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VOLUME 12

Palaeontology

1969

PUBLISHED BY THE
PALAEONTOLOGICAL ASSOCIATION
LONDON

Dates of publication of parts of Volume 12

Part 1, pp. 1-172, pis. 1-33
Part 2, pp. 173-350, pis. 34-67
Part 3, pp. 351-535, pis. 68-98
Part 4, pp. 537-718, pis. 99-130

25 April 1969
24 July 1969
11 September 1969
19 December 1969

THIS VOLUME EDITED BY N. F. HUGHES, GWYN THOMAS, ISLES STRACHAN, ROLAND GOLDRING.

AND M. R. HOUSE

Dates of publication of Special Papers in Palaeontology
Special Paper No. 1 21 June 1967

Special Paper No. 2

31 January 1968

Special Paper No. 3
Special Paper No. 4
Special Paper No. 5

7 October 1968
1 May 1969
17 October 1969

© The Palaeontological Association, 1969

PRINTED IN GREAT BRITAIN

CONTENTS

Part Page

Armstrong, J. The cross-bladed fabrics of the shells of Terrakea solida (Etheridge and
Dun) and Streptorhynchus pelicanensis Fletcher 2 310

Austin, R. L., and Rhodes, F. H. T. A conodont assemblage from the Carboniferous of
the Avon Gorge, Bristol 3 400

Badam, G. L. See Tewari, B. S.

Baker, P. G. The ontogeny of the thecideacean brachiopod Moorellina granulosa ( Moore)
from the Middle Jurassic of England 3 388

Batten, D. J. Some British Wealden megaspores and their facies distribution 2 333

Carroll, R. E. A new family of Carboniferous amphibians 4 537

Chamberlain, J. A. Technique for scale modelling of cephalopod shells 1 48

Churkin, M., Eberlein, G. D., Hueber, F. M., and Mamay, S. H. Lower Devonian
land plants from graptolite shale in south-eastern Alaska 4 559

Eberlein, G. D. See Churkin, M.

Eggert, D. A., and Kryder, R. W. A new species of Aulacotheca from the Middle
Pennsylvanian of Iowa 3 414

See Taylor, T. N.

Fisher, M. J. Benthonic Foraminifera from the Maestrichtian Chalk of Galicia Bank,
west of Spain 2 189

Friend, J. K. See Funnell, B. M.

Funnell, B. M., Friend, J. K., and Ramsay, A. T. S. Upper Maestrichtian planktonic
Foraminifera from Galicia Bank, west of Spain 1 19

Hallam, A. Faunal realms and facies in the Jurassic 1 1

Hibbert, F. A., and Lacey, W. S. Miospores from the Lower Carboniferous Basement
Beds in the Menai Straits region of Caernarvonshire, north Wales 3 420

Holland, C. H., Rickards, R. B., and Warren, P. T. The Wenlock graptolites of the
Ludlow district, Shropshire, and their stratigraphical significance 4 663

Hueber, F. M. See Churkin, M.

Hughes, N. F., and Moody-Stuart, J. C. A method of stratigraphic correlation using
early Cretaceous miospores 1 84-

Jakobson, M. E. See McKerrow, W. S., also Kennedy, W. J.

Jefferies, R. P. S. Ceratocystis perneri Jaekel — a Middle Cambrian chordate with
echinoderm affinities 3 494

Johnson, R. T. See McKerrow, W. S., also Kennedy, W. J.

Kennedy, W. J., and Macdougall, J. D. S. Crustacean burrows in the Weald Clay
(Lower Cretaceous) of South-eastern England and their environmental significance 3 459

Jakobson, M. E., and Johnson, R. T. A Favreina-Thalassinoides association from

the Great Oolite of Oxfordshire 4 549

Kier, P. M. A Cretaceous echinoid with false teeth 3 488

Kilenyi, T. I. The Ostracoda of the Dorset Kimmeridge Clay 1 112

Kryder, R. W. See Eggert, D. A.

Lacey, W. S. See Hibbert, F. A.

Lister, T. R. See Richardson, J. B.

Matthews, S. C. A Lower Carboniferous conodont fauna from East Cornwall 2 262

Two conodont faunas from the Lower Carboniferous of Chudleigh, South Devon 2 276

Macdougall, J. D. S. See Kennedy, W. J.

Mamay, S. H. See Churkin, M.

IV

CONTENTS

Part Page

McKerrow, W. S., Johnson, R. T., and Jakobson, M. E. Palaeoecological studies in
the Great Oolite at Kirtlington, Oxfordshire 1 56

Moody-Stuart, J. C. See Hughes, N. F.

Norford, B. S., and Steele, H. Miriam. The Ordovician trimerellid brachiopod Eodino-

bolus from south-east Ontario 1 161

Norris, G. Miospores from the Purbeck Beds and marine Upper Jurassic of southern
England 4 574

Owen, D. E. Wenlockian Bryozoa from Dudley, Niagara, and Gotland and their palaeo-

geographic implications 4 621

Ramsay, A. T. S. See Funnell, B. M.

Rhodes, F. H. T. See Austin, R. L.

Richardson, J. B., and Lister, T. R. Upper Silurian and Lower Devonian spore assem-
blages from the Welsh Borderland and South Wales 2 201

Rickards, R. B. See Holland, C. H.

Savage, N. M. New spiriferid brachiopods from the Lower Devonian of New South
Wales 3 472

Soot-Ryen, H. A new species of Babinka (Bivalvia) from the Lower Ordovician of Oland,

Sweden 2 173

Sorauf, J. E. Lower Devonian Hexagonaria (Rugosa) from the Armorican Massif of
Western France 2 178

Spinner, E. Megaspore assemblages from the Visean deposits at Dunbar, East Lothian,

Scotland 3 441

Steele, H. Miriam. See Norford, B. S.

Tavener-Smith, R. Skeletal structure and growth in the Fenestellidae (Bryozoa) 2 281

Taylor, T. N., and Eggert, D. A. On the structure and relationships of a new Pennsyl-
vanian species of the seed Pachytesta 3 382

Tewari, B. S., and Badam, G. L. A new species of fossil turtle from the Upper Siwaliks
of Pinjore, India 4 555

Thomas, B. A. A new British Carboniferous calamite cone Paracalamostachys spadaci-
fonnis 2 253

Valentine, J. W. Patterns of taxonomic and ecological structure of the shelf benthos

during Phanerozoic time 4 684

Wade, M. Medusae from uppermost Precambrian or Cambrian sandstones, central
Australia 3 351

Wallace, P. Specific frequency and environmental indicators in two horizons of the

Calcaire de Ferques (Upper Devonian), northern France 3 366

Warren, P. T. See Holland, C. H.

Webby, B. D. Ordovician stromatoporoids from New South Wales 4 637

Westbroek, P. The interpretation of growth and form in serial sections through brachio-
pods, exemplified by the trigonorhynchiid septalium 2 321

Whitworth, P. H. The Tremadoc trilobite Pseudokainella impar (Salter) 3 406

Zammit-Maempel, G. A new species of Coelopleurus (Echinoidea) from the Miocene of

Malta 1 42

VOLUME 12 • PART 1

Palaeontology

APRIL 1969

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© The Palaeontological Association 1969

FAUNAL REALMS AND FACIES IN THE JURASSIC

by A. HALLAM

Abstract. Differences in the composition and diversity of marine invertebrates in the Tethyan and Boreal
Realms of the Jurassic are outlined, and previous interpretations based on control by temperature, physical
barriers, and depth of sea are discussed and rejected. Three sedimentary facies associations, termed terrigenous
clastic, intermediate, and calcareous, are distinguished in the Jurassic of Europe and a correlation with faunal
realms is shown to exist. Taking this into account a hypothesis is proposed relating the establishment and main-
tenance of the Boreal Realm to an extensive inland sea of slightly reduced salinity in the Northern Hemisphere,
which had free connections with the Tethyan and Pacific Oceans. The influence of other environmental factors
and some ecological implications are briefly discussed.

Since the pioneer study of Neumayr (1883) it has been widely recognized that many
Jurassic marine invertebrate faunas are not cosmopolitan in distribution but restricted
to two or more faunal realms. The problems this has posed in stratigraphy are numerous
and a correct interpretation of the causal factors is crucial to a proper understanding
both of the contemporary environment and of organic evolution.

Previous workers have mainly restricted their attention to particular fossil groups,
usually ammonites, and the sedimentary facies has received little attention. Considera-
tion of data both from several major invertebrate groups and from the rocks in which
they occur has led to the formulation of a new hypothesis of the origin and maintenance
of Jurassic faunal realms. Arkell (1956), Imlay (1965), and Stevens (1967) review earlier
work.

DISTINCTION OF FAUNAL REALMS

Of the three realms recognized by Arkell (1956, chap. 28) on the basis of ammonites,
the Tethyan and Boreal Realms are accepted here as being readily distinguishable by
numerous fossils from several invertebrate groups. Arkell’s Pacific Realm is characterized
by only a few ammonites, notably the Bajocian genera Pseudotoites and Zemistephanus ,
occurring with a fauna of otherwise overwhelmingly Tethyan affinities; hence I propose
that it be relegated to a province of this realm.

The Boreal Realm occupies the northern part of the Northern Hemisphere. Its southern
boundary is gradational and oscillated somewhat with time but generally corresponds
quite closely in Europe with the line of the Alpine fold belts, and in the North Pacific
region with a line through northern California and between Japan and eastern Siberia.
The rest of the world belongs to the Tethyan Realm. While reading the following section
documenting the differences between the two realms, it should be borne in mind that
they are gradational and characterized more often by relative abundance than by com-
plete mutual exclusion of contemporary organisms. There are many fossils, moreover,
that occur commonly in both realms.

The following summary is intended to be fairly comprehensive but is far from
exhaustive.

Ammonites. Because the data are relatively familiar and because of the large number of
genera involved, the basic data have been condensed into a table listing only families and

[Palaeontology, Vol. 12, Part 1, 1969, pp. 1-18.]

O 6289

B

2 PALAEONTOLOGY, VOLUME 12

subfamilies (Table 1). Cosmopolitan groups are excluded. This generalized picture is
adequate for present purposes as long as it is borne in mind that some groups are more
restricted than others. Thus the Oxfordian perisphinctids, though essentially Tethyan,
range more freely into the Boreal Realm than the contemporary oppeliids; and the
Toarcian Hildoceratinae, though common in the southern part of the Boreal Realm,
are absent from the Arctic regions. By Tithonian/Volgian times, the ammonites of the
two realms are almost totally mutually exclusive.

Stages

tithonian and

VOLGIAN

KIMMERIDGIAN

OXFORDIAN

CALLOVIAN

BATHONIAN

BAJOCIAN

TOARCIAN

PLIENSBACHIAN

sinemurian and

HETTANGIAN

TABLE 1

Ammonite families and subfamilies
Boreal

Craspeditidae
Virgatitinae

Dorsoplanitidae
Certain Aulacostephaninae
(Aulaco Stephanas, Rasenia)

Cardioceratinae

Kosmoceratidae

Cadoceratinae

Cadoceratinae

Cadoceratinae
(U. Bajocian) £

Amaltheidae

Liparoceratidae

re!

rs

a

a.

C

cfl

<D

as

"O

Tethyan

Berriasellidae

Spiticeratinae

Virgatosphinctinae

Ataxioceratinae

Virgatosphinctinae

Simoceratidae

Peltoceratinae

Perisphinctinae

Aspidoceratinae

Peltoceratinae

Aspidoceratinae

Reineckiidae

Macrocephalitidae

Sphaeroceratidae

Tulitidae

Morphoceratidae etc.

Hammatoceratidae

Sonniniidae

Leptosphinctinae

Hammatoceratidae

Bouleiceratinae

Hildoceratidae

Dactylioceratidae

Juraphyllitidae

Juraphyllitidae

Ectocentritidae

Arkell (1956) thought that the separation into Boreal and Tethyan realms was only
clearly established in the Callovian but, since the work of Callomon (1959), it has been
widely recognized that a distinctive fauna of Cadoceratinae existed in the Bathonian
and probably also the Upper Bajocian of the Arctic and that the Callovian marked the
time of the southward spread of their descendants. Furthermore, as both Donovan
(1967) and Sapunov (in press) have pointed out, the first major boreal groups are found
as early as the Pliensbachian. Before this time, the Boreal Realm is generally only
distinguishable as an impoverished version of the Tethyan fauna, though a number of
Sinemurian genera have a predominantly northerly distribution in Europe.

Belemnites. We owe to Stevens (1965) a detailed account of world belemnite distribution.
According to him, the Lias was marked only by a cosmopolitan subfamily, the Passalo-

A. HALLAM: FAUNAL REALMS AND FACIES IN THE JURASSIC 3

teuthinae, but one must add here that the Triassic ‘survivor’ Atractites ranged into the
Pliensbachian and is almost confined to the Tethyan Realm. A clear faunal differentia-
tion emerged from Callovian times onwards, the Boreal Realm being characterized by
species of the genera Cylindroteuthis, Acroteuthis, and Pachyteuthis, the Tethyan Realm
by Belemnopsis, Dicoelites , Hibolithes, and, in the Tithonian, Duvalia. The post-
Oxfordian restriction of some of these elements to an Indo- Pacific province need not
concern us here.

Bivalves and gastropods. Most bivalves appear to be cosmopolitan in distribution but
certain heavy-hinged early Jurassic genera such as Opisoma, Pachymegalodon, Pachy-
risma, Pachymytilus, and Gervilleoperna occur only in the Tethyan Realm and the late
Jurassic diceratid rudists are likewise confined. Trigonia, Lithiotis, and the peculiar
pectinid Weyla are three other genera confined during the Lias to the Tethyan Realm.

The genus Buchia was formerly cited as a boreal element, because it occurs abundantly
in the Arctic and in northern Europe but rarely in southern Europe. However, it has
since been shown that Buchia occurs commonly also in the Indo-Pacific region in associa-
tion with Tethyan ammonites. In the Northern Hemisphere, both Gryphaea and Inocera-
mus have a predominantly boreal distribution.

As regards gastropods, lmlay (1965) recognized a predominantly southern distribu-
tion of the Nerinacea, Naticacea, and Neritidae in North America. The same pattern
appears to be the case in Europe, certainly for Nerinea and its relatives, confined to the
Mediterranean countries in the Lias and predominantly Tethyan also in the Upper
Jurassic (Ziegler 1964).

Brachiopods. According to Ager (1967) the most typical Tethyan brachiopods are the
Pygopidae, with exaggerated anterior lobes or central perforations. Other Tethyan
groups include costate terebratuloids (e.g. Hesperithyris in the Lias and Flabellothyris
and Eudesia in the Middle Jurassic), sulcate terebratuloids, and the rhynchonellids
Prionorhynchia and Cirpa, and axiniform Zeilleria. The Boreal Realm at this time is
characterized by the dominance of Tetrarhynchia, Gibbirhynchia , Lobothyris, indentate
Zeilleria, and ribbed Spiriferina.

Foraminifera. Many foraminifera are common in the Boreal Realm but cosmopolitan in
distribution. They include the Nodosariidae (formerly grouped as Lagenidae), Ammo-
discidae, and, from Middle Jurassic onwards, the Ceratobuliminidae, together with such
genera as Rheophax, Haplophragmoides, Trocholina, Spirillina, Trochammina, and
Ophthalmidium. Another group, belonging to the Lituolacea, is mainly or completely
confined to the Tethyan Realm. This includes Orbitopsella (Lower Jurassic), Orbitam-
mina , Meyendorffina (Middle Jurassic), Pfenderina (Middle-Upper Jurassic), and Kur-
nubia, Anchispirocyclina, and Pseudo cylammina (Upper Jurassic).

Other groups. Much attention has been paid in the past to the distribution of hermatypic
corals in Europe. These exhibit a marked falling off in abundance and diversity in the
late Jurassic northwards from southern regions such as Portugal, the Jura Mountains,
and Swabia. The pattern of sponge distribution is similar. Groups, including algae,
which appear to be mainly or exclusively Tethyan in distribution include dasycladaceans,
tintinnids (first appearing in the Tithonian), coccospheres, radiolaria, and stromato-
poroids.

4

PALAEONTOLOGY, VOLUME 12

It is a fair generalization to state that at every taxonomic level the Tethyan faunas
are more diverse than the Boreal. This is well documented, for example, among cosmo-
politan Liassic ammonite genera by Donovan (1967). This difference in diversity
allows a distinction between the two realms to be made throughout the Jurassic, but
distinctive faunal elements restricted to the Boreal Realm appear to be limited essentially
to the ammonites and belemnites.

A CRITIQUE OF PREVIOUS INTERPRETATIONS

Although many environmental factors are known to influence the distribution of
marine invertebrates most of these are local in effect and marine zoogeographers
recognize essentially three major controlling factors on regional distribution operating
at the present day; these are temperature, salinity, and physical barriers (Ekman 1953).
Temperature control, of prime importance in the modern oceans, operates in restricting
diversity progressively from the tropics to the poles (Fischer 1961). Salinity decrease into
river estuaries and inland seas such as the Baltic and Black Seas also correlates with
progressive reduction in diversity, owing to the restriction on stenohaline organisms.
Physical barriers are of two sorts. Land barriers can effect a pronounced if not total
separation of closely adjacent faunas. The outstanding example dates back to the mid-
Tertiary, when the old Tethyan seaway, which had extended continuously across the
Old and New Worlds, became divided into two by the creation of a land barrier in the
Middle East, hence separating an Indo-West Pacific from an Atlantic-East Pacific
Realm. Deep-sea barriers, such as that extending north and south in the East Pacific,
appear to be almost as effective as land barriers in separating neritic organisms (Ekman
1953).

Regional differences in Jurassic faunas have been referred by palaeontologists to
several factors, which will be discussed in turn.

Temperature. Some form of temperature control was proposed by Neumayr (1883) and
Uhlig (1911) and remains the most popular interpretation among current workers (e.g.
Sato 1960, Stevens 1963, 1965, 1967, Ziegler 1964, Saks et a/. 1964, Jeletsky 1965,
Donovan 1967). The evidence proposed in favour is, first, that there is a northward
decrease in diversity from the Tethyan to the Boreal Realm (especially among reef
corals) suggesting a comparison with climatic zonation at the present day in the
Northern Hemisphere, and secondly, there is a concomitant marked decline in the
abundance of limestone northwards from southern Europe.

There are a number of objections to the hypothesis of temperature control:

1. Land plant distributions reflect temperature differences and should give indication
of climatic zones. Yet Jurassic plants exhibit an approach to world-wide uniformity and
suggest a more equable climate than the present day. The only suggestion of climatic
zonation comes from the distribution of gymnosperms in Eurasia. In the more southerly
regions the flora is characterized by an abundance of cycadophytes together with conifers
and subordinate gingkophytes, while the Siberian region is poorer in diversity, especially
in the first-named group, and gingkophytes are more abundant (Vakhrameev 1964).
Bearing in mind that living cycads characterize the tropics, this change is reasonably
interpreted as controlled by climate, but the Siberian flora nevertheless signifies a humid
and moderately warm climate, quite unlike the present day. In Vakhrameev’s words,

A. HALLAM: FAUNAL REALMS AND FACIES IN THE JURASSIC

5

‘The climatic differences . . . were incomparably less sharp than the Recent epoch’, and
winter temperatures in Siberia could not apparently have fallen below 0 JC.

Marine invertebrates should reveal climatic differences less clearly than terrestrial
plants but diversity data have been used (notably by Ziegler 1964) to support the notion
of temperature control. Ziegler’s data are presented in Table 2. Two further examples
may be quoted here. Donovan (1967) has estimated that, among Liassic ammonite
genera in Europe, 67 are chiefly or exclusively Tethyan, 30 Boreal, and 76 unrestricted.
The Tithonian deposits of the Carpathians contain 30 ammonite genera (Arkell 1956)
as opposed to 18 in the contemporaneous Volgian stage (as newly defined by Gerasimov
and Mikhailov 1966) of the Volga Basin and Moscow region.

TABLE 2

Species of Upper Oxfordian reef corals
239 in Southern Jura
53 in Lower Saxony
13 in Southern England

7 in Yorkshire

Species of Kimmeridgian-Tithonian reef corals
1 13 in Portugal
143 in Wiirttemberg
1 7 in Lower Saxony

1 in Normandy

Genera of Kimmeridgian ammonites
22 in Ardeche
21 in Wiirttemberg

9 in Southern England

8 in Central European U.S.S.R.

5 in Greenland

Genera of Tithonian/Volgian gastropods
46 in Southern Jura
40 in Wiirttemberg
1 7 in Southern England
13 in Central European U.S.S.R.

8 in Greenland

These figures should be compared with some Recent data, of which the best docu-
mented are those by Stehli et al. (1967) on bivalves. Their statistical analysis suggests that
data for genera are more reliable than those for species. Within the Atlantic the generic
diversity decreases northwards as follows (number of species in parentheses): Guinea
Coast 92 (259), south Portugal 73 (208), south-west England 76 (180), north Scotland
46 (96), south-east Greenland 28 (57). Gradation on the western side of the Atlantic is
essentially similar. There is somewhat greater diversity in the Indo-Pacific Realm, with
up to 118 genera off Queensland.

In terms of degrees of latitude. Recent bivalve generic diversity decreases to approxi-
mately one-half within 50° and to one-third within 60° (if we take the Indo-Pacific
values of about 120 tropical genera a change of about 50° of latitude is still required to
halve the number). From 5° to 50° N. the number of genera is decreased in the Atlantic
by about a quarter, the number of species by about a third.

6

PALAEONTOLOGY, VOLUME 12

Turning to Ziegler’s data, the number of both Tithonian/Volgian gastropod and
Kimmeridgian ammonite genera is reduced to less than half in a mere 5° of latitude,

i.e. the northward change is much more drastic than with Recent molluscs. (Possible
crustal shortening within the Alpine fold belts would affect this only slightly if at all.)
On the temperature-control interpretation, this would suggest that the Jurassic climate
was appreciably less, rather than more, equable than that at the present day, which
seems unlikely.

Changes in faunal composition between the two realms may be equally striking over
a short distance. Thus in the Lower Oxfordian Renggeri Marls of the southern French
Jura, Cardioceras dominates in the north but diminishes to a rare element in the south,
where oppeliids and phylloceratids are commoner (Enay 1966).

2. With regard to the reef corals, it is true that they are limited to the tropics today
by temperature, but the present world ‘model’ may be inapposite for the Jurassic.
Within an area where corals live today, such as the Caribbean or the Seychelles, develop-
ment of coral reefs is notably patchy even in shallow water and the controlling factor on
distribution can hardly be temperature, which is nearly constant; other controlling
factors are important, such as turbidity, food supply, salinity, and intensity of wave
exposure.

3. The distribution of limestones is a misleading guide to temperature and fails to
account for the occurrence of Tethyan faunas in geosynclinal belts around the margins
of the Pacific, where limestones are subordinate. Far more important than climate is
the tectonic-sedimentational regime. This is true in tectonically stable as well as unstable
regimes, as is clearly in evidence from the passage of shelf carbonates in the Bahamas and
off southern Florida into the terrigenous clastic sequence of the Mississippi Delta, on a
similar latitude. Clearly, when the clastic sequence is thicker than that of contemporary
carbonate deposits the influence of river drainage should be suspected.

It is also true, however, that bed sequences in the Boreal Realm may be very con-
densed but still deficient in limestones. An outstanding instance is the Volgian of the
Moscow region. In this case, however, modern researches on carbonate sediments indi-
cate that they are overwhelmingly of organic origin, and temperature is not the only
factor controlling the distribution of calcium carbonate-secreting organisms. Indeed, the
drastic lateral passage from limestones in southern Europe to shales and sandstones in
northern Europe is accomplished in only a few degrees of latitude, suggesting that some
other explanation than temperature control be sought.

4. The temperature-control hypothesis, based though it is on analogy with modern
climatic belts, fails to account for the lack of a distinctive Austral or Anti- Boreal fauna,
and no plausible explanation has yet been offered for this. The subject is discussed more
fully by Stevens (1967). The fact that certain Madagascan faunas show closer affinities to
contemporaneous faunas in north-west Europe than to those in the Mediterranean
region relates to sedimentary facies and cannot be construed as an argument in favour
of an anti-boreal fauna in this island, because all the ammonites in question belong to the
Tethyan Realm.

5. Within Europe, the transition from the Tethyan to the Boreal Realm does not relate
in a simple way to latitude. Thus the Lower and Middle Jurassic faunas of the Caucasus
and Turkmen, on the same latitude as the Mediterranean countries, have a notable Boreal
component. While this could possibly be dismissed as due to the divergence of isotherms

A. HALLAM: FAUNAL REALMS AND FACIES IN THE JURASSIC 7

from lines of latitude as at the present day, such an explanation cannot plausibly account
for the fact that the Liassic ammonite fauna of the Balkan Mountains of Bulgaria is put
in the Boreal Realm by both Donovan (1967) and Sapunov (in press), while a short
distance to the north-west a typical Tethyan fauna occurs in the Bakony Mountains of
Hungary. This is a serious handicap unless one accepts a drastic reshutfling of southern
European fold belts such as that proposed by Carey (1958).

Physical barriers. A smaller number of authors (e.g. Uhlig 1911, Arkell 1956, Imlay
1965) have invoked some sort of physical barrier such as a land mass, as at least a con-
tributary factor. Such an interpretation may be objected to on several grounds:

1 . The changes from one realm to the other are gradational in character and there are
many faunal elements common to both. This is not compatible with what is known
about physical barriers in the modern oceans.

2. The boundary between the two realms oscillated geographically with time, as
between the Callovian-Lower Oxfordian and Upper Oxfordian.

3. Arkell’s invocation of a land barrier to isolate the Arctic Ocean and hence allow
the development of a distinctive ammonite fauna in the Callovian has been rendered
less plausible by the discovery of a rich boreal fauna of Bathonian Cadoceratinae in
the Arctic.

