurcating ribs appear near the aperture. The ribs are arched 
forwards on the venter and weaken along the siphonal line. 

DIMENSIONS. C.76641-135: 40 (30), 42 (31), 68 (50). 

REMARKS. The figured specimen is similar in whorl section, dimensions and 
ornamentation to Spath’s holotype from Cutch. The other fragments are com- 
parable to P. vobustus Spath, and also to the allied species P. major Spath (1931 : 
489) and P. bathyplocus (Waagen) (Spath 1931 : 493) in whorl section and ornamen- 
tation. P. vobustus Spath is very closely allied in ornamentation and whorl section 
to P. major Spath. 


Loca.itiges. Punnu Mines (C.76641-3), Trans Indus Ranges. 


Genus AULACOSPHINCTOIDES Spath, 1923 
Aulacosphinctoides hazaraensis sp. nov. 
(Plate 8, figs 1a, b, 2a, b) 


DiaGnosis. Evolute, depressed whorls, with distant, prorsiradiate coarse ribs 
that bifurcate and occasionally trifurcate just ventral of the middle of the whorl side. 
Slight mid-ventral depression. 3 or 4 well marked constrictions per whorl. 


MATERIAL. Two specimens, C.76644—the holotype, and C.76645—the paratype. 


Horizon. Basal bed of Lumshiwal Formation (“Giumal Sandstone’’), Lower 
Tithonian. 


Description. The holotype consists of a complete body chamber, probably of 
an immature specimen, two-thirds of a whorl long and 83 mm maximum diameter. 
The mouth-border is flared especially on the venter, and is preceded by a constriction, 
and there is a constriction at the beginning of the body chamber. The paratype 
consists of half a specimen, 63 mm diameter, showing parts of 3 whorls. The final 
third of the outer whorl is body chamber. In both specimens, the whorl section is 
rounded and depressed, and there is a slight mid-ventral depression. The ribs are 
almost straight prorsiradiate and strong; the holotype has 17 or 18 ribs per half 
whorl at 83 mm diameter, the paratype 17 ribs per half whorl at 63 mm. On the 
outer third of the whorl, the ribs bifurcate or sometimes trifurcate on the outer 
whorls, then pass straight across the venter and are partly interrupted at the mid- 
ventral depression. There are 3 or 4 deep constrictions per whorl parallel to the 
ribs. 


344 JURASSIC AND LOWER CRETACEOUS ROCKS 


DIMENSIONS. C.76644-75: 25 (33), 32°5 (43), 43°5 (46). 
C.76645-62: 20°5 (33), 26 (42), 27 (44). 

REMARKS. Uhlig (1910) described a number of Auwlacosphinctoides species from 
the Himalayas. This new species compares well with A. infundibulus (Uhlig) 
(1910 : pl. LXVI, fig. 3; pl. LX XII, figs 1-4) and A. hundestanus (Uhlig) (1910: 
pl. LXXI, fig. 3; pl. LXXII, fig. 2; pl. LXVI, fig. 4) in ribbing, whorl section and 
dimensions, but differs in having coarser, less dense and more commonly trifurcating 
ribs on the outer whorl at comparative sizes. In the presence of frequent and fairly 
prominent constrictions, it is close to A. hundesianus (Uhlig), but differs in ornamen- 
tation details. A. infundibulus (Uhlig) has 41 to 44 ribs at 83 mm diameter, while 
the new species (which has a complete body-chamber at 83 mm) has about 34 to 36 
primary ribs. A. hundesianus (Uhlig) has about 46 to 48 primary ribs at the same 
size. 


Locality. Kathwal, Hazara. 


Aulacosphinctoides uhligi Spath 
(Plate 8, figs 3a, b) 
1910 Perisphinctes (Aulacosphinctes) torquatus (J. de C. Sowerby); Uhlig: 368, pl. LXIX, 
figs 2a—d; pl. LX XI, figs 1a—d, 2a-c. 


1923 Aulacosphinctoides uhligi Spath: 299. 
1939 Aulacosphinctoides aff. uhligi Spath: 120, pl. XV, figs 8a—b. 


MATERIAL. Two specimens, C.76646-7. 


Horizon. Two feet above the base of Lumshiwal Formation (‘“Giumal Sand- 
stone’) in Hazara and 20 feet above the base of Chichali Formation in the Trans 
Indus Ranges, Lower Tithonian. 


DESCRIPTION. The shell is evolute, septate and 62 mm in diameter. The whorl 
section is rounded, sub-circular on the outer whorl, but depressed and with flatter 
whorl sides on the inner whorls. The ribs are prorsiradiate and bifurcate at the 
middle or slightly higher on the whorl side. On the inner whorls, the bifurcation 
point is higher, near the ventral shoulder. There are 23 ribs per half whorl at 62 mm 
diameter, and slightly more on the inner whorls. There are two oblique constric- 
tions on the outer whorl, and the one at the apertural end appears to mark the 
beginning of the body chamber. The constrictions cut across several secondary 
ribs immediately preceding them. The rib following a constriction is simple. 

DIMENSIONS. C.76646-62: 20 (32), 22°5 (36), 29°5 (48). 

C.76646-21: 7 (33), 12 (57), 0 (47). 

REMARKS. The figured specimen compares well in ornamentation and dimensions 
with the type specimens of A. uhligi Spath (1923 : 299; 1933 : 476) which were 
figured by Uhlig (1910: 368, pl. 69, fig. 2; pl. 71, figs 1, 2). In the Himalayas it is 
quite common at various localities. The change from depressed inner to elevated 
outer whorls, and the change of the bifurcation point trom the ventral shoulder on 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 345 


the inner whorl to lower on the side of the outer whorl, compares well with Uhlig’s 
illustrations. It differs, however, in having a smaller number of primary ribs. It is 
distinguished from A. infundibulus (Uhlig) by its straight, prorsiradiate ribs, bifur- 
cating higher on the whorl side and more compressed whorl section. It is like A. 
willist (Uhlig 1910: pl. LX XIII, figs ra-c) in ornamentation, but differs in whorl 
section and other details. The fragmentary specimen described by Spath (1939) 
from the Trans Indus Ranges as A. aff. whligi Spath is also similar. 


Locatities. Kathwal, Hazara, and a doubtful fragment from the Trans Indus 
Salt Ranges. 


Aulacosphinctoides sp. indet. 
(Plate 8, figs 4a, b) 


MATERIAL. Four specimens, C.76648-51. 


Horizon. One foot above the base of Lumshiwal Formation (‘“Giumal sand- 
stone’), Hazara, and 20 feet above the base of Chichali Formation, Trans Indus 
Ranges, Lower Tithonian. 


DeEscriPTION. The figured specimen has a maximum diameter of 78 mm; slightly 
more than half of the outer whorl is body chamber, the last septum occurring at 
57 mm diameter. The whorl section is well rounded and depressed, and has a 
shallow mid-ventral groove. The ribs are prorsiradiate, bifurcating high on the 
whorl side, then pass straight across the venter, but are weakened along the siphonal 
line. On the last whorl trifurcating ribs are dominant, but near the aperture the 
ribbing becomes irregular and simple. There are 35 ribs at 57 mm diameter. There 
are two oblique, moderately deep constrictions on the septate whorls, which cut 
across the ribs preceding them. The rib following a constriction is simple. 


DIMENSIONS. C.76648-57: 28 (35), 25 (44), 22°5 (39). 


REMARKS. In whorl section, straight ribs and deep constrictions, this species 
resembles Aulacosphinctoides willisi (Uhlig 1910: pl. LXV, figs 3c-d; pl. LX XIII, 
figs Ia—c), but differs in having frequent trifurcating ribs on the outer whorl. Uhlig’s 
species is based on a mature adult specimen of 84 mm diameter, which has a 
lappet, but on the body chamber only two out of 22 to 23 primary ribs trifurcate, 
the rest bifurcate. Contrary to this, in the present specimens more than 75% of 
the ribs trifurcate on the outer half whorl. In the trifurcating ribs it resembles 
A. hazaraensis sp. noy., but is more involute, has finer straight ribs and a deeper 
umbilicus. The three other specimens (C.46649-51) of Awulacosphinctoides are 
indeterminate due to poor preservation. They have very evolute shells, depressed 
whorl sections and dense, fine ribs. 


Localities. Kathwal (C.76648), Hazara; Chichali Pass (C.76649), Shaikh Budin 
Hills, (C.76650-51), Trans Indus Ranges. 


346 JURASSIC AND LOWER CRETACEOUS ROCKS 


Genus VIRGATOSPHINCTES Uhlig 1910 
Virgatosphinctes denseplicatus (Waagen) 
(Plate 8, figs 5a, b) 


1875 Perisphinctes denseplicatus Waagen: 201, pl. XLVI, figs 3a—b; pl. LV, fig. ta—b. 

1910 Perisphinctes (Virgatosphinctes) denseplicatus Waagen; Uhlig: 313, pl. LIII, figs 3a-d; 
pl. LIV, figs 1a—c; pl. LV, figs 1a—d, 2a—d, 3a-d; pl. LVI, figs tac. 

1933 Virgatosphinctes densplicatus (Waagen) ; Spath: 532, pl. LX XVII, figs 3a-c; pl. XC, fig. 1; 
pl. XCVI, figs 3a—b; pl. CII, fig. 4 (see for synonymy). 


MATERIAL. Two specimens, C.76652-3. 


Horizon. Basal part of Lumshiwal Formation (‘‘Giumal sandstone’’), Hazara, 
and 20 feet above the base of Chichali Formation, Trans Indus Ranges, Lower 
Tithonian. 


DEscRIPTION. The figured specimen is wholly septate and 57 mm diameter. 
The outer whorl embraces half to two-thirds of the previous whorl. The whorl 
section is rounded and slightly wider than high. The sharp, dense ribs are prorsi- 
radiate, bifurcate near the middle of the whorl side, and cross the venter arched 
slightly forwards. There are a few shallow constrictions parallel to the ribs, and 
they are followed by a simple rib. The rib density is 50 at 57 mm diameter. 

DIMENSIONS. C.76652-57: 22 (39), 23°5 (41), 21 (37). 

REMARKS. This specimen has ribbing typical of V. denseplicatus (Waagen) and 
compares closely with Spath’s figure of an evolute form of the species V. rotunda 
Spath (1933: pl. CII, fig. 4) from the lower Umia group of Cutch and with Uhlig’s 
figure of the inner whorls of V. denseplicatus (Waagen) from Spiti area (Uhlig 
rgi0: pl. LILI, figs 3a—c; pl. LXV, figs 2a-d). It differs primarily in having slightly 
less dense ribbing than Uhlig and Spaths’ specimens. 

Locatities. Kathwal, Hazara (C.76652), west of Makerwal, Trans Indus Ranges 
(C.76653). 


Virgatosphinctes frequens (Oppel) 
(Plate 9, fig. ra, b) 
1865 Ammonites frequens Oppel: 295, pl. 87. 
1910 Perisphinctes (Virgatosphinctes) frequens (Oppel), Uhlig: 325, pl. LXIII, figs ta—c, 3a-c; 
pl. LXXXV, figs ra—c; pl. LX XV A, figs ra—c (see for synonymy). 

MATERIAL. Three specimens, C.76654-6. 

Horizon. Lower 2 to 3 feet of Lumshiwal Formation, Giumal sandstone, Lower 
Tithonian. 

DESCRIPTION. The figured specimen is evolute and 98 mm in diameter. The whorl 
section is oval with sides that converge towards a rather narrow venter. The ribs 


are prorsiradiate, moderately distant on the outer whorl, but more dense on the 
inner whorls. They bifurcate or trifurcate near the middle of whorl side, then the 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 347 


fine secondary ribs recurve to cross the ventral shoulder and the venter radially. 
There are 56 or 57 primary ribs at 98 mm diameter. 


DIMENSIONS. C.76654—-08: 33 (34), 31 (32), 42 (43). 

REMARKS. The figured specimen resembles strongly, in ornamentation, Oppel’s 
holotype and other specimens figured by Uhlig (1910) from the Spiti area. It differs 
in being more evolute and in having a less inflated and elevated whorl section. It 
has almost identical dimensions to Virgatosphinctes subfrequens Uhlig (1910: 327, 
pl. XLIX, figs ta—d; pl. LXI, figs ra-d). One of the two fragmentary specimens, 
C.76655, is more inflated and appears to be closer in dimensions to Oppel’s holotype. 
V. frequens was recorded from different localities in Hazara by Middlemiss (1896 : 
33-34) and Spath (1933 : 804). Itis the most abundant Virgatosphinctes in northern 
Hazara and occurs in association with Aulacosphinctoides. One fragment from 20 
feet above the base of Chichali Formation in the Makerwal area is doubtfully 
assigned to this species and is also associated with Aulacosphinctoides. Arkell 
(1956 : 407) similarly pointed out the close association of these two genera in the 
Middle Spiti shales of Himalaya. 


Locatities. Kathwal—Kalapani (C.76654-5), Hazara, one fragment from 
Makerwal, Trans Indus Ranges (C.76656). 


Virgatosphinctes sp. indet. 


MATERIAL. One specimen, C.76657. 


Horizon. 2 feet above the base of Lumshiwal Formation (‘‘Giumal sandstone’’), 
Lower Tithonian. 


REMARKS. The specimen has strong, sharp and dense ribs which cross the venter 
transversely. The ribs usually bifurcate from the middle of whorl side, but a few 
trifurcate and there are occasional simple ribs on the inner whorls. It has part of 
the body chamber on which the ribs trifurcate in a virgatome fashion and are more 
distant. Dimensions are: 72: 28 (39), 29 (40), 23°5 (33). It is comparable with V. 
subquadratus Uhlig (1910: pl. LXVIII, figs 1a—c) and V. indistinctus Uhlig (1910: 
pl. LXVI, figs 2a—b) in whorl section and ornamentation, but is more involute and 
has denser ribs. 


Locatity. Kathwal, Hazara. 


Family ASPIDOCERATIDAE Zittel 1895 
Sub-family ASPIDOCERATINAE Zittel 1895 
Genus EUASPIDOCERAS Spath 1931 
Euaspidoceras cf. wagurense (Spath) 
1931 Neaspidoceras wagurense Spath: 614, pl. CXX, figs 7a-d (see for synonymy). 
MATERIAL. One fragment, C.76658. 
Horizon. Basal one foot of Chichali Formation, Upper Oxfordian. 