4. The hypothesis suffers from vagueness. The physical barriers are usually not clearly
specified nor independent evidence sought for their existence. A modified version of the
hypothesis invokes ocean currents as well (Imlay 1965). This also is of doubtful signific-
ance, because the zoogeographic influence of ocean currents today is primarily one of
temperature, which was probably of subordinate importance in the Jurassic.

Depth of sea. Depth is not a primary environmental factor but it often correlates with
other more significant factors such as food supply, temperature, pressure, and incidence
of light. There is a widespread notion, dating probably back to Haug (1907), that the
phylloceratid ammonites occupied deeper water than other ammonites, hence accounting
for their restriction in Europe substantially to the Mediterranean region, where rocks of
supposed deep-water facies occur. A similar explanation has been tentatively proposed
for certain brachiopods by Ager (1967). There may be some truth in this interpretation
to the extent that, for instance, phylloceratids may dominate in beds which may reason-
ably be considered as having been laid down in deeper water, whereas other ammonites
dominate in associated shallower-water beds, often containing algae and hermatypic
corals in situ (e.g. Ziegler 1963). However, both types of facies occur within the Tethyan
Realm and hence such data as these have nothing to do with the contrast between realms,
a point well appreciated many years ago by Ortmann (1896).

It may be concluded that none of the existing explanations accounts satisfactorily for
the existence of Jurassic faunal realms. Before the matter is discussed further it will be
necessary to follow up a largely unheeded suggestion of Ortmann (1896), that these
realms are related in some way to sedimentary facies.

JURASSIC FACIES IN EUROPE

I propose to distinguish three major marine facies associations; attention is con-
centrated on lithology and limited to Europe because adequate data are generally lack-
ing from other continents.

8

PALAEONTOLOGY, VOLUME 12

A. Terrigenous clastic facies association (= Ferruginous facies of Hallam 1966)

Silty micaceous shales and siltstones with sideritic nodules, and generally subordinate
fine- to medium-grained quartz sandstones and sideritic chamosite oolites, the latter
representing relatively shallow-water condensed deposits. Kaolinite abundant but subor-
dinate to illite; finely divided organic matter varies from common to uncommon; drift-
wood abundant; chert, red limestones, and concentrations of manganese oxide absent.
Characteristic trace fossils include Diplocraterion , Rhizocoral/ium, and Thalcissinoides.
Abundant benthos, dominated by bivalves; faunal diversity moderate.

Examples. Most of Jurassic of Hebrides, Denmark, north Germany; much of Yorkshire
Jurassic.

b. Intermediate facies association ( = Calcareous facies of Hallam 1966)

Smooth-textured shales or marls with calcitic concretions or regular bands of fine-
grained limestone; detrital quartz and mica uncommon or rare. Shallower- or more
agitated-water facies represented by calcareous oolites and organic limestones containing
hermatypic corals of low diversity. Poorly-aerated or anaerobic deposits represented by
laminated bituminous shales. Kaolinite moderately common to uncommon, always very
subordinate to illite; pyrite moderately common in shales. Chamosite and siderite rare
but goethitic ‘iron-shot’ limestone oolites occur. Chert usually uncommon; red lime-
stones absent. Trace fossils as for the terrigenous clastic facies association. Benthos
abundant, dominated usually by bivalves; plankton usually uncommon to rare; faunal
diversity moderately high.

Examples. Most of Jurassic of southern England and Paris Basin.

c. Calcareous facies association

1. Shallower water. Massive reefoid limestones with rich and diversified fossil
organisms including dasycladacean algae, hermatypic corals, and stromatoporoids in
situ, megalodontid or diceratid bivalves, etc.; associated oolites and detrital limestones;
faunal diversity high.

Examples. Calcare grigi (Lias of southern Alps), Panto Crater Limestone (Lias of
Greece), Plassenkalk (Upper Jurassic of Austria), much of Jurassic of central and
southern Appennines.

2. Deeper water. Bedded fine-grained grey or white limestones with subordinate marls,
replaced where sequence is condensed by red nodular limestones and marls. Intercala-
tions of allodapic limestones (thin graded shelly beds brought in from shallower zone
by turbidity currents). Chert abundant as secondary nodules or as regular beds (e.g.
Malm Radiolarite of Alpine region); manganese/iron oxide incrustations common in
condensed beds. Detrital quartz, kaolinite, particulate organic matter, driftwood, pyrite,
chamosite, and siderite all rare or absent. Characteristic trace fossil Zoophycos. Benthos
mostly sparse but plankton (coccoliths, radiolaria, tintinnids, etc.) abundant; faunal
diversity high.

Examples. Ammonitico Rosso, Adneterkalk, Fleckenmergel, Aptychenkalk, Maiolica,
Biancone, etc. of Alps and Appennines.

A. HALLAM: FAUNAL REALMS AND FACIES IN THE JURASSIC 9

Facies associations a and c can be readily distinguished on lithology alone and
exhibit no overlap. Chamositic ironstones are especially characteristic of the former
and nodular red limestones of the latter. Towards landmasses, facies association a passes
characteristically into sandy coal-measure facies (e.g. Hettangian of Scania), facies
association c into calcareous, perhaps dolomitic lagoonal deposits with stromatolites
and/or evaporites (e.g. Lower Purbeck Beds of southern England, Lower Lias of southern
Appennines and Morocco).

It has been thought desirable to introduce a third category of facies association, b,
intermediate between a and c. In certain respects, e.g. the presence of limestones, facies
association b resembles c; in others, e.g. the relative abundance of clay and organic
matter, it resembles a. There is the usual problem, intrinsic to all natural classifications,
that any limit imposed on intergrading phenomena must be to some extent arbitrary,
but facies association b should be distinguishable without difficulty provided lithological
and faunal evidence are considered in conjunction. Allowing for inevitable exceptions,
such as coarse clastic and volcanic deposits in the Caucasus, experience suggests that
this threefold division of facies is practicable for the whole of the European marine
Jurassic and provides for environmentally significant general description.

CORRELATION OF FAUNAL REALMS AND SEDIMENTARY FACIES

When an attempt is made to plot in a generalized way the distribution of the three
facies associations in Europe for particular Jurassic stages (text-figs. 1, 2, and 3, compiled
from numerous sources) it becomes apparent that there is a general passage from cal-
careous facies association (c) in the south to terrigenous clastic facies association (a) in
the north (the same is true for other stages). Since the fauna changes in the same general
direction the possibility of a correlation between fauna and sedimentary facies readily
suggests itself. This must therefore be examined in more detail.

The Pliensbachian stage (text-fig. 1) marks the first emergence of a major group of
boreal ammonites (although not one that persisted for long) in the Jurassic. The broken
line in text-fig. 1 represents the approximate boundary between Tethyan and Boreal
Realms, according to data given by Donovan (1967) and Sapunov (in press). The
Tethyan fauna is substantially confined to facies association c, the Boreal to facies
associations a and b. The pronounced southern swing of the faunal boundary from the
Carpathians to the Balkan Mountains and thence eastwards to cross between the Black
and Caspian seas appears to correlate with a southward spread of facies association a
in the east.

The Callovian stage (text-fig. 2) marks the time of the great ‘ Boreal Spread’ of Arkell
and shows a rather similar picture. The faunal boundary this time is taken as the southern
limit of Kosmoceras , the most characteristic boreal ammonite genus in the European
Callovian. The line is taken from Tintant (1963, fig. 86) but modified to allow for the
recent discovery of Kosmoceras in the Balkan Mountains (Howarth and Stephanov
1965); it is closely similar to the equivalent line in text-fig. 1, and once more the correla-
tion between fauna and facies is good, the Tethyan fauna being substantially confined
to facies association c.

The Upper Oxfordian substage (text-fig. 3) was selected because it marked the time
of the great ‘Tethyan Spread’ of Arkell, when southern elements in the ammonite fauna

10

PALAEONTOLOGY, VOLUME 12

spread north. It is not so easy in this case to draw a simple faunal boundary, because
certain groups such as the perisphinctids, though undoubtedly Tethyan, spread further
north than other, presumably less tolerant, groups such as the oppeliids. In fact the true
boreal fauna, in which perisphinctids are rare or absent, is restricted to the Arctic. The
line displayed in text-fig. 3, showing the approximate northern limit of abundant oppe-
liids, while not entirely satisfactory, is thought to be the most useful one to portray. The
diagram clearly shows that there was also a notable northward migra tion of facies belts,

Facies association A

Facies association B

Facies association C

Presumed land

Boundary of faunal realms (ammonites)

text-fig. 1 . Palaeogeographic sketch map for Europe in Pliensbachian times, showing the distribution

of facies associations and faunal realms.

with facies association c spreading for the first time far into Central Europe, and facies
association b being in general more calcareous than the equivalent facies in the under-
lying Callovian and Lower Oxfordian. A map for the Lower Kimmeridgian would show
a further Boreal Spread of ammonites and other fossils (Arkell 1956, Ziegler 1964),
correlating with a southward shift of facies belts, most notably in north-west Europe.

It is clear therefore that there is a good general correlation, both in space and time,
between the ammonite fauna and facies, and the same holds true for other groups, i.e.
facies association c of southern Europe belongs to the Tethyan Realm, facies association

A. HALLAM: FAUNAL REALMS AND FACIES IN THE JURASSIC 11

a in northern Europe to the Boreal Realm. The question arises whether this correlation
also applies in detail, because the maps are too generalized to take account of small-scale
variations. A close study of regional and sequential facies variations in the Upper Pliens-
bachian and Lower Toarcian within one country (Hallam \961b) reveals a good cor-
relation in both space and time. Southwards in England, the sedimentary facies changes
in the direction a to b and Tethyan elements in the molluscs and brachiopods occur in
the extreme south. The change from Pliensbachian to Toarcian is marked by a wide-

Southern boundary of Kosmoceras

text-fig. 2. Palaeogeographic sketch map for Europe in Callovian times. Explanation as in text-fig. 1 .

spread change from facies association a to b and correlates with a ‘Tethyan Spread’ of
ammonites. Another English example is shown in the transition from the Bathonian to
the Callovian. South of Yorkshire a calcareous version of facies association b, with
ammonites of Tethyan affinities, passes up into more sandy and argillaceous strata
containing Boreal ammonites.

INTERPRETATION

Marine zoogeographers consider salinity to be one of the major factors controlling
regional distribution of fauna, yet this has never been seriously considered to be relevant
in accounting for Jurassic faunal realms. There are, however, a number of grounds for
considering salinity to be a major influence:

1. The pattern of sedimentary change in Europe from calcareous (c) via intermediate
(b) to terrigenous clastic (a) facies associations is best explained as a consequence of

12

PALAEONTOLOGY, VOLUME 12

passage from a pelagic or oceanic environment in a locally shallow and never especially
deep sea towards a non-pelagic environment under the strong influence of rivers. This
interpretation has previously been considered in some detail (Hallam 1967a, b) and
consequently need only be referred to briefly here. The rivers brought into the marine
environment quantities of quartz/feldspar sand and silt together with clay including
substantial quantities of kaolinite; also iron, in dissolved or suspended form, and plant
matter. Phytoplankton flourished in the inshore zone, partly as a result of the influx of

text-fig. 3. Palaeogeographic sketch map for Europe in Upper Oxfordian times. Explanation as in

text-fig. 1.

nutrients from the land. The presence of red limestones and manganese concentrations
in condensed beds in the calcareous facies association relates to the relative sparsity of
organic matter in the oceanic environment. Salinity of the inland sea or ‘inshore’ region
must have been lowered somewhat by the influx of fresh water from the land and the
good correlation that appears to exist between litho- and biofacies points to the opera-
tion of this factor in controlling faunal distribution.

2. Besides temperature, salinity is effectively the only major inorganic factor that
can produce such faunal diversity gradients on a regional scale. The nature of the diver-
sity contrast between the Tethyan and Boreal realms accords with the salinity-control
hypothesis in that the greatest diversity is found in the pelagic environment. Moreover,
among the organisms with close relatives surviving today, it is notable that representa-
tives of the bivalves, gastropods, ostracods, and agglutinating foraminifera with simple

13

A. HALLAM: FAUNAL REALMS AND FACIES IN THE JURASSIC

structure flourished in the Boreal Realm, as they do in present-day seas with reduced
salinity. On the other hand, known stenohaline groups such as the hermatypic corals
were very largely confined to the Tethyan Realm. Dasycladacean and other types of
benthonic lime-secreting algae were, like the planktonic coccospheres, largely confined
to the normal salinities of the open sea. Now that electron microscopy has revealed that
many Upper Jurassic fine-grained limestones in the Mediterranean region contain
numerous coccoliths (Garrison 1967, Farinacci 1964, Fliigel 1967) there is an explana-
tion of why limestone is sparse even in condensed clay sequences in the Boreal Realm.
Likewise, the restriction of diagenetic chert mainly to facies association c correlates
with the occurrence in abundance of calcitized radiolaria and siliceous sponges.

TABLE 3

Kattegat

Belt Sea

Arkona Sea

Gulf of Finland

Salinity of bottom waters

c- 35%0

0

o

rn

1

l/A

<N

1 0—1 5%0

5°/

-1 /oo

No. of species of bivalves

92

34

24

4

„ „ polychaetes

193

143

15

3

„ „ crustaceans

232

97

29

11

„ „ fish

75

55

30

22

Total species

592

329

98

40

The best-documented example of salinity gradients in modern seas is that of the Baltic
Sea. Table 3 is compiled from Segerstrale (1957, table 2, and fig. 2). Segerstrale recorded
a ‘filtering out’ of stenohaline groups such as coelenterates, brachiopods, cephalopods,
radiolaria, and echinoderms and a reduction in the diversity of more tolerant groups
passing eastward into the Baltic from the North Sea. It will be noted from Table 3
that even the euryhaline groups exhibit a large reduction in numbers of species with only
a small change of salinity; thus a drop of only 5— 10%o correlates with a reduction in
species number by almost a half. If stenohaline groups are included then the reduction
is by much more than a half.

3. The faunal abundance (for a given thickness of deposit) is usually, in contrast to
the diversity, greater in the Boreal Realm. This is true especially of the bivalves. Genera
such as Buchia, Inoceramus, and Gryphaea often occur in large quantities in faunas of
quite low diversity. This phenomenon exactly parallels the situation in modern estuaries
and inland seas, where the abundant food supply favours mass colonization by those
organisms that can survive the reduced salinity.

4. Wall (1965) described non-calcareous microplankton of Liassic Beds in Britain
(Boreal Realm) that are low in diversity, associated with pollen and spores of greater
diversity; he interpreted these facts to signify that the environment was an inshore one,
with close proximity to coastal vegetation.

5. At the present day (Bandy 1960) agglutinating foraminifera with a simple shape
are characteristic of bays and lagoons, whereas labyrinthine forms and those with
siphonate chambers are found in the central and outer parts of shelf areas and the
bathyal zone.

This accords precisely with the salinity-control hypothesis for the Jurassic. Simple
agglutinating foraminifera such as Anvnodiscus, Ammobaculites, Hyperammina,
and Rheophax are among the few faunal elements that occur in marginal marine-
continental clastic deposits of the sort that pass laterally into coal measures

14

PALAEONTOLOGY, VOLUME 12

(Kaptarenko-Tschernousowa 1964). On the other hand, complex forms belonging to
the Lituolacea are characteristic of, and mainly restricted to, the Tethyan Realm.

It may be objected that the Boreal Realm, with its abundant echinoderms, cephalo-
pods, and brachiopods, which are all stenohaline groups judging from their present-day
distribution, signifies marine rather than brackish-water conditions. This, while per-
fectly true, does not affect the argument, since what is envisaged is an extensive inland
sea with only slightly reduced salinity, unlike the eastern Baltic or Black Seas. Echino-
derms, in fact, are more tolerant of salinity than is generally realized and Binyon (1966)
lists seventeen species that are known to survive in waters of less than 20%o. Cephalopods
and brachiopods are undoubtedly less tolerant, but in both cases species are known
that can survive in waters down to about 30%o (Mangold-Wirz 1963, Cori 1933). This
difference in tolerance probably helps to account for the fact that a number of echino-
derms are known from the Rhaetic in England (H. Ivimey Cook, personal communica-
tion), having entered the succession earlier than the first cephalopods and brachiopods
which first appear a short distance above the base of the Lias. This accords well with the
usual palaeogeographic notion of a slowly transgressing sea bringing progressively
increasing marine influence to this region.

Taking into account the Baltic Sea data, it is clear that even a slight reduction in
salinity can exert strong influence on the fauna and that the Jurassic diversity data are
more plausibly explained by this means than by the only reasonable alternative, tem-
perature.

It is not difficult to show, however, that salinity could not have been the only factor
responsible for the differentiation of faunal realms. The relatively straight-forward
relationship that exists between litho- and biofacies throughout Europe outside the
Caucasus breaks down in the unstable eugeosynclinal belts, where Tethyan faunas
occur in terrigenous and volcanic clastic facies, locally passing into continental coal
measures. Even in tectonically stable zones undoubted brackish-water faunas occur
locally within the Tethyan Realm. Evidently the general palaeogeographic setting must
be taken into account, for the Boreal Realm needed both space and time to develop;
mere local reduction in salinity was not enough. In other words, it is necessary to invoke
an extensive area of relatively stable palaeogeography where an inland sea of slightly
reduced salinity (perhaps on average down to about 30%o) could persist long enough to
allow a separate fauna (derived from some Tethyan ancestors) to evolve unmolested,
being protected from biological competition by a ‘salinity bar’. This may well account
for the progressive differentiation of a boreal fauna of ammonites and belemnites
(marked by a false start, i.e. the liparoceratid-amaltheid lineage which became extinct
at the close of the Pliensbachian) which correlates with the progressive transgression of
the Jurassic seas that continued at least until late Oxfordian times. This gradual trans-
gression, which can be discerned despite local tectonic disturbances and minor oscilla-
tions, caused a progressively larger area of a boreal continent to be flooded, so expanding
the ‘niches’ available for colonization. Arkell’s two ‘boreal spreads’, in the Callovian
and Lower Kimmeridgian, which can also be recognized in western North America
(Imlay 1965), correlate in Europe with a southward migration of terrigenous elastics
presumably related to tectonic uplift in the north. The Upper Oxfordian marks the
time when the Jurassic transgression reached its climax and the Tethyan fauna achieved
its greatest extent as river mouths were pushed back.

A. HALLAM: FAUNAL REALMS AND FACIES IN THE JURASSIC

15

The sort of palaeogeography envisaged is represented diagrammatically in text-fig. 4.
I consider on independent grounds that the Atlantic Ocean probably did not exist
during the Jurassic. While not crucial to the interpretation proposed above, it appears
more plausible if there were only one northern continent rather than two, since this
allows for the extensive development of a shallow boreal inland sea with free oceanic
connections but persistently kept at a slightly lower salinity. This indicates a humid
climate, with abundant freshwater run-off from the well-vegetated northern land masses
emergent from this inland sea. The sparsity of terrigenous elastics further south is clearly
a function of reduced river influence but land was not necessarily distant (text-fig. 4).
Perhaps the climate further south was more arid, a suggestion which is supported by the
widespread occurrence of evaporites in lagoonal deposits associated with the calcareous
facies.

text-fig. 4. Proposed Upper Oxfordian palaeogeography for the northern hemisphere, using the fit of
the Atlantic continents suggested by Bullard et al. 1965. Explanation as in text-fig. 1. P — Perisphinc-
tacea common, C = Cardioceratinae dominant, perisphinctids absent or subordinate; V = volcanic-

clastic beds of West Cordilleran geosyncline.

Did climate play no role other than this? There is, of course, no denying that on
astronomical grounds temperature must have been higher at the equator than at the
poles. It is my contention, however, that the difference was too slight to have had more
than, at most, a minor influence on the faunal distributions. In so far as there would have
been a temperature gradient from south to north, its effect would have served to reinforce
that due to salinity. Thus, Arctic Callovian faunas are dominated by Cadoceras rather
than the common European genus Kosmoceras, and other Arctic faunas often show lower

16

PALAEONTOLOGY, VOLUME 12

diversity than those in Europe. Such differences as these could possibly be the con-
sequence of a slight temperature gradient.

Turbidity and food supply are other factors which should not be ignored. They might,
for instance, help to account for the abundance of Buchia in Oxfordian and younger
Jurassic deposits wherever the rocks are rich in terrigenous elastics, regardless of whether
the associated fauna is Tethyan or Boreal.

Finally, there is the possibility of biological competition. Once a boreal fauna was
established, elements of the Tethyan fauna might have been prevented from entering the
Boreal Realm even though they could tolerate the lowered salinity. A possible example
concerns the coexistence during the late Pliensbachian of amaltheids in the Boreal and
hildoceratids and dactylioceratids in the Tethyan Realm. Not until after the amaltheids
died out was there a significant extension of the other families into the Boreal Realm.
This was probably due at least in part to the Toarcian transgression but biological
competition may also have played a role.

The hypothesis that finally emerges obviously involves rather more than simple
salinity control, but I believe this to be by far the most important environmental variable,
apart from palaeogeographic configuration. To test the hypothesis adequately in detail,
many more data need to be amassed on relative faunal abundances and associated litho-
logy than are currently available.

In conclusion, a few ecological implications can be suggested. There is a tendency
for Jurassic cephalopods to fall into two categories which may be called pelagic (or
stenohaline) and non-pelagic (slightly euryhaline). This finds a parallel among living
cephalopods (Mangold-Wirz 1963). Among the pelagic group, the phylloceratids and
lytoceratids probably had a wider depth range than other ammonites such as the oppeli-
ids, judging from their facies distribution in southern Europe, as documented for instance
by Ziegler (1963). Among the benthos, brachiopods are relatively more important in the
‘deeper water’ calcareous facies than bivalves, in contrast to the shallower-water facies
of the Boreal Realm. This may well signify better adaptation among characteristic
Tethyan brachiopods to relative sparsity of food, as indeed Vogel (1966) has argued
specifically in the case of Pygope. As already indicated, however, it is not necessary to
invoke water of any great depth. Likewise, the organism that produced the characteristic
Tethyan trace fossil Zoophycos, clearly a systematic sediment-feeder, was probably
better adapted to a limited food supply than the organisms responsible for the common
trace fossils of the Boreal Realm.

REFERENCES

ager, d. v. 1967. Some Mesozoic brachiopods in the Tethys region. Systematics /Es. Pub!. 7, 135-50.
arkell, w. j. 1956. Jurassic geology of the world. Edinburgh.

bandy, o. l. 1960. General correlation of foraminiferal structure with environment. Rep. 21st lnt. geol.
Congr., part 22, 7-19.

binyon, j. 1966. Salinity tolerance and ionic regulation. In boolootian, r. a., (ed.) Physiology of Echino-
dermata, 359-77 . New York, etc.

bullard, e. c., everett, j. e., and smith, a. g. 1965. The fit of the continents around the Atlantic.
Phil. Trans. R. Soc. 258 A, 41-51.

callomon, j. h. 1959. The ammonite zones of the Middle Jurassic beds of East Greenland. Geol. Mag.
96, 505-13.

A. HALLAM: FAUNAL REALMS AND FACIES IN THE JURASSIC 17

carey, s. w. 1958. A tectonic approach to continental drift. Geol. Dept. Univ. Tasmania, Symp. 5,
177-355.

cori, c. i. 1933. Brachiopoda. In : Die Tienvelt der Nord- and Ostsee, teil 7, c. 3, lief. 24, 133-50, Leipzig.
donovan, d. t. 1967. The geographical distribution of Lower Jurassic ammonites in Europe and
adjacent areas. Systematics Ass. Publ. 5, 1 1 1-32.
ekman, s. 1953. Zoogeography of the sea. London.

enay, r. 1966. L'Oxfordien dans la moitie sud du Jura franqais — etude stratigraphique. Nouv. Arch.
Mas. His. nat. Lyon, fasc. VIII, 1, 2.

farinacci, a. 1964. Microorganismi dei Calcari ‘Maiolica’ e ‘Scaglia’ osservati al microscopio elle-
tronico (Nannoconi e Coccolithophoridi). Boll. Soc. Paleont. Ital. 3, 172-81.
fischer, a. g. 1961. Latitudinal variations in organic diversity. Am. Scientist, 49, 50-74.
flugel, e. 1967. Elektronenmikroskopische Untersuchungen an mikritischen Kalken. Geol. Rdsch. 56,
341-58.

garrison, r. e. 1967. Pelagic limestones of the Oberalm Beds (Upper Jurassic-Lower Cretaceous),
Austrian Alps. Bull. Canad. Petrol. Geol. 15, 21-49.

Gerasimov, p. a. and mikhailov, n. p. 1966. The Volgian stage and the standard scale for the upper
series of the Jurassic System. Izv. Akad. Nauk SSSR, ser. geol. 2, 118-38 (in Russian).
hallam, a. 1966. Depositional environment of British Liassic ironstones considered in the context of
their facies relationships. Nature, Load. 209, 1 306-7.

1967u. Sedimentology and palaeogeographic significance of certain red limestones and associated

beds in the Lias of the Alpine region. Scot. J. Geol. 3, 195-220.

1 9676. An environmental study of the Upper Domerian and Lower Toarcian of Great Britain.