348 JURASSIC AND LOWER CRETACEOUS ROCKS 


DESCRIPTION. The specimen is evolute with a sub-rectangular whorl section; 
whorl height 42 mm and thickness 39 mm at the aperture. The whorl sides converge 
gradually towards a broad sub-tabulate venter. Two rows of tubercles at the 
umbilical edge and ventral shoulder are connected by weak, blunt ribs. The 
umbilical tubercles extend rursiradially on the umbilical wall. The tubercles on the 
ventral shoulder are obliquely elongated. 

REMARKS. The specimen is poorly preserved, but closely resembles, in ornamen- 
tation and whorl section Spath’s figure of a specimen from the Kantcote sandstone 
(Bimammatum Zone) of Cutch. It may also be compared with EF. varians Spath 
(1931: pl. CV, figs 7a—b ; pl. CX, figs ta—b) from the same horizon in Cutch, but 
differs in having a less compressed whorl section and arched whorl sides. 


LocaLity. Mazari Tang, Nizampur. 


Genus ASPIDOCERAS Zittel 1868 
Sub-genus ASPIDOCERAS Zittel 1868 
Aspidoceras (Aspidoceras) sp. indet. 


MATERIAL. One specimen, C.76659. 

Horizon. 5 to 7 feet above the base of the Chichali Formation, Lower Kim- 
meridgian. 

DEscRIPTION. The specimen is involute, probably septate, and approximately 
56 mm diameter. It has a subcircular whorl section, wider than high. There is a 
distinct row of tubercles near the umbilical shoulder, and a suggestion of an indistinct 
row of outer tubercles on the side of the inner whorl. There are no ribs. 


DIMENSIONS. C.76659-56: 25 (45), 30°5 (54), 61 (29). 


REMARKS. In inflated shell and weak outer row of tubercles, the species may be 
compared with A. (A.) iphiceroides (Waagen) (Spath, 1931: 635, pl. CX XIII, figs 
8a—b). In dimensions it is similar to a small example from Mombasa described by 
Spath as A. (A.) mombasense (Spath 1931 : 636). The whorl section is very similar 
to a form from Cutch figured by Spath (1931: pl. CX XII, fig. 9) as A. (Aspidoceras) 
sp. indet. 


Locatity. Punnu Mines, Trans Indus Ranges. 


Sub-genus PSEUDOWAAGENIA Spath 1931 
Aspidoceras (Pseudowaagenia) sp. indet. 
(Plate 9, figs 2a, b) 
MATERIAL. One specimen, C.76660. 
Horizon. One foot above the base of Chichali Formation, Lower Kimmeridgian. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 349 


DescripTion. The shell is half involute, septate, and 36 mm diameter. The 
whorl section is oval and higher than wide. There are noribs. There are 15 to 16 
small, rounded tubercles at the umbilical shoulder at 36 mm diameter. 

DIMENSIONS. C.76660—36: 16 (44), 15 (42), 10 (28). 

REMARKS. The suture line of this specimen is very similar to that of Pseudo- 
waagenia hyanaldi (Neumayr) and Pseudowaagenia micropla (Oppel) as figured by 
Spath (1933: pl. CXVIII, fig. 11; pl. CX XII, fig. 30) from Cutch. Spath (1933: 623, 
pl. CXXII, figs 3a-c) figured a specimen of P. micropola (Oppel) from the lower 
Katrol beds of Cutch, which had dimensions of 55 mm: 42%, 369%, compared with 
55 mm: 40%, 25%, 33%, in Oppel’s type. The specimen described here is dis- 
tinguished from both Neumayr’s and Oppel’s species in being more involute and 
more inflated. 


Locatity. Punnu Mines, Trans Indus Ranges. 


Genus PHYSODOCERAS Hyatt 1900 
Sub-genus SIMASPIDOCERAS Spath 1925 
Physodoceras (Simaspidoceras) sp. indet. 


MATERIAL. One fragment, C.76661. 

Horizon. About one foot above the base of Chichali Formation, Lower Kim- 
meridgian. 

DeEscriPTIon. This fragment has a rounded, trapezoidal whorl section, with 
greatest thickness just above the umbilical shoulder, and a broad venter. The 
umbilicus is narrow. There are weak ribs and weak blunt tubercles near the 
umbilical shoulder. 


Remarks. The weak ribs, umbilical tubercles, broadly rounded venter and 
squarish whorl section, may be compared with Simaspidoceras argobbae Dacque 
(1905). The suture line also compares well with Dacque’s species. 


LocaLity. Punnu Mines, Trans Indus Ranges. 


Sub-family SIMOCERATINAE Spath 1924 
Genus HYBONOTICERAS Breistroffer 1947 
Hybonoticeras sp. indet. 


MATERIAL. One fragment, C.76662. 

Horizon. 5 feet above the base of Chichali Formation, Lower Kimmeridgian. 

DEscRIPTION. This is a septate fragment, with a sub-rectangular whorl section 
and nearly flat whorl sides. There is a deep sulcus in the middle of the venter, 
bordered by sharp ridges. The ornamentation consists of very weak, distant 
rectiradiate or gently prorsiradiate ribs. These swell into blunt, thick tubercles at 


350 JURASSIC AND LOWER CRETACEOUS ROCKS 


the umbilical shoulder and again on the whorl side near the ventral shoulder. The 
ventral tubercles tend to be clavate while the umbilical tubercles are obliquely 
elongated backwards and extend partly on to the umbilical wall. 


Remarks. The species is comparable in weak ribs, size, side and ventral views 
with Hybonoticeras kachensis (Spath) from Lower—Middle Katrol beds of Cutch 
(Spath 1933 : 645, pl. CXXII, fig. 6), and with H. pressulum (Neumayr) and ZH. 
ciliatum Berckhemer and Holder, both figured by Berckhemer and Holder (1959: 
pl. I, fig. 1; pl. II, fig. 6, pl. 3, fig. 9). The suture line is comparable with a specimen 
figured by Spath (1933: pl. XCV, fig. 2) as H. sp. nov. aff. hybonata (Oppel) from 
Lower Katrol beds of Cutch. 


Locatity. East of Chichali Pass (Kutch Mines), Trans Indus Ranges. 


Family OLCOSTEPHANIDAE Haug rIgi1o 
Sub-family SPITICERATINAE Spath 1924 
Genus PRONICERAS Burckhardt 1919 
Proniceras indicum Spath 
(Plate 9, figs 3a, b) 
1939 Proniceras indicum Spath: 34, pl. III, figs 4a-d. 

MATERIAL. One specimen, C.76663. 
HOoRIzon. 25 to 30 feet above the base of Chichali Formation, Lower Tithonian. 


DeEscriPTIon. This specimen is an almost complete immature of 38 mm diameter. 
The whorl section is almost circular. The prorsiradiate ribs bifurcate near the 
middle of the whorl side, and cross the venter as forwardly-directed chevrons, but 
are weak at the mid-ventral line. There are a few simple ribs on the outer whorl. 
There are about 50 ribs per whorl at 38 mm diameter. Three moderately deep 
oblique constrictions per whorl are present on outer and inner whorls. The rib 
following each constriction is simple. 

DIMENSIONS. C.76663-38: 15 (39), 15 (39), 14 (37). 

REMARKS. The specimen is very similar to Spath’s holotype which was based 
on a fragmentary specimen, Ig mm in diameter, from the Trans Indus Salt Range. 

LocaLity. Chichali Pass, Trans Indus Salt Ranges. 


Genus SPITICERAS Uhlig 1903 
Spiticeras multiforme Djanelidze 
(Plate 9, figs 4a, b) 


1922 Spiticevas multiforme Djanelidze: 143, pl. VII, figs 3a-b; pl. XV, figs 1a—c, 2a—c; pl. XX 
figs ra—c; pl. XXII, figs 3a-b. 


MATERIAL. One specimen, C.76664. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 351 


Horizon. 3 feet below the base of the middle member of the Chichali Formation, 
Upper Tithonian. 


DEscriPTION. This is a wholly septate specimen, of approximately 66 mm 
diameter. The whorl section is oval with greatest breadth near the umbilicus. 
There are 16 or 17 prominent, umbilical tubercles on the outer whorl. Prorsiradiate 
ribs issue from the tubercles in bundles of 4 or 5 and pass over the venter arched 
forwards. Occasional ribs bifurcate higher up on the side of the whorl, and some 
ribs are intercalated. The ribs weaken along the mid-ventral line. There are an 
estimated 105 ribs on the final whorl. 


Remarks. This specimen is almost identical in dimensions and ornamentation 
with Djanelidze’s figure (Pl. VII, figs 3a—b) of a specimen from France. It also 
compares well with Sfzticeras bilobatus (Uhlig) and Spiticeras subbilobatus (Uhlig) 
(1910 : 96, 98, pl. X, figs Ia and 2) in ornamentation, side and ventral views. It 
however, shows more elevated whorl section, denser ribs, less evolute shell and 
absence of prominent constrictions. 


Locatity. South west of Malla Khel, Trans Indus Ranges. 


Spiticeras sp. indet. 


MATERIAL. Two fragments, C.76665-6. 


Horizon. 3 feet below the base of the middle member of the Chichali Formation, 
Upper Tithonian. 


REMARKS. These fragments are characterized by strong forwardly projected ribs 
on the upper half of the whorl side and acute forward chevrons on the venter. There 
are prominent radially elongated tubercles at the umbilical shoulder. In ribbing 
style and strong forward projection of the ribs they compare well with Spiticeras aff. 
scriptus (Strachey) (Uhlig, 1910 : 112, pl. XIV, figs 3a-d) from Lochambelkichak, 
Spiti area. They, however, differ in whorl section, and Uhlig’s form has a less 
acutely rounded venter. 


LocaLity. South west of Mallakhel, Trans Indus Ranges. 


Sub-family PROVALANGINITINAE nov. 
Genus PROVALANGINITES nov. 


TYPE SPECIES. Provalanginites rhodes sp. nov. 


Diacnosis. Involute, inflated sphaerocones, with an eccentrically coiled and 
contracted adult body-chamber of 40-60 mm maximum diameter. Whorl section 
depressed, semicircular, with an occluded umbilicus on septate whorls and a very 
narrow eccentric umbilicus on the body-chamber. Adult body-chamber occupies 
about seven-eighths of a whorl. Ribs moderately dense, simple, or bifurcating and 


352 JURASSIC AND LOWER CRETACEOUS ROCKS 


trifurcating from the middle of the whorl side, but fading towards umbilical shoulder. 
Ribs prorsiradiate on side of whorl and venter. Suture line fairly simple with 
multifid asymmetric first lateral lobe and retracted suspensive lobe. 


Remarks. The species recalls the sphaerocone—cadicone shells and eccentric 
coiling of the earlier families Tulitidae (Middle Jurassic) and Oecoptychidae (Middle 
Callovian to Lower Oxfordian), and the later family Olcostephanidae, especially the 
type species, Ammonites nuculeus Roemer (Koenen 1902 : pl. IV, figs 6-7) of the 
genus Valanginites (Upper Valanginian). The sub-family Provalanginitinae nov. 
is characterized by sphaeroconic, involute, eccentrically coiled shell, with weak, 
non-tuberculate ribs. It may include the genus Valanginites and range from 
Tithonian to Valanginian. 

In the Trans Indus Ranges the two new species of the genus and sub-family occur 
in the Tithonian beds of the Chichali Formation. 


Provalanginites rhodesi sp. nov. 
(Plate io, figs 1a, b, 3a, b) 


Diacnosis. Moderately-sized species, adult body chamber of 45-50 mm diameter. 
Inner whorls sphaeroconic, body chamber eccentrically coiled, contracted. Ribs 
simple or bifurcating, smooth near umbilical shoulder, but becoming strong and 
forwardly arched on venter. 


MATERIAL. Three specimens; C.76671, the holotype, and C.76672-73, paratypes. 


Horizon. 20 to 30 feet above the base of the Chichali Formation, Lower 
Tithonian. 


DEscRIPTION. The holotype has most of its body chamber complete, only the 
final quarter whorl is missing; its maximum diameter is 44 mm. Both paratypes 
are wholly septate, and of 29 and 25 mmdiameter. The septate whorls are depressed 
sphaerocones with the umbilicus occluded. The venter of the adult body chamber 
uncoils away from the spiral of the previous whorl, so that the umbilicus opens 
slightly; the body chamber also contracts markedly towards the aperture. The 
mouth border is not preserved. 

The ribs are fairly dense on inner whorls, but stronger on the body-chamber. 
They are simple, bifurcating or occasionally trifurcating, and are weak near the 
umbilicus. They are strongly prorsiradiate, and cross the venter arched forwards. 
There are an estimated 45-46 ribs per whorl at 44 mm diameter. 

DIMENSIONS. C.76671-—44: 24 (55), 27 (61), 4°5 (10). 

C.76671-34: 18 (53), 27 (79), 2°5 (7). 
C.76672-21: II (52), 18 (86), 0-0 (0). 

REMARKS. The species resembles in eccentric coiling and sphaerocone shell the 
type species of Callovian genus Kheraiceras and the Lower Oxfordian genus Proto- 
phites, but differs in details of coiling, whorl section and ornamentation. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 353 


In eccentric coiling and sphaerocone shell, it resembles more closely V alanginites 
nucleus (Roemer) (Koenen, 1902: pl. IV, figs 6-7) from the Valanginian beds of 
Europe, but differs in ornamentation details. The genus Valanginites is restricted 
(Wright, 1957) to the Upper Valinginian. 

Loca.ities. Lunda mines (C.76671), and Chichali Pass (C.76672~-73), Trans 
Indus Ranges. 


Provalanginites howarthi sp. nov. 
(Plate 10, figs 2a, b) 
Diacnosis. Larger than P. rhodesi, adult body chamber being 52 mm diameter, 


septate whorls sphaetoconic but more depressed, ribs almost absent on whorl sides 
and less strong on the venter than in P. rhodest. 


MATERIAL. One specimen C.76674, the holotype. 
Horizon. About 25 feet above the base of Chichali Formation, Lower Tithonian. 


DeEscriPTION. The single specimen is a complete adult, with a body chamber 
seven-eighths of a whorl long, which coils eccentrically on the venter, contracts in 
whorl thickness half way along the body chamber, then flares slightly at the aperture. 
Some of the mouth border is preserved on the venter. The inner whorls are 
sphaeroconic and very depressed although only the final part of the last septate 
whorl can be seen. The sides of the body chamber are smooth, weak ribs being 
confined to the venter where they arch gently forwards, and appear to fade along 
the mid-ventral line. 


DIMENSIONS. C.76674—52: 23 (44), 32 (62), 26 (12). 


REMARKS. The species differs from Provalanginites rhodesi sp. nov. in having 
weaker ornament, smoother body-chamber, a more depressed whorl section and a 
broader venter. 


Locatity. Punnu Mines, Trans Indus Ranges. 


Family BERRIASELLIDAE Spath 1922 
Sub-family BERRIASELLINAE Spath 1922 
Genus BLANFORDICERAS Cossman 1907 

Blanfordiceras cf. wallichi (Gray) 
(Plate 10, figs 4a, b, 5a, b) 


1832 Ammonites wallicht Gray: Pl. C, fig. 3. 

1910 Hophites (Blanfordia) wallicht (Gray); Uhlig: 186, pl. XXXI, figs ra—c, 2; pl. XXIX, 
figs 1a—b, 2a—b, 3a-c; pl. XXX, figs 1a—c. 

1939 Blanfordiceras aff. wallichi (Gray); Spath: 43, pl. IV, fig. 6; pl. V, figs 1, 9, ro (see for 
synonymy). 


MaTeERIAL. Three fragments, C.76675-7. 


354 JURASSIC AND LOWER CRETACEOUS ROCKS 


Horizon. 10 to 60 feet below the base of the middle member of the Chichali 
Formation, Upper Tithonian. 

DESCRIPTION. The whorl section is sub-quadrate, higher than wide, with a 
tabulate venter that has a marked sulcus in the middle. Strong, gently sinuous and 
prorsiradiate ribs, bifurcate near the middle of the whorl side. A few ribs are 
simple. The ribs are high and sharp on the venter and are interrupted by the 
sulcus. On the body-chamber, the ribs tend to cross the venter with only slight 
degeneration along the mid-venter. 

REMARKS. These fragmentary specimens broadly resemble the examples of 
Blandfordiceras wallicht (Gray) figured by Uhlig (1910). In the Spiti area the 
species has been reported from both the upper and middle shales, suggesting a long 
time range in the Tithonian. In the Trans Indus Ranges, it is found above the 
Aulacosphinctoides horizon, and as high as the Himalayites and Spiticeras beds. 

Locatities. North of Kalabagh, Chichali Pass, Punnu Lunda Mines, and south 
west of Malla Khel, Trans Indus Ranges. 


Blanfordiceras cf. latidomus (Uhlig) 
(Plate 10, figs 6a, b, 7a, b) 
1910 Hoplhites (Blanfordia) latidomus Uhlig: 196, pl. XX XV, figs ra—c. 
1939 Blanfordiceras aff. latidomus (Uhlig); Spath: 46, pl. V, figs 12a—b. 

MATERIAL. Two specimens, C.76678-9. 

Horizon. About 20 feet below the base of the middle member of the Chichali 
Formation, Upper Tithonian. 

DEscrIPTION. These evolute, wholly septate specimens have sub-quadrate or 
polygonal whorl sections, with whorl thickness equalling whorl height, and sulcate 
venters. The ribs are prorsiradiate, sharp, fairly distant, and bifurcate at the 
middle of the whorl side; the point of bifurcation being marked by a small, sharp 
tubercle. They are sharp and elevated on the venter and are interrupted by the 
sulcus. A few ribs remain simple. 

DIMENSIONS. C.76678—?47: 16 (34), 17 (36), 18 (38). 

C.76679-36: 13 (36), 13 (36), 14 (39). 

REMARKS. The specimens resemble, in whorl shape and ornamentation, Uhlig’s 
holotype from Lochambelkichak, Spiti area. They are wholly septate and of smaller 
size, but all of them show the sharp tuberculation on the middle of the whorl side, 
and rather straight prorsiradiate ribs. 

Locatity. Lunda Mines, Trans Indus Ranges. 


Blanfordiceras sp. indet. 
(Plate 10, figs 8a, b) 
MATERIAL. Four fragments, C.76680-83. 
Horizon. 2 to 3 feet above the base of Chichali Formation in Kala Chitta, and 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 355 


10 to 30 feet below the base of middle member of Chichali Formation in the Trans 
Indus Ranges, Upper Tithonian. 


REMARKS. These fragments may belong to one or more species of the genus. 
Poor preservation does not allow a specific determination. C.76680 has a rounded 
whorl section, ribs that bifurcate near the middle of whorl side and the point of 
bifurcation is marked by radially elongated blunt tubercles. The ribs are interrupted 
at the mid-venter but are without any prominent tuberculation. In ventral view 
and whorl section it resembles a small inner whorl fragment figured by Spath (1930 : 
pl. IV, fig. 5; pl. V, fig. 2,; pl. VI, figs 5, 11, 12 and 15) as Blanfordiceras cf. boehmi 
(Uhlig). C.76681 has a higher than wide whorl section, sharp fairly distant prorsi- 
radiate ribs, sharp tubercles at the point of bifurcation on whorl side and at the 
termination of ribs on the grooved venter. The fragment may be compared in 
ribbing and higher than wide whorl section with B. acuticosta (Uhlig 1910 : 301, 
pl. XX XVIII, figs 2a-c). 


Loca.ities. Chichali Pass and Kalabagh, Trans Indus Ranges (C.76682-83), and 
north north west of Jhallar, Kala Chitta Range (C.76680-81). 


Genus PROTACANTHODISCUS Spath 1923 
Protacanthodiscus cf. michaelis (Uhlig) 
(Plate: x11; figs xa; b) 


1902 Hoplites michaelis Uhlig: 35, pl. VII, figs 1-4. 


MATERIAL. One fragment, C.76684. 


Horizon. 3 feet below the base of the middle member of the Chichali Formation, 
Upper Tithonian, just below Subthurmnnia fermori horizon. 


DescrieTIon. A detached fragment of the body chamber has a rectangular 
whorl section with a broadly rounded venter, whorl height of 61 mm and breadth 
of 38 mm. It has only very weak ribs, but prominent umbilical and ventrolateral 
tubercles and weak lateral ones. The septate part of the specimen (as figured) has 
a more compressed whorl section, with flat sides and a flat sulcate venter. The ribs 
are strong and nearly straight, and they branch at the middle of the whorl side at 
the lateral tubercle. Occasional ribs branch from an umbilical tubercle, and there 
are frequent non-tuberculate simple ribs. There are prominent umbilical tubercles, 
smaller mid-lateral tubercles, and all the ribs swell into blunt transverse tubercles 
at the ventral shoulder and are interrupted at the mid-ventral sulcus. 

DIMENSIONS. C.76684—?96: 36 (38), 24 (25), 238 (40). 

REMARKS. The specimen compares well with Hoplites michaelis Uhlig in whorl 
section and general ornamentation, but differs in having frequent intercalatory ribs, 
less frequent bifurcation from the umbilical shoulder, transverse rather than oblique 
ventral tubercles and greater forward projection of the ribs. It is also similar to 
forms like Berriasella chaperi (Pictet, 1868 : 242, pl. 37, fig. 3; Mazenot, 1939: 80, 
pl. VIII, figs 5-9, pl. IX, figs 1a-b), Berriasella aspera Mazenot (1939: pl. IX, 


350 JURASSIC AND LOWER CRETACEOUS ROCKS 


figs 2-3) and Berriasella malbosi (Pictet, 1863: 77, pl. XIV, figs 1-2; Mazenot, 1939 : 
98, pl. XIII, figs 8a-c; pl. XIV, fig. 1). B. chaperi attains a diameter of about 
150 mm, and at 63 mm has the following dimensions (Mazenot, 1939 : 81): whorl 
height 36%, whorl thickness 23°%, umbilical width 38°%. All these species have 
prominent tubercles and tabulate venters and are closer to Protacanthodiscus than 
to Berriasella. 

This specimen has great stratigraphic importance in the area, for it lies just below 
the zone of Subthurmannia fermort and close to the Jurassic/Cretaceous boundary. 


Locatity. Lunda Mines, Trans Indus Ranges. 


?Protacanthodiscus sp. indet. 
(Plate 11, figs 4a, b) 
1939 Himalayites? (Gen. nov.) ?sp. indet. Spath: 66, pl. VII, figs ra—c. 


MATERIAL. One specimen, C.76685. 


Horizon. Five feet below the base of the middle member of the Chichali Forma- 
tion, Upper Tithonian. 


DESCRIPTION. The specimen is wholly septate, with a hexagonal section and a 
sulcate venter. The ribs are concave forwards, mainly simple, but some bifurcate 
at the lateral tubercle. At the ventro-lateral edge, they swell into high, thin tubercles 
which form chevrons along the sides of the ventral sulcus. Prominent, radially 
elongated tubercles occur sporadically on some simple and all bifurcating ribs at the 
middle of the whorl side. 


REMARKS. This specimen is provisionally placed in the genus Protacanthodiscus 
because of its fairly broad venter, large size and presence of mid-lateral and ventro- 
lateral tubercles. It differs from the type species and other species of Protacantho- 
discus in details of ribbing and in having a Himalayites-type hexagonal whorl section. 
In ornamentation and forward projection of ribs near the ventral shoulder, it is 
closer to Raimondiceras, e.g. R. raimondi (Arkell and Wright 1957 : 351) and R. 
?salinarium Spath (1939 : 62, pl. XIV, figs 4, 5), but differs in ventral aspects, whorl 
section and its less dense ribs. In whorl section and the forward projection of the 
ribs near the venter, it recalls the Valanginian species Neohoploceras baumbegert 
Spath (1939: pl. XXII, figs 3a-b). It strongly resembles a form described and 
figured by Spath from the Trans Indus Ranges as Himalayites? (Gen. nov.?) sp. 
indet. (1939: pl. VII, fig. ra—c), except that Spath’s form is more inflated and has 
a few trifurcating ribs. 

The specimen incorporates the whorl section of Himalayites, the tabulate, broad 
venter of Protacanthodiscus, and the forward projection of ribs on the ventral shoulder 
of Raimondiceras. It probably represents a new Tithonian genus, intermediate 
between Protacanthodiscus and Raimondiceras which could have given forms like 
Kilianella and Neohoploceras during Berriasian and Valanginian times. 


LocaLity. Lunda Mines, Trans Indus Ranges. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 357 


Sub-family HIMALAYITINAE Spath 1925 
Genus HIMALAYITES Uhlig in Boehm 1904 
Himalayites ci. depressus Uhlig 
1910 Himalayites depressus Uhlig: 148, pl. XL, figs 2a-c. 
MATERIAL. One specimen, C.76669. 


Horizon. 24 feet above the base of the Chichali Formation in Mazari Tang 
section, Nizampur, Upper Tithonian. 


DEscRIPTION. The specimen is evolute and roughly 56 mm in diameter. The 
whorl section is highly depressed, much wider than high with a broad flattish 
sulcate venter. Strong primary ribs end at large lateral tubercles, from which 
secondary ribs issue in bundles of 2 to 4, and pass onto the venter as sharp, high 
ribs. They are interrupted by the mid-ventral sulcus, and there are occasional 
small ventral tubercles (about 4 per half whorl) at each side of the sulcus. 

REMARKS. In spite of the poor preservation the specimen resembles closely in 
whorl section and ornamentation Uhlig’s holotype from the Spiti area, except for the 
occasional tubercles on some ribs near the ventral margin. 


Locatity. Mazari Tang, Nizampur. 


Himalayites middlemissi (Uhlig) 
(Plate 9, figs 6a, b) 
1910 Hoplites (Blanfordia) middlemissi Uhlig: 197, pl. XX XVII, figs ta—c. 


MATERIAL. One specimen, C.76668. 


Horizon. 10 feet below the base of the middle member of the Chichali Formation 
in the Trans Indus Ranges, Upper Tithonian. 


DeEscripTIon. The specimen has a much depressed whorl section with a sulcate 
venter. The coarse primary ribs terminate near the middle of the whorl sides in 
large knob-like tubercles. From the tubercles bundles of 2 or 3 secondary ribs 
cross the venter with slight forward arching, and are interrupted at the mid-ventral 
sulcus. The whorl height is 22 mm, and the whorl thickness over the tubercles is 
36-5 and 32 mm between the tubercles. 

Remarks. Uhlig (1910) placed the species, established by him from Locham- 
belkichak, Spiti area, in the genus Blanfordia. The prominent lateral tubercles, the 
depressed whorl section and trifurcating ribs on the outer whorl indicate generic 
affinities with Himalayites. 


Locatity. Chichali Pass, Trans Indus Ranges. 


358 JURASSIC AND LOWER CRETACEOUS ROCKS 


Himalayites sp. indet. 


MATERIAL. One specimen, C.76670. 


Horizon. 10 feet below the base of the middle member of the Chichali Formation, 
Upper Tithonian. 


DEscRIPTION. This isa large wholly septate half whorl fragment of about 180 mm 
diameter. At the aperture the whorl height is 62 mm, the thickness about 70 mm. 
The whorl section is rounded at the apertural end but subquadrate at the smaller 
end, and the venter has a slight sulcus. The primary ribs are coarse, distant, 
slightly prorsiradiate and end at a large ventro-lateral tubercle. From the tubercles, 
2 or 3 times as many secondary ribs cross the venter with slight forward arching, but 
fade along the mid-ventral line. There are smaller umbilical tubercles on the ribs. 


REMARKS. This specimen is comparable with Himalayites celebrans (Uhlig 
1g10 : pl. XXXVI, figs ra—c) from the Spiti area, in its whorl section, ventral view 
and partly in ornamentation, but differs in having longer primary ribs, with higher 
ventro-lateral tubercles and a smaller number of secondary ribs. 


Locatity. Punnu Mines, Trans Indus Ranges. 