Phil. Trans. R. Soc. 252B, 393-445.
haug, e. 1907. Traite de geologie. Paris.

howarth, m. k. and stephanov, j. 1965. The genus Kosmoceras in Bulgaria. Bulg. Akad. Nauk, Geol.
Inst., Tr. Geol. Bulg., Ser. Pal. 7, 135-49.

imlay, r. 1965. Jurassic marine faunal differentiation in North America. J. Paleont. 39, 1023-38.
jeletzky, j. a. 1965. Late Upper Jurassic and early Lower Cretaceous fossil zones of the Canadian
Western Cordillera. Bull. Geol. Surv. Can. 103.

kaptarenko-tschernousowa, o. k. 1964. Versuch eines stratigraphisches Vergleiches der Jura-Abla-
gerungen auf Grund ihrer Foraminiferen-Fauna. le Colloque Jurass. Luxemb. Publ. Inst. gr. ducal.
Sect. sc. nat., phys. math. 429-37.

mangold-wirz, k. 1963. Biologie des cephalopodes benthiques et nektoniques de la Mer Catalane.

In 'Vie et Milieu ’, Publ. Lab. Arago, Univ. Paris, suppl. 13.
neumayr, m. 1883. Uber klimatische Zonen wahrend der Jura- und Kreidezeit. K. Akad. fViss. Wien
Denkschr., Math-naturh. Kl. 47, 277-310.

ortmann, a. e. 1896. An examination of the arguments given by Neumayr for the existence of
climatic zones in Jurassic times. Am. J. Sci. 4 ser. 1, 257-70.
saks, v. n., mesezhnikov, m. s., and shulgina, n. i. 1964. About the connection of the Jurassic and
Cretaceous marine basins in the north and south of Eurasia. Dok. Sovetsk. Geol. Mezh. Geol. Kong.
22nd Ser. 163-74 (in Russian).

sapunov, i. g. (in press). Notes on the geographic differentiation of the Lower Jurassic faunas.
2e Colloque Jurass. Luxemb.

sato, t. 1960. A propos des courants oceaniques froids prouves par l’existence des ammonites d'origine
arctique dans le Jurassique japonais. Rep. 21st Int. geol. Congr. part 12, 165-9.
segerstrale, s. g. 1957. Baltic Sea. Mem. geol. Soc. Am. 67, 1, 751-800.

stehli, f. g., mcalester, a. l., and helsley, c. e. 1967. Taxonomic diversity of Recent bivalves and
some implications for geology. Bull. geol. Soc. Am. 78, 455-66.
stevens, g. R. 1963. Faunal realms in Jurassic and Cretaceous belemnites. Geol. Mag. 102, 175-8.

1965. The Jurassic and Cretaceous belemnites of New Zealand and a review of the Jurassic and

Cretaceous belemnites of the Indo-Pacific region. Bull. geol. Surv. N.Z. Palaeont. 36.

1967. Upper Jurassic fossils from Ellsworth Land, West Antarctica, and notes on Upper Jurassic

biogeography of the South Pacific region. N.Z. Journ. Geol. Geophys. 10, 345-93.
tintant, h. 1963. Les Kosmoceratides du Callovien inferieur et moyen d’Europe occidentale. Dijon
Univ. Publ. 29.

C 6289

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PALAEONTOLOGY, VOLUME 12

uhlig, v. 1911. Die marinen Reiche des Jura und der Unterkreide. Mitt. Geol. Gesell. Wien, 4, 329-448.
vakhrameev, v. a., 1964. Jurassic floras of the Indo-European and Siberian botanical-geographical
regions. le Colloq. Jurass. Luxemb. Publ. Inst. gr. chic Luxemb. Sect. Sci. not., phys. math. 41 1-21.
vogel, k. 1966. Eine funktionsmorphologische Studie an der Brachiopodengattung Pygope (Malm bis
Unterkreide). Neues Jb. Geol. Palaont. Abh. 125, 423-42.
wall, d. 1965. Microplankton, pollen and spores from the Lower Jurassic in Britain. Micropaleon-
tology, 11, 151-90.

ziegler, b. 1963. Die Fauna der Lemes-Schichten (Dalmatien) und ihre Bedeutung fur den mediter-
ranen Oberjura. Neues Jb. Geol. Palaont. Mh. 8, 405-21.

1964. Boreale Einfliisse im Oberjura Westeuropas? Geol. Rc/sc/t. 54, 250-61.

A. HALLAM

Department of Geology and Mineralogy

Typescript received 3 April 1968 University of Oxford

UPPER MAESTRICHTIAN PLANKTONIC
FORAMINIFERA FROM GALICIA BANK,
WEST OF SPAIN

by B. M. FUNNELL, J. K. FRIEND, and A. T. S. RAMSAY

Abstract. An upper Maestrichtian assemblage of planktonic foraminifera is described from a sample of chalk
dredged from Galicia Bank, a non-magnetic seamount off the west coast of Spain. The presence of post-
Maestrichtian planktonic species in the sample is attributed to the burrowing of mud-feeding organisms. It is
suggested that the very high percentage of planktonic individuals in the upper Maestrichtian limestone of Galicia
Bank is a product of depth and proximity to an open oceanic environment during deposition.

This paper describes the members of an assemblage of planktonic foraminifera which
were used to date a fragment of soft chalky limestone (Funnell 1964) dredged from the
upper slopes of the Galicia Bank, a flat-topped non-magnetic seamount off the west coast
of Spain. The sample D. 3804.1, which was dredged from a depth of 650-700 m. at
42° 36' N., 11° 35' W. (station D. 3804), is one of a series of samples obtained from the
slopes of the seamount during the summer of 1958 (Black el a/. 1964).

The assemblage contains species and subspecies diagnostic of the upper Maestrich-
tian, and equates with the Abathomphalus mayaroensis zone of Trinidad (Bolli 1957),
the Globotruncana contusa zone of Tunisia (Dalbiez 1955), the KF zone of Upper Austria
(Wille-Janoschek 1966), and the Pseudotextularia elegans zone of southern Scandin-
avia (Berggren 1962), which are the highest Maestrichtian zones in their respective areas.

In a count of 507 specimens, 95% were planktonic (including 22% heterohelicids),
5% benthonic, and 0-2% post-Maestrichtian contaminants.

The contaminants, which include planktonic species of mid-Tertiary and upper Ter-
tiary to Recent origin, were probably introduced into the samples via burrows or borings
(Funnell 1964). Black (1964) attributed a mixed assemblage of Cretaceous and Tertiary
coccoliths in the same sample to the burrowing of mud-feeding organisms.

Investigations of the ratio of planktonic to benthonic individuals in Recent sediments
by Smith (1955), Grimsdale and Morkhoven (1955), and Hay (1960) suggest that, despite
variations attributable to local conditions, a general relationship exists between increas-
ing proportion of planktonic individuals, depth, and proximity to the open oceans.
Grimsdale and Morkhoven considered sediments containing over 98% planktonic
individuals as indicative of a depth of deposition of at least 700 m. Hay (1960) suggested
that the upper Cretaceous Mendez and Palaeocene Velasco formations of the Tampico
embayment, whose faunas both contain 90% or more planktonic species, were deposited
‘in waters at least 250 and probably more than 500 m deep’.

The paucity of data concerning conditions in the Upper Cretaceous, and the debatable
procedure of including the heterohelicids in planktonic counts, suggests that the plank-
tonic/benthonic ratio provides at the most an approximation of the depth of deposition
during this period (see Funnell 1967, pp. 339-40). Nevertheless the high ratio of plank-
tonic species (95% including the heterohelicids; 73% excluding the heterohelicids) in

[Palaeontology, Vol. 12, Part 1, 1969, pp. 19-41, pis. 1-5.]

20

PALAEONTOLOGY, VOLUME 12

the upper Maestrichtian limestone of the Galicia Bank is most probably indicative of
an open oceanic environment, and is not at variance with the depth of deposition from
which the sample was dredged.

The line illustrations were prepared by Mrs. J. K. Friend (nee Bean) in 1964; the
electron micrographs were taken by the Cambridge Instrument Company Ltd. on a
Stereoscan II in 1967. In all cases except one the same specimens were used on both
occasions. ‘Hypotype’ and illustrated specimens have been deposited in the Sedgwick
Museum, Cambridge, together with complete synonymies and bibliography of the species
described.

Acknowledgements. Mr. M. J. Fisher kindly assisted in bringing the synonymies up to date. The
work was supported in part by a N.E.R.C. research grant.

1834 Textilaria globidosa Ehrenberg, p. 135, pi. 4, fig. 4 (fide Ellis and Messina 1940 et seq.).
1951 Guembelina globidosa (Ehrenberg); Visser, p. 254, pi. 8, fig. 8.

1960 Guembelina globidosa (Reuss); Hofker, p. 224, fig. 18, p. 225, fig. 39.

1961 Heterohelix globidosa (Ehrenberg); Said and Kerdany, p. 331, pi. 2, fig. 1.

1966 Heterohelix globidosa (Ehrenberg); Barr, p. 503, pi. 78, figs. 5, 6.

1966 Guembelina globidosa (Ehrenberg); Elofker, p. 107, pi. 10, fig. 110.

1966 Guembelina cf. globidosa (Ehrenberg); Elofker, p. 170, pi. 29, fig. 63.

1966 Heterohelix globidosa (Ehrenberg); Lehmann, p. 314, pi. 2, fig. 9.

? 1966 Heterohelix globidosa (Ehrenberg); Wille-Janoschek, pp. 148, 149, 151, no fig.

Description. In the specimens examined the test is composed of 15 chambers. The first
4 or 5 are small and coiled about the proloculus, later chambers are biserially arranged
and increase in size and globosity, a development which is most apparent in the last
4 chambers. The chamber surfaces are ornamented with fine longitudinal costae; pores
are confined to the intercostate surfaces. The aperture is simple, slit-like, interiomarginal.

Stratigraphical distribution. H. globidosa is recorded from the Santonian (Ktipper 1956) to upper
Maestrichtian.

Geographical distribution. A widely distributed species ranging from approximately 55° N. (Vigso and
Rodvig, Denmark; Hofker 1960) to 25° S. (Carnarvon Basin, W. Australia; Belford 1960). Within
these latitudes it is recorded from the Pacific Ocean (Hamilton 1953), California (Martin 1964), the
U.S. Gulf Coast (Cushman 1946), Mexico (Olvera 1959), Cuba (van Wessem 1943), northern Europe
(Visser 1951), the circum-Mediterranean, and India (Nagappa 1959).

SYSTEMATIC DESCRIPTIONS

Family heterohelicidae Cushman 1927
Subfamily heterohelicinae Cushman 1927

Genus heterohelix Ehrenberg 1843
Heterohelix globulosa (Ehrenberg)
Plate 1, figs. 1,2; text-fig. 1

text-fig. 1. Heterohelix globidosa (Ehrenberg),
b (a) lateral view, ( b ) apertural view; No. 1165, X 100.

FUNNELL, FRIEND, AND RAMSAY: PLANKTONIC FORAMINIFERA

21

Heterohelix striata (Ehrenberg)

Plate 1, figs. 3, 4; text-fig. 2

1839 Textilaria striata Ehrenberg, p. 1 35, pi. 4, figs. 1, 2, 2>(fide Ellis and Messina 1940 et seq.).
1946 Guembelina striata (Ehrenberg); Cushman, p. 104, pi. 45, figs. 4, 5.

1953 Pseudoguembelina striata (Ehrenberg); Bronnimann and Brown, p. 154, fig. 6.

1959 Heterohelix striata (Ehrenberg); Olvera, pp. 71, 72, pi. 2, figs. 4, 8.

1964 Heterohelix striata (Ehrenberg); Martin, p. 85, pi. 11, fig. 1.

1964 Pseudoguembelina striata (Ehrenberg); Said and Sabry, p. 394, pi. 3, fig. 21.

? 1966 Heterohelix striata (Ehrenberg); Wille-Janoschek, pp. 148, 149, 151, no fig.

1966 Guembelina striata (Ehrenberg); Hofker, pp. 31, 64, 79, 150, 189, 318; pi. 3, fig. 68;
pi. 10, fig. 109; pi. 14, figs. 80, 81; pi. 23, figs. 116, 117; pi. 33, fig. 76; pi. 34, fig. 105;
pi. 73, fig. 166.

1966 Heterohelix striata (Ehrenberg); Lehmann, p. 315, pi. 2, fig. 8.

text-fig. 2. Heterohelix striata (Ehrenberg),

(a) lateral view, ( b ) apertural view; No. 1164,
b x 1 00.

Description. In the specimens examined 10-12, more or less globular, biserially arranged
chambers increase gradually in size, and are ornamented with fine longitudinal costae
which do not extend across the sutures. The aperture is simple, lunate, interiomarginal ;
pores are confined to the intercostate surfaces.

Stratigraphical distribution. Common in the Maestrichtian but also occurs in the upper Campanian
(Wille-Janoschek 1966).

Geographical distribution. H. striata is geographically widespread. It ranges from approximately
57° N. (Kjolby Gaard, Denmark; Berggren 1960) to 25° S. (Carnarvon Basin, West Australia; Belford
1960); between these latitudes it is recorded from the Pacific Ocean (Hamilton 1953), California
(Martin 1964), the U.S. Gulf Coast (Cushman 1946), Mexico (Olvera 1959), Cuba (Bronnimann and
Brown 1953), Puerto Rico (Pessagno 1960), northern Europe, the circum-Mediterranean, and Pakistan
(Nagappa 1960).

Heterohelix ultimatumida (White)

Plate 1, figs. 5, 6; text-fig. 3

1929 Guembelina ultimatumida White, p. 39, pi. 4, fig. 13.

1959 Heterohelix ultimatumida (White); Olvera, pp. 72, 73, pi. 1, fig. 16.

b

text-fig. 3. Heterohelix ultimatumida
(White), (a) lateral view, (b) apertural
view; No. 1166, X 100.

22

PALAEONTOLOGY, VOLUME 12

Description. The specimens examined consist of about 10 biserially arranged chambers;
the first 6 are radially costate and increase gradually in size and globosity, the last
4 chambers are large, globose, smooth or finely costate; the ultimate chamber is smaller
than the penultimate. The aperture is large, simple, lunate, interiomarginal; pores are
distributed between the costae.

Stratigraphical distribution. Campanian (Pessagno 1962) to upper Maestrichtian.

Geographical distribution. Records of this species are confined to the northern hemisphere between
50° N. (Glons, Belgium; Hofker 1958) and 18° N. (Puerto Rico; Pessagno 1962). Within these latitudes
it is reported from the Pacific Ocean (Hamilton 1953), the U.S. Gulf Coast (Pessagno 1962), Mexico
(Olvera 1959), Cuba (Voorwijk 1937), Germany (Hofker 19566), and Egypt (Said and Kenawy 1956).

Genus planoglobulina Cushman 1927
Planoglobulina acervulinoides (Egger)

Plate 1, figs. 7, 8; text-fig. 4

1900 Guembelina acervulinoides Egger, p. 36, pi. 14, figs. 20-22 (fide Ellis and Messina 1940
et seq.).

1926 Pseudotextularia acervulinoides (Egger); Cushman, p. 17, pi. 2, fig. 5.

1927a Planoglobulina acervulinoides (Egger); Cushman, p. 158, pi. 27, fig. 3.

1966 Pseudotextularia acervulinoides (Egger); Wille-Janoschek, pp. 99, 151, taf. 9, taf. 8, fig. 8.

text-fig. 4. Planoglobulina acervulinoides (Egger), (a) lateral view, ( b ) apertural view; No. 1158, x 100.

EXPLANATION OF PLATE 1

Figs. 1-6. Heterohelix spp. 1,2 , H. globulosa (Ehrenberg), lateral and apertural views; No. 1165,
x 150. 3, 4, H. striata (Ehrenberg), lateral and apertural views; No. 1164, X270. 5, 6, H. ultima-
tuinida (White), lateral and apertural views; No. 1166, X95.

Figs. 7-8. Planoglobulina acervulinoides (Egger), lateral and apertural views; No. 1158, X 76.

Figs. 9-10. Pseudotextularia elegans (Rzehak), lateral and apertural views; No. 1159, X68.

Figs. 11-12. Pseudoguembelina costulata (Cushman), lateral and apertural views; No. 1163, X 165.

Palaeontology, Vol. 12

PLATE 1

FUNNELL, FRIEND and RAMSAY, Foraminifera from Galicia Bank

FUNNELL, FRIEND, AND RAMSAY: PLANKTONIC FORAMINIFERA

23

Description. In the specimens examined the early chambers are biserially arranged,
longitudinally costate, and increase gradually in size and globosity. Later chambers
proliferate bilaterally; though initially inflated and strongly costate, they become less
inflated, with weak and discontinuous costae. When observed the aperture is multiple;
pores are arranged in single or double rows between the costae.

Stratigraphical distribution. P. acervulinoides is restricted to the Maestrichtian.

Geographical distribution. Records of this species are confined to the northern hemisphere between
approximately 56° N. (Mors, Denmark; Berggren 1962) and 22° N. (Tampico, Mexico; Cushman
1926). Within these latitudes it has been recorded from Cuba (Voorwijk 1937), Alabama (Cushman
1946), New Jersey (Olsson 1960), northern Europe, and the circum-Mediterranean as far east as the
Sinai Peninsula (Said and Kenawy 1956).

Genus pseudotextularia Rzehak 1891

Pseudotextularia elegans (Rzehak)

Plate 1, figs. 9, 10; text -fig. 5

1888 Cuneolina elegans Rzehak, p. 191, no fig.

1929 Guembelina elegans (Rzehak); White, pp. 34, 35, pi. 4, fig. 8.

1946 Guembelina plummerae Loetterle; Cushman, p. 104, pi. 45, figs. 1-3.

1959 Guembelina plummerae Loetterle; Nagappa, p. 163, pi. 7, figs. 5-6.

? 1960 Pseudotextularia elegans (Rzehak); Berggren, pp. 185, 190, no fig.

? 1960 Guembelina plummerae Loetterle; Nagappa, p. 48, no fig.

b

a

text-fig. 5. Pseudotextularia elegans (Rzehak), (a) lateral view, (b) apertural view; No. 1159, X 100.

Description. The specimens examined have a more or less conical test, with biserially
arranged, longitudinally costate chambers which increase gradually in size and globosity.
The aperture is simple, lunate, interiomarginal; pores are confined to the surfaces
between the costae.

Stratigraphical distribution. Santonian (Wille-Janoschek 1966) to upper Maestrichtian.

Geographical distribution. A widespread species ranging from approximately 57° N. (Kjolby Gaard,
Denmark; Berggren 1960) to 16° S. (Madagascar; Lys 1960). Between these latitudes it is recorded
from the Pacific Ocean (Hamilton 1953), the U.S. Gulf Coast (Cushman 1946), Mexico (White 1929),
Cuba (van Wessem 1943), Puerto Rico (Pessagno 1960), the north Atlantic (Saito et al. 1966), northern
Europe, the circum-Mediterranean, Pakistan, and India (Nagappa 1959, 1960).

24

PALAEONTOLOGY, VOLUME 12

Genus pseudoguembelina Bronnimann and Brown 1953

Pseudoguembelina eostulata (Cushman)

Plate 1, figs. 11, 12; text-fig. 6

1938 Guembelina eostulata Cushman, p. 16, pi. 3, figs. 7-9.

1953 Pseudoguembelina eostulata (Cushman); Bronnimann and Brown, pp. 153, 154, fig. 5.

b

text-fig. 6. Pseudoguembelina eostulata (Cushman),
(a) lateral view, (b) apertural view; No. 1163, x 100.

Description. In the specimens examined the test consists of 5-7 pairs of somewhat
depressed, biserially arranged chambers which increase in size and are ornamented with
fairly fine longitudinal costae, some of which extend across the sutures. The primary
aperture is narrow, simple, lunate; accessory apertures are developed at the chamber
bases on the central suture line.

Stratigraphical distribution. Campanian (Pessagno 1960) to Maestrichtian.

Geographical distribution. Records of this species are confined to the northern hemisphere between
34° N. (Arkansas; Cushman 1949) and 18° 15' N. (Puerto Rico; Pessagno 1960). Within these latitudes
it has been reported from the Pacific Ocean (Hamilton 1953), Texas (Montanaro Gallitelli 1957), the
U.S. Gulf Coast, Cuba (van Wessem 1943), and Egypt (Ansary and Fakhr 1958).

Pseudoguembelina excolata (Cushman)

Plate 2, figs. 1,2; text -fig. 7

1926 Guembelina excolata Cushman, p. 20, pi. 2, fig. 9.

1953 Pseudoguembelina excolata (Cushman); Bronnimann and Brown, p. 153, figs. 1-4.

b

text-fig. 7. Pseudoguembelina excolata
(Cushman), (a) lateral view, ( b ) aper-
tural view; No. 1162, X 100.

Description. In the specimens examined 4-7 pairs of chambers are arranged biserially;
the initial 3 pairs increase gradually in size, later chambers increase rapidly in size and

EXPLANATION OF PLATE 2

Figs. 1-2. Pseudoguembelina excolata (Cushman), lateral and apertural views; No. 1161, X 114.

Figs. 3-4. Racemiguembelina fructicosa (Egger), lateral and apertural views; No. 1160, x 74.

Figs. 5-10. Abathomphalus spp. 5-7, A. mayaroensis (Bolli), ventral, edge, and dorsal views; No. 1 177,
X70. 8-10, A. intermedia (Bolli), ventral, edge, and dorsal views; No. 1178, X 129.

Figs. 11-13. Globotruncana area (Cushman), ventral, edge, and dorsal views; No. 1167, x 71.

Palaeontology, Vol. 12

PLATE 2

FUNNELL, FRIEND and RAMSAY, Foraminifera from Galicia Bank

FUNNELL, FRIEND, AND RAMSAY: PLANKTONIC FORAMINIFERA 25

degree of inflation. The chambers are coarsely costate, some costae extend across the
sutures. The aperture is small, simple, lunate.

Stratigraphical distribution. Maestrichtian, but also occur in the upper Campanian (U. Taylor Forma-
tion, U.S. Gulf Coast; Cushman 1946).

Geographical distribution. A widespread species in the northern hemisphere where it ranges from
approximately 47° N. (Salzburg and Gams, Austria; Kiipper 1956, Wicher 1956) to 19° N. (Pacific
Ocean; Hamilton 1953). Between these latitudes it is recorded from the Tampico embayment, Mexico
(Olvera 1959), Cuba (Bronnimann and Brown 1953), U.S. Gulf Coast (Cushman 1946) and New Jersey
(Olsson 1960), and the circum-Mediterranean as far east as the Sinai Peninsula (Said and Kenawy
1956).

Genus racemiguembelina Montanaro Gallitelli 1957
Racemiguembe/ina fructicosa (Egger)

Plate 2, figs. 3, 4; text-fig. 8

1895 Pseudotextularia various Rzehak, pp. 217, 218, pi. 7, figs. 2, 3 ( fide Ellis and Messina
1940 et seq.)

1900 Guembelina fructicosa Egger, p. 35, pi. 14, figs. 8, 9 (? 24, 25, 26) ( fide Ellis and Messina
1940 et seq.).

1929 Pseudotextularia various var. mendezensis White, p. 41, pi. 4, fig. 16.

1929 Pseudotextularia various var. textulariformis White, p. 41, pi. 4, fig. 17.

1946 Pseudotextularia various Rzehak; Cushman, p. 110, pi. 47, figs. 4-9.

? 1956 Pseudotextularia various Rzehak; Wicher, p. 104, no fig.

1957 Pseudotextularia various Rzehak; Hofker, pp. 422, 424, text-fig. Alfta-h.

1957 Racemiguembelina fructicosa (Egger); Montanaro Gallitelli, pp. 142, 143, pi. 32, figs.

14, 15.

1958 Pseudotextularia elegans (Rzehak); Witwicka, p. 195, pi. 8, figs. 6, 7.

1959 Pseudotextularia elegans (Rzehak); Nagappa, p. 197, pi. 7, figs. 7, 8.

1960 Pseudotextularia various Rzehak; Hofker, pp. 212, 216-17, 219, 220, 229-31, 237-9,

241, figs. 11, 42-44.

1960 Pseudotextularia various Rzehak; Vinogradov, pi. 6, figs. 34, 35, tabs. 1, 2.

text-fig. 8. Racemiguembelina fructicosa (Egger), (a) lateral view,
(b) apertural view; No. 1160, x 100.

26

PALAEONTOLOGY, VOLUME 12

Description. In the specimens examined the test is conical. Its chambers, which initially
are biserially arranged, later proliferate, increase in size, and become more globular.
The chambers are ornamented with coarse longitudinal costae. The aperture is multiple;
apertures open into the lumen of the cone through a bridge of shell material which joins
opposing chambers.

Stratigraphical distribution. Common in the Maestrichtian, but is also recorded from the upper
Campanian (Kikoine 1948).

Geographical distribution. This species is widely distributed in the northern hemisphere. It ranges from
approximately 57° N. (Vigso, Denmark; Hofker 1960) to 19° 34' N., 171° 54' W. (Pacific Ocean;
Elamilton 1953); within these latitudes it is recorded from the Tampico embayment, Mexico (White
1929), the U.S. Gulf Coast (Cushman 1946), Cuba (Voorwijk 1937), the north Atlantic (Saito et al.
1966), English Channel (Curry 1962), Germany (Hofker 1957), Austria (Wicher 1956), Poland (Wit-
wicka 1958), Roumania (Vinogradov 1960), Egypt (Said and Kerdany 1961), and India (Nagappa
1959).

Family globotruncanidae Brotzen 1942
Genus abathomphalus Bolli, Loeblich, and Tappan 1957
Abathomphalus mayaroensis (Bolli)

Plate 2, figs. 5-7 ; text-fig. 9

1951 Globotruncana mayaroensis Bolli, p. 198, pi. 35, figs. 10-12.

? 1953 Globotruncana mayaroensis Bolli; Subbotina, p. 181, pi. 8, figs. 2 a-c.

1955 Rugotruncana mayaroensis (Bolli); Bronnimann and Brown, pp. 553-4, pi. 22, figs. 10-12.
1957 Abathomphalus mayaroensis (Bolli); Bolli, Loeblich, and Tappan, p. 43, pi. 11, figs. 1 a-c.
1957 Abathomphalus mayaroensis (Bolli); Bolli, p. 54, text-fig. 10.