Himalayites cf. hyphaisis (Blanford) 
(Plate 9, figs 5a, b) 


1863 Ammonites hyphaisis Blanford: 132, pl. IV, figs 2, 2a—b. 
1910 Himalayites hyphaisis (Blanford); Uhlig: 149, pl. XX XVIII, figs 2a—b, 3-ad. 
1910 Himalayites sp. nov. indet. Uhlig: 150, pl. XX XVIII, figs 5a—d. 


MATERIAL. One specimen, C.76667. 


Horizon. 10 feet below the base of the middle member of the Chichali Forma- 
tion, Upper Tithonian. 


Description. A small, wholly septate half whorl fragment, with a subhexagonal 
whorl section, and grooved venter. The ribs are moderately distant, and fine 
simple ribs alternate with heavier ribs that bifurcate at a prominent mid-lateral 
tubercle. 

All the ribs swell into radially elongated weak tubercles at the edge of the mid- 
ventral groove. 


DIMENSIONS. C.76667—28-5: II (39), II (39), 10 (35). 


REMARKS. The specimen compares favourably with H. hyphasis (Blanford) from 
Spiti, in ornamentation and whorl shape, but it differs in its less evolute shell, more 
prominent lateral tubercles, and more elevated whorl section. These differences 
may partly be due to the larger size of Uhlig’s specimens (49 mm and 46-5 mm). In 
ribbing and prominent lateral tubercles, it is closer to Himalayites sp. nov. indet. 
(Uhlig, 1910 : 150) which in turn is closely allied to H. hyphasis (Blanford). 


LocaLity. South west of Malla Khel, Trans Indus Ranges. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 359 


Genus AULACOSPHINCTES Uhlig rg10 
Aulacosqhinctes spitiensis (Uhlig) 
(Plate 11, figs 2a, b, 3a, b) 
1910 Perisphinctes (Aulacosphinctes) spitiensis Uhlig: 351, pl. XX XIII, figs ra—c, 3a—-c; pl. XLI, 
figs Ia—c. 

MATERIAL. Two specimens, C.76686-7. 

Horizon. About 2 feet below the base of the middle member of the Chichali 
Formation, Upper Tithonian. 

Description. The larger specimen is evolute, moderately compressed, 72 mm in 
diameter, and part of the outer whorl is body-chamber. The whorl section is sub- 
quadrate, and the venter has a moderately deep groove. The ribs are straight and 
prorsiradiate, and commonly bifurcate on the upper part of the whorl side. Ribs 
that bifurcate twice are common on the outer whorl, but only occasional on the inner 
whorls. The first bifurcating point of these ribs is in the middle or the lower part of 
the whorl side. There are a few simple ribs, and rarely the ribs branch near the 
umbilical shoulder and one or both bifurcate again in the middle of the whorl side. 
The outer whorl has 42 ribs at 72 mm diameter. There are occasional shallow 
constrictions parallel to the ribs. 

DIMENSIONS. C.76687-72: 20 (28), 20°5 (28), 36 (50). 

REMARKS. These specimens are very similar in dimensions, rib density and 
multiple ribs to Uhlig’s (1910) figured examples of A. spitiensis from the Himalayas. 
Aulacosphinctes moerikeanus (Oppel) is a very closely related species, also from the 
Himalayas (Uhlig, 1910 : 350, pl. XXXIII, fig. 2; pl. XX XVIII, fig. 6), which 
differs in being slightly more evolute and in having slightly fewer ribs. 

Locatity. South-west of Shaikh Budin, Shaikh Bud in Hills, Trans Indus Ranges. 


APTYCHI 
Laevaptychus 


MATERIAL. Six fragments. 

Horizon. 4 to 5 feet above the base of the Chichali Formation, Lower Kim- 
meridgian. 

DEscrRIPTION. The shell is moderately broad and thick, covered with fine pores 
on the convex side and concentric growth line or striae on the concave side (the 
inside). 

Remarks. They are similar to the aptychus figured by Spath (1931: pl. LX X XVI) 
from the Katrol Beds of Cutch. In the Trans Indus Ranges they occur at the same 
horizon and locality as Aspidoceras (Aspidoceras) sp. indet. 

Locatity. Punnu Mines, Trans Indus Ranges. 


360 JURASSIC AND LOWER CRETACEOUS ROCKS 


VII. CORRELATIONS 


a. Jurassic and Cretaceous stages 
in northern West Pakistan 


The condensed nature of fossiliferous beds and the irregular distribution of 
ammonites in all the sections of northern West Pakistan do not warrant a detailed 
zonation. The zonal scheme (Fig. 6) adopted here is that of North West Europe for 
the Lower—Middle Jurassic (inclusive of the Callovian), Central and Southern 
Europe for the Upper Jurassic, and Western Europe for the Lower Cretaceous 
(Arkell and Wright 1957). 


JURASSIC 
Lower Toarcian 
The earliest marine fossiliferous Jurassic rocks are of Lower Toarcian age and 
contain a Bouleiceras fauna (including B. nitiscens Thevenin) which agrees well with 
that of Madagascar and Jebel Tuwaiq, Saudi Arabia (Arkell 1952, 1956). 


Bajocian—Bathonian 
No ammonites have been found in rocks of this age. 


Callovian 


The Callovian ammonites show a strong similarity with Cutch. The dominant 
genera are Reineckeia, Obtusicostites, Hubertoceras, Choffatia. The recognition of 
Reineckeva anceps in the assemblage places the beds in the Anceps Zone of the Middle 
Callovian. 

No ammonites occur in the Lower Callovian beds and most of the Upper Callovian 
and Lower Oxfordian is missing from the area. 


Upper Oxfordian 

The Upper Oxfordian ammonites are again closely comparable with those of the 
“Upper Dhosa Oolite’” and “Kantcote Sandstone” of Cutch (Spath 1933). The 
recognition in the assemblage of Perisphinctes (Kranaosphinctes) sp. indet., Pert- 
sphinctes (Dichotomosphinctes) cf. rotoides Ronchadze, and Mayaites cf. waagent 
(Uhlig), from the Trans Indus Ranges, and Perisphinctes (Arisphinctes) orientalis 
Siemiradzki and Prososphinctes virguloides (Waagen) from Kala Chitta—Nizampur 
area, places the assemblage in the Transversarium Zone. The higher Bimammatum 
Zone may also be presented in the highly condensed rubbly Upper Oxfordian beds 
(less than 2 feet thick) of northern West Pakistan. The ammonites are worn and 
indicate reworking. Spath (1934) placed the Kala Chitta fauna in the Trans- 
versarium Zone but pointed out that some species may belong to the Bimammatum 
Zone. 


Lower Kimmeridgian 
Above the Upper Oxfordian ammonite bed of the Chichali Formation in the Trans 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 361 


Indus Range Aspidoceras (Pseudowaagenia) sp. indet. and Physodoceras (Simaspido- 
ceras) sp. indet. occur. Five to ten feet above these beds are found A. (Aspidoceras) 
sp., Laevaptychus, Pachysphinctes robustus Spath and Katroliceras cf. pottingent 
(J. de C. Sowerby) followed by Ptychophylloceras ptychoicum (Quenstedt) and 
Hybonoticeras sp. The assemblage indicates a Lower Kimmeridgian age. Associa- 
ted with the ammonites are Belemnopsis gerard: (Oppel) which, though occurring in 
the underlying Upper Oxfordian rocks, does not extend into the overlying Lower 
Tithonian beds with Aulacosphinctoides and Hildoglochiceras. 


Lower Tithonian 

About 5 feet above the higher Kimmeridgian bed Aulacosphinctoides (including 
A. uhligi Spath), Hildoglochiceras sp. indet. (comparable with H. kobelli), Virgato- 
sphinctes (V. frequens, V. denstplicatus) and Provalanginites gen. nov. occur followed 
higher up by Proniceras indicum Spath and Holcophylloceras silestacum (Oppel). 
The first appearance of Aulacosphinctoides is taken here as marking of the base of the 
Tithonian, but the placing of the faunas in the detailed zonal scheme of Arkell (1957) 
is not yet possible because of the rare occurrence of these genera, uneven distribution 
in the area and condensed nature of the deposits. 


Upper Tithonian 

In the Upper Tithonian the commonly occurring genus is Blanfordiceras (including 
B. wallicm). The first appearance of Blanfordiceras in the area is taken to mark the 
boundary between the Lower and Upper Tithonian. Blanfordiceras is associated 
higher up with Himalayites and Aulacosphinctes. 

Immediately below the Swbthurmannia beds (considered here to mark the base of 
the Cretaceous) Protacanthodiscus aff. michaelis (Uhlig), Protacanthodiscus sp. indet., 
Spiticeras multiforme Djanelidze, Spiticeras sp. indet. occur. This assemblage 
suggests the highest Tithonian (Chaperi Zone). 

The Upper Tithonian beds of the Chichali Formation have abundant Hibolithes 
(also abundant in the Lower Tithonian and Kimmeridgian) but are not very rich in 
ammonites. 


Jurassic—Cretaceous Boundary 

The Cretaceous boundary is drawn at the first appearance of Subthurmannia 
(including S. fermort) in the upper part of the Lower member of the Chichali Forma- 
tion. The Jurassic-Cretaceous boundary is transitional in most areas, except in 
parts of Hazara, where non-sequences are present in the succession. 


LOWER CRETACEOUS 
Berriasian 
Subthurmania is the most abundant genus, associated with Neocosmoceras (N. aff. 
spitiensis) and Negreliceras. The assemblage is typically Berriasian and indicates 
the Boissieri Zone. 


362 JURASSIC AND LOWER CRETACEOUS ROCKS 


The ammonites of Berriasian age are also present in the western part of the Main 
Salt Range, though they are less abundantly developed. This is in contrast to 
Spath’s suggestion (presumably based on failure of collections) that they are absent 
from the Salt Range (1939 : 131). In Hazara and Kala Chitta Range their occur- 
rence is rare, and in parts of Hazara they are missing because of non-sequence. 


Valangimian 

The Valanginian ammonites, though condensed in beds 15 to 20 feet thick and 
missing in parts of Kala Chitta and Hazara (because of a non-sequence), include 
three faunal assemblages in the Trans Indus Ranges and Western Kohat. These 
are (from top to bottom) as follows :— 


3. Olcostebhanus (Olcostephanus) salinarius Zone, including many species of 
O. (Olcostephanus), less commonly O. (Rogersites), Distoloceras, Lyticoceras and 
Leopoldia. 

2. Neocomites (Odontodiscoceras) similis Zone, including species of Neocomites 
(Parandiceras) such as N. (P.) theodorii (Oppel), Kilianella (K. asiatica Spath, 
K. leptosma Uhlig, Kilianella sp. nov.), Neocomites (Calliptychoceras) and 
Neohoploceras. 

I. Sarasinella uhligi Zone. This is a provisional poorly defined zone and 
includes Sarasinella subspinosa (Uhlig), Thurmanniceras sp. Neocomites 
(Neocomites) sp. nov. 

The Sarasinella uhligi Zone seems to correspond to the unnamed zone below the 
Roubaudiana Zone of Wright (1957) or to Gratianopolitense Zone of Spath (1939 : 
132). 

The Neocomites (Odontodiscoceras) similis Zone is equivalent to the Kilianella 
voubaudiana Zone of Wright and Spath. 

The highest Olcostephanus (O.) salinarius Zone corresponds to the Schenki and 
Verrucosum Zones of Spath (1939). The dominant genus in this zone is Olco- 
stephanus (Olcostephanus) which is associated with O. (Rogersites), Distoloceras, 
Leopoldia and Lyticoceras. 


b. Correlations within Pakistan 
(i) Baluchistan 


In Baluchistan ammonites of Lower (Toarcian and doubtful Sinemurian), Middle 
(Upper Bathonian—Lower Callovian) and Upper Jurassic (Lower Tithonian) age 
have been recorded (Noetling 1897; Vredenburg 1909; Spath 1933, 1936; Arkell 
1956). The main similarities between the ammonite faunas are found in the Lower 
Toarcian and Tithonian. 

The Bouleiceras species are similar, but the other recorded Lower Jurassic 
ammonite genera from Baluchistan do not occur in the Lower Toarcian ammonite 
bed of Kala Chitta and Hazara. The associated rhynchonellids and Pecten sp., 
however, are closely comparable. A detailed study of the Lower Jurassic sequence 


SYSTEM. 


CRETACEOUS 


CIN PART ). SERIES. 


LOWER 


OF THE L4 


NORTH W656) 


JURASSIC 


ARKELL 1957 
CRETACEG 
WRIGHT 1957 


STAGES. 


BARREMIAN 


HAUTERIVIAN 
VALANGINIAN 


TITHONIAN 


SIP int 


(AFTER ARKELL 1956 
PASCOE 1959 ) 


No ammonites 
(Flysch) 


Rogersites schenki 

Olcostephanus maidani 
Bochianites 
kilianella, 
Sarasinelia, 
Thurmanniceras 


(Not 


Neocomites 


zoned ) 
2: 


Subthurmannia_ boisseri 


Neocosmoceras , 
( Not 


Spiticeras 


zoned ) 
2 


Blanfordiceras 
Aulacosphinctes 


Kossmatia 


Virgatosphintes 
Hildoglochiceras 
Aulacosphinctoides 


(Not zoned) 


Sandstone 


Giumal 


Shale 


Upper Spiti 


CUTCH. 
(AFTER SPATH 1933, 
CALLOMAN 1955 AND 

ARKELL 1956). 


Trigonia cressa 


Trigonia ventricosa 


No evidence (Unfossiliferous ) 


Aulacosphinctes Umia 


Micracanthoceras 


(Not zoned ) Bed 
2 


Virgatosphinctes 


Upper 
Hildoglochiceras 
rae Upper 


Aulacosphinctoides Katrol 


5 Sandstone 


OXFORDIAN 


[ 


CALLOVIAN 


BAJOCIAN 


2 


B. gerardi, 8, uhligi 


“Perisphinctes” biplicatus 
(Not zoned ) 


Mayaites (Grayiceras ) 
M. ( Epimayites ), B gerard/ 


No evidence 7 Missing) 


? Represented locally 


Macrocephalites 


Aloclytoceras 


Belemnopsis sulcacutus 


Limestone ) 


Upper Kioto 


Pachysphinctes , Aspidoceras 
Hybonoticeras, Katroliceras 
Torquatisphinctes, Streblites 


grame erg No oned 


Dichotomosphinctes 
Discosphincte 
Mayaites, Perisphinctes 


Ochetoceras ( Camphylites ) 
Peltoceratides 
? 


lamberti 


Peltoceras athleta oper 


Reineckeia anceps 
Indocephalites diadematus 


Macrocephalites dimeru 
triangularis 


Ammonite 


Katrol orale 


NORTHERN PAKISTAN. 