1957 Globotruncana (Globotruncana) planata Edgell, p. 115, pi. 4, figs. 7-9.

text-fig. 9. Abathomphalus mayaroensis (Bolli), (a) dorsal, (b) edge,
and (c) ventral views; No. 1177, X 100.

Description. In the specimens examined the test is trochospiral, concavo-convex, with
two widely separated keels and a tegillum covering the umbilicus. In spiral view the
periphery is lobed. About 12-14 chambers are arranged in 3 whorls with 4-5 chambers in
the last whorl. The spiral and radial sutures are arcuate, thick, raised, and beaded. The
surface of the chambers is generally smooth and finely perforate. In umbilical view the

FUNNELL, FRIEND, AND RAMSAY: PLANKTONIC FORAMINIFERA 27

radial sutures are straight and unthickened. The chambers are slightly inflated and
slope rather steeply towards the narrow umbilicus; their surfaces have a granular and
finely porous appearance. The primary aperture is extra-umbilical. A delicate tegillum
extends across the umbilicus from the margin of the last chamber, and is provided with
accessory intralaminal apertures. In peripheral view the two strongly beaded keels are
separated by a wide band of granular appearance.

Stratigraphical distribution. Generally regarded as characteristic of, and confined to, the uppermost
Maestrichtian.

Geographical distribution. Ranges from approximately 57° N. (Kjolby Gaard, Denmark; Berggren
1960) to 22° S. (NW. Australia; Edgell 1957). It has also been recorded from the western side of the
Gulf of Mexico (Hay 1960), Trinidad (Bolli 1951), the Pyrenees (Mangin 1960), and the circum-
Mediterranean area generally as far as the eastern side of the Black Sea (Subbotina 1953) and Mada-
gascar (Lys 1960). Though regarded by Olsson (1964) as a Tethyan form (it does not occur in New
Jersey, U.S.A.) it was clearly wide-ranging at least as occasional examples.

Abathomphalus intermedia (Bolli)

Plate 2, figs. 8-10; text-fig. 10

1951 Globotruncana intermedia Bolli, p. 197, pi. 35, figs. 7-9.

1955 Rugotruncana intermedia (Bolli); Bronnimann and Brown, p. 553, pi. 22, figs. 13-15.
19566 Marginotruncana intermedia (Bolli); Hofker, p. 75, pi. 10, figs. lAa-c.

? 1957 Abathomphalus intermedia (Bolli); Bolli, p. 54, no fig.

? 1960 Abathomphalus intermedia (Bolli); Bolli and Cita, pp. 153, 154, no fig.

1962 Praeglobotruncana (Praeglobotruncana) intermedia (Bolli); Berggren, p. 31, pi. 7, figs.

c

text-fig. 10. Abathomphalus intermedia (Bolli), (a) dorsal, (b) edge,
and (c) ventral views; No. 1178, X 100.

Description. In the specimens examined the test is trochospiral concavo-convex with
two delicate keels separated by a granular area. In dorsal view the periphery is lobed.
Approximately 8-9 chambers are arranged in 3 whorls with 3-4 chambers in the last
whorl. The spiral and radial sutures are arcuate, thickened but not raised. The chamber
surfaces are smooth and finely perforate. On the ventral surface the chambers are weakly
inflated, the radial sutures are thickened and slightly depressed. The primary aperture is
extra-umbilical; a delicate tegillum which extends across the umbilicus from the margin
of the last chamber is provided with at least 3 infralaminal apertures.

Stratigraphical distribution. Middle to upper Maestrichtian (El-Naggar 1966).

Geographical distribution. The species ranges from approximately 57° N. (Kjolby Gaard, Denmark;
Berggren 1962) to 10° N. (Trinidad; Bolli 1951). It has also been recorded from Mexico, Colombia
(Gandolfi 1955), Cuba (Bronnimann and Brown 1955), NW. Germany and Holland (Hofker 19566),
and from the Nile Valley (El-Naggar 1966).

28

PALAEONTOLOGY, VOLUME 12

Genus globotruncana Cushman 1927
Globotruncana area (Cushman)

Plate 2, figs. 11-13; Plate 3, figs. 1-3; text -fig. 11

1926 Pulvinulina area Cushman, p. 23, pi. 3, fig. 1.

19276 Globotruncana area (Cushman); Cushman, p. 91, pi. 19, figs. 11 a-c.
1960 Globotruncana leupoldi Boll i ; Olsson, p. 50, pi. 1 1, figs. 1-3.

text-fig. 1 1. Globotruncana area (Cushman), (a) dorsal, (b) edge,
and (c) ventral views; No. 1167, X 100.

Descriptions. In the specimens examined the test is trochospiral, biconvex, with the
strongest convexity on the spiral surface. On the spiral surface 14-19 chambers are
arranged in 3-4 whorls, with 5-7 chambers in the final whorl. Both spiral and radial
sutures are arcuate, thickened, raised, and beaded; on some specimens granules
developed on the apex of the spire obscure the early chambers. The chamber surfaces
are planar, sometimes concave, generally smooth and finely porous. The radial sutures of
the umbilical surface are thickened and beaded; the thickening extends around the
umbilical edge of each chamber. Chamber surfaces are smooth, sometimes granular,
finely porous. The wide umbilicus is sometimes covered by a non-porous plate; the
primary aperture is intra-umbilical; both it and relict apertures of preceding chambers
open into the umbilicus. Apertures associated with the umbilical plate are both infra-
and intralaminal. The lobed peripheral margin is bordered by two keels which are
separated by a wide granular area.

Stratigraphical distribution. Mainly Maestrichtian, but has also been recorded from the upper Cam-
panian (Ksiazkiewicz 1956).

Geographical distribution. G. area is apparently cosmopolitan; it ranges from approximately 57° N.

( Kjolby Gaard, Denmark; Berggren 1960) to 22° S. (NW. Australia; Edgell 1957). Within these latitudes
it is recorded from the Pacific (Elamilton 1953), Vancouver (McGugan 1964), on the west coast
(Douglas and Sliter 1966), Gulf (Cushman 1946), and east coast (Olsson 1960) of North America.
Mexico (Hay 1960), Cuba, Trinidad (Bolli 1951), northern Europe, the circum-Mediterranean area,
the Caucasus (Subbotina 1953), and West Pakistan (Nagappa 1960).

FUNNELL, FRIEND, AND RAMSAY: PLANKTONIC FORAMINIFERA 29

Globotruncana conica White

Plate 3, fig. 4-6; text-fig. 12

1928 Globotruncana conica White, p. 285, pi. 38, fig. 7.

1955 Globotruncana stuarti conica (White); Gandolfi, p. 65, pi. 5, fig. 8.

1956 Globotruncana cf. conica White; Ksiazkiewicz, p. 283, fig. 61.

text-fig. 1 2. Globotruncana conica White, (a) dorsal, ( b ) edge,
and (c) ventral views; No. 1170, X 100.

Description. In the specimens examined the test is spiroconvex; its umbilical side is
obtusely conical and truncated. On the spiral surface 27 chambers are arranged in 4
whorls with 8 chambers in the last. The chambers increase rapidly in size in the first
2 whorls, less so in the third, and are approximately equal in the fourth; they are tri-
angular in the early whorls, quadrangular in the last. Both spiral and radial sutures are
thickened, raised, and beaded; beading is pronounced on the last whorl. On the umbilical
surface the radial sutures are thickened, weakly beaded, and extend on to the umbilical
edges of the chambers. The primary and relict apertures of preceding chambers open
into the umbilicus. The circular periphery is characterized by a single prominent keel
with traces of a second.

Stratigraphical distribution. Santonian to upper Maestrichtian (Cita 1948, Douglas and Sliter 1966).

Geograpbical distribution. G. conica is widely distributed in the northern hemisphere where it ranges
from approximately 50° N. (Bachowice, Poland; Ksiazkiewicz 1956) to 11°N. (NE. Colombia;
Gandolfi 1955). Between these latitudes it is recorded from the west coast of N. America (Douglas and
Sliter 1966), Tampico, Mexico (Hay 1960), Trinidad (Bolli 1951), Puerto Rico (Pessagno 1960),
Tunisia (Dalbiez 1955), and the circum-Mediterranean area as far as the Sinai Peninsula (Said and
Kenawy 1956).

Globotruncana contusa (Cushman)

Plate 3, figs. 7-9; text-fig. 13

? 1926 Pulvinulina area var. contusa Cushman, p. 23, no fig.

1966 Globotruncana fornicata Plummer; Douglas and Sliter, pp. 1 10-1 1, pi. 2, figs. 2, 4 {non
figs. 1, 3).

30 PALAEONTOLOGY, VOLUME 12

1966 Globotruncana contusa patelliformis Gandolfi; El-Naggar, pi. 8, figs. 1 a-c.
1966 Marginotruncana contusa (Cushman); Hofker, p. 95, pi. 17, fig. 78.

text-fig. 13. Globotruncana contusa (Cushman), (a) dorsal, (b) edge,
and (c) ventral views; No. 1169, X 100.

Description. In the specimens examined the test is trochospiral, slightly lobed, strongly
spiroconvex with a deep umbilicus. Its spiral surface contains 13-19 chambers arranged
in three whorls with 4-7 in the last. The chambers, which are initially circular and
inflated, become triangular and flat and finally crescentic with undulating surfaces.
The sutures are thick and beaded, the chamber surfaces finely porous. On the umbilical
side the chamber surfaces are coarsely papillate and porous, and the thickened, beaded
radial sutures extend around the umbilical edges of the chamber. The primary and
relict apertures open into the umbilicus; associated apertural portici are present on
some specimens. Two closely spaced carinae are developed on the umbilical side of the
peripheral surface.

Stratigraphical distribution. Probably exclusively Maestrichtian, though the species has been recorded
in the upper Campanian of Poland (Bieda 1958).

Geographical distribution. The species is widely distributed. It ranges from approximately 57° N.
(Kjolby Gaard, Denmark; Hofker 1960) to 22° S. (NW. Australia; Edged 1957). It is also recorded
from the west coast of North America (Douglas and Sliter 1966), and New Jersey (Olsson 1960),
Tampico embayment, Mexico (Hay 1960), Trinidad (Bolli 1951), northern Europe, the circum-
Mediterranean area, and West Pakistan (Nagappa 1960).

Globotruncana falsostuarti Sigal

Plate 3, figs. 10-12; text-fig. 14

1951 Globotruncana conica White; Bolli, p. 196, pi. 34, figs. 13-15.

1952 Globotruncana falsostuarti Sigal, p. 43, fig. 46.

EXPLANATION OF PLATE 3

Figs. 1-12. Globotruncana spp. 1-3, G. area (Cushman), ventral, edge, and dorsal views; No. 1168,
X71. 4-6, G. conica White, ventral, edge, and dorsal views; No. 1170, x71. 7-9, G. contusa
(Cushman), ventral, edge, and dorsal views; No. 1169, X71. 10-12, G. falsostuarti Sigal, ventral,
edge, and dorsal views; No. 1173, X 70.

Palaeontology, Vol. 12

PLATE 3

FUNNELL, FRIEND and RAMSAY, Foraminifera from Galicia Bank

FUNNELL, FRIEND, AND RAMSAY: PLANKTONIC FORAMINIFERA 31

a b c

text-fig. 14. Globotruncana falsostuarti Sigal, (a) dorsal, (b) edge,
and (c) ventral views; No. 1173, X 100.

Description. In the specimens examined the test is trochospiral, circular, weakly lobed,
and biconvex. Its spiral surface contains 25 chambers arranged in 3f whorls with 7-8
approximately equal chambers in the last. Sutures are thick, raised, and beaded. The
chamber surfaces are smooth and finely porous on both sides of the test; on the umbilical
side the thickened radial sutures extend around the umbilical edge of the chambers. Both
primary and relict apertures open into the wide umbilicus; their associated portici
extend obliquely into the umbilicus. Traces of a tegillum are preserved on some speci-
mens. A single prominent keel and weak traces of a closely separated second keel on the
final chambers, are present on the peripheral surface.

Stratigraphical range. Campanian to upper Maestrichtian (Bolli 1951).

Geographical distribution. Records of this species are confined to the northern hemisphere. It has been
reported from Trinidad (Bolli 1951), Southern Limburg (Hofker 1966), Upper Bavaria (Knipscheer
1956), Morocco (Lehmann 1966), Algeria (Sigal 1952), and Tunisia (Dalbiez 1955).

Globotruncana gansseri Bolli

Plate 4, figs. 1-3; text -fig. 15

? 1950 Globotruncana gansseri Bolli, p. 87, no fig.

1951 Globotruncana gansseri Bolli; Bolli, p. 196, pi. 35, figs. 1-3.

1957 Globotruncana (Globotruncana) lugeoni Tilev; Edgell, p. 113, pi. 2, figs. 7-9.

1960 Globotruncana monmouthensis Olsson, p. 50, pi. 10, figs. 22-24.

Description. In the specimens examined the test is trochospiral, umbilical-convex, with
a lobed periphery. On its spiral surface 15 chambers are contained in 2\ whorls with 5-6
chambers in the last. Initially inflated, they are followed by chambers whose surfaces
slopes towards the spiral apex. The sutures are curved, raised, and beaded, the chamber
surfaces smooth and finely porous, weakly papillose on the final whorl. Ventrally the
chambers are coarsely papillose, the papillae becoming scattered on the last chamber;
the sutures are radial and depressed. Both the primary and relict apertures open into

32

PALAEONTOLOGY, VOLUME 12

the umbilicus; the primary has a delicate porticus. A single heavily beaded keel is
developed on the peripheral surface.

text-fig. 15. Globotruncana gansseri Bolli, (a) dorsal, (b) edge,
and (c) ventral views; No. 1175, x 100.

Stratigrap/iical distribution. Lower to upper Maestrichtian (Wille-Janoschek 1966).

Geographical distribution. A widely distributed species which ranges from approximately 57° N.
(Kjolby Gaard, Denmark; Berggren 1962) to 22° S. (NW. Australia, Edgell 1957). Between these
latitudes it is reported from the Pacific (Hamilton 1953), the West Coast and New Jersey (North
America; Douglas and Sliter 1966, Olsson 1960), Mexico (Olvera 1959), the Caribbean area, the North
Atlantic (Saito et ah 1966), Northern Europe, the circum-Mediterranean area, and Madagascar
(Lys 1960).

Globotruncana havanensis Voorwijk

Plate 4, figs. 4-6; text-fig. 16

1937 Globotruncana havanensis Voorwijk, pp. 195, 197, pi. 1, figs. 25, 26, 29.

1951 Globotruncana citae Bolli, p. 197, pi. 35, figs. 4-6.

1955 Rugotruncana havanensis (Voorwijk); Bronnimann and Brown, p. 552, pi. 22, figs. 4-6;
pi. 24, figs. 5, 10.

1955 Globotruncana citae Bolli; Gandolfi, p. 51, pi. 3, fig. 11.

19566 Marginotruncana citae (Bolli); Hofker, pp. 76, 79, fig. 72.

1957 Globotruncana (Globotruncana) citae Bolli; Edged, p. Ill, pi. 1, figs. 13-15.

1959 Globotruncanella havanensis (Voorwijk); Olvera, pp. 94-6, pi. 4, figs. 12, 13, 14.

? 1960 Praeglobotruncana havanensis (Voorwijk); Berggren, pp. 185, 190, no fig.

1960 Rugoglobigerina jersey ensis Olsson, p. 49, pi. 10, figs. 19-21.

1960 Globotruncana citae Bolli; Hofker, pp. 217, 225, 231, 234, 235, fig. 20.

a b c

text-fig. 16. Globotruncana havanensis Voorwijk, (a) dorsal, (b) edge,
and (c) ventral views; No. 1176, X 100.

Description. In the specimens examined the test is trochospiral, spiroconvex, ventrally
flat or weakly concave. On the spiral surface 9 weakly inflated chambers are arranged

FUNNELL, FRIEND, AND RAMSAY: PLANKTONIC FORAMINIFERA 33

iii approximately 2 whorls with 4 chambers in the last. The sutures are arcuate depressed,
on the ventral surface radial depressed; the chamber surfaces are smooth and porous.
The aperture is intra-umbilical, bordered by a porticus which extends towards the
umbilicus. A single weakly developed keel is present on the peripheral surface.

Stratigraphical distribution. Recorded mainly from the Maestrichtian though it is also reported from
the Campanian of Trinidad (Bolli 1957).

Geographical distribution. G. havanensis ranges from approximately 57° N. (Kjolby Gaard, Denmark;
Hofker 1960) to 22° S. (NW. Australia; Edged 1957). Within these latitudes it is recorded from the
West Coast of North America (Douglas and Sliter 1966), Tampico embayment, Mexico (Olvera 1959),
NE. Colombia (Gandolfi 1955), Cuba (Bronnimann and Brown 1955), Trinidad (Bolli 1951), northern
Europe, and the circum-Mediterranean region as far east as Scotchi on the north-east shores of the
Black Sea (Subbotina 1953).

Globotruncana stuarti (de Lapparent)

Plate 4, figs. 7-9; text-fig. 17

a c

text-fig. 17. Globotruncana stuarti (de Lapparent), (a) dorsal, (b) edge,
and (c) ventral views; No. 1171, X 100.

C 6289

D

34

PALAEONTOLOGY, VOLUME 12

1918 Rosalina stuarti de Lapparent, pp. 11, 12, pi. 12, fig. 4, pi. 13, fig. 5 a-c.

1936 Globotruncana stuarti (de Lapparent); Renz, pp. 19, 20, pi. 6, figs. 35-41 ; pi. 8, fig. 6.
1962 Globotruncana (Globotruncana) stuarti stuarti Pessagno, chart 2, pi. 2, figs. 1-3.

Description. In the specimens examined the test is trochospiral, almost biconvex; its
periphery is circular and entire. On the spiral surface 12-26 chambers are contained in
24-34 whorls, with 4-7 in the last; the initially circular chambers are followed by tri-
angular and finally quadrangular chambers. The sutures are thickened, raised, beaded;
ventrally the radial sutures extend on to the umbilical edge of each chamber. Chamber
surfaces are smooth and finely porous. Both primary and secondary apertures open into
the umbilicus; delicate asymmetrical triangular portici extend obliquely into the umbili-
cus from each chamber. A single prominent keel is developed on the peripheral surface.

Stratigraphical distribution. Upper Campanian to upper Maestrichtian (Bolli 1951).

Geographical distribution. A widely distributed species, ranging from approximately 57° N. (Kjolby
Gaard, Denmark; Berggren 1962) to 16° S. (Madagascar; Lys 1960). It is also recorded from Trinidad
(Bolli 1951), Puerto Rico (Pessagno 1962), W. Nigeria (Reyment 1960), northern Europe, the circum-
Mediterranean region, and Pakistan (Nagappa 1959).

Globotruncana stuarti stuartiformis Dalbiez

Plate 4, figs. 10-12; text-fig. 18

1951 Globotruncana stuarti de Lapparent; Tilev, pp. 34-41, pi. 1, figs. 1, 4 (non 3); text-figs.
7, 8 (non 9).

1955 Globotruncana (Globotruncana) elevata stuartiformis Dalbiez, p. 169, text-fig. 10.

1961 Globotruncana elevata stuartiformis Dalbiez; Scheibnerova, p. 70, pi. 13, fig. 1.

1962 Globotruncana (Globotruncana) stuarti stuartiformis Dalbiez; Pessagno, p. 362, pi. 2,

figs. 4-6.

1966 Globotruncana elevata stuartiformis Dalbiez; Wille-Janoschek, pp. 103-5, 147, 148,
149, 150, pi. 7, figs. 6-8, taf. 9.

Description. In the specimens examined the test is trochospiral, biconvex, with a weakly
lobed periphery. On its spiral surface 19-22 chambers are arranged in 3-34 whorls with
5-6 in the last; chambers are triangular but the final 2 or 3 are quadrangular. Both
spiral and radial sutures are raised, thick, and beaded; ventrally the thickened radial
sutures extend around the umbilical edges of the chambers. The chamber surfaces are
smooth and finely porous. Both the primary and relict apertures open into the umbilicus;
delicate portici which extend obliquely into the umbilicus are sometimes preserved. The
peripheral surface is unicarinate.

Stratigraphical distribution. Upper Campanian to upper Maestrichtian (Wille-Janoschek 1966).

Geographical distribution. G. stuarti stuartiformis is so far unrecorded from the southern hemisphere;
it ranges from approximately 49° N. (W. Carpathians; Scheibnerova 1961) to 18° N. (Puerto Rico;

EXPLANATION OF PLATE 4

Figs. 1-12. Globotruncana spp. 1-3, G. gansseri Bolli, ventral, edge, and dorsal views; No. 1175,
x 85. 4-6, G. havanensis Voorwijk, ventral, edge, and dorsal views; No. 1176, X 170. 7-9, G. stuarti
(de Lapparent), ventral, edge, and dorsal views; No. 1171, x59. 10-12, G. stuarti stuartiformis
Dalbiez, ventral, edge, and dorsal views; No. 1172, X 59.

Palaeontology, Vol. 12

PLATE 4

FUNNELL, FRIEND and RAMSAY, Foraminifera from Galicia Bank

FUNNELL, FRIEND, AND RAMSAY: PLANKTONIC FORAMINIFERA 35

Pessagno 1962). Between these latitudes it has been recorded from the Pacific Ocean (Hamilton 1953),
the west coast of North America (Douglas and Sliter 1966), New Jersey (Olsson 1964), the north
Atlantic (Saito et at. 1966), northern Europe, and the circum-Mediterranean area as far as SE. Turkey
(Tilev 1951).

text-fig. 18. Globotruncana stuarti stuartiformis Dalbiez, (a) dorsal, (b) edge,
and (c) ventral views; No. 1172, X 100.

Globotruncana cf. aspera Hofker

Plate 5, figs. 1-3; text-fig. 19

1956c Globotruncana aspera Hofker, p. 327, figs. 14, 15.

1966 Globotruncana aspera Hofker, p. 30, pi. 3, fig. 66.

a b c

text-fig. 19. Globotruncana cf. aspera Hofker, (a) dorsal, (b) edge,
and (c) ventral views; No. 1174, X 100.

36

PALAEONTOLOGY, VOLUME 12

Description. In the specimens examined the test is umbilico-convex, with a lobed periphery
and flat or apically concave spiral surface. In spiral view 13-16 chambers are arranged
in approximately 2\ whorls with 5 or 6 in the last. Sutures are arcuate, thick, and beaded;
ventrally they are radial depressed. The chamber surfaces are rough, finely porous
dorsally, rugose ventrally. The primary aperture is intra-umbilical; a tegillum extends
across the umbilicus and is provided with at least 3 intralaminal apertures. Two widely
separated keels are developed on the peripheral surface.

Stratigraphical distribution. Hitherto G. aspera has not been recorded from rocks younger than lower
Upper Campanian.

Geographical distribution. Previous reports of this species are restricted to NW. Germany and Holland
(Hofker, 1956c, 1966).

Genus rugoglobigerina Bronnimann 1952
Rugoglobigerina pustulata Bronnimann
Plate 5, figs. 4—6; text-fig. 20

1952 Rugoglobigerina reicheli pustulata Bronnimann, p. 20, pi. 2, figs. 7-9, text-figs. 6 a-m,
la-i.

1 952 Rugoglobigerina reicheli hexaeamerata Bronnimann, p. 23, pi . 2, figs. 10-12; text-figs. Sa-m.
1955 Rugoglobigerina hexaeamerata hexaeamerata Bronnimann; Gandolfi, p. 33, pi. 1, figs.
1 2 a-c.

1956a Globigerina rugosa Plummer; Hofker, p. 53, text-fig. 1.

1960 Rugoglobigerina reicheli pustulata Bronnimann; Olsson, p. 50, pi. 10, figs. 13-15.

1962 Rugoglobigerina pustulata Bronnimann; Berggren, pi. 13, figs. 1 a-c, text-fig. 10 (6-12).

? 1966 Rugoglobigerina pustulata Bronnimann; El-Naggar, p. 148, no fig.

text-fig. 20. Rugoglobigerina pustulata Bronnimann, (a) dorsal, (b) edge,
and (c) ventral views; No. 1181, X 100.

C

Description. In the specimens examined the test is low trochospiral tending towards
planispiral, biconcave with a markedly lobed periphery. On the spiral surface 12-16
chambers are contained in 2-3 whorls with 5-6 in the last. The sutures are depressed,
the chamber surfaces granulate with or without costellae on the adult chambers. Both

EXPLANATION OF PLATE 5

Figs. 1-3. Globotruncana cf. aspera Hofker, ventral, edge, and dorsal views; No. 1 174, x85.

Figs. 4-12. Rugoglobigerina spp. 4-6, R. pustulata Bronnimann, ventral, edge, and dorsal views;
No. 1181, X 129. 7-9, R. rotundata Bronnimann, ventral, edge, and dorsal views; No. 1179, x85.
10-12, R. scotti (Bronnimann), ventral, edge, and dorsal views; No. 1180, x 129.

Palaeontology, Vol. 12

PLATE 5

FUNNELL, FRIEND, and RAMSAY, Foraminifera from Galicia Bank

FUNNELL, FRIEND, AND RAMSAY: PLANKTONIC FORAMINIFERA 37

primary and relict apertures open into the umbilicus. An umbilical tegillum with associ-
ated infralaminal and possibly intralaminal apertures is preserved on some specimens.

Stratigraphical distribution. R. pustulata has been recorded only from Maestrichtian sediments.

Geographical distribution. Geographically widespread in the northern hemisphere. It ranges from
approximately 57° N. (Kjolby Gaard, Denmark; Berggren 1962) to 10° N. (Trinidad; Bronnimann
1952). It is also recorded from New Jersey (U.S. A. ; Olsson 1960), NE. Colombia (Gandolfi 1955), the
Netherlands (Hofker 1956a), and the Nile Valley (El-Naggar 1966).

Rugoglobigerina rotundata Bronnimann 1952

Plate 5, figs. 7-9; text-fig. 21

1952 Rugoglobigerina rugosa rotundata Bronnimann, pp. 34-6, pi. 4, figs. 7-9; text-figs. 15, 16.
1955 Globotruncana (Rugoglobigerina) rotundata rotundata (Bronnimann); Gandolfi, p. 70,
pi. 7, fig. 2.

? 1957 Rugoglobigerina rugosa (Plummer); Edgell, pp. 115, 118, pi. 4, figs. 10-12.

1962 Rugoglobigerina rugosa rotundata Bronnimann; Herm, pp. 61-2, pi. 3, fig. 4.

1966 Rugoglobigerina rotundata Bronnimann; Douglas and Sliter, p. 1 16, pi. 1, figs. 5, 6.

text-fij. 21. Rugoglobigerina rotundata Bronnimann, (a) dorsal, (b) edge,
and (c) ventral views; No. 1179, x 100.

Description. In the specimens examined the test is trochospiral umbilico-convex with a
lobed periphery. On the spiral surface the chambers are contained in 2 whorls with 5
chambers in the last. The sutures are radial depressed; the chamber surfaces are granu-
late; the adult chambers granulate, radially costellate. The primary aperture has a
triangular porticus and is intra-umbilical.

Stratigraphical distribution. Campanian to Maestrichtian (Douglas and Sliter 1966).

Geographical distribution. The species is geographically widespread, ranging from approximately
57° N. (Kjolby Gaard, Denmark; Berggren 1962) to 22° S. (NW. Australia; Edged 1957). It is also
recorded from the west coast of America (Douglas and Sliter 1966), NE. Colombia (Gandolfi 1955),
Trinidad (Bronnimann 1952), Austria (Herm 1962), and the Nile Valley (El-Naggar 1966).

Rugoglobigerina scotti (Bronnimann)

Plate 5, figs. 10-12; text-fig. 22

1952 Trinitella scotti Bronnimann, p. 57, pi. 4, figs. 4-6; text-fig. 30.

1957 Rugoglobigerina scotti (Bronnimann); Bold, Loeblich, and Tappan, pp. 43, 44, pi. 1 1, figs. 3, 4.

38

PALAEONTOLOGY, VOLUME 12

text-fig. 22. Rugoglobigerina scotti (Bronnimann), (a) dorsal, (b) edge,
and (c) ventral views; No. 1180, X 100.

Description. In the specimens examined the test is trochospiral, umbilico-convex with
a flattened spiral surface and lobed periphery. On the dorsal surface approximately
13 chambers are arranged in 2\ whorls with 5 chambers in the last. The sutures are
arcuate dorsally, radial and depressed ventrally. The chamber surfaces are smooth or
weakly granular dorsally, granulate ventrally, with costellae developed on the adult
chambers on both surfaces. The primary aperture is umbilical; a tegillum with associated
accessory infralaminal apertures covers the umbilicus. A single thickened beaded keel is
developed on the peripheral surface.

Stratigraphica I distribution. R. scotti has been recorded from the middle to upper Maestrichtian
(El-Naggar 1966).

Geographical distribution. So far only recorded in the northern hemisphere. The species ranges from
approximately 47° N. (Salzburg, Austria; Herm 1962) to 10° N. (Trinidad; Bronnimann 1952). Between
these latitudes it has been recorded from Puerto Rico (Pessagno 1960), New Jersey (U.S.A.; Olsson
1964), Switzerland (Corminboeuf 1961), and the Nile Valley (El-Naggar 1966).

REFERENCES

ansary, s. e. and fak.hr, b. y. 1958. Maastrichtian Foraminifera from Um El Huetat area, west of
Safaga. Egypt J. Geol. 2, 105-45, pi. 1-2.

barr, f. t. 1966. Upper Cretaceous foraminifera from the Ballydeenlea Chalk, County Kerry, Ireland.
Palaeontology , 9, 492-510, pi. 77-79.

belford, d. j. 1960. Upper Cretaceous Foraminifera from Toolonga Calcilutite and Gingin Chalk,
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1962. Some planktonic Foraminifera from the Maastrichtian and type Danian stages of southern

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bieda, e. 1958. Otwornice przewodnie i wiek kredy piszacej Mielnika (Index foraminifers and the age
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black, m. 1964. Cretaceous and Tertiary coccoliths from Atlantic seamounts. Palaeontology, 7, 306-16,
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1951. The genus Globotruncana in Trinidad, B.W.I. J. Paleont. 25, 187-99, pi. 34-35.

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and cita, m. b. 1960. Upper Cretaceous and Lower Tertiary planktonic Foraminifera from the

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FUNNELL, FRIEND, AND RAMSAY: PLANKTONIC FORAMINIFERA 39

loeblich, a. r., JR., and tappan, H. 1957. Planktonic foraminiferal families Hantkeninidae,

Orbulinidae, Globorotaliidae and Globotruncanidae. Bull. U.S. natn. Mus. 215, 3-50, pi. 1-11.
bronnimann, p. 1952. Globigerinidae from the Upper Cretaceous (Cenomanian-Maastrichtian) of
Trinidad, B.W.I. Bull. Am. Paleont. 34, 1-70, pi. 1-4.

and brown, n. k. 1953. Observations on some planktonic Heterohelicidae from the Upper

Cretaceous of Cuba. Contr. Cushman Fdn. foramin. Res. 4, 150-6.

1955. Taxonomy of the Globotruncanidae. Eclog. geol. Helv. 48, 503-61, pi. 20-24.

cita, m. b. 1948. Ricerche stratigrafiche e micropaleontologiche sul Cretacico e sull’Eocene di Tignale
(Lago di Garda). Riv. ital. Paleont. Stratigr. 54, fasc. 4, 49-74, 117-34, 143-69, pi. 2-4.
corminbceuf, p. 1961. Tests isoles de Globotnmcana mayaroensis Bolli, Rugoglobigerina, Trinitella et
Heterohelicidae dans le Maestrichtien des Alpettes. Eclog. geol. He/v. 54, 107-22, pi. 1-2.
curry, d. 1962. A Lower Tertiary outlier in the central English Channel with notes on the beds
surrounding it. Q. J! geol. Soc. Load. 118, 177-205.
cushman, j. a. 1926. Some Foraminifera from the Mendez shale of Eastern Mexico. Contr. Cushman
Lab. foramin. Res. 2, 16-24, pi. 2-3.

1927a. Some characteristic Mexican fossil Foraminifera. J. Paleont. 1, 147-72, pi. 23-28.

1 9276. An outline of a re -classification of the Foraminifera. Contr. Cushman Lab. foramin.

Res. 3, 1-105, pi. 1-21.

1938. Cretaceous species of Guembelina and related genera. Contr. Cushman Lab. foramin. Res.

14, 2-28, pi. 1-4.

1946. Upper Cretaceous Foraminifera of the Gulf Coastal Region of the United States and

adjacent areas. Prof Pap. U.S. geol. Surv. 206, 1-241, pi. 1-66.

1949. The foraminiferal fauna of the Upper Cretaceous Arkadelphia Marl of Arkansas. Ibid.

221 A, 1-17, pi. 1-4.

dalbiez, f. 1955. The genus Globotruncana in Tunisia. Micropaleontology, 1, 161-71, charts 1-2.
douglas, r. and sliter, w. v. 1966. Regional distribution of some Cretaceous Rotaliporidae and
Globotruncanidae (Foraminiferida) within North America. Tulane Stud. Geol. 4, 89-132, 2 tabs.,
pi. 1-5.

edgell, h. s. 1957. The genus Globotruncana in Northwest Australia. Micropaleontology, 3, 101-26,
tab. I, pi. 1-4.

ellis, b. f. and messina, a. 1940 et seq. Catalogue of Foraminifera: American Museum Natural
History, New York, Spec. Pub., 30 vols. and supplements.
funnell, b. m. 1964. Studies in North Atlantic geology and palaeontology: 1. Upper Cretaceous.
Geol. Mag. 101, 421-34.

1967. Foraminifera and Radiolaria as depth indicators in the marine environment. Mar. Geol.

5, 333-47.

gandolfi, r. 1955. The genus Globotruncana in north eastern Colombia. Bull. Am. Paleont. 36, 1-118,
pi. 1-10.

grimsdale, t. f. and morkhoven, f. p. c. m. van 1955. The ratio between pelagic and benthonic
Foraminifera as a means of estimating depths of deposition of sedimentary rocks. Wld. Petrol.
Congr. 4, sect. 1/D, paper 4, 473-91.

Hamilton, e. l. 1953. Upper Cretaceous, Tertiary and Recent planktonic Foraminifera from mid-
Pacific flat-topped seamounts. J. Paleont. 27, 204-37, pi. 29-32.
hay, w. w. 1960. The Cretaceous-Tertiary boundary in the Tampico embayment, Mexico. Int. geol.
Congr. 21 Session, part 5, 70-7.

herm, d. 1962. Stratigraphische und mikropalaontoiogische Untersuchungen der Oberkreide im Lat-
tengebirge und Nierental. Bayer. Akad. Wiss. 104, 7-119, taf. 11.

HOFKER, j. 1956a. Foraminifera of the Cretaceous of Southern Limburg, Netherlands. 19. Planktonic
Foraminifera of the Chalk Tuff of Maastricht and environments. Natuurh. Maandbl. 45, 50-7,
pi. 1-3.

1956A Die Pseudotextularia-Zone der Bohrung Maasbiill I und ihre Foraminiferen-Fauna.

Paldont. Z. 30, Sonderh., 59-79, pi. 5-10.

1956c. Die Globotruncanen von Nordwest-Deutschland und Holland. Neues Jb. Miner. Geol.

u. Paldont. Abh. 103, 3, 312-40.

1957. Foraminiferen der Oberkreide von Nordwest-Deutschland und Holland. Beih. geol. Jb.

27, 1-464.

40 PALAEONTOLOGY, VOLUME 12

hofker, j. 1958. Les Foraminiferes du Cretace superieur de Glons. Annals. Soc. geol. Belg. 81,
467-93, pi. 1-8.

1960. The Foraminifera of the lower boundary of the Danish Danian. Meddr. dansk geol. Foren.

14, 212-42.

1966. The Foraminifera of the type-Maastrichtian in South Limburg, Netherlands, together with
the Foraminifera of the underlying Gulpen Chalk and overlying calcareous sediments; the Foramini-
fera of the Danske Kalk and the overlying greensands and clays as found in Denmark. Palaeonto-
graphica , Suppl. Bd. 10, 1-376, pi. 1-86.

kikoine, j. 1948. Les Heterohelicidae du Cretace superieur pyreneen. Bull. Soc. geol. Fr., Ser. 5, 18,
15-35, pi. 1-2.

knipscheer, h. c. g. 1956. Biostratigraphie in der Oberkreide mit Hilfe der Globotruncanen. Paldont.
Z. 30, Sonderh., 50-6, 1 pi.

ksiazkiewicz, m. 1956. Jura i Kreda Bachowic. Roczn.pol. Tow. geol. 24, 118-405, pi. 11-32 (English
summary).

kupper, k. 1956. Stratigraphische Verbreitung der Foraminiferen in einem Profil aus dem Becken von
Gosau, (Grenzbereich Salzburg-Oberosterreich). (Mit Beniitzung von Aufzeichnungen von R.
Noth). Jb. Geol. Bundesanst., Wien, 99, 273-320, Taf. 10-11, 1 Tab.
lapparent, j. de 1918. Etude lithologique des terrains cretaces de la region d'Hendaye. Mem.
Serv. Carte geol., Fr. 1-152, pi. 1-10.

lehmann, r. 1966. Description des Globotruncanides et Heterohelicides d'une faune Maestrichtienne
du Prerif (Maroc). Eclog. geol. Helv. 59, 309-17, pi. 1, 2.
lys, m. 1960. La limite Cretace-Tertiare et l’Eocene inferieur dans la Basin de Majunga (Madagascar).
Int. geol. Congr. 21 session, part 5, 120-30.

mangin, j. ph. 1960. Reflexions sur la limite Cretace-Tertiare a propos du domaine pyreneen. Ibid.
21 session, part 5, 145-9.

martin, l. 1964. Upper Cretaceous and Lower Tertiary Foraminifera from Fresno County, California.

Jb. geol. Bundesanst., Wien, Sonderbd. 9, 1-128, tabs. 1-8, pi. 1-16.
mcgugan, a. 1964. Upper Cretaceous zone foraminifera, Vancouver Island, British Columbia,
Canada. J. Paleont. 38, 933-51, pi. 150-2.

montanaro gallitelli, e. 1957. A revision of the foraminiferal family Fleterohelicidae. Bull. U.S.
natn. Mas. 215, 133-54, pi. 31-34.

nagappa, y. 1959. Foraminiferal biostratigraphy of the Cretaceous-Eocene succession of the India-
Pakistan-Burma region. Micropaleontology, 5, 145-92, tabs. 1-9, charts 1-4, pi. 1-1 1.

1960. The Cretaceous-Tertiary boundary in the India-Pakistan subcontinent. Int. geol. Congr.

21 session, part 5, 41-9.

naggar, z. r. el- 1966. Stratigraphy and planktonic Foraminifera of the Upper Cretaceous-Lower
Tertiary succession in the Esna-Idfu Region, Nile Valley, Egypt, U.A.R. Bull. Br. Mus. nat. Hist.,
Geol. Suppl. 2, 1-291, pi. 1-23.

olsson, r. k. I960. Foraminifera of the latest Cretaceous and earliest Tertiary age in the New Jersey
Coastal Plain. J. Paleont. 34, 1-58, pi. 1-12.

1964. Late Cretaceous planktonic foraminifera from New Jersey and Delaware. Micropaleon-
tology, 10, 157-88, pi. 1-7.

olvera, y. e. 1959. Foraminiferos del Cretacio superior Tampico Tuxpan. Boln. Asoc. Mex. Geol.
Petrol. 11, 63-134, pi. 1-9.

pessagno, e. a. j. 1960. Stratigraphy and micropaleontology of the Cretaceous and Lower Tertiary
of Puerto Rico. Micropaleontology, 6, 87-110, charts 1-3, pi. 1-5.

1962. The Upper Cretaceous stratigraphy and micropaleontology of south-central Puerto Rico.

Ibid. 8, 349-68, pi. 1-6.

renz, o. 1936. Stratigraphische und micropalaontologische Untersuchung der Scaglio (Oberkreide-
Tertiar) im zentralen Apennin. Eclog. geol. Helv. 29, 1-135, pi. 1-15.
reyment, r. a. 1960. Notes on the Cretaceous-Tertiary transition in Nigeria. Int. geol. Congr. 21
session, part 5, 131-5.

said, r. and kenawy, a. 1956. Upper Cretaceous and Lower Tertiary foraminifera from northern
Sinai, Egypt. Micropaleontology, 2, 105-73, pi. 1-7.

and kerdany, m. t. 1961. The geology and micropaleontology of Farafra Oasis, Egypt. Ibid.

7, 317-36, pi. 1, 2.

41

FUNNELL, FRIEND, AND RAMSAY: PLANKTONIC FORAM1NIFERA

andsABRY, h. 1964. Planktonic foraminifera from the type locality of the Esna Shale in Egypt.

Ibid. 10, 375-95, pi. 1-3.

saito, t., ewing, m., and burckle, l. h. 1966. Lithology and paleontology of the reflective layer
Florizon A. Science , 154, 1173-6.

scheibnerova, v. 1961. Microfauna strednej a vrchnej kreidy bradloveho pasma Zapadnych Karpat
na Slovensku. Acta Geo/. Geogr. Univ. Comen. 5, 4-108, pi. 1-14 (English summary).

sigal, J. 1952. Aper<;u stratigraphique sur la micropaleontologie du cretace. Int. geo/. Congr. 19
session, Monogr. Reg., ser. 1 (Algeria), 26, 1-45.

smith, f. d. 1955. Planktonic foraminifera as indicators of depositional environment. Micropaleonto-
logv , 1, 147-51.

subbotina, n. n. 1953. Foraminiferes fossiles d’U.R.S.S., Globigerinidae, Globorotaliidae, Hantken-
inidae. Trudy vses. neft. nauchno-issled. geol.-razv. Inst. Leningrad-Moscow (n.s.), 76, pp. 1-294,
pi. 1-25.

tilev, n. 1951. Etude des Rosalines maastrichtiennes (genre Globotruncana ) du Sud-Est de la Turquie
(Sondage de Ramandag). Bull. Lab. Geo/., Min. Geophys., Mus.Geol., Univ. Lausanne, 103, 1-101,
pi. 1-3.

vinogradov, c. 1960. Limita cretacie-paleogen in bazinul vaii Prahova. Acad. Republ. Pop. Romina,
sect. Geol. , Geogr., si Inst, de Geo/., Geofiz. si Geogr., 5, 299-324, pi. 1-6 (Russian and French
summaries).

visser, a. m. 1951. Monograph on the Foraminifera of the type-locality of the Maastrichtian (South
Limburg, Netherlands). Leid. geol. Meded. 16, 197-359, pi. 1-16.

voorwijk, G. H. 1937. Foraminifera from the Upper Cretaceous of Habana, Cuba. Proc. Sect. Sci. K.
ned. Akad. Wet. 30, 2, 190-8, pi. 1-3.

wessem, a. van 1943. Geology and palaeontology of central Camaguey, Cuba. Geogr. geol. Meded
Physiogr. geol. Reeks, ser. 2, 5, 1-90, pi. 1-3.

white, m. p. 1928. Some index foraminifera of the Tampico embayment area of Mexico (Part 1 and
Part 2). J. Paleont. 2, 177-215, 280-317, pi. 27-9, 38-42.

1929. Some index foraminifera of the Tampico Embayment area of Mexico (Part 3). J. Paleont.

3, 30-58, pi. 4-5.

wicher, c. a. 1956. Die Gosau-Schichten im Becken von Gams (Osterreich) und die Foraminiferen-
Gliederung der hoheren Oberkreide in der Tethys. Palaont. Z. 30, Sonderh., 87-136, pi. 12, 13.

wille-janoschek, u. 1966. Stratigraphie und Tektonik der Schichten der Oberkreide und des Altter-
tiars im Raume von Gosau und Abtenau (Salzburg). Jb.geol. Bundesanst., Wien, 109, 91-172, taf.

1-11.

witwicka, e. 1958. Stratygrafia mikropaleontologiczna kredy gornej wiercenia w Chelmie (Micro-
palaeontological study of Upper Cretaceous of the Chelm bore-hole (Lublin Upland)). Biul. panst.
Inst. geol. 121, tom 3, 177-267, 14 pi. (Russian and English summaries).

B. M. FUNNELL
A. T. S. RAMSAY

School of Environmental Sciences
University of East Anglia
Norwich

J. K. FRIEND

Department of Geology
Sedgwick Museum
Cambridge

Typescript received 29 February 1968

A NEW SPECIES OF COELOPLEURUS
(ECHINOIDEA) FROM THE MIOCENE OF MALTA

by G. ZAMMIT-MAEMPEL

Abstract. Coeloplewus melitensis sp. nov. is described from the Lower Miocene of Malta. The genus has not
previously been recorded from the Miocene of the Mediterranean region.

Apart from a few Quaternary deposits, all the rocks that outcrop on Malta are marine
sediments that are now thought to be Lower Miocene in age (Eames et al. 1962). The
new species was found just beneath the transition strata known as the Scutella Bed,
overlying the lowest formation, the Lower Coralline Limestone, at Qammieh, on the
north-west coast of Malta, on the edge of a raised platform, about 5 m. above sea-level
and 180 m. west of slipway (grid reference 4395.3981). Coeloplewus was previously con-
sidered (Mortensen 1935) to have disappeared from the Mediterranean region in the
Oligocene. The specimen was found attached to an irregular, brownish-grey, bryozoa-
and cirripede-encrusted nodule, though it was not buried in the nodule.

DESCRIPTION

Family arbaciidae Gray 1855
Genus coelopleurus Agassiz 1840
Coeloplewus melitensis sp. nov.

Plate 6 and text-fig. 1

Derivation of name. After the Island of Malta (Latin: Melita).

Hoiotype (monotype). Natural History Museum, Malta, MM/E 300.

Diagnosis. On its apical disc the species has a distinctive star-shaped raised area with
arrowhead-like promontories protruding into the naked bands on the inter-ambulacra.
These naked areas are bordered by prominent protuberant tubercles and are decorated
with zigzag grooves, striae, lateral ditches, oblique ridges, and microscopic granulations.

Description. Test. Small, low hemispherical, with a somewhat flattened apical region.
Oral surface mainly flat, but concave round the peristome. Peristome 5-3 mm. diameter
(just under one-half diameter of test). The presence of 3-4 sphaeridial pits along the
median suture of each ambulacrum helps to distinguish the genus from Arbacia (one
pit) and from Arbi a (none). Test subpentagonal in outline with a maximum diameter
of 10-9 mm., height 4-3 mm. The width of ambulacra at ambitus is 3-5 mm., whilst that
of interambulacra at ambitus is 2 mm.

Apical system. Dicyclic. The apical disc has a highly characteristic star-shaped raised
area and well-developed exsert ocular plates that end in a protuberance. This raised area
protrudes deeply into the naked areas on the interambulacra in the form of five arrow-

[Palaeontology, Vol. 12, Part 1, 1969, pp. 42-7, pi. 6.]

ZAMMIT-MAEMPEL: COELOPLEURUS FROM MALTA

43

head promontories with slightly concave sides. The arrowhead shape is due to the
characteristic quadrangular depression on either side of each promontory. Genital
plates are large. The genital pores are five large openings aboral to the arrowhead
promontory, and suggest full sexual maturity. The periproct, which is large and central,
lacks a prominent ring-like edge. It is polygonal (min. diam TO mm., max. diam.
T5 mm.) and about one-tenth diameter of test. There is a circle of 10 small tubercles
(0-2 mm. diam.) in the apical disc adjacent to the periproct, a feature which Duncan and
Sladen state to be ‘very generally present’ in the genus (1885, p. 48).

3

text-fig. 1 . Coelopleurus melitensis sp. nov. Adapical, adoral, and side views of holotype MM/E 300,
from base of Scutella Bed (transition Aquitanian-Burdigalian) at Qammieh, Malta (scale in milli-
metres).

Ambulacra. Each ambulacrum is made up of two columns of compound trigeminate
plates with two rows of imperforate, non-crenulate, primary tubercles which extend
from periproct to peristome. These primary tubercles progressively increase in size
adorally reaching a maximum size at the third tubercle, just above ambitus. Below the
ambitus, the tubercles abruptly diminish in size, becoming very small and flatter at
peristome. All tubercles, except the first four near the apex, have an associated granule
in each corner. The ambulacral plates are arbacioid. in each ambulacral column there
are 15 above-ambital non-conjugate pore pairs arranged in a sinuous line. The pores
are round, equal, and conspicuous. The pores of a pair are arranged oblique to the
column, with the adradial pore more oral than the perradial pore. Above the ambitus,

44

PALAEONTOLOGY, VOLUME 12

but not below it, the adradial pore is sometimes situated on the boss of the adjacent
primary ambulacral tubercle (ap PI. 6). This conflicts with the statement of Duncan
and Sladen (1885, p. 293) that the pores situated on the bosses of ambulacral tubercles,
both above and below the ambitus, were characteristic of the genus Coelopleurus. The
interporiferous distance increases till halfway down the aboral surface, and then pro-
gressively decreases toward the peristome with the pores progressively diminishing in
size, and the pores of a pair becoming arranged more obliquely.

Interambulacra (PI. 6). Each interambulacrum consists of two columns of alternating
plates, each plate being broader than high. The horizontal sutures are very shallow, but
the longitudinal ones are deeply grooved. An additional pentagonal plate, higher than
broad, is present on the interradius of one of the interambulacra at the level of the third
protuberant tubercle from the apex ( aip ). This additional plate lacks tubercles but has
a surface decoration similar to that of neighbouring plates on the naked area.

Below the ambitus, there are 14-15 tubercles in each interambulacral area, arranged in
4 longitudinal rows, with a maximum of 5 tubercles per row, and with the largest
tubercles at the ambitus. Above the ambitus the outer two rows are continued
by a single series of small tubercles (smt) that extend to the apical system. The
inner two rows do not continue above the ambitus so that each interambulacrum has,
adapically, a naked median space, on each side of which are 4-5 prominent pro-
tuberant tubercles (ppt). Unlike ambulacral tubercles, their height is greater than
their width. Each interambulacral plate contains only one such prominent tubercle, to
which are generally associated two of the small marginal tubercles (smt). The fourth and
fifth prominent protuberant tubercles, however, are associated with 3 and 4 small
marginal tubercles respectively. The naked areas are ornamented with deep grooves
arranged in a zigzag (zzg), together with striations, sunken marginal areas or lateral
ditches (Id), oblique ridges (or), and microscopical granulations that are larger and
more conspicuous in the central region of each plate. The protuberant tubercles lie
interradial to the marginal tubercles (smt) of the interambulacral areas and are totally
different from them. They (ppt) are all very prominent, with the third one from the
apex being most so, and the fourth one almost as large as the third. Each protuberant
tubercle alternates with its counterparts on the opposite side of the naked area.