No ammonites 


Olcostephanus (0) salinarius 
O(Rogersites), Lyticoceras, 
? 


with 
Distoloceras 


Neocomites ( Odontodiscoceras ) similis with 
Kilianella , N (Calliptychoceras ). 
Bochianites, N.(Parandiceras ), 
Saras/nella, _ N (Neocomites) copei 


Thurmanniceras (Lower part not zoned ) 


Subthurmannia fermori with many 
S.spp, Spiticeras (Spiticeras), S.(Negreliceras), 
Neocosmoceras, Protocanthodiscus 


Protocanthodiscus, 
Himalayites, 


Aulacosphinctes 


Blanfordiceras 


Proniceras indicum, Holcophylloceras (Not zoned ) 


Aulacosphinctoides, Virgatosphinctes 


Hildoglochiceras 


( Not zoned ) 


? 


Hybonoticeras, Ptychophylloceras ptychoicum 


Pachysphinctes, Katroliceras, Aspidoceras 


Se | 
Simaspidoceras, P. (Pseudowaagenia,) B 
P (Dichotomosphinctes ), P (Arisphinctes) 


P (Kranaosphinctes ) Euaspidoceras, M(Grayiceras) 


No evidence (Missing ) 


? 
R anceps, Obtusicostites , 
Hubertoceras Kinkeliniceras 


? No 
Reported 


ammonites 


Indocephalites by Spath, 1933 


Corbula lyrata, 
Stephonoceratid 


Protocardia | Kuar 


Corbula lyrata, P. grandidieri 


bceras spalinum 
kyloceras _jurense 


Dactylioceras tenvicostatum 


— 


Boulecerss 


STANDARD STAGES & AMMONITE ZONES [SOUTHERN FRANCE BULG aa | 1 
Oe TE EO Sunes (BORDERS/OF MASSIF, ) LGARIA MEXICO, ARGENTINA. RUSSIA (CAUCASUS) MADAGASCAR. TANGANYIKA, SPITI CUTCH NORTHERN PAKISTAN. 
ROPE, (AFTER 
Naeasetes OF WESTERN TETHYS (arTer (AFTER ARKELC 1956. ER NIKOLOV 1965) (AFTER IMLAY 1939 1944 (AFTER LEANZA 1945, GIOVINE (AFTER CAZANOV 1953, (AFTER ARKELL 1956) ( AFTER ARKELL 1956) (AFTER ARKELL 1956 (AFTER SPATH 1933, 
ARKELL 1057) AND OF PART OF THE LOWER BUSNARDO AND HEGART 1965, & 1960 ), 1950, ARKELL 1956 AND & IMLAY 1960 ) PASCOE 1959) CALLOMAN 1955 AND 
>t wv IS OF WESTERN EUROPE (arter BARBIER AND THIEULOY 1965. IMLAY 1960). ARKELL 1956) 
wld ICRETACEOU: DEBELMAS AND THIEULOY 
| — | WRIGHT 1957). 1965) 
wie 
>} Ww 
0) | staces. ZONES. 
Thal Cesnaacus _recheostolvs IL 
_< |BARREMIAN : 
Ww) a trleceralites emericionus : 
>| < Paeudotnurmannia _ongulicostata PF engulicostota Pl ehgucostata Holcodiscus subostarla = 
< Sudsaynelia sayni 5. sayni S saynr Not identifies |___P anguticostata No ammonites s No ammeates 
O} o |xaurervian SST = ai i ; 5) Simberskites_subinersus [Not zoned ) (Fiysch) z 
Jennie aaa D1ees!ephans Tylleccerasy pseidoregalis ceTacsraviteanslan? 5 
icanthediscus Fodiatus Udesiarus ose ond = 
a 2 SETS 2 eras! Thurmeonieeras ieanthoaheustecAradlalis lepaal da lee) — ——— = s 
= Rogersites 1 ae etd A Re 
Soynoceros verrucosum Sayneceras verrucosum 5g fenuicostarus Glcoslephanus curacoensi= Raccnnilaa nl Oleaslenhans va jogersites schenk) Dlcostepanis (0) solrarius with 
<q We ; aceGeane oynecere! : Olgostephanus volanginites Rogersites laticestatum. [__Dichotomites bidichotemus __] Regersites , Olcostephanus Ee ee Oieostepanus maldand Ot Ragersites). _Lyticcceras, Disfolocercs 
e Wianelia revdau (Nol -zened not foned Sa TT Neocommiles, /Heahoploceres Bochianites Bechianites 3 
= VALANGINIAN| Nevcomites Thurmanniceras nevih/spanieus Aoehlenltes, sThirmoDlearae B Naccanlien Kiltanella, Neccomites Trigenia. cressa Neccorvies { Odentod/scocercs 1 similis with 
ul Hilionelia * Nechoploceras, Kilianella Neocomites wichmanni Sarasinelia Kilianetia . N (Calliptychoceras } 
W|= roubaudiana "wrmanniceras Kilianelia reubauvdiang (Not toned) on Thurmanniceros Sorasinelia Thurmamniceras : Trigonia ventricosa Bectenites. N(Parandiceras }. 
ZONE UNNAMED Kilionelia > Thurmanniceras pertransiens > Ne ne Not zone & Soros ney aireiea eoconl ie eee 
am|o Not identified bile ie URE, ASSURE Soothes =| i 5 Thurmannicercs (Lower part not zoned } 
O J Berriaselia boissieri Spiticeros Uhlig) and Spiticeras domes) and Subthurmannia boisseri = Subthurmannia fermert with mony 
BERRIASIAN | Thurmarnicercs beissier: — — — — — ——~J _Subthurmanna bolssieri seeematmancie ,éensisiriatus Cuyoniceras _transgrediens Saiticeras) inegrel Kidenallalieex/pLchoaes > Missing Neacosmiocaraz yt splllcecex || Soh | (Nallevidencel Ua eselll farce) Sion. Spiticeres (Spiticercs), S (Negrecerca), 
Berriaselia grandis purmannia tenoehl ant irgenticer juliferum an in eli uthurmenni 7 
ereloselleTiigcend api pirmonala lensed ken Argenticeras neduliferim and Thurmanniceras off T boiss/er! {Not zoned) (Noll zened ) S (ee 
= Berriaselia chap viewaren Berriosella chaperi Subsieureceras, Himolayites Substeureceras hoenen/ Himalayites,  dulacosphinctes PMisstogtiny ratty) Blanferdiceras S | dvtecosphirctes Umia | Prefecantheaacus, 4ulacasphvnctes 
Berriaselia._celphinensis |transiterivs| Berriasella_celphinensis Aulacosphinctes PseangNerroemCINeRane Blanferdiceras, Micracanthoceras Pyne ee Aulacosphinctes Micrecanthsceras  |Ammonite | Himalayites,  Blanfordiceras 
[S| Semirormiceras semifarme Ree ER ne: (Hol zoned) 2 o Kossmatia (Not ‘zoned I pes Franeeras iNGeum. Ablecptytiocercs (Net zoned J 
; ae 
ce | TITHONIAN feeien Gent ne Virgatesphinetes > Viegatesshinctes Virgotosphintes 5 ce | 
aaa Holcophyiloceras Hildoglochiceras Miidoglechiceros | hiccoatochlceres epee aaa arate 
Ww erg nenes Hildeglechiceras Avlacosphinct ices Aulacesphinctontes $§-—-——— — = CEES) 
a TinagraanTcam iNet) zoned 1 Se Aas ae BL auicccspnnciaces | Beer, (worl racers 
2 Uniigites (MW eee a = 4 Esndetone 
a Hybencticeras sipdichetemoceral) egyriyewrall oePosirs HyBenat/ceres : Bgerarai, 8, uhligi — | Pochysahinetes. Assudoceras Hybareticeras._Ptychepkettoceres, ptychaless’— || 
2) Pachysphinctes, , Aspidoceras Pochysphinetes,_dspidoceres [Fervsphinetes= biplicaius || = | HyBenaticeras, Katroliceras Poshysphinctes. Kotrelieeras_Aspidoceres, _ 
(deceras , Aspldoceras ; , Be SS SSS 
pe iE Neus Téseeras | Aspideceras (Ne evidence J P er |_CNot_zonee.d 3 Simospicccercs_ > [Prevcemcagea) 8 gerarai 
are Bimammatum peony eC i. (No evidence) sale Rayalles!isregiesresl) $6 ® (Oicholemeserinctes J, P (Ariaphinetes!) 
P| areseryeeras transverserium | ome pe a Mt Epimayites).B gerardi_| © _ [/Mayaites. Perisphine Erase eed 
O}  loxronouan |=) eeserveteasitcanarerse Ferlsphincles.  Euespidsceras FP ldichatemasehinctes | Eurspuccceres || P.(Arigphinctes | enlentali Epimayites J. geraral es. Periashincles ni tes) Evaspicacr 2 
aa an } Waeteeigitntal $ | eretoceras ¢ Compnylites | 
3 | aoenatedfateros mari reser jo evidence (Missing ? Seco S| reitoceratices 
Guenstectocerss morige _|3 5 sy eldipea Soe 
[3 a Pulealicerss ond Halleyeencel (Hisar 9 > Represented ioecily | . 
ee Peiteceras athleta Pelloceras | | ee ete 7: a, mite 
[[Eurymosceras corenatum ____+| TaacheleMeeGrencins $5 [Reineckera _ancens Nopectoceresj — Minketintceres 
¥ ceras corenaty: Aelneckelanjetrancep: Obtusicostites. Hubertoceros a° 
CALLOVIAN Obtusicostites, Hubertoceras ; 3 [[Reineckeia: rehmani 
: 7 5 2) No) onunceites 
5 Mec re Reported Incecesrctites by Soath 103 
Wi) w 4 s Present Mecrecesralifes dimervs 
Mocrocephalites macrocepholux Mi. tricnqueris 
4 Siydeniceras discus Corbujallyrateneovanaidlert Corbula Iyrata, Pretecerde |Rcr | Cortule tyrate, P. grander 
> | Steprenccerstia 
Q|PATHONIAN [Trutites aupeontractus | = 
a) Graci/i=sphineten_progracilis | 2 
€ 
a Zigeagiceros zigzai Present = 
= oa igeag 
_ Porkinsenia _parkinsent = 
me = 
2 3 
Sirephancceras_humphriesianum & 
BAJOCIAN | oreites saute) = 
[taeteceras scissum | eee 
Aloclytoceres 
Bouleiceras, Ne/dia 


Fic. 6, Correlation of Jurassic and Lower Cretaceous faunas of northern West Pakistan. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 363 


of Baluchistan should prove of great interest in comparing the supposed Upper 
Pliensbachian age of the Bouleiceras in Spain by Bizon et al. (1966), as the sequence 
in Baluchistan is believed to extend below the Toarcian. 

The Virgatosphinctes species, V. denseplicatus (Waagen) compare well with the 
Virgatosphinctes species, found associated with Aulacosphinctoides in Hazara and 
the Trans Indus Ranges. 

The ?Berriasian or Valanginian ‘“‘Belemnite shales” (Arkell 1956 : 396) apparently 
succeed Lower Callovian limestone with Macrocephalites, and have Hibolithes 
(H. pistillifornis and H. subfusiformis), which have also been recorded by Spath 
(1939) from the Salt Range and Trans Indus Ranges. Stevens (1965 : 150), review- 
ing the belemnites of the Salt Range, confirmed Spath’s identification of H. pistilli- 
formis and H. subfusifornis, but has suggested that “‘It is likely that the belemnites 
recorded by Spath from this locality, and all Belemnopsis recorded by him from the 
Salt Range, have been derived from the underlying Upper Jurassic horizon, the 
belemnite in place being Hzbolithes”’. Spath (1939), however, described Hibolithes 
(A. pistilliformis and H. subfustformis) associated with the less commonly occurring 
Belemnopsis from Trans Indus and Salt Ranges. 

The present investigations indicate that Hzbolithes occurs in association with 
Belemnopsis and other Upper Jurassic ammonites, and none of the assemblage 
appears derived. In the major part of the Tithonian Hzbolithes occurs without 
association of Belemnopsis, but lower down the two species of Hzbolithes are asso- 
ciated with less commonly Belemnopsis. Forms resembling H. pistilliformis and 
H. subfusifornus continue in the Berriasian and Valanginian, but are not so well 
preserved as those in the Kimmeridgian and Lower Tithonian beds of the Chichali 
Formation (““Belemnite Beds” of Spath). In fact the preservation of the Hzbolithes 
monographed by Spath, suggests that they are mostly from the Tithonian and 
Kimmeridgian beds of the “‘Belemnite shales’ of the Trans Indus and Salt 
Range. These observations suggest that H. pistilliformis and H. subfusiformis are 
either long ranging (Upper Jurassic to Lower Cretaceous) or their identification as 
such from the Salt Range and the Trans Indus Ranges needs more careful examina- 
tion. A long range for these species seems to be a more logical conclusion. Their 
presence in Baluchistan in the ““Belemnite shales’ may not restrict the age of these 
beds to Berriasian or Valanginian, but in all probability the ““Belemnite shales” of 
Baluchistan range in age from Tithonian to Neocomian, for Lower Tithonian is 
indicated by the presence of Virgatosphinctes in certain areas of Baluchistan. 


c. Correlations with areas outside Pakistan 
(i) Cutch 


The Middle and Upper Jurassic faunas of Cutch show close similarity with those 
of northern West Pakistan, particularly those of Trans Indus and Kala Chitta 
Ranges (Fig. 6). The Jurassic and Lower Cretaceous succession of Cutch has been 
summarized by Spath (1933) and Arkell (1956). 