The deep grooves arranged in zigzags cross the naked areas obliquely, being directed
towards points just aboral to the protuberant tubercles. They do not, however, extend
the whole distance across the naked area (zzg). Aboral to most of these grooves, and
making an angle of about 10° with them, is a weak striation (zzg). On the interradial

EXPLANATION OF PLATE 6

Enlarged view (x 36) of the interambulacrum arrowed in text-fig. 1 showing ornamentation and other
specific characteristics of Coelopleurus melitensis sp. nov. Note additional interambulacral plate
(aip). ap adradial pore perforating boss of a supra-ambital ambulacral tubercle; ppt prominent
protuberant interambulacral tubercles bordering the naked areas; zzg deep zigzag grooves with
overlying shallower groove or stria; Id lateral ditch or sunken longitudinal area at sides of naked
interambulacra; or hook-like, oblique ridges limiting lateral ditches aborally and adorally; smt
small marginal tubercles bordering naked areas; qd quadrangular depressions giving promontory
(ahp) its characteristic shape; sta small tubercles in apical disc.

Palaeontology, Vol. 12

PLATE 6

ZAMMIT-MAEMPEL, Coelopleurus

ZAMMIT-MAEMPEL: COELOPLEU RUS FROM MALTA

45

side of each protuberant tubercle, adjacent to the aboral part of the latter, a short, hook-
like ridge or process is present. It gaps the sunken areas (lateral ditches) that are found
at the sides of the naked interambulacra, decreasing in strength interradially until it
finally dies out (or). The depressed longitudinal areas on the lateral sides of each naked
interambulacrum, bounded adorally by successive ‘lateral ridges’, are herein referred
to as ‘lateral ditches’ (Id).

Comparisons. Arbacia (Pliocene to Recent) differs from Coelopleurus by being more
heavily ornamented, by having only a single sphaeridial pit in each ambulacrum, by
having straight pore zones (widening at peristome), in the absence of a proper naked
area in the interambulacra, and by having numerous primary tubercles arranged in
several horizontal and vertical series.

Arbia (U. Oligocene to L. Miocene, U.S.A.) can be distinguished from Coelopleurus
by having simple ambulacral plates, no sphaeridial pits, smaller peristome, pore zones
that are in a straight line above the ambitus and raised with pore pairs forming ‘slightly
oblique groups of three at and below it’ (Cooke 1959, p. 21), and complete absence of
lateral ditches which results in the median naked areas being flush with the lateral parts.

Comparison with material in the British Museum (Natural History). C. forbesi Archiac and Haime
1853 and C. sindensis Duncan and Sladen 1885 are the only two other Miocene species so far known.
C. sloani Clark 1915 and C. improcerus (Conrad) Clark and Twitchell 1915, from the Miocene of the
United States and originally regarded as belonging to the genus Coelopleurus, have since been trans-
ferred to Arbacia by Cooke (1941).

C. forbesi, which is the most typical Coelopleurus of the Indian Miocene, has been recorded from the
Middle Oligocene Lower Nari Series and from the Lower Miocene (Burdigalian) Gaj Series of Sind,
West Pakistan (Duncan and Sladen 1885, p. 287). The species was refigured and redescribed by
Stockley (1927) from the Lower Miocene Chake Chake Beds of the Pemba Series in East Africa. Com-
pared with C. melitensis Stockley’s specimen (E 17897) is larger and has flatter (less inflated) and more
spread out ambulacral tubercles, but it lacks the distinctive star-shaped area on apical disc, the arrow-
head promontories, the wide genital pores, and the protuberant tubercles adjacent to the naked areas.

C. sindensis (E 702), from the Lower Miocene (Burdigalian) Gaj Series, W. Pakistan, though showing
marked similarities to C. melitensis sp. nov., such as the band-like naked areas with prominent grooves
and wide genital pores on conspicuous arrowhead promontories that protrude deeply into the bare
areas, lacks the highly characteristic star-shaped raised area on the apical disc. Both specimens in the
collection have a larger size. Their diameter is 33 mm. and 20 mm. whilst their height is 16 mm. and
12 mm. respectively. (C. melitensis has a diameter of 10-9 mm. and a height of 4-3 mm.) The more
highly ornamented, conical apical region, the less prominent protuberant tubercles, and the more
developed grooves of the naked area are also distinguishing features.

C. coronalis (Leske) (E 3179), from the Eocene of France, shows considerably more ambital diverg-
ence of the naked areas, whose marginal granules are as prominent, but whose marginal tubercles are
not as protuberant as C. melitensis sp. nov.

C. equis Agassiz, a subjective junior synonym of C. coronalis (Leske), (E 10982, E 10983) are from the
Eocene of Biarritz, France. The specimen E 10982, which has a broken apical system, lacks supra-
ambital swelling, and the primary interambulacral tubercles extend above the ambitus. A broken per-
forated tubercle has a crenulated base, a feature usually inconsistent with Arbacioida. In E 10983, the
apical system is crushed, it has naked areas that widen up towards the ambitus, even more so than
in E 10982.

C. agassizi Archiac (E 75697), from the Eocene of Biarritz, has similar subpentagonal outline, but
wider poriferous zone, more heavily tuberculate apex, and a more continuous (though less spread out)
row of tubercles. (The abactinal surface is abraded.)

C. spinosissimus Agassiz (E 38718), from the Calcaire Grossier of the Paris area, though showing
close similarity in all features, is not quite identical with C. melitensis sp. nov. of which it may well be

46

PALAEONTOLOGY, VOLUME 12

an ancestor. Though crushed sideways its shape is more rounded. The ambulacral tubercles are more
pointed and spiny looking, but less protuberant above the ambitus. The ambulacral marginal granules
are more pronounced.

A Recent dry specimen in the Spirit Room Collection of the Museum 6.19.104, C. maillardi (Miche-
lin), collected from ‘Station 24’, from a depth of 73-200 m., is similar to C. melitensis in smallness of
size (13 mm. x8 mm.), subpentagonal shape, outline of periproct, and band-like naked areas on the
interambulacra. Major distinctions are the shape of the raised promontories, which are polygonal
instead of arrowhead, due to the absence of lateral quadrangular depressions, the presence of radiating
lines round the fairly wide genital pores, the absence of the round-topped, higher-than-broad, protuber-
ant tubercles (which are replaced by tubercles that are only slightly more prominent than adjacent
ones), and the presence of a row of small tubercles inside and parallel to the interambulacral marginal
wall. The oblique ridges are straighter and longer, and, with the exception of one ridge (which covers
only three-quarters of the distance), they extend over the whole width of the naked area.

PALAEOECOLOGY

The associated faunule of C. melitensis sp. nov. consists of rock-borers, sponges,
echinoids of the genera Clypeaster, Eehinolampas , Echinocyamus, and Cidaris (spines),
bryozoa, and nests of the small Terebratula minor Philippi, which, according to David-
son (1864, p. 9), still abounds in the near-shore sediments of Sicily. It is quite likely that
C. melitensis sp. nov. lived at much smaller depths than modern Coelopleurus, which is
now confined to the deep waters of the Indo-Pacific region (56-1,323 m.), with a record
of C. floridanus Ag. from 102-2,419 m. (Cottreau 1913, p. 46). Specimens in the Spirit
Room Collection of the British Museum (Nat. Hist.), however, were recovered (1892-
1948) from depths ranging from 73-200 m.

Although in the Mediterranean Echinocyamus is in modern times found also in the
neritic zone (Cottreau 1913, p. 153), a littoral bathymetry is suggested by the associated
echinoid fauna and by the animal borings in the Nodule Bed in which C. melitensis
was found. In addition, the animal borings are also indicative of a stratigraphic break.
The entire associated faunule is indicative of a rocky bottom of a relatively clear and
shallow warm sea of normal salinity with possibly small sandy or muddy patches, as
suggested by the small pockets of Echinocyamus.

An abrupt radical change of these environmental conditions, with onset of stronger
currents and greater turbidity, is indicated by the sudden disappearance of the associated
faunule and its replacement by numerous fragmented Scutellae scattered in a disorderly
fashion and embedded in a very coarse matrix.

Acknowledgements. The author is deeply indebted to Dr. R. P. S. Jefferies of the British Museum
(Nat. Hist.) for his help with the identification of the specimen and for his encouragement to publish
this note, as well as to Dr. Porter Kier of the Smithsonian Institution for his constructive criticism and
for providing photographic facilities. The help of Captain C. G. Zammit, Director of the National
Museum, Malta, and of Miss Attard and Mr. J. Spiteri is gratefully acknowledged.

REFERENCES

archiac, E. J. A. d. de st. s. and haime, j. 1853. Description des animaux fossiles dugroupe nummulitique
de Vlnde: Les Echinodermes, 373 pp., 36 pi. Paris.

Clark, w. b., and twitchell, m. w. 1915. The Mesozoic and Cenozoic Echinodermata of the United
States. Monogr. U.S. geol. Surv. 54, 341, pp. 108 pi.
cooke, c. w. 1941. Cenozoic regular echinoids of eastern United States. J. Paleont. 15, 1-20, pi. 1-4.
— — 1959. Cenozoic regular echinoids of the eastern United States. Prof. Pap. U.S. geol. Surv. 321,
106 pp., 43 pi.

ZAMMIT-MAEMPEL: COELOPLEURUS FROM MALTA 47

cottreau, j. 1913. Les Echinides neogenes du Bassin mediterraneen. Ann. Inst, oceanographique , 6,
192 pp., 15 pi.

DAvrosoN, t. 1864. Description of the Brachiopoda (of the Maltese Islands). Ann. Mag. Nat. Hist.
ser. 3, 14, 5-11, pi. 1.

duncan, p. m. and sladen, w. p. 1882-6. Monograph of the fossil Echinoidea from the Gaj Series of
strata in Western Sind. Palaeont. Indica, ser. 14, 1, pt. 3, 392 pp., 58 pi.

eames, F. E., banner, F. T., blow, w. H., and clarke, w. j. 1962. Fundamentals of Mid-Tertiary strati-
graphical correlation. 160 pp., 17 pi. Cambridge University Press.

fell, h. b. and pawson, d. l. 1966. Family Arbaciidae, U409-14. In moore, r. c. (ed.), Treatise on
invertebrate paleontology. Part U Echinodermata 3(2). Kansas University Press.

mortensen, t. 1935. A monograph of the Echinoidea, 2, Bothriocidaroida, Melonechinida, Lepidocen-
troida and Stirodonta, 647 pp., atlas, 89 pi.

stockley, g. m. 1927. Neogene Echinoidea from the Zanzibar Protectorate. In Report on the palaeon-
tology of the Zanzibar Protectorate, 103-17, pi. 20-1. His Majesty’s Stationery Office, London.

G. ZAMMIT-MAEMPEL, M.D.

53 Main Street
Birkirkara

Typescript received 5 December 1967 Malta

TECHNIQUE FOR SCALE MODELLING OF
CEPHALOPOD SHELLS

by JOHN A. CHAMBERLAIN, JR.

Abstract. Previous work by Raup on the mathematical description of coiled shells provides a foundation for the
construction of three-dimensional scale models of cephalopod shells. A computer programme, based on the
method of Raup, has been developed which contours planispiral surfaces of the cephalopod type. The computer
output is then used to construct plastic models of these surfaces. The morphological range covered by this pro-
gramme includes the entire suite of planispiral cephalopod forms. Provision is made for the simulation of both
actual fossil species and hypothetical morphologies. In addition, mathematical simulation of accretionary growth
allows the modelling of different stages of ontogenetic series.

The term ‘scale model’ has been used to describe those models which are physical
reproductions of a prototype. Most scale models are used to adjust the dimensions of the
prototype to a size more readily or accurately studied. Size change is not essential,
however, as scale models with dimensions similar to those of the prototype may be
employed if the prototype itself is unsuitable. Scale models are real, physical objects
and thus differ from mathematical models in that the latter are abstractions. The two are
not exclusive, however, since a scale model may be based upon a mathematical model.
The scale cephalopod models figured in this paper, for example, are true scale models,
but their construction is formulated on Raup’s (1961, 1963, 1966) mathematical model of
shell coiling.

The experimental use of scale models has become a technique of considerable impor-
tance to the physical sciences and engineering. Due primarily to the greater complexity
of the organic world, problems concerning organisms are not yet as amenable to the
scale-model approach as are purely physical phenomena. Our understanding of organic
mechanics and the level of modelling technology are usually inadequate to deal with
the intricate nature of organic mechanisms. Where the requirements for model-building
are reasonable, however, the scale-model technique can be productive.

COMPUTER TECHNIQUE FOR CEPHALOPOD SHELLS

It has been known since the work of Moseley (1838, 1842) that the logarithmic spiral
is fundamental to the molluscan shell plan. Not until the work of Raup (1961, 1963,
1966) and Raup and Chamberlain (1967), however, were the cumbersome mathematics
of earlier workers replaced by equations which could be readily applied to actual shells.
According to Raup, the basic form of a spiral shell may be defined by four parameters:
the shape of the generating curve (5); the whorl expansion rate (IT); the distance from
the generating curve to the coiling axis (D); and the translation rate along the coiling
axis (T). These parameters are further defined and the mathematical methodology set
forth in the above papers. Raup (1962) and Raup and Michelson (1965) have demon-
strated the utility of these parameters in the application of both digital and analog
computers to the investigation of shell geometry. The equations used here to simulate

[Palaeontology, Vol. 12, Part 1, 1969, pp. 48-55, pi. 7.]

J. A. CHAMBERLAIN: SCALE MODELLING OF CEPHALOPOD SHELLS 49

cephalopod morphology are based on Raup’s mathematical model and his previous
work with computers.

A computer programme, written in Fortran IV and intended for use in the l.B.M.
S/360 machine, has been developed by the author. This programme yields, as plotter
output, contour maps of planispiral surfaces. These maps are then used in constructing
laminated plastic replicas of planispiral cephalopods. Each lamina is parallel to the
median plane and has a thickness equal to the contour interval. The programme has
been deposited in the reprint files (reprint no. 227) of the Department of Geological
Sciences, University of Rochester, Rochester, N.Y., and is available upon request.

Since cephalopod shells are bilaterally symmetrical, the mathematical reconstruction
of an entire surface is unwarranted; instead this programme considers the median plane
as a base and treats only a single side. Symmetry is restored by duplicating this one half
during the actual construction of the model. The models herein described are thus three-
dimensional reproductions of planispiral surfaces.

text-fig. 1. Cephalopod sectioned along median plane to show the
fundamental relationships for computer simulation.

While the programme itself is relatively involved, it preserves simplicity in its input
requirements. The user is required to include as input data only three of Raup’s para-
meters (T is zero for planispiral forms and so is excluded here), and the value of a few
constants and logical variables. An orthogonal grid system is assumed in defining the
position of the surface in space (text-fig. 1). The coiling axis lies at the centre of the
system perpendicular to the Z = 0 plane. The aperture has the coordinates of distance
from the coiling axis (A), and distance above the median plane (Z). The shape of the
generating curve is taken as the outline of the aperture above the median plane, and is
defined by a series of points whose (A, Z) coordinates are either directly read in as input,
or calculated from the equations of simple geometric curves whose half axes and dis-
tance to the coiling axis constitute the input data. Other input parameters include the
whorl expansion rate (IF), and the length of the spiral expressed in numbers of whorls.

The computer defines new planes, the number of which depends on the Z coordinate
of the highest point on the aperture. These planes lie above the median plane and parallel

C 6289

E

50

PALAEONTOLOGY, VOLUME 12

to it such that a constant interplanar distance is maintained. The Z coordinate of each
aperture point is compared to each plane in turn. If a point lies below a given plane, it is
ignored; if it lies on or above the plane, its intersection with the plane is calculated
from the logarithmic decay of its Z coordinate using the following equations:

Zp,ane = Zpl . eaS,

e = [ln(Zplane)— ln(Zpt)]/fl. (1)

In the above, which are simply different forms of the equation of a logarithmic spiral,
Zplane is the Z coordinate of the plane and Zpt is the Z coordinate of the aperture
point, e is the base of the natural logarithms. 9 is the angle, expressed in radians, through
which the aperture point must be rotated so that the Z coordinate of the point will be
the same as the Z value of the plane, a is the spiral constant and is equal to cot a, where
a is the spiral angle of Thompson (1942). a may be further expressed as a = InW/lv
or W = e2™, where W is the whorl expansion rate of Raup. In equation 1, since
Zpt > Zplane and a > 0, 6 will always be negative or zero. The latter case is trivial,
however, as no rotation is involved. Since 9 is thus actually negative, the planispiral
surface is constructed inward from the aperture rather than outward from the first
generating curve, which in molluscs is that portion of the shell immediately adoral to the
protoconch. A negative 9 permits mathematical consideration of the easily measured
aperture, and eliminates the critical drawback, inherent in nearly all previous work, of a
positive 9 requiring a set of equations based on the shape of the minute and often
unavailable first generating curve. The importance of a negative 9 to the mathematical
analysis of real shells has been further demonstrated by Raup and Chamberlain (1967).
Once 9 is known, the X and Y coordinates for Zplane, the new Z coordinate, may be
calculated from the following:

Apiane = Apt.ea0.sin 9,

Tp.ane = Apl . ea9 . COS 9,

where ZpIane and Tplane are the new {X, Y ) coordinates respectively, and Xpt is the X
coordinate of the undecayed aperture point. Other terminology is as before. The
(A, Y) coordinates of all logarithmically decayed aperture points for a given Z plane
are scaled and fed into a Calcomp plotter which then plots them. A sagittal section

EXPLANATION OF PLATE 7

Lateral and anterior views of some cephalopod models. Figs. 1-6 show various stages in the assembly

of a model. Figs. 7-12 show three members of a hypothetical ontogenetic series: W = 2 0, D = 0-2.

Figs. 1-2. Specimen of Lytoceras fimbriatum (Sowerby) from which measurements for model in figs.
3-6 were taken. The shell is severed 0-4 whorls from the aperture. x0-3.

Figs. 3-4. Unfinished model showing contoured Plexiglas surface. Reference points for section align-
ment appear near section numbers: 12, 15, 19, 25, 28, in fig. 3. xO-4.

Figs. 5-6. Finished model showing smooth epoxy surface. White portion of umbilical area in this and
other models has no morphological significance, it is used merely as a means of emphasizing surface
relief. xO-4.

Figs. 7-8. Model A, 2-4 whorls, growth increment = —0-6. x04.

Figs. 9-10. Model B, 3 0 whorls, growth increment = 0 0; stage A adapical of line BA. xO-4.

Figs. 11-12. Model C, 3-4 whorls, growth increment = 0-4; stage B adapical of line BC, stage A
adapical of line BA. x 0 4.

Palaeontology, Vol. 12

PLATE 7

CHAMBERLAIN, Cephalopod models

Expansion Rate (W)

J. A. CHAMBERLAIN: SCALE MODELLING OF CEPHALOPOD SHELLS

Distance (D) of Generating Curve from Axis |y>

0 0.2 0.4 0.6

51

0.8

text-fig. 2. Position of various models on a contoured density graph of the natural occurrence of
planispiral ammonoids (adapted from text-fig. 4 of Raup 1967). Contour parameters are W and D.
90% of sample lies inside outermost contour. Sample size is 405 species. All models but 3, which is the
model of L. fimbriaium, have hypothetical morphologies. All models X0-2.

52

PALAEONTOLOGY, VOLUME 12

lying above the median plane of line a distance of Zp,ane is thus formed. Moreover, since all
points on a given sagittal section have identical elevations (Zplane), each plot is actually
a contour line, and the plots for all Z planes form a contour map. Plate 7, figs. 3 and 4,
shows the contoured surface of an unfinished model.

In addition to the mathematical treatment described above, the computer programme
incorporates several operations which provide for the reproduction of most of the varia-
tions observed among cephalopod shells. The simulation of all types of smooth plani-
spiral shells (involute to gyroconic and cyrtoconic) is created by the inclusion of a number
of options for inputting Raup’s parameters to the computer. Among these, the options
for defining aperture shape make possible the modelling of real species or completely
hypothetical and, in terms of real animals, non-existent morphologies. Plate 7, figs. 1-6,
shows a specimen of Lytoceras fimbriatum (Sowerby) and a model constructed from
measurements taken from it. Text-fig. 2 shows several models with hypothetical mor-
phologies.

The wide range in size displayed by coiled cephalopods is accommodated in the
programme by scaling. The size of a model is independent of other input data and
depends only on the operator’s prescribed size instructions. There are thus no restric-
tions on the size of a prototype (where real shells are being copied) except those con-
cerning precision in measurement. Models are limited by the width of the plotter paper
to a maximum diameter of 10 in., although if the computer output is used in conjunc-
tion with a blue-print enlarger this size may be exceeded.

Although scaling accounts for a wide range of variation, it does not duplicate the
accretionary nature of size increase in cephalopods. The ontogenetic development of
the shells of these animals occurs by addition of shell material along the margins of the
aperture; there is no uniform expansion of the entire shell, as is accomplished by scaling.
To alleviate this deficiency, a mathematical simulation of accretionary growth has been
built into the programme and functions when instructed by the operator. Plate 7,
figs. 7-12, shows three members of a hypothetical ontogenetic series produced by making
three computer runs, each time varying the magnitude of the growth increment while
keeping other input data constant.

Although the programme can reproduce, and in some respects exceed, much of the
morphological range of normal cephalopods, it retains certain limitations which prevent
simulation of all cephalopod types. Since its operation is founded on the equation of a
logarithmic spiral, which by definition is a spiral without translation, helicoid forms, such
as those morphologies characterized by non-planispiral heteromorphs, are excluded.
These exceptions do not notably detract from the over-all scope of the programme as the
morphological range of the great majority of fossil species is still reproducible.

While the basic shape of planispiral forms may be simulated, the surface texture and
much of the shell sculpture can not. Except for prominent spiral ornamentation, such as
keels, no ornamentation can be rigorously duplicated. This includes the many kinds of
radial sculpture (e.g. ribs, spines, tubercles) and apertural contrivances (e.g. rostra,
lappets). Ornamentation of this sort is not readily susceptible to objective mathematical
treatment, nor is the precision of the assembly technique adequate to reproduce the
finer sculpture. Sculptured models are not precluded, however, since surface ornamenta-
tion may be added once the smooth surface is finished.

The programme is also not in strict accord with nature in its implicit assumption of

J. A. CHAMBERLAIN: SCALE MODELLING OF CEPHALOPOD SHELLS 53

ontogenetic constancy in the whorl expansion rate and in the shape of the generating
curve. Ontogenetic variation in both of these parameters is well known among cephalo-
pods, especially ammonoids.

The length of time required for a complete computer run depends primarily on the
maximum thickness of a model, since more sagittal sections are required for a thick
model than for a thin one. All models illustrated in this paper consumed less than ten
minutes of computer time, and for most, the average run took about seven minutes.

TECHNIQUE FOR MODEL ASSEMBLY

The computer sagittal sections are traced on to sheets of clear Plexiglas. The thickness
of the sheets used in the construction of these models is 0-031 in., 0-001 in. less than the
section spacing. Other thicknesses can be handled by the computer, but this one was
considered best for the purpose at hand since it combines precision with practicality.
A second Plexiglas sheet of equal thickness is temporarily glued over those inscribed
with the sections. This allows both model halves to be shaped at once — the reason for the
treatment in the programme of only one symmetrical side. The sections are then
cut out of the double sheets with an electric band-saw and trimmed with a rotary sander.
A model 2 Moto-Tool, manufactured by the Dremel Mfg. Co., Racine, Wisconsin, was
found to be ideal for trimming. The Plexiglas sagittal sections are separated from one
another and divided into two stacks, one for each half of the model. They are then fastened
permanently to one another with a layer of acrylic cement, the thickness of which is
estimated at 0-001 in. When this thickness is added to that of the Plexiglas sheets, the
sum equals the Z spacing defined in the programme. Section alignment and positioning
are controlled by reference points, which are part of the computer output and appear
at the same place (have the same ( X , Y) coordinates) on all plotted sections and plastic
templates (PI. 7, fig. 3). Distortion due to section displacement is thus minimal. Plate 7,
figs. 3 and 4, shows that at this stage of assembly, models have a contoured surface. In
order to simulate more closely the surface of cephalopod shells, the edges are smoothed
by infilling the steps with plastic resin. The common type of epoxy plastic, Epoxi-Patch
Kit3X, made by the Hysol Chemical Co., Olean, N.Y., was found to be well suited for
this purpose. The steps are filled in rather than sanded down because it is the upper edges
of the templates that lie on the computed surface. When mixed, the epoxy is a viscous
paste that may be easily applied with small spatulas. The model is coated with epoxy
and placed in an oven at 140 °F to 170 °F for two hours, after which the hardened model
is removed and the surface sanded down until the edges of the Plexiglas reappear. If
necessary, a second and third coat is applied, each time removing the excess epoxy,
until a smooth, even surface is produced. Finally the model is painted. The construction
time varies with the size and thickness of the model and with the number of applications
of epoxy. Generally, however, assembly requires 10-20 working hours from the receipt
of the computer output to the finished model.

APPLICATIONS

These cephalopod models illustrate a number of advantageous properties possessed by
scale models of fossil organisms. Perhaps their most significant feature is that they can,
in a sense, act as a substitute for a thorough theoretical or mathematical understanding

54

PALAEONTOLOGY, VOLUME 12

of a problem. For example, the forces acting on the hull of a moving ship still defy
complete mathematical description. Thus, in designing hulls, reliance has been placed
not so much upon theory as upon scale models of hulls, the reason being that while the
physical interrelationships may not be totally understood, the use of scale models enables
the important ones to be studied and conclusions to be drawn. The history of experi-
mental physics shows that scale models can be used to derive empirically laws which
escape theoretical analysis because of inadequate data. The same holds true for many
areas of palaeoecology, particularly those dealing with the palaeoautecological problems
of function and adaptation. Although scale models may supplant conceptual depth, their
use does not presume complete naivete , as there must be sufficient understanding of
basic relationships to build models and design appropriate experiments.

A second important attribute of fossil scale models is functionability, a property which
actual fossils, in their lithified state, do not have. Thus, Rudwick (1961) used a working
model of Prorichthofenia instead of inoperable specimens. Preservation is important
here since even so-called excellent preservation is rarely adequate to maintain a shell as
it was in life. One of the reasons the present author is using models such as these in
experiments on cephalopod hydrodynamics is that they do not possess the common
deformities of real fossil shells. Models are not distorted, fragmentary, or embedded in
sediment.

Scale models can be used to simulate actual species or hypothetical morphologies.
Models therefore provide for a wider range of morphologic variability than actual
fossils. They facilitate the study of evolutionary trends, as models of hypothetical
morphologies may be used in tracing the evolution of function and adaptation from one
real form to another. Hypothetical forms are also useful in evaluating the function of
characters which do appear in real animals since they allow the relative advantages of
real and non-real characters to be compared. This is especially significant in determining
the characters which delimit a taxon’s morphological range. The work of Raup (1966,
1967) illustrates the value of hypothetical shell forms in this type of functional morpho-
logic research and the importance of investigation of characters not exhibited by actual
fossils.

The value of models is further demonstrated by their utility in studying the effects of
changes in morphological characters. It is often difficult or impossible to isolate indivi-
dual characters for study, particularly in the case of many fossil taxa, where functionable
specimens are rare and sample size necessarily small. Modelling facilitates investigations
of this sort since models varying from one another in only a single character may be
constructed. Use of models frees the investigator from dependence on fossil material.
Such autonomy is important since it eliminates the problem of scarcity of serviceable
fossils and the laborious and often unrewarding process of searching the various museums
and repositories for usable specimens.

Models can be designed to fit the experiment, whereas prototypes may possess charac-
ters— perhaps size, weight, or surface texture — in magnitudes detrimental to their use.
In cases where only a portion of a fossil or a particular set of characters is being studied,
experimentation on the whole fossil, especially if it is morphologically complex, may
conceal the desired effects or make the work unnecessarily complicated. It is not man-
datory to construct models patterned after fossils in every detail; it is sufficient to build
models that resemble the prototypes only in those characters being investigated. The

J. A. CHAMBERLAIN: SCALE MODELLING OF CEPHALOPOD SHELLS

55

practicality of model construction should therefore depend on the number and nature
of the characters involved rather than on the complexity of the fossil as a whole.

While the models figured here are designed for hydrodynamic research, adaptations
of the technique could provide models suitable for other purposes, as for example,
shell strength experiments similar to those of Raup and Takahashi (1966), and Denton
and Gilpin-Brown (1966), or the orientation work of Reyment (1958). Although the
computer programme was designed specifically for the simulation of cephalopod mor-
phology, it retains sufficient versatility to simulate other planispiral forms as well. Of
particular interest is its ability to reproduce many of the forms exhibited by brachio-
pods, scaphopods, and planispiral foraminifera. By including the appropriate equations
for translation, it could be adapted to reproduce the helicoid form of bivalves, gastro-
pods, and many foraminifera.

Acknowledgements. The writer acknowledges the assistance of David M. Raup, who offered valuable
advice at various stages of this study and with S. M. Stanley reviewed the manuscript. This research
was supported by the National Science Foundation, through its traineeship programme, and by the
Petroleum Research Fund, administered by the American Chemical Society. The computer work was
done at the University of Rochester Computer Center. R. M. Eaton prepared the figures.

REFERENCES

denton, e. j., and gilpin-brown, j. b. 1966. On the buoyancy of the Pearly Nautilus. J. mar. biol. Ass.
U.K. 46, 723-59, pi. 1-2.

moseley, h. 1838. On the geometrical forms of turbinated and discoid shells. Phil. Trans. R. Soc. for
1838, 351-70.

1842. On conchyliometry. Philos. Mag. 21, 300-5.

raup, d. m. 1961. The geometry of coiling in gastropods. Proc. Nat. Acad. Sci. 47, 602-9.

1962. Computer as aid in describing form in gastropod shells. Science , 138, 150-2.

■ 1963. Analysis of shell form in gastropods. Spec. Pap. geol. Soc. Amer. 73, 222 pp.

1966. Geometric analysis of shell coiling: general problems. J. Paleont. 40, 1 178-90.

1967. Geometric analysis of shell coiling: coiling in ammonoids. Ibid. 41, 43-65.

and chamberlain, j. a., jr. 1967. Equations for volume and center of gravity in ammonoid shells.

Ibid. 41, 566-74.

and michelson, a. 1965. Theoretical morphology of the coiled shell. Science, 147, 1294-5.

and takahashi, t. 1966. Experiments on strength of cephalopod shells. Geol. Soc. Amer. Program

1966 annua / meetings, 172-3.

reyment, r. a. 1958. Some factors in the distribution of fossil cephalopods. Stock h. Contr. Geol. 1,
97-184, pi. 1-7.

rudwick, m. j. s. 1961. The feeding mechanism of the Permian brachiopod Prorichthofenia. Palaeon-
tology, 3, 450-71, pi. 72-74.

Thompson, d’arcy. 1942. On Growth and Form, New York. 1116 pp.

j. a. chamberlain, jr.
Department of Geological Sciences
University of Rochester
Rochester, New York

Typescript received 31 May 1968

PALAEOECOLOGICAL STUDIES IN THE GREAT
OOLITE AT KIRTLINGTON, OXFORDSHIRE

by W. S. McKERROW, R. T. JOHNSON, and M. E. JAKOBSON

Abstract. Middle Jurassic (Bathonian) limestones and clays at a quarry north of Oxford have yielded faunas,
some of which are life assemblages, and others which have been transported before burial. Size distributions
and articulation ratios are among the criteria discussed for distinguishing between the life and death assemblages.

The White Limestone, the lower of the two formations studied, consists of two facies: (a) limestones disturbed
by burrowing molluscs, worms, and crustaceans which are interpreted as having lived in inter-tidal flats; and
( b ) channels cut into the inter-tidal deposits, which are either poorly fossiliferous or which contain an epifauna
of terebratulid brachiopods ( Epithyris ) and mussels ( Modiolus ); the floors of these channels were sub-tidal.

The inter-tidal facies continues locally into the basal metre of the Forest Marble, but this higher formation is
dominantly sub-tidal. The Forest Marble (in Oxfordshire) is distinguished from the White Limestone in contain-
ing an abundant epifauna (with a large proportion of oysters) and few signs of bioturbation. Shelly limestones and
clays with lignite are the characteristic Forest Marble lithologies; one corat- Epithyris bed is present which
contains a mixture of drifted and endemic forms.

Kirtlington Old Cement Works (Grid reference: SP 494199) lies 10 miles north of
Oxford on the east bank of the River Cherwell. It has been abandoned as a working
quarry for about 40 years, but the exposures of the White Limestone and the lower part
of the Forest Marble are still excellent, except on the long east face, where there has
been considerable slipping of the beds with the formation of much scree material. The
higher beds (the Cornbrash and the upper part of the Forest Marble) are only sporadic-
ally exposed and are not discussed in this work.

The most detailed account of the beds at Kirtlington is given by Arkell (1931,
pp. 570-4), but he records only a few of the many lateral changes in thickness and
lithology present, and there is little discussion of the relationships between lithology and
fauna. Subsequent descriptions (Richardson et al. 1946, Arkell 1947, McKerrow and
Baden-Powell 1953) have been based almost entirely on Arkell’s (1931) account. Klein
(1963, 1965) records channels in the Forest Marble at Kirtlington (1965, p. 176); he also
records (pp. 187-8) thin graded beds, which he ascribes to storms in areas of tidal flats.
Klein (1965, fig. 19, p. 190) shows that most of the channel directions in the Kirtlington
area are towards the south-east, and he concludes (pp. 185, 191) that they are channels
in a tidal flat. We agree with these conclusions with regard to the White Limestone, but
we find no palaeontological or other evidence to suggest that the Forest Marble above
the fimbriatus-waltoni Clay is intertidal.

STRATIGRAPHY

Only three beds below the Cornbrash can be traced with certainty through all parts
of the Kirtlington quarry; these are:

1 . A coral -Epithyris limestone (text-fig. 1, beds 3o, 4i, and 6j ; Arkell 1 93 1 , p. 570, the
Upper Epithyris Bed, bed 1 1 ).

2. The Eomiodon [Astarte] fimbriatus-Bakevellia [Gervillia] waltoni Clay, or, more

[Palaeontology, Vol. 12, Part 1, 1969, pp. 56-83, pis. 8-12.

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOG1CAL STUDIES 57

briefly, the fimbriatus-waltoni Clay (text-fig. 1, beds 2o, 31, 4e, and 6f; Arkell 1931,
p. 572, bed 10).

3. An oyster-Epithyris marl immediately below the fimbriatus-waltoni Clay (text-fig.
1, beds 2n, 6e; Arkell 1931, p. 572, the Middle Epithyris Bed, bed 9). This bed is seen
to pass laterally into a limestone with oysters in Profile 4 (bed 4d), and a limestone with-
out oysters in Profile 3 (bed 3k).

It is proposed to assign to the Forest Marble all the beds between the base of the
oyster-Epithyris marl (and its equivalents: 2n, 3k, 4d, 6e) and the base of the Cornbrash,
and the beds below this marl to the White Limestone. This is in accord with Arkell’s
(1931) usage, but not with later classifications (Richardson et al. 1946, Arkell 1947).
The reasons for selecting this oyster-Epithyris marl as the base of the Forest Marble are
many. It is the lowest bed in which oysters are abundant at Kirtlington, and oysters are
seen to be characteristic of the Forest Marble throughout Oxfordshire. Arkell (1931,
1947), Richardson (1933, p. 49 et seq.), Richardson et al. (1946, p. 38 et seq.), and
Worssam and Bisson (1961, p. 97) all record the abundance of oysters in the Forest
Marble (which they subdivide into the Kemble Beds and the Wychwood Beds). Together
with the oysters, there is a marked increase in the abundance of other epifaunal bivalves
in the Forest Marble compared with the White Limestone, which suggests a marked
change of environment. The Forest Marble clays contain much more lignite than those
in the White Limestone; some also contain dinosaur remains (Arkell 1931, p. 572,
Bed 10) and freshwater ostracods (Bate, 1965). The limestones in the White Limestone
are usually oolites, much disturbed by burrowers (except for some channel fills), and
some contain a large proportion of microcrystalline calcite in their matrices. Shell
fragments make up most of the Forest Marble limestones, and when ooliths occur they
are often merely a thin veneer of carbonate around shell fragments.

The flaggy nature of the Forest Marble has often been assumed to be a characteristic
lithological feature of this formation. However, examination of the Great Oolite quarries
in Oxfordshire shows that the limestones in the top three or so metres are always flaggy,
whether they are shelly, bioturbated, or composed of microcrystalline calcite. Most old
quarries, opened for building stone, were worked so that the Forest Marble and Lower
Cornbrash were the highest beds exposed, but in the past 25 years many quarries wholly
in the White Limestone have been opened for road metal and lime, and it is clear that
weathering alone can be responsible for the flaggy nature of any type of Great Oolite
Limestone.

It should be noted that though faunas play a part in the separation of the White
Limestone and the Forest Marble, they are not of chronological significance in correla-
tion. It is very probable that the transition from one environment to the other took place
at different times throughout the Oxford area.

We have not attempted to subdivide either the Forest Marble or the White Limestone
in this study, as these formations cannot be split into easily recognizable lithological
members. In the absence of the Bradford Clay fauna, it is not possible to separate the
Kemble Beds from the Wychwood Beds, either by lithology or by faunas (Arkell 1931,
pp. 593-5; 1947, pp. 44-6); both are thus grouped as Forest Marble.

The distinction between the two subdivisions of the White Limestone, the Bladon
Beds and the Ardley Beds (Arkell 1947, pp. 42-3), is based on the evolution of the
gastropod Aphanoptyxis ardleyensis Arkell 1931 (spiral angle 10-12°; length less than

LITHOLOGIES

58

PALAEONTOLOGY, VOLUME 12

text-fig. 1. Six profiles at Kirtlington. For locations see text-fig. 2.

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOGICAL STUDIES 59

36 mm.), which grades upwards into A. b/adonensis Arkell 1931 (spiral angle 23-26°;
length in adult 60-70 mm.). This evolutionary change appears to be a reliable time indi-
cator in the Oxford area, but, as the lithologies of the two sets of beds are often identical,
they cannot be distinguished in the absence of Aphanoptyxis. At Kirtlington, the beds
immediately below the oyster -Epithyris marl (text-fig. 1 , beds 21, m, 3i, j, 4b, c, 5g, 6c, d ;
i.e. beds 6-8 of Arkell 1931) have no Aphanoptyxis and cannot be definitely assigned
to either the Ardley or Bladon Beds (see Arkell 1947, p. 57; ‘ ? Bladon Beds. Two bands
of blue-hearted limestone with a marl parting’). It would seem best to use the occurrence
of these species as zonal (i.e. time) indicators and not as diagnostic of formations.

There is a case for renaming the Forest Marble and the White Limestone with forma-
tion names based on a locality, but this should await further study of the Great Oolite
Series around Oxford and a full description of the type localities of these formations.

Acknowledgements. Thanks are due to P. J. Green for help in collecting and preparing the fossils in
the early stages of this work. We are grateful to A. Hallam, W. J. Kennedy, D. Nichols, H. G. Reading,
and B. R. Rosen for helpful discussion, and to Miss S. V. Preston for drafting the illustrations.

DESCRIPTION OF THE ROCKS AND FAUNAS

Six vertical profiles (text-fig. 2) were selected for the best exposures over maximum
thicknesses of rock. The relationships between these profiles are shown in text-fig. 1.

60

PALAEONTOLOGY, VOLUME 12

Profile 1 shows the rocks exposed on a pinnacle left by the quarrying operations in the
south-west of the pit (text-fig. 2). All the rocks present are within the White Limestone.

There is strong evidence of burrowing activity in beds lb and Id (text-fig. 1), where
very little sign of bedding is left within the limestones; coarse ooliths (0-5-2-0 mm. in
diameter) and shell fragments are randomly mixed with finer ooliths and microcrystal-
line calcite. Some of the animals responsible for the disturbance of the bedding are
preserved fossil (e.g. Anisocardia ) and others can be recognized by their burrows or
faecal trails (e.g. Favreina , PI. 12, fig. 2), but there were probably others which left no
diagnostic trace. (The genus Favreina Bronniman 1955, was founded for faecal trails of

table 1

<

Z

D

<

u.

E

UJ

<

z

D

<

u.

Z

WHITE LIMESTONE

le« A O

Id O C

lc

lh O C

Faunal and lithological details for the beds of Profile 1.

Bedding

disturbed

Bedding

undisturbed

Epithyris

Modiolus

Oysters

Other

epifauna

Anisocardia

Aphanoptyxis

Terebelloid
worm tubes

Other

infauna

Lima

Yes

Aws

Aws

Cucullaea

bryozoa

Ows

C

Favreina

Yes

Ows

Ows

echinoid

Cws

A

gastropods

spines

Favreina

burrows

Yes

bivalves

C

bivalves
Favreina C

la

Key :

O = occurs.

C = common.

A = abundant,
w = whole shell,
s = single shell,
t = top of bed.

b = bottom of bed.

§ = coral Epithyris limestone,
f = fimbriatus-waltoni Clay.

* = oyster Epithyris limestone.

• = Epithyris limestone.

Nerinea

an anomuran crustacean; these consist of rods with a diameter of 1-2 mm., sculptured
externally with longitudinal and transverse ridges and grooves.) Many of the burrows
are vertical tubes 1-2 cm. in diameter lined with shell fragments and filled with fine lime-
stone (PI. 12, fig. 1); we consider it is likely that they were formed by terebelloid worms,
but it is possible that they were formed by other burrowing organisms (perhaps cerian-
thid sea anemones).

Similar bioturbation of sediments close to the low tide level is seen on the present-day
Atlantic coast of America produced by the decapod CaUianassa (MacGinitie 1934,
Weimer and Hoyt 1964), and on the Dutch coast by Arenico/a (van Straaten 1952).

Table 1 lists the fossils occurring in each bed of Profile 1. Bed la contains Nerinea;
lithologically it is similar to beds lb and Id and it is considered that all these beds were
laid down in a similar environment with an abundant infauna. Turritella (Yonge 1946)

EXPLANATION OF PLATE 8

Photograph of the south face of the Kirtlington Old Cement Works quarry, Oxfordshire.

PLATE 8

Palaeontology, Vol. 12

o c £ v, o

fN CN (N r) (N O'! CN CN CN

McKERROW, JOHNSON, and JAKOBSON, Great Oolite at Kirtlington

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOGICAL STUDIES 61

is a burrower at the present day, and, from their faunal and lithological associations,
we think that the turreted Nerinea and Aphanoptyxis also burrowed; however, this is by
no means certain. A useful summary of the Mesozoic adaptive radiation of bivalves has
recently been given by Stanley (1968).

The highest bed on the pinnacle (le, text-fig. 1) is largely made up of specimens of the
brachiopod Epithyris and the mussel Modiolus', some are whole shells, with valves
attached, others are single valves. Some burrowing has occurred in this bed; terebelloid
worm tubes are common and some burrowing molluscs are present.

Profile 2 (text-fig. 1) is on the south side of the quarry (text-fig. 2); its position is
indicated on the elevation of the south face (PI. 8). It should be noted that beds 2a, 2b,
2d. and 2j, while present in Plate 8, do not occur on the line of Profile 2. This is a reflec-
tion of the greater variability in the White Limestone at Kirtlington when viewed along
a section extending from east to west; a fact which conforms with the suggestion that
most of the channels in this area had a direction with a large north/south component.

Beds 2a, b, c contain a small amount of silt grade quartz (0-002%), but all the beds
in this profile consist largely of terrigenous clay, shell fragments, ooliths, and micro-
crystalline calcite. Bed 2a is similar to bed la in containing a burrowing turreted gastro-
pod, although the genus present is Aphanoptyxis, instead of Nerinea.

Beds 2k and 2i(2) are full of Epithyris', they continue across the south face of the
quarry, merging eastwards into bed 2j and westwards into bed le (the Lower Epithyris
Bed of Arkell 1931, 1947). In addition to the faunas recorded in Table 2, extensive
collections were made from beds 2k and 2i(2) and their lateral equivalent, le (Table 8);
some hundred pounds of rock was brought back to the laboratory and broken up to
extract all the fossils present. The size distributions of the Epithyris and Modiolus collec-
tions from this bed are discussed in a later chapter.

Laminations of coarse and fine limestone with some clay pellets make up most of
bed 21, which rests on the Epithyris limestone; it is one of the few beds in the White
Limestone that is not disturbed by burrowers. Bed 2m, which follows, is similar in gross
lithology to 21, but it has been bioturbated. This suggests that the deposition of beds 21
and 2m (together 90 cm. thick) occurred rapidly; then, during a subsequent pause in
sedimentation, the infauna only disturbed the top 53 cm. (bed 2m).

Other beds at Kirtlington (e.g. 5c and 6c) and at Gibraltar Quarry (477185), \ \ miles
south-west of Kirtlington Old Cement Works (where a large channel is well exposed),
show that the Epithyris beds (like 2k) were laid down in channels, and it is suggested
that the succeeding well-bedded (21) and disturbed beds (2m) are part of a channel fill.

Bed 2n, the oyster -Epithyris marl, is the Middle Epithyris Bed of Arkell (1931, 1947).
Although none of the shells seem to be in position of growth, the majority of the
Epithyris are complete, but the Ostrea and Modiolus are largely single valves, suggesting
variable resistance to disturbance by currents.

The fimbriatus-waltoni Clay (bed 2o) is not now well exposed at Kirtlington; in the
south face it is only seen sporadically by digging into the grass at the top of the lime-
stone face. It is recognized here by its dark colour and by the abundance of lignite.
Arkell (1931, p. 572) records ‘an impersistent layer of white pellets at the top’ of this
bed. Thirty metres north-east of Profile 2, some caliche-like nodules, similar to those
recorded by Klein (1965, p. 177) and presumably similar to those seen by Arkell, are
visible now, but we have not found them elsewhere at Kirtlington. They are best seen at

62

PALAEONTOLOGY, VOLUME 12

the present time in the freshly exposed fimbriatus-waltoni Clay of Shipton Cement
Works (475175), 2 miles south-west of Kirtlington quarry. Klein concluded that these
indicate mud flats which were periodically exposed.

Profile 3 (PI. 9) illustrates the largest complete section seen at Kirtlington; our mea-
sured section is in the north-east corner of the quarry (text-fig. 2 and PI. 9) and includes
the major portions of both the White Limestone and the Forest Marble. Table 3 lists
the fauna in each bed; the thickness and some sedimentary features are given in text-
fig. 1.

Beds 3a to 3j show a dominance of bioturbation similar to the White Limestone seen
in Profiles 1 and 2 (though 3b(2) shows lamination), but no individual bed can be
correlated with the south face of the quarry.

TABLE 2

Faunal and lithological details for the beds of Profile 2 (for key see Table 1).

<
z

D
<

Uh

E

W

FOREST MARBLE

2of A

"ft

11

if .a
72 "s

«3 s

I

2n A

Cvv

Bakevellia
Eomiodon C
Aw

^3

A

WHITE LIMESTONE

2m

O

c

Yes

Cw

O

burrows

21

Yes

2k*

A

c

Yes

Aws

Cws

O

See Table 8

Os

A

See Table 8

O

2j

O

A

Yes

Yes

Os

Os

Lima

Os

A

2j

O

c

Yes

Os

Os

echinoid spines
Pinna

Cw

o

C

Lavreina

O

2h

O

o

Os

Ow

o

2g

O

o

Os

echinoid spines

Ow

Lavreina

2f

O

o

Yes

Os

Bakevellia

Ow

o

Lavreina

o

t

trochids

2e

O

o

Yes

Yes

Os

Lima

t

b

echinoid spines

2d

C

c

Yes

L,

Os

O

Lima

Ow

cardiids

o

2c

C

c

D

Yes

Cs

Cw

c

burrows C

o

2b

o

c

Yes

Cucullaea

Cw

c

burrows C

2a

o

c

Cs

echinoid spines

Cw

o

burrows

o

Bed 3k is an Epithvris limestone with drifted single valves dominant; it occurs im-
mediately below the fimbriatus-waltoni Clay and is equivalent to the oyster -Epithyris
Marl (2n); it passes westwards into a limestone which contains oysters (4d), (see text-
fig. 1). Many pounds of this bed were broken up in the laboratory; Table 9 lists the
fauna obtained. Bed 3k is the lowest at Kirtlington with abundant oysters, and is taken
as the local base of the Forest Marble.

EXPLANATION OF PLATE 9

Photograph of the north-east face of the Kirtlington Old Cement Works quarry, Oxfordshire.

NORTH-EAST FACE Profile 3

Palaeontology, Vol. 12

PLATE 9

McKERROW, JOHNSON, and JAKOBSON, Great Oolite at Kirtlington

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOGICAL STUDIES 63

In Profile 3, the fimbriatus-waltoni Clay (31) can usually only be exposed by digging,
and even then it is often in such a weathered state that none of the bivalve shells are
preserved. The abundance of large (up to 20 cm.) pieces of lignite, the caliche-like

TABLE 3

Faunal and lithological details for the beds of Profile 3 (for key see Table 1).

EPIFAUNA

INFAUNA

Bedding

disturbed

Bedding

undisturbed

Epithyris

Modiolus

Oysters

Other

epifauna

Anisocardia

FOREST MARBLE

3v

C

o

Yes

Aw

echinoid spines

b

freshwater

ostracods

3u

3t

c

Cws

3s

3r

c

Cws

freshwater and
marine ostracods

3q

c

Cws

echinoid spines

3p

3o§

A

o

As

As

Ow

See Table 10

3n

c

Bakevellia C
freshwater and
marine ostracods
Cetiosaurus

3m

c

Cws

31

3k*

c

o

Yes

Awt

Cws

See Table 9

Ow

Owb

WHITE LIMESTONE

3j

c

o

Yes

Ow

Ows

Lima

Ow

3i

c

c

Yes

coral

3h

bivalves?

3g

c

c

Yes

Os

Os

echinoid spines
bivalves C

Os

3f

c

o

Yes

echinoid spines
Cucullaea
Bakevellia C

Os

3e

A

o

Yes

echinoid spines
Cucullaea
bivalves, coral

3d

c

Yes

reptile tooth
echinoid spines

3c

c

o

Yes

echinoid spines
coral

Cucullaea ;
bivalves C

3b

o

Os

echinoid spines

3a

c

c

echinoid spines

gastropods A

S

5 -s

& I

O .5

burrows

O

O

o

o

See Table 10
Eomiodon C C

O C Favreina

gastropods C
bivalves

gastropods

Favreina

O Favreina C/A

gastropods
bivalves ?

O Corbis O

Favreina C

gastropods
bivalves ?

O gastropods A O

Favreina

Favreina O

O

O

Trigonia
gastropods A

64

PALAEONTOLOGY, VOLUME 12

nodules, and the record of the sauropod dinosaur Celiosaurus (Arkell 1931, p. 572)
suggest an intertidal swamp environment in which this large herbivore could wade and
find sufficient food supply. Bate (1965) records freshwater ostracods in the fimbriatus-
waltoni Clay; these had presumably drifted into the area to become mixed with the
marine or semi-marine elements of the fauna (Eomiodon fimbriatus , Bakevellia waltoni ,
and other bivalves).

The succeeding clays and limestones in Profile 3 (3m-3v, but excluding 3o) nearly all
contain abundant oysters; in the limestones, the oyster shells are usually fragmented and
deposited with pectinids and other marine epifauna; in the clays, the shells are some-
times complete, but it is never certain that they are in growth position. The increase in
the abundance of the epifauna in the Forest Marble is associated with a decrease in the
bioturbation by infauna, which is so characteristic of the White Limestone. This oyster-
pectinid epifauna may indicate a sub-tidal environment, and it is perhaps significant that
we know of no occurrence of caliche-like nodules in any Forest Marble beds above the
fimbriatus-waltoni Clay in Oxfordshire.