The Upper Bathonian bivalves fauna of Kuar Bet Beds of Cutch can be correlated 


304 JURASSIC AND LOWER CRETACEOUS ROCKS 


with a similar fauna from the uppermost beds of the Samana Suk Limestone in Kala 
Chitta (fig. 6). The faunas of the Macrocephalus and Rehmanni Zones have not 
been found by the present survey. There is a suggestion of the presence of the 
Rehmanni Zone in the Subkossmatia fleming: Bed north of Kalabagh (reported by 
Spath 1933, but not found by the present survey), and the Belemnopsis grantana 
Bed of Western Kohat (uppermost part of the Samana Suk Limestone). These 
faunas suggest that the uppermost part of the Samana Suk Limestone in these areas 
may be slightly older than the Anceps fauna of the rest of the Trans Indus Ranges 
(west of Chichali Pass). 

The Anceps Zone of Cutch is well represented in commonly occurring genera and 
species in the uppermost 2 feet of the Samana Suk Limestone of the Trans Indus 
Ranges (west of Chichali Pass). The major part of the Athleta Zone and Lower 
Oxfordian are missing from northern West Pakistan. The Upper Dhosa Oolite 
(Transversarium Zone) and Kancote Sandstone (Bimammatum Zone) faunas may 
be correlated with a similar assemblage in the condensed bed (less than 2 feet) at the 
base of the Chichali Formation in the Trans Indus Ranges and the Kala Chitta— 
Nizampur areas. 

The ammonite faunas of the Lower and Middle Katrol Beds compare favourably 
with those found in the Trans Indus Ranges, except that not all the genera occurring 
in Cutch (such as Tavamelliceras, Glochiceras, Streblites) have been found in Pakistan. 
These Lower—Middle Katrol Beds have been doubtfully placed by Spath and Arkell 
in the Middle Kimmeridgian, though both authors have pointed out the presence of 
Pseudomutabilis and Upper Tenuilobatus Zones in the assemblage. 

In the Trans Indus Range it was found that Aulacosphinctoides occurs a few feet 
above the Pachysphinctes, Katroliceras and Hybonoticeras Beds, and the lowest 
Kimmeridgian beds have A. (Pseudowaagenia) and P. (Simaspidoceras), and no 
Pachysphinctes. These two Kimmeridgian horizons are comparable with the Middle 
and Lower Katrol Beds of Cutch. 

The placing of Lower and Middle Katrol Beds in the Middle Kimmeridgian by 
Spath (1933) and Arkell (1956) presumably was based on the identification of 
Hybnoticeras beckerit in the Lower Katrol Beds. The other elements of the fauna 
point to a Lower Kimmeridgian age of the assemblage. In Europe and parts of 
Africa Pachysphinctes, Taramelliceras, Torquatisphinctes and Katroliceras have been 
more typically reported from the Lower Kimmeridgian rather than from the H. 
beckert Zone. In the Tellian Atlas Streblites tenwilobatus occurs in association with 
Hybonoticeras (Arkell 1956 : 273). It is, therefore, likely that the genus Hybonott- 
cevas may have appeared earlier in the Kimmeridgian in Cutch and the Trans Indus 
Ranges, and very likely it does not represent the true Beckeri Zone. 

It is interesting to note that more definite evidence of the occurrence of Aulaco- 
sphinctoides is reported from the next higher horizon, the Upper Katrol Sandstone, 
which is over 700 feet thick and in main is unfossiliferous. The Trans Indus 
Kimmeridgian and Tithonian Beds on the other hand are much condensed, but even 
there a slight unfossiliferous interval occurs between the Pachysphinctes Beds and 
the overlying Aulacosphinctoides Beds. It is suggested that the time interval 
represented by the true Beckeri Zone may be present in the unfossiliferous Upper 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 365 


Katrol Sandstone of Cutch or the beds above the Pachysphinctes horizon in the Trans 
Indus Ranges. 

The Upper Katrol Sandstone, Upper Katrol Shales and the lower part of Umia 
Ammonite Bed, can be correlated with the Lower Tithonian Beds of the Trans Indus 
Range and Hazara. There are, however, some differences: in Cutch Aulacosphinc- 
toides is reported from the Upper Katrol Shales which has Hildoglochiceras and other 
faunas; it is doubtfully and rarely recorded from the Umia Ammonite Bed which 
has more typically a good representation of Virgatosphinctes. 

In the Trans Indus Ranges and especially in Hazara, Awlacosphinctoides and 
Virgatosphinctes occur in close association. Hildoglochiceras has been found 
associated with Auwlacosphinctoides in the Trans Indus Ranges. 

In northern West Pakistan the appearance of Aulacosphinctoides has proved to 
be a useful and convenient horizon to mark the base of the Lower Tithonian. The 
Upper Tithonian/Lower Tithonian boundary is placed at the appearance of Blan- 
fordiceras, followed by Himalayites and Aulacosphinctes. From the Umia Ammonite 
Bed of Cutch, there is no record of Himalayites and Blanfordiceras (common in 
Spiti, Pakistan and Madagascar), but Awlacosphinctes is reported, which suggests 
that part of the Umia Ammonite Bed is Upper Tithonian. 


(ii) Spote 

The Upper Jurassic, Berriasian and Valanginian faunas of the Spiti Shales (thick- 
ness 500 feet) compare favourably with northern West Pakistan (fig. 6). The 
ammonites were monographed by Uhlig (1903-10) who defined the stratigraphic 
position of some within the three-fold division of the Spiti shales. Other faunas 
were placed undefined in the Spiti shales, but many of these are considered by 
Pascoe (1959 : 1174) to have been collected from the Chidamu Beds (Middle Spiti 
Shales). The succession is described by Diener (1895), Hayden (1904), Uhlig (1910), 
Arkell (1956) and Pascoe (1959). 

Giumal sandstone (up to 495 ft). This formation is regarded as Middle Neo- 
comian by Arkell (1956) and post Valanginian by Pascoe (1959). 

Spiti shales (500 ft), consisting of the following three divisions: Upper Spiti 
shales (Lochambel Beds), with Olcostepbhanus (Olcostephanus), O. (Rogersites), 
Neocomites (Calliptychoceras), N. (Parandiceras), N. (Odontodiscoceras), Kilianella, 
Neocomites, Sarasinella, Thurmanniceras, Subthurmannia, Neocosmoceras, Spiticeras, 
Blanfordiceras, Himalayites and Aulacosphinctes. 

Middle Spiti shales. A number of Upper Tithonian and Lower Neocomian 
genera have been doubtfully listed from these beds (Pascoe 1959 : 1174-75). In 
addition, more definite forms reported include Blandforiceras, Pterolytoceras exoticum, 
Paraboliceras, Kossmatia and Uhligites. This assemblage suggests that at least 
part of the Middle Spiti Shales is Upper Tithonian. Other ammonites from the 
Middle Spiti Shales include Virgatosphinctes, Aulacosphinctoides and Hildoglochiceras 
(stratigraphical position unknown), and Belemnopsis uhligi Stevens (=B. gerardi 
of Uhlig). 


366 JURASSIC AND LOWER CRETACEOUS ROCKS 


Lower Spiti shales (Belemnopsis gerardi Beds), with Belemnopsis gerardi (Stevens 
1965, p. 149 doubts its identification), Mayaites, Grayiceras and Epimayites. 

The Lower Spiti shales are regarded as Upper Oxfordian by Uhlig (1910), Spath 
(1933, 1939), Arkell (1956), Pascoe (1959) and Krishnan (1960), but Stevens 
(1965 : 149) on the basis of identification of B. uhligi (=B. gerardi of Uhlig) con- 
siders them to be Middle Kimmeridgian. In the present correlation, on the basis of 
the mayaitid ammonites, these are regarded as Upper Oxfordian to Lower Kim- 
meridgian. 

The Lower Spiti shales can be broadly correlated with the lowest bed of the 
Chichali Formation of the Trans Indus Range, the basal 2 to 3 feet condensed bed 
of the Chichali Formation of Kala Chitta and Nizampur areas, and with the whole 
of the Chichali Formation (“‘Spiti Shale” facies) of Kalapani-Kathwal sections of 
Hazara. In Hazara there is no evidence of Upper Oxfordian beds, and it is likely 
also that in parts of Spiti the Upper Oxfordian mayaitid beds may not have been 
deposited, and the whole of the Lower Spiti Shales may be Lower Kimmeridgian 
in age. 

The ammonites faunas of the Middle Spiti shales (Chidamu Beds) compare well 
with those of northern West Pakistan, except that such genera as Kossmatia and 
Paraboliceras are not known from Pakistan. The Awlacosphinctoides and Virgato- 
sphinctes compare closely with those found in the Trans Indus Ranges, Budin Hills 
and Hazara. In Hazara these two genera occur in the lower part of the “Giumal 
sandstone” (Lumshiwal Formation) and are not found in the “‘Spiti shale’’ facies of 
the Chichali Formation of the Kathwal—Kalapani sections. This correlation 
requires caution, for in the vast outcrop of the Spiti shales in the Himalayas the 
fauna may not be restricted to the same lithological division of the Spiti shales. 
This presumably accounts for the Lower Tithonian—Valanginian fauna listed by 
Pascoe (1959 : 1174), who believed most of them to have come mainly from the 
Middle Spiti shales. It is, therefore, probable that the three divisions of Spiti shales 
in the Spiti area may be diachronous as in Hazara. 

The Upper Spiti shales have a very interesting assemblage which is of upper 
Tithonian to Valanginian age. The Upper Tithonian can be correlated with a 
similar fauna from northern West Pakistan, except that Protacanthodiscus seems to 
be not represented in the Spiti shales. . The Jurassic/Cretaceous boundary occurs 
within the Upper Spiti shales without a break similar to that of the Trans Indus 
Ranges. The Berriasian is indicated by Subthurmannia boissiert and S. surgharensis. 
The more common occurrence of Neocosmoceras and Spiticeras as compared to 
Subthurmannia in Spiti, is contrasted with the abundance of Subthurmannia in the 
Berriasian of the Trans Indus Ranges. 

The three Valanginian zones of the Trans Indus Ranges (0. salinarius, N. similis 
and S. whligt) are represented in the Valanginian assemblages of the Spiti shales. 

The overlying Giumal Sandstone can be broadly correlated with the Lumshiwal 
Formation of Kala Chitta, with the Upper member of the Chichali Formation, and 
the Lumshiwal Formation of Western Kohat and the Trans Indus Ranges. In 
Pakistan, Aptian and Albian ammonites occur, but apparently no ammonites are 
reported from the ““Giumal sandstone”’ of Spiti. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 367 


(iii) Persia (Elburz Mountains) 


In the Elburz Mountains marine succession from Toarcian to Lower Cretaceous is 
developed, and the Lower and Middle Jurassic rocks have many ammonite horizons. 
There appears to be a faunal break between the Middle Callovian and Upper 
Oxfordian, and the Toarcian marine rocks overlie the rest of the continental Lower 
Jurassic (Arkell 1956). 

The Reineckeva Beds of Persia (with R. anceps) are comparable with those of the 
Trans Indus Ranges, except that in Persia genera like Obtusicostites, Hubertoceras 
have not been reported. 

The perisphinctid fauna and associated Euaspidoceras of Upper Oxfordian age 
compare well with that of the Trans Indus Ranges and Kala Chitta. 

There is hardly any similarity with the Kimmeridgian faunas, but from the 
Tithonian Virgatosphinctes, Berriasella and Substeueroceras have been recorded 
which show the presence of Lower and Upper Tithonian (Spath 1933 : 831). 

On the Lower Cretaceous Spath (1939 : 141) commented, “‘There is only one small 
suite, submitted to me . . . . which showed a remarkable similarity even in the 
preservation, to the fauna of the Valanginian marls of the south of France’. He 
further remarked, “‘there is abundant evidence of the presence of forms lke Berr1- 
asella, Substeuroceras and allies in southern and south western Persia and of a com- 
plete succession from the uppermost Jurassic into the Lower Cretaceous’’. 


(iv) Saudi Arabia (Jebel Tuwaig) 


The Jurassic and Cretaceous sequence in Saudi Arabia (Powers, Remirez, 
Redmond and Elberg 1966) indicates disconformities between Triassic and Lower 
Toarcian, between Middle Callovian and Oxfordian and within the Lower and 
Upper Cretaceous which are comparable with Northern Pakistan. 

Ammonites are recorded from Toarcian, Middle-Upper Bajocean, Middle Bathon- 
ian, Middle Callovian and there is a small perisphinctid assemblage from Oxfordian 
(Transversarium Zone) and Kimmeridgian (Tenuilobatus Zone). The Jurassic/ 
Lower Cretaceous boundary is considered transitional. 

A firm correlation exists with the Lower Toarcian Bouleiceras Beds (Marrat 
Formation) of Jebel Tuwaiq (Arkell 1956 : 300). 


(v) Ivagq (Kurdistan) 


An interesting Upper Jurassic assemblage was described by Spath (1950) from 
Kurdistan. The lowest Upper Jurassic fauna (Arkell 1956 : 376) is placed in the 
Lower Kimmeridgian (Pseudomutabilis Zone) and has the genera Ataxioceras and 
Aulacostephanus which are not found in northern West Pakistan. 

The next fossiliferous beds (with Pseudolissoceras) are separated from the under- 
lying Lower Kimmeridgian by 39 meters of unfossiliferous sediments. The fauna 
of the Pseudolissoceras Beds includes Pseudolissoceras, Promceras, Phanerostephanus 
and ?Glochiceras, and was placed into the Middle Tithonian by Spath. He (1950 : 


368 JURASSIC AND LOWER CRETACEOUS ROCKS 


100-101) doubtfully assigned two specimens to Glochiceras, though one was closely 
compared with Hildoglocheras grossicostatum Imlay, and the other has a pronounced 
mid-lateral groove and is more evolute than a typical Glochiceras. The presence of 
Promiceras in the assemblage suggests its correlation with the Proniceras indicum 
Bed of the Trans Indus Ranges, where it occurs above the Aulacosphinctoides and 
Virgatosphinctes horizon. The latter two genera are not known from Kurdistan and 
it appears that this zone will occupy a position in the 39 meters of unfossiliferous 
sediments below the Pseuwdolissoceras Beds. The fauna of the Lower Tithonian 
(lower part) thus seems to be missing from Kurdistan. 

The ammonites of higher beds are placed in the Upper Tithonian which include 
Substeueroceras, Berriasella and Paradontoceras, and can be broadly correlated on the 
basis of Berriasella with northern West Pakistan. 

Spath (1950) mentioned that the fauna of the Boissieri Zone of the Lower Creta- 
ceous is present in Kurdistan and thus the Jurassic-Cretaceous boundary appears 
transitional. 


(vi) Madagascar 


In the northern areas of Madagascar a more complete Jurassic-Lower Cretaceous 
sequence is developed and the Jurassic-Cretaceous boundary is transitional 
(Thevenin 1906, 1908; Besairie 1932, 1936, 1946; Collignon 1949; Arkell 1956) 
Firm correlations with northern West Pakistan can be made in the Lower Toarcian, 
Upper Bathonian, Middle Callovian, Upper Oxfordian, Lower Kimmeridgian, 
Tithonian, Berriasian and Valanginian (fig. 6). The rest of the Jurassic ammonite 
sequence is better developed and more complete in Madagascar than in northern 
West Pakistan. 

The earliest marine Jurassic fauna reported from Madagascar is dated as Lower 
Toarcian on the basis of Bouleiceras, which is associated with Protogrammoceras, 
Nejdia, Speriferina rostrata and Pecten. These beds can be correlated with the 
Bouleiceras Beds of the Datta Formation in Kala Chitta and Hazara. 

The next strata that can be correlated are the Upper Bathonian Bivalve Beds of 
Madagascar with Corbula lyvate and Protocardia grandidieri also found in the upper- 
most beds of the Samana Suk Limestone in Kala Chitta. 

From the Middle Callovian of Northern and Southern Madagascar, Obtusicostites, 
Hubertoceras, Reineckeia ct. anceps and other ammonite genera have been recorded 
(Arkell 1956 : 340). This assemblage compares well with that of the Trans Indus 
Ranges, except that other associated ammonite genera are lacking in northern West 
Pakistan. 

In the Upper Oxfordian of Madagascar a P. (Dichotomosphinctes) and Euaspido- 
cervas fauna of the Transversarium Zone is present, but the higher Bimammatum 
Zone is believed to be absent. These faunas are comparable with the Upper 
Oxfordian faunas of the Trans Indus Ranges and Kala Chitta. 

The Lower Kimmeridgian succession in Madagascar is probably incomplete, 
extending to the Pseudomutabilis Zone. The lowest Tenuilobatus Zone is believed 
to be absent. The fauna includes Aspidoceras, Pachysphinctes, Lithacoceras, 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 369 


Torquatisphinctes and Taramelliceras. Aspidoceras and Pachysphinctes are com- 
parable with the similar forms found in the Lower Kimmerdigian succession of the 
Trans Indus Ranges. 

The Tithonian of Madagascar again has some common faunal elements. In the 
Lower Tithonian Virgatosphinctes occurs quite commonly and is associated with 
Holcophylloceras, Huildoglochiceras kobelli (Oppel), and other ammonites. This 
associated is comparable with northern West Pakistan where, Aulacosphinctoides also 
occurs. Apparently no Aulacosphinctoides are known from Madagascar. 

The Upper Tithonian Beds of Madagascar, with Aulacosphinctes, Blanfordiceras 
acuticosta Uhlig and Himalayites, can be correlated with a similar assemblage in 
northern West Pakistan. It is interesting to note that Blanfordiceras and Himalay- 
ites are shared by Madagascar, Northern Pakistan and Spiti, but are not known 
from Cutch where only Aulacosphinctes is reported. The genus Micracanthoceras 
reported from the Upper Tithonian of Madagascar is not known from northern 
West Pakistan or Spiti. 

The Upper Tithonian clays and marls pass into the overlying Neocomian Beds in 
Madagascar. In the Berriasian Spath (1939 : 137) has listed Swubthurmannia, 
which was previously identified as Berriasella by Besairie, and associated with this is 
Kilianella. In Pakistan Kilianella occurs commonly associated with Neocomuites 
rather than Subthurmannia. 

From the Rogersites Beds of Madagascar Spath (1930 : 138) has listed a number 
of genera and species which are similar to the Valanginian beds of the Chichali 
Formation of the Trans Indus Ranges. These include Thuyvmanniceras, Sarasinella, 
Neoconutes, Neohoploceras, Bochianites, Olcostephanus (Olcostephanus), O. (Roger- 
sites), Distoloceras and ?Leopoldia. O. (Rogersites) is more abundantly distributed 
in Madagascar than O. (Olcostepbhanus), while in the Trans Indus Ranges O. (Olco- 
stephanus) occurs more abundantly than O. (Rogersites). The association of these 
two genera with Distoloceras and Leopoldia is very closely comparable with Northern 
Pakistan. 

Neolissoceras grasianum (d’Orbigny), though listed from the Valanginian beds of 
Madagascar, was found to occur both in the Berriasian and Valanginian beds of the 
Trans Indus Ranges. The genus Subthuymannia is also not so well represented in 
Madagascar. 


(vii) Tanganyika 


The Middle Callovian and Upper Jurassic fauna of Kilwa—Kiswere Lindi Hinter- 
land (Arkell 1956 : 331) show strong similarity with parts of northern Pakistan. 
The common genera in the Callovian are Obtusicostites, Hubertoceras and Choffatia. 
The upper Oxfordian has perisphinctids, myaitids and Ewaspidoceras. 

Dietrich (1925) and Arkell (1956) placed the Kimmeridgian ammonites from the 
Septarian marls in the Mutabilis and/or Pseudomutabilis Zones (Lower Kim- 
meridgian). The assemblage includes some common genera such as Pachysphinctes, 
Aspidoceras and Ptychophylloceras, but others, such as Streblites, Glochiceras, Tara- 
melliceras (known from the Middle and Lower Katrol Sandstone of Cutch) and 


370 JURASSIC AND LOWER CRETACEOUS ROCKS 


Nebrodites (not recorded from Cutch), are not known from Northern Pakistan. On 
the basis of Pachysphinctes and Aspidoceras, the Trans Indus Kimmeridgian beds 
can be correlated with that of Tanganyika. 

The Virgatosphinctes fauna of the Smeei Beds is comparable with a similar fauna 
from Northern Pakistan, except that no Aulacospiinctoides is reported from the 
Kiswere—Lindi Hinterland. In the Tendaguru area, however, the Smeei Beds 
(Arkell 1956 : 335) have yielded Holcophylloceras, Hildoglochiceras and Subdicho- 
tomoceras, which compares well with the Upper Katrol Hildoglochiceras Beds of 
Cutch. At a lower level (Nerinella Bed), Haploceras, ?Pachysphinctes staffi (generic 
affinities strongly doubted by Spath 1933, who regarded it an Aulacosphinctotrdes) 
and Subdichotomoceras sparstplicatum (Waagen) occur. It appears that the doubtful 
Aulacosphinctoides of the Nerinella Beds of Tendaguru occur below the Hildoglochi- 
ceras Beds, and occupy a position similar to the Upper Katrol Sandstone of Cutch 
with Aulacosphinctoides. In northern Pakistan, Awlacosphinctoides is associated 
with Hildoglochiceras and Virgatosphinctes and may thus indicate a rather condensed 
Lower Tithonian sequence in Pakistan. 

From the Trigonia schwartz Beds of Tendaguru, which disconformably succeed 
the Jurassic rocks, Olcostephanus, Bochianites and a doubtful Neocomites are recorded 
(Spath 31930: 140) and these compare with similar Valanginian fauna from 
Pakistan. 


(viii) Jubaland 


Although rocks of Lower Jurassic, Kimmeridgian and Cretaceous ages are known 
from Jubaland (Arkell 1956 : 317), the best correlation is established with the Lower 
Toarcian Bouleiceras Beds of Didimtu Hill, which overlie, with intervening con- 
glomeratic or gritty beds, the metamorphic basement complex. 

The Upper Oxfordian fragmentary perisphinctid (Kvanaosphinctes), Dhosaites and 
Euaspidoceras assemblage can be correlated with that of the Kala Chitta Range. 


(ix) Somaliland 


The Lower Toarcian Bouleiceras Beds and the Lower—Middle Kimmeridgian 
formations of Somaliland are comparable with northern West Pakistan. In the 
Tithonian a different ammonite assemblage (Anavirgatites and Pseudoinvoluticeras) 
is developed (Arkell 1956: 309). The Kimmeridgian Daghani Shale underlies 
Tithonian Gawan Limestone and has Streblites, Subdichotomoceras, Torquatisphinctes, 
Idoceras and Hybonoticeras in the upper part. Lower down Idoceras, Sutneria, 
Aspidoceras and Aptychus latus occur. 


(x) Southern France (borders of the Massif Central) 


The Upper Jurassic (Tithonian) and Lower Neocomian ammonite faunas of the 
classic areas of Berrias show close similarity in genera and some similarity in species 
with northern West Pakistan (fig. 6). There are, however, discrepancies which 
raise correlation problems. 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 371 


In the type section of the Upper Tithonian (Ardeche), Neumayr (1871) proposed 
Virgatosphinctes (2 an Aulacosphinctes) transitorius (Oppel) as the zonal index of the 
Upper Tithonian. Mazenot (1939) used two other indices, Berriasella chaperi 
(Pictet) above and Bb. delphinensis (Kilian) below, with the associated fauna of 
Corongoceras, Micracanthoceras, Proniceras and Spiticeras particularly well developed 
near Chomerac. Some of the Berriasella species of the Upper Tithonian, including 
B. chaperi, are more closely related to Protacanthodiscus because of their development 
of tubercles. The genera shared between Pakistan and France, are Proracantho- 
discus and Shiticeras. The two zones of Mazenot may thus correspond to the 
Protacanthodiscus, Himalayites, Spiticeras fauna above and the Blanfordiceras fauna 
below. 

Proniceras indicum Spath, the only species known from Pakistan, occurs lower 
down in the sequence, and similarly a number of Virgatosphinctes species known 
from Pakistan occur associated with Aulacosphinctoides in the Lower Tithonian. 
The occurrence of Proniceras in France seems to be higher in the Tithonian. 

The ammonite succession of the classic type area of Berrias was summarized by 
Hegart (1965) and Busnardo and Hegart (1965). The dominant Berriasian genus 
in France is Berriasella, while in the Trans Indus Ranges it is Subthurmanmia. 
This discrepancy seems to be partly due to non-recognition of the genera Protacan- 
thodiscus and Subthurmannia by the French authors. A number of species listed by 
Mazenot (1939) and others under Berriasella (chaperit, malbost, paramimouna, 
aspers etc) seem to be closely related to Protacanthodiscus. Similarly boissiert has 
been placed in Berriasella, though American and British palaeontologists have put 
itin Subthurmannia. Boissert is closely related to the type species of Subthurmanma, 
(S. fermort Spath), and its inclusion in Subthurmannia is preferred here. 

A comparison with the frequency and range of Tithonian—Berriasian—Valanginian 
ammonite genera and species in France given by Busnardo and Hegart (1965 : 27, 
Table VI) leads to the following conclusions: 


1. The genus Berriasella, though starting in the Lower Tithonian, has a maxi- 
mum development in the Berriasian and dies out about the beginning of 
Valanginian. In the Berriasian of northern West Pakistan, Subthurmannia is 
abundantly distributed and only one doubtful Berriasella species is recognized. 

2. Busnardo and Hegart have shown that Himalayites extends from the Upper 
Tithonian to fairly high in the Berriasian (in Arkell and Wright 1957, the 
genus is treated as Tithonian). In Pakistan no species of Himalayites were 
found associated with a typical Berriasian assemblage. The genus occurs 
below the Subthurmanma Beds in horizons which have yielded Protacantho- 
discus and even Blanfordiceras and Spiticeras, suggesting it to be a good 
indicator of Upper Tithonian in Pakistan. 

3. The range of Sfiticevas is from the Upper Tithonian to about the middle of 
the Lower Valanginian, with a maximum development in the Berriasian. In 
Pakistan Spiticeras and Negreliceras occur with Subthurmannia and Neocosmo- 
ceras in the Berriasian. It is not found in the Valanginian, and only a few 
species occur in the Upper Tithonian. Sfiticeras multiforme Djanelidze, 


372 JURASSIC AND) LOWER TERE TACEOUS ROCKS 


reported by Hegart (1965) from Boisseri Zone, occurs in the Trans Indus 
Range 3 feet below the Subthurmannia Beds at a horizon which indicates 
uppermost Tithonian. 

4. The range and maximum development of Thurmanniceras in the Lower 
Valanginian is closely comparable with Pakistan. 

5. The range and distribution of Neocosmoceras in the Berriasian of France is 
similar to Pakistan. 

6. The distribution of Kilianella is again comparable with Pakistan except that 
its occurrence is somewhat higher in the Lower Valanginian of Pakistan. 

7. In France, Busnardo and Hegart have shown that the genus Neocomutes 
extends from almost the base of the Upper Tithonian to the Valanginian and 
probably higher. If this is the range of Neocomites sensu stricto, it seems to 
be long ranging in France. No true Neocomites (Neocomites) has been found 
in Pakistan below the Subthurmannia beds, or in the Olcostephanus beds of the 
Upper Valanginian. It is more typical of the Lower Valanginian of Northern 
Pakistan. 

8. Olcostephanus has been shown by the French authors start in the Lower 
Valanginian, and show a maximum development in the Upper Valanginian 
and Hauterivian. In Pakistan O. (Olcostephanus) occurs more abundantly 
and O. (Rogersites) less abundantly in the Upper Valanginian condensed beds, 
and is much less frequently associated with Leopoldia, Lyticoceras, and Distolo- 
cevas. The Olcostephanus species includes comparable forms like O. (R.) 
atherstoni (reported from the Upper Valanginian and Lower Hautervian of 
France) and O. (0.) filosus Baumberger (reported from the Lower Hauterivian 
of France). Thus there appears to be overlap of the lower zone of Lower 
Hauterivian of France with the O. (O.) salinarius zone of the present author 
from the Upper Valanginian of Pakistan. The lower Hauterivian of France, 
in contrast to Pakistan, shows abundance of Leopoldia, Lyticoceras, and 
Acanthodiscus. The Olcostephanus Beds of Pakistan show rare occurrence of 
Leopoldia, Lyticoceras and Distoloceras (Upper Valanginian—Hauterivian 
genera), and thus are regarded here as Upper Valanginian. 


To conclude, the Berriasian and Valanginian ammonite faunas of France have 
many affinities with the faunas of northern West Pakistan, but the range of many 
genera in France and the association of some do not tally with the noted sequence in 
Pakistan. No doubt the succession in France is more complete and the fauna is 
rich in number of species and specimens. 

The zone of B. grandis is difficult to correlate with the succession in Pakistan 
where the base of Subthurmania has been found to be a convenient and logical 
horizon to place the base of Cretaceous, and this (Fermori Zone) corresponds well 
with the Boisseri Zone of France. In a comparable position to the Grandis Zone, 
Himalayites hypaisis (Blanford), Himalayites sp., Protacanthodiscus spp., S. multi- 
forme, Aulacosphinctes sp., have been found. If this assemblage is put in the Grandis 
Zone, the Tithonian and Cretaceous boundary becomes vague and undeterminable 


AND JURASSIC AMMONITES FROM WEST PAKISTAN 373 


in the continuous glauconitic sandy Upper Tithonian—Berriasian sequence of 
Pakistan. 

The present author thus considers the base of the S. botssevi (or S. fermort) as a 
most suitable place to draw the Cretaceous—Jurassic boundary, as this zone has been 
recognized by Imlay (1961) in Mexico, Leanza (1945) in South America, Cazanov 
(1953) in Russia and has been discussed in more detail by Casey (1963). 


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380 JURASSIC AND LOWER CRETACEOUS ROCKS 
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A. N. Fatt, B.Sc., Ph.D. 
GEOLOGICAL SURVEY OF PAKISTAN 
QUETTA 

WEST PAKISTAN 


rN we 


PEAT En 


Holcophylloceras silesiacum (Oppel). 20 ft above base of Chichali Formation. Lower 
Tithonian. Chichali Pass, Trans Indus Ranges. C.76546, «0-55. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 7 PLATE 1 


PLATE 2 

Fics ta, 1b. Ptychophylloceras ptychoicum (Quenstedt). About to ft above base of 
Chichali Formation. Lower Kimmeridgian. Punnu Mines, Trans Indus Range. C.76547. 

Fics 2a, 2b. Pterolytoceras exoticum (Oppel). Lower member of Chichali Formation. 
Upper Tithonian. Chichali Pass, Trans Indus Ranges. C.76548. 

Fics 3a, 3b. Pterolytoceras sp. indet. Lower member of Chichali Formation. Upper 
Tithonian. S.W. of Mallakhel, Trans Indus Ranges. C.76551, 0-6. 

All figures natural size, except Fig. 3. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 7 IPL JN ANID, 73 


PLATE 3 

Fics 1a, 1b; 3a, 3b. Bouleiceras nitescens Thévenin. Middle member of Datta Formation. 
Lower Toarcian. Chakdalla, Kala Chitta Range. Fig. 1, C.76554. Fig. 3, C.76555, 0-6. 

Fics 2a, 2b; 4. Bouleiceras chakdallaense sp. nov. Middle member of Datta Formation. 
Lower Toarcian. Chakdalla, Kala Chitta Range. Fig. 2, C.76557, holotype. Fig. 4. C.76558, 
paratype. 

Fic. 5. Hildoglochiceras sp. indet. 20 ft above base of Chichali Formation. Lower 
Tithonian. W. of Makerwal, Trans Indus Ranges. C.76562. 

Fics 6a, 6b; 7a, 7b. Mayaites cf. waageni (Uhlig). Basal 3 inches of Chichali Formation. 
Upper Oxfordian. Punnu Mines, Trans Indus Range. C.76563—64. 

All figures natural size, except Fig. 3. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 7 


PATE 4 


Fics 1-3. Reineckeia anceps (Reinecke). Top 1 ft of Samana Suk Limestone. Middle 
Callovian. Lunda Mines, Trans Indus Ranges. Fig. 1, C.76565. Fig. 2, C.76566. Fig. 3, 
C.76568. 

Fics 4a, 4b. Reineckeia cf. torulosus (Spath). Top 1 ft of Samana Suk Limestone. 
Middle Callovian. W. of Makerwal, Trans Indus Ranges. C.76572, 0-75. 

Fics 5a, 5b. Obtusicostites buckmani Spath. Top 1} ft of Samana Suk Limestone. 
Middle Callovian. Punnu Mines, Trans Indus Range. C.76581. 

All figures natural size, except Fig. 4. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 7 PIL NII, 21 


IPIBIN IDI, 5 

Fics ta, 1b; 2a, 2b. Obtusicostites buckmani Spath. Top 1 ft of Samana Suk Lime- 
stone. Middle Callovian. Punnu Mines, Trans Indus Ranges. Fig. 1, C€.76583, 0-7. 
Fig. 2, C.76584. 

Fics 3-6. Hubertoceras sp.indet. Top 2 ft of Samana Suk Limestone. Middle Callovian. 
Lunda Mines, Trans Indus Range. Fig. 3, C.76592. Fig. 4, C. 76594. Fig. 5, C.76595. 
Fig. 6, C.76597. 

All figures natural size, except Fig. 1. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 7 IPILINADIT, FF 


IIL INIWS, © 


Fics 1; 2a, 2b. Prososphinctes virguloides (Waagen). Basal 1 ft of Chichali Formation. 
Upper Oxfordian. Mazari Tang, Nizampur. Fig. 1, C.76608. Fig. 2, C.76609. 
Fics 3a, 3b. Perisphinctes sp. indet. Basal 3 inches of Chichali Formation. Upper 
Oxfordian. N. of Kalabagh, Trans Indus Range. C.76620. 
Fics 4a, 4b. Perisphinctes (Kranaosphinctes) sp. indet. Basal 3 inches of Chichali 
Formation. Upper Oxfordian. Chichali Pass, Trans Indus Ranges. C.76624. 
All figures natural size. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 7 PLATE 6 


PIC VAI, 7) 

Fics ta, 1b; 2. P. (Dichotomosphinctes) cf. rotoides Ronchadzé. Basal 4 inches of 
Chichali Formation. Upper Oxfordian. Chichali Pass, Trans Indus Ranges. Fig. 1, C.76629. 
Fig. 2, C.76630. 

Fics 3a, 3b. P.(?Dichotomosphinctes) sp. indet. Basal 3 inches of Chichali Formation. 
Upper Oxfordian. Punnu Mines, Trans Indus Ranges. C.76635. 

Fics 4a, 4b. Katroliceras cf. pottingeri (J. de C. Sowerby). Between 6 and 7 ft above 
base of Chichali Formation. Lower Kimmeridgian Punnu Mines, Trans Indus Ranges. C.76637. 

Fics 5a, 5b. Pachysphinctes robustus Spath. Between 5 and 7 ft above base of Chichal 
Formation. Lower Kimmeridgian. Punnu Mines, Trans Indus Ranges. C.76641, x0-6. 

All figures natural size, except Fig. 5. 


Mus. nat. Hist. (Geol.) 20, 7 


] 
i 


Bull. Br. 


IPILAN IIS, {3} 


Fics 1a, 1b; 2a, 2b. Aulacosphinctoides hazaraensis sp. nov. Basal bed of Lumshiwal 
Formation. Lower Tithonian. Kathwal, Hazara. Fig. 1, holotype, C.76644. Fig. 2, 
paratype, C.76645. 

Fics 3a, 3b. Aulacosphinctoides uwhligi Spath. 2 ft above base of Lumshiwal Formation. 
Lower Tithonian. Kathwal, Hazara. C.76646 

Fics 4a, 4b. Aulacosphinctoides sp. indet. 1 ft above base of Lumshiwal Formation. 
Lower Tithonian. Kathwal, Hazara. C.76648. 

Fics 5a, 5b. Virgatosphinctes denseplicatus (Waagen). Basal bed of Lumshiwal 
Formation. Lower Tithonian. Kathwal, Hazara. C.76652. 

All figures natural size. 


PLATE 8 


Bull. By. Mus. nat. Hist. (Geol.) 20, 7 


PLATE 9 


Fics 1a, 1b. Virgatosphinctes frequens (Oppel). Basal Lumshiwal Formation. Lower 
Tithonian. Kathwal—Kalapani, Hazara. C.76654. 

Fics 2a, 2b. Aspidoceras (Pseudowaagenia) sp. indet. 1 ft above base of Chichali 
Formation. Lower Kimmeridgian. Punnu Mines, Trans Indus Ranges. C.76660. 

Fics 3a, 3b. Proniceras indicum Spath. Between 25 ft and 30 ft above base of Chichali 
Formation. Lower Tithonian. Chichali Pass, Trans Indus Ranges. C.76663. 

Fics 4a, 4b. Spiticeras multiforme Djanelidze. 3 ft below base of middle member of 
Chichali Formation. Upper Tithonian. S.W. of Malla Khel, Trans Indus Ranges. C.76664. 

Fics 5a, 5b. Himalayites cf. hyphaisis (Blanford). 10 ft below base of middle member of 
Chichali Formation. Upper Tithonian. S.W. of Malla Khel, Trans Indus Ranges. C.76667. 

Fics 6a, 6b. Himalayites middlemissi (Uhlig). 10 ft below base of middle member of 
Chichali Formation. Upper Tithonian. Chichali Pass, Trans Indus Ranges. C.76668. 

All figures natural size. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 7 PLATE 9 


PLATE xo 


Fics 1a, 1b; 3a, 3b. Provalanginites rhodesi sp. nov. 20-30 ft above base of Chichali 
Formation. Lower Tithonian. Trans Indus Ranges. Fig. 1. Lunda Mines, C.76671, holotype. 
Fig. 3, Chichali Pass, C.76672, paratype. 

Fics 2a, 2b. Provalanginites howarthi sp. nov. 25 ft above base of Chichali Formation. 
Lower Tithonian. Punnu Mines, Trans Indus Ranges. C.76674, holotype. 

Fics 4a, 4b; 5a, 5b. Blanfordiceras cf. wallichi (Gray). 10-60 ft below base of middle 
member of Chichali Formation. Upper Tithonian. Chichali Pass, Trans Indus Ranges. 
Fig. 4, C.76675. Fig. 5, C.76676. 

Fics 6a, 6b; 7a, 7b. Blanfordiceras cf. latidomus (Uhlig). 20 ft below base of middle 
member of Chichali Formation. Upper Tithonian. Lunda Mines, Trans Indus Ranges. 
Fig. 6, C.76678. Fig. 7, C.76679. 

Fics 8a, 8b. Blanfordiceras sp. indet. 2-3 ft above base of Chichali Formation. Upper 
Tithonian. N.N.W. of Jhallar, Kala Chitta Range. C.76680. 

All figures natural size. 


Bull. Br. Mus. nat. Hist. (Geol.) 20, 7 PLATE ro 


NEN INIT, kit 

Fics 1a, 1b. Protacanthodiscus cf. michaelis (Uhlig). 3 ft below base of middle member 
of Chichali Formation. Upper Tithonian. Lunda Mines, Trans Indus Ranges. C.76684. 

Fics 24a, 2b; 3a, 3b. Aulacosphinctes spitiensis (Uhlig). 2 ft below base of middle member 
of Chichali Formation. Upper Tithonian. S.W. of Shaikh Budin Hills, Trans Indus Ranges. 
Fig. 2, C.76686. Fig. 3, C.76687. 

Fics 4a, 4b. ?Protacanthodiscus sp. indet. 5 {ft below base of middle member of Chichali 
Formation. Upper Tithonian. Lunda Mines, Trans Indus Ranges. C.76685. 

All figures natural size. 


Bull. By. Mus. nat. Hist. (Geol.) 20, 7 PIL AIT, Wi 


. , 7 Trew ae he / mrs, “ 5 
o é a te fet eae; eit eme on) ee 
y - ; Ps a ie 7 ae q i ae a ‘ 
} ’ : : .. au } ' i ; 
f ‘ rs” md io ‘ / 
fy j ‘4 s r 


A LIST OF SUPPLEMENTS 
TO. THE GEOLOGICAL SERIES 
OF THE BULLETIN OF 
THE BRITISH MUSEUM (NATURAL HISTORY) 


. Cox, L. R. Jurassic Bivalvia and Gastropoda from Tea and Kenya 
Pp. 213; 30 Plates; 2 Text-figures. 1965. £6. ei 
. Et-Nacear, Z. R. Stratigraphy and Planktonic Foraminifera of the Upper 
Cretaceous—Lower Tertiary Succession in the Esna-Idfu Region, Nile Valley, 
Egypt, U:A.R. Pp. 291; 23 Plates; 18 Text-figures. — 1966. £10. 

. Davey, R. J., Downie, C., Sarceant, W. A. S. & Wictiams, G. L. Studies on 


Mesozoic and Cainozoic Dinoflagellate Cysts. Pp. 248; 28 Plates; 64 Text- Aba 


figures. 1966. £7. 

. APPENDIX. Davey, R. J., Dow C., SARGEANT, W. A. S. & WILLIAMS, G. L. 

Appendix to Studies on Mesozoic and Calnosbis Dinoflagellate Cysts. Pp. ats 5 

1969. 8op. 

. Extiotr,G. F, Permian to Palaeocene Calcareous Algae (Dasycladaceae) of the 
Middle East, Pp. III; 24 Plates; 17 Text-figures. 1968. {5.12}. 


. Ruopss, F. H. T., Austiy, R. L. & Druce, E, C. British Avonian (Carbane. F 


ferous) Conodont faunas, and their value in local and continental correlation. 
Pp. 315; 31 Plates; 92 Text-figures. 1969. 11. 


- Cups, A. Upper Jurassic Rhynchonellid Brachiopods from Northwestern eae 


Europe. Pp. 119; 12 Plates; 40 Text-figures. 1969. £4.75. 
. Goopy, P. C. The relationships of certain Upper Cretaceous Teleosts with — 
special reference to the Myctophoids. Pp. 255; 102 Text-figures. 1969. £6.50. 


- Owen, H. G. Middle Albian Stratigraphy in the Paris Basin. Pp. 164; Ws 3 


3 Plates; 52 Text-figures. 1971. £6. 
. Sippigui, Q. A. Early Tertiary Ostracoda a the family Trachyleberididae 
from West Pakistan. Pp. 98; 42 Plates; 7 Be cae 197%. £8. 


sat . Printed in England by Staples Printers Limited at their Kettering, Northants, establishment 


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