The coral -Epithyris limestone (bed 3o) differs from all the other beds at Kirtlington in
having abundant corals in growth position (the few corals recorded in other beds are
usually simple forms, and are often fragmented). Isastreci and Thamnasteria have two
growth forms: either the corallum is hemispherical, with a flat base, or it consists of
cylindrical branches 1-2 cm. in diameter; in both forms of corallum, all the compound
corals have similar small (2-5 mm.) polygonal corallites. Table 10 lists the fauna
obtained by breaking up many pounds of this bed in the laboratory. The terebratulids
and bivalves in this bed appear to have drifted (see below), perhaps being trapped among
the corals as currents carried them into the area. There is an unusually small proportion
of burrowers. This bed accumulated when the substrate was sufficiently stable for coral
growth to a height of 50-100 cm., but we are not clear whether any change in depth is
involved compared with the remainder of the Forest Marble beds. The coral -Epithyris
limestone is most easily examined on the boulders resting on the platform cut above
bed 3k.

Profiles 4 and 5 are on the north face of the quarry (text-fig. 2 and PI. 10). A fault
downthrowing 1 15 cm. to the west occurs 8 m. east of Profile 4, lowering the oyster-
Epithyris limestone (bed 4d, text-fig. 1 and PI. 10) so that the platform formed at the top
of bed 3k continues west at the top of bed 4g. Correlation in the field is also made
difficult because beds 4e, f, g, and h are thinner than their equivalents in Profile 3
(31, m, and n) so that the coral -Epithyris bed is only 155 cm. above the base of the
fimbriatus-waltoni Clay (4e) in Profile 4. Beds 4e and 4f have been separated, although
they may both correspond to bed 31 in Profile 3 ; the characteristic black colour of the
fimbriatus-waltoni Clay is only present in a thickness of 6 cm. We are not certain whether
the fine muddy limestone (4f) can be correlated with the upper part of bed 31.

Profile 5 can be correlated with Profile 4 by the close similarity of bed 5g to bed 4b(3)
(both are bioturbated with clay pellets at the top), and bed 5f is similar to 4b(l) in having
numerous drifted shells of Epithyris and Modiolus in a matrix containing terebelloid
worm tubes.

EXPLANATION OF PLATE 10

Photograph of the north face of the Kirtlington Old Cement Works quarry, Oxfordshire.

Profile 5 NORTH FACE Profile 4

Palaeontology, Vol. 12

PLATE 10

McKERROW, JOHNSON, and JAKOBSON, Great Oolite at Kirtlington

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOG1CAL STUDIES 65

The faunas obtained from Profiles 4 and 5 are listed in Tables 4 and 5. They show a
broad similarity to the profiles already described, but only the coral -Epithyris limestone,
the fimbriatus-waltoni Clay, and oyster-Epithyris bed can be directly correlated with the
other profiles.

table 4

Faunal and lithological details for the beds of Profile 4 (for key see Table 1).

•«

<

. ts

Op cu

•^2

<

U-I

s: <5

11

rS,

Z

05 -5

I

<0

6'

.Sb

FOREST MARBLE

4i§

A

O

As

As

Ow

4h

4g

O

4f

C

Yes

4ef

C

4d*

A

C

Yes

Cw

Cw

Ow

See Table 10

See Table 10

trails

trails

coral

C

pectinids C
Bakevellia C

Eomiodon C

See Table 9 Cw

Natica
burrows C
Favreina

WHITE LIMESTONE

4c Yes

4b A C Yes Yes Cws Cws
b t b b

4a O

Cb burrows Cb

bivalvia

Favreina

Profile 6 is in the north-west part of the quarry, on the side of the Cherwell valley; as
a result of cambering, the thicknesses of the clay beds may be in error, but, as they are
consistent along 20 m. of outcrop, this error is not likely to be very great. It is also
probable that the coral -Epithyris limestone (6j, text-fig. 1 and PI. 1 1 ) has slipped slightly,
but its height above the fimbriatus-waltoni Clay corresponds well with Profile 4. There is
no uncertainty about the thicknesses of the other limestones. The faunas are listed in
Table 6. The White Limestone of Profile 6 is similar to the other White Limestone pro-
files, but bed 6c (and to a lesser extent 6d) shows clearly the relation between drifted
shells of the epifauna ( Epithyris and Modiolus) and the bedding; both beds have a con-
centration of shells towards the base (6c(l) and 6d(l)), suggesting a lag concentration in
a channel.

The lower Forest Marble beds, from the oyster-Epithyris marl (6e) to the base of the
eorsd-Epithyris limestone (6j), are all clays and marls. The absence of limestone (cf.
Profiles 3 and 4, text-fig. 1) does not necessarily mean that there was a major lateral
change in lithology; some limestones grade into some clays; a continuous range of car-
bonate content is known in the Oxfordshire Great Oolite (Sugden and McKerrow 1962).

The oyster-Epithyris marl (6e) contains abundant oysters, with subsidiary Epithyris ;
it is remarkable in that about 10% of the oysters have shallow irregular grooves on the
interior of their valves (PL 12, fig. 3). Revelle and Fairbridge (1957, p. 281) report
Dugal’s (1939) observations on the erosion of the interior of modern Venus under anaero-
bic conditions, and they suggest that such features could result from (a) exposure above
tide level, ( b ) oxygen-poor conditions in the water, or (c) bacterial decay after death.

F

C 6289

66 PALAEONTOLOGY, VOLUME 12

In each case corrosion would appear to be due to a lowering of the pH by the production
of organic catabolic acids. We have not seen this etching in any oysters in beds above 6e,

TABLE 5

Faunal and lithological details for the beds of Profile 5 (for key see Table 1).

WHITE LIMESTONE

5g

5f

5e

5d

5c

5b

5a

C

o

c

c

o

c

c

o

c

o

o

A

T3

Oo

II

y

oq -5

Yes

Yes

Yes

"a

5 -3

cq

Yes

13

,3

Cw Cw

Cs

Cws Cws

o §•

trails
trails
bivalves
echinoid spines
echinoid spines

echinoid spines

Bakevellia

coral

trails

3

"g

2

o

o

Cw

Cw

•S ^
o "9

C

O

O

Cb trails
trails
bivalves

gastropods

Favreina

bivalves

.60

O

O

o

gastropods C O
Trigonia C
trails
Favreina
burrows C

TABLE 6

Faunal and lithological details for the beds of Profile 6 (for key see Table 1).

„ -qs

Oo

•S "5

^3

-C>

it

^3 y

cq -S cq

£

0

1

9

6 &

o

o

FOREST MARBLE

.O Ҥ
O K
£ 1

If

.&o

6j§

A

o

As

As

Ow

See Table 10
also fish teeth

See Table 10

C

6i

6h

O

Ows

o

6g

O

Yes

Ows

6ft

O

0

pectinids

Bakevellia

Eomiodon

o

6e

C

o

Cw

Ows

Cws

Lima

O

bivalves

echinoid spines

serpulids

bryozoa

Favreina

WHITE LIMESTONE

6d

O

o

Yes

echinoid spines

O

6c

O

o

Yes

Yes

Cb

Ct

Ob

Ot

bivalves b

b

t

Favreina b

6b

c

o

Yes

Yes

Cws

Cws

echinoid spines

Ot

t

b

6a

o

o

Ows

echinoid spines

O

Favreina

and our interpretation is that these oysters became widespread at the base of the Forest
Marble with slight deepening of the water, though the inter-tidal environment, charac-

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOGICAL STUDIES 67

teristic of the White Limestone, continued locally after the first influx of oysters. These
markings could have been made by predators (possibly gastropods), in which case they
could result from chemical and/or mechanical abrasion. No suitable predators have,
however, been found in this bed.

The Epithyris- oyster bed shows a lateral transition (within 90 m.) from a marl rich
in oysters (6e, 2n) to a limestone with more abundant Epithyris and fewer oysters (4d),
and finally to an Epithyris limestone with rare oysters (3k). Though this last bed (3k)
is not as rich in Epithyris as beds 2k and le (Table 11, p. 76), it has a similar ratio of
whole to single valves as well as a similar lithology; it was probably deposited in a
similar channel to these White Limestone Epithyris beds.

THE EPITHYRIS AND MODIOLUS ASSEMBLAGES
Life and death assemblages

Much mixing of animals from different habitats has undoubtedly taken place at
Kirtlington, for example:

(i) Transportation of faunas between greatly different habitats; e.g. the presence of
freshwater ostracods in several Forest Marble clays which also contain oysters and
other marine shells suggests fluviatile outflows into the sea.

(ii) Mixing at one locality: burrowers can mix dead shells of the epifauna and the
infauna.

(iii) Lateral mixing of adjacent assemblages, e.g. the accumulation of Epithyris and
bivalves among the corals in the coral -Epithyris bed.

There are several ways in which life and death assemblages may be distinguished:

(i) Broken and fragmented material. This is probably transported, though some shell
banks may have been broken up almost in situ.

(ii) Epifauna showing no signs of wear and tear and including some young forms.
These indicate a life assemblage (e.g. the Epithyris collection from the Epithyris bed
2k— text-fig. 3), and are either in place or have only been transported a very short
distance.

(iii) Infauna in position of growth. This indicates a life assemblage; it occurs occasion-
ally (e.g. the isolated vertical Anisocardia ) in some of the White Limestone beds.

(iv) Infauna may show signs of transportation — single or broken valves, or (rarely
at Kirtlington) randomly oriented bivalves with the valves in an open position.

Rock samples from the Epithyris limestone in the White Limestone (2k, 2j, and le)
and at the base of the Forest Marble (3k), and from the coral -Epithyris limestone (3o),
were broken up in the laboratory, and every possible shell extracted. The unbroken shells
were measured, and the proportions of articulated shells noted (Table 11).

A low articulation ratio (i.e. the percentage of articulated valves in each collection)
indicates transportation or disturbance under turbulent conditions. Before the valves
of Epithyris can be separated, the teeth must be broken, whereas teeth in Modiolus are
absent and the valves open after decay of the adductor muscles, and separate when the
ligament either decays or is torn. Few Modiolus are found with their valves opened and
connected, and it would appear that, in the three beds studied, the turbulence was such
that, once the adductor muscles decayed, the valves were ripped apart unless the shell
was already buried with the valves closed. There was certainly rapid burial of many of

68

PALAEONTOLOGY, VOLUME 12

the Epithyris in these beds; the presence of calcite filling most of the interior of some of
the shells points to burial before the pedicle had decomposed enough to let sediment
enter through the pedicle opening.

Size-frequency distributions at Kirtlington

(i) The Epithyris limestone (beds le, 2j, and 2k).

Both the length and breadth distributions of whole (articulated) Epithyris have a
strong negative skew (text-fig. 3), whereas a normal distribution is present in the single
(disarticulated) pedicle valves. The means for the whole shells are significantly greater
than for the single valves (Table 7). A similar pattern is obtained for Modiolus (text-fig.
3 and Table 7) where the maximum height of the shell was measured. Some Anisocardia
were also collected; the majority were articulated and their height distribution has a
strong negative skew.

TABLE 7

Numerical and statistical data for the Epithyris and Modiolus collections from some of the beds

discussed in the text.

Number

Standard

deviation

of

Standard

of the

specimens

Mean

Mode

deviation

mean

Epithyris (length of pedicle

valve)

Bed 3o: whole

37

20-74

20-24

7-2

1-183

single

54

20-72

12-16

8-7

1-181

Bed 3k: whole

20

31-7

32-36

8-9

1-986

SINGLE

13

20-38

—

11-5

3-194

Bed le/2k: whole

127

31-16

32-36

9-3

0-828

SINGLE

52

25-93

16-20

9-1

1-266

Modiolus (maximum height)

Bed le/2k: whole

35

24-46

24-28

4-6

0-777

single

17

211

16-20

5-5

1-34

Significance of differences between

means of sample pairs :

Difference 1 standard deviation

Significance

of difference

(5% significance level: 1-96)

Epithyris

Bed 3o: whole v. single

0-0012

None

Bed le/2k: whole v. single
Bed 3o, whole v. Bed

3-456

Sign. (1%)

le/2k, whole

7-216

Sign. (1%)

Bed 3o, single v. Bed

le/2k, single

3-009

Sign. (2%)

Modiolus

Bed le/2k: whole v. single

2-445

Sign. (5%)

(ii) The Epithyris limestone at the base of the Forest Marble (3k).

Sample numbers for Epithyris and Modiolus were small, but the size-distributions
(Table 7 and text-fig. 4) were similar to those in the White Limestone Epithyris bed (2k).

EXPLANATION OF PLATE 1 1

Photograph of the north-west face of the Kirtlington Old Cement Works quarry, Oxfordshire.

Profile 6 NORTH-WEST FACE

Palaeontology, Vol. 12

PLATE 11

McKERROW, JOHNSON, and JAKOBSON, Great Oolite at Kirtlington

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOGICAL STUDIES 69

The Anisocardia distribution shows a strong positive skew, in contrast to the Epithyris
limestone in the White Limestone.

w

text-fig. 4. Size distributions of Epithyris from the coxA-Epithyris bed (3o).

70

PALAEONTOLOGY, VOLUME 12

(iii) The coral -Epithyris limestone (3o).

Normal distributions are obtained for both whole and single valves of Epithyris
(text-fig. 4). The latter show a tendency towards positive skewness. This bed contains
very few whole specimens of Modiolus , while the single valves show a slight positively
skewed distribution.

TABLE 8

Faunal list for beds 2k, 2j, and le with the total numbers collected for each item (in parentheses) and
the Oxford University Museum registration numbers.

Annelida

INFAUNA

terebelloid worm tubes

(27) J28066-092

Brachiopoda

EPIFAUNA

Epithyris oxonica Arkell

whole shells (measured)

(127) J275 16-642

„ ,, (unmeasured)

(15) J27643-657

single pedicle valves (measured)

(52) J27658-709

single valves (unmeasured)

(58) J277 10-867

Mollusca: Bivalvia

INFAUNA

Nuculacea Nucula sp.

J28041

Cardiacea Pterocardia sp.

Arcticacea Anisocardia istipensis (Lycett)

J 28030

whole shells

(17) J27957-973

left valves

(9) J27974-982

right valves

(8) J27983-990

EPIFAUNA

Mytilacea Modiolus imbricatus J. Sowerby

whole shells

(39) J27868-906

left valves

(15) J2779 1-805

right valves

(15) J27806-820

Pinnacea Trichites sp.

J28033

Pteriacea Bakevettia sp.

(2) J2803 1-032

Pectinacea Entolium sp.

J28052

Limacea Lima sp.

J28034

Ostreacea Ostrea sp.

(2) J28039-040

Exogyra sp.

(4) J28035-038

Gastropoda

INFAUNA

Aphanoptyxis ardleyensis Arkell

(7) J28042-048

Natica sp.

(3) J28049-051

EPIFAUNA

Nil

Arthropoda

INFAUNA

Favreina sp.

(175) J28053

Echinodermata

EPIFAUNA

pseudodiadematid

J28054

spines

(9) J28055-063

Vertebrata

EPIFAUNA

bone fragments

(2) J28064-065

Comparison of fossil and modern size-frequency distributions

Size-frequency distributions will depend on the interaction of populations of a given
species with the environment, both in life (recruitment, growth, and mortality) and in
death (turbulence, hydrodynamic properties of shells, rate of disarticulation, etc.). It is

EXPLANATION OF PLATE 12

Fig. 1. Disturbed White Limestone (bed 3k) showing terebelloid tubes in transverse and longitudinal
sections ( x 2).

Fig. 2. Favreina sp. (bed 3k); faecal remains of a burrowing anoniuran crustacean (x 10-5).

Fig. 3. Ostrea ( Liostreci ) hebridicci (bed 6e) showing internal etching (x3).

Fig. 4. Unusual type of terebelloid tube (bed 2k) showing interior filled with shell fragments (x4).

Palaeontology, Vol. 12

PLATE 12

McKERROW, JOEINSON, and JAKOBSON, Great Oolite at Kirtlington

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOGICAL STUDIES 71

of interest that the modes of Epithyris and Modiolus in the Kirtlington samples (Table 7)
are all lower for the disarticulated shells than for the articulated shells; the smaller
shells are clearly selectively transported.

TABLE 9

Faunal list for bed 3k with the total numbers collected for each item (in parentheses) and the Oxford

University Museum registration numbers.

Coelenterata

EPIFAUNA

simple scleractinian

J28147

Annelida

INFAUNA

terebelloid worm tubes

(25) J28 148-72

Bryozoa

EPIFAUNA

Cyclostomata (4 colonies)

J28176

Brachiopoda

EPIFAUNA

Epithyris oxonica (Arkell)

whole shells (measured)

(20) J27425-44

,, „ (unmeasured)

(6) J27445-50

single pedicle valves (measured)

(13) J27451-63

single valves (unmeasured)

(12) J27464-75

Mollusca: Bivalvia

INFAUNA

Nuculacea Nucula sp.
Arcticacea Anisocardia sp.

J28182

whole shells

(4) J27907-10

left valves

(17) J279 11-27

right valves

(12) J27928-39

A. sp. (small shells)

J27940-4

A. minima

J28184

Pseudotrapezium sp.

J28183

Lucinacea ? Corbis (3) J28173-5

epifauna Arcacea (5) J28 177-81

Mytilacea Modiolus imbricatus J. Sowerby
whole shells (7) J27476-82

left valves (15) J27483-97

right valves (12) J27498-509

fragments (6) J275 1 0—1 5

Pteriacea Bakevellia waltoni (Lycett) (20) J28 185-204

Pectinacea Lima sp.

J28205

? Lima

J28206

Ostreacea Ostrea sp.

J28207

Gastropoda

INFAUNA

Aphanoptyxis sp.

(4) J27423

J28208-10

Natica sp.

(2) J282I 1-12

EPIFAUNA

trochid

J28213

Ataphrus comma (Lycett)

J28214

Arthropoda

INFAUNA

Favreina sp.

(6) J28215-20

Echinodermata

EPIFAUNA

spines

(4) J28221M

Vertebrata

EPIFAUNA

bone fragments

(2) J28225-6

Unidentifiable gastropod and bivalve fragments are abundant.

The following evidence from living species has been taken mainly from temperate
zone communities, as little information other than Craig (1967) is available on the
biology of species in tropical or semi-tropical areas comparable to the environment of
the Great Oolite Series. The life histories and the over-all patterns of survivorship in
sessile benthonic bivalves and brachiopods are similar; they are discussed together
below:

1. Much of the high juvenile mortality of the survivorship curve given by Deevey
(1947) for a sessile benthonic invertebrate occurs in the pelagic larval stage, either

72

PALAEONTOLOGY, VOLUME 12

through predation (Paine 1963, Elliott 1950, Craig and Hallam 1963) or through factors
such as loss in respiratory currents of adult bivalves (Thorson 1950).

2. On the abandonment of pelagic life, mortality is at once much reduced, though
a high rate is maintained in the oyster (Walne 1961).

3. Site selectivity on the benthos is influenced by the presence of adult individuals of
the same species on the substratum (Wilson 1958) or by the nature of the substratum
itself (Rudwick 1961, Craig and Jones 1966). Mortality is low as compared with the
pelagic phase, and may be further reduced by the double settling technique found in
Mytilus and Glottidia (Bayne 1964, Paine 1963), where metamorphosis occurs away from
the final position taken up in the colony.

4. Mortality after metamorphosis and in the young adult can be less than at any other
time in the life history (Savage 1956, Rudwick 1962, Rowell 1960); but examples are
known of high mortality at this stage (Hallam 1967, p. 33).

5. Later, mortality rises sharply as the pressure on the animal's resources increases
with large size (Rowell 1960) and reproductive activity (Paine 1963), except in those
cases where larger individuals cease to breed (Percival 1960).

6. Multimodicity will be introduced in size-frequency distributions by cyclic repro-
ductive activity, particularly when the periods are long, e.g. seasonal reproduction in
temperate zone species (Craig and Hallam 1963, Rudwick 1962, Sheldon 1965). In
semi-tropical species, cyclic activity is present, though this may not have such a marked
effect on size-frequency distributions.

Using the classification of mortality, growth, and recruitment of Craig and Oertel
(1966), it is clear that a generalized bivalve or brachiopod population living in tropical
or semi-tropical environments will exhibit (a) a ‘tropical type’ recruitment, ( b ) an
‘increasing’ mortality, and (c) a ‘high to low’ or ‘very high to zero’ growth-rate. Craig
and Oertel predict a normal size-frequency distribution for the living members of a
population with these characteristics (1966: experiments 20 and 23). The dead members
of the population show a normal distribution in the case of a ‘high to low’ growth-rate,
and a slight negative skew with a ‘very high to zero’ growth-rate.

Other factors will, however, alter the shape of such a distribution in a fossil population.
First, with regard to the living sector some small shells may have been missed in break-
ing up the rock (however, we consider the methods employed here ensured that this
error was reduced to a minimum — all our samples were extracted from the rock in the
laboratory). Secondly, the distribution will be distorted by the presence of transported
members of the populations that have not become disarticulated, and therefore cannot
be distinguished from the living sector. The direction of this distortion is hard to predict,
as it will depend on numerous factors such as the rate of disarticulation in different
size groups. Physical actions, including transportation and selective fragmentation, will
produce a variety of distributions ( Menard and Boucot 1951, Lever 1958, Hallam 1967),
some of which may have no similarity to the living population (van Straaten 1956, 1960).

Interpretation of the Kirtlington size distributions

The different distributions for whole and single Epithyris and Modiolus from the
Epithyris limestone (text-fig. 3) suggest a mixture of living and transported populations
in the cases of both genera.

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOGICAL STUDIES 73

The negative skew of the whole shells is an unusual distribution for living populations,
but an analysis of living Cardium (Craig and Hallam 1963, text-fig. 5 a) shows an
approximation to the distribution of the whole shells from the Epithyris limestone, and
the fact that the shells are articulated helps to confirm that they have suffered relatively
little disturbance before burial. By contrast the normal distribution of the disarticulated
shells is typical of transported populations (Craig 1967) and is, therefore, more a reflec-
tion of the post-mortem disturbance than of the population structure.

Two factors could be responsible for the negative skew of the whole shells:

1. The slowing down of growth in the older individuals, and

2. The accumulation of generations in the large sizes (cf. Craig and Hallam 1963,
text-fig. 3).

But, until we know how long the animals lived after the growth-rates decreased and how
many generations are present in our sample, we cannot tell which of these two effects is
responsible for the negative skew.

Anisocardia from the same bed (le, 2j and k) also have a negative skew in the size
distribution of articulated shells. These appear to represent a living population burrow-
ing on the floor and sides of the channel where the Epithyris and Modiolus were living.

Bed 3k did not yield large samples of Epithyris and Modiolus (Table 7 and text-fig. 4),
but the fragmentation and articulation ratios point to a dominantly transported assem-
blage (Table 1 1 ). The positively skewed Anisocardia distribution suggests a living assem-
blage of these burrowers in this bed.

The coxal-Epithyris limestone (3o) differs markedly from the other Epithyris- rich
beds in that the Epithyris show normal distributions for both whole shells and single
valves. The relatively few whole Epithyris suggest that this was dominantly a transported
assemblage, though a small epifaunal population may have been present. Transportation
of the shells into the area where corals were growing may have been due to the influence
of the corals on currents near the sea floor. The sample of Modiolus shows a slightly
positive skew. This might imply a death assemblage, but the fewer fragmentary shells
suggest that the Modiolus were living nearer the corals than the majority of the
Epithyris.

ECOLOGICAL INTERPRETATION

As a present-day equivalent to the Great Oolite environment at Kirtlington, the
Bahama Banks offer the most useful comparison; not only are they similar in many
physical and biological respects, but they have been well described in many recent
publications (Newell et al. 1959, Purdy 1963, Craig 1967). The principal difference is in
the lack of elastics on the Bahama Banks. Oolites are present in both environments, and
so are corals, of similar form and distribution, associated with comparable epifaunas
and infaunas. Both the corals and the ooliths indicate that Kirtlington had warm shallow
seas with good connections to the open ocean, like the Bahamas. If the palaeolatitude
proposed by Hargraves and Fischer (1959) is correct, then this would indicate that
Oxford was about 30° north in the Middle Jurassic (Dr. J. C. Briden, personal com-
munication); this compares with 25° north for the Bahamas and 25-30° north for the
Persian Gulf. The Persian Gulf is another region of oolite formation, but this is in areas
where high evaporation creates excessively hypersaline conditions (Evans et al. 1963);
none the less some useful comparisons can be made with the Great Oolite (Kinsman
1963, Sugden 1963).

74

PALAEONTOLOGY, VOLUME 12

On the south margin of the Persian Gulf, Kinsman (1963) has described several
profiles across tidal areas of the Trucial Coast. Coral and oolite sands, of a similar
nature to those found at Kirtlington, are cut by channels up to a quarter of a mile wide;
the surface of the sand flats range from sea level to a depth of 20 ft. and bases of channels
can reach 40 ft. below sea level. The channels support prolific growth of the branching
coral Acropora, while on the shallower sands there occurs a more patchy growth of
corals, with intervening stretches of open sand. Growth within the coral colonies found
on the sands is more limited than that of the channel assemblages; many of the coral
heads are dead in the former environment.

The White Limestone

Klein (1963, 1965) deduced that the White Limestone environment was one consisting
of meandering channels separated by inter-tidal mud-flats. Little sedimentation would
occur between the channels, and the mud-flats are largely composed of old channel-fills.
The faunas of the mud-flats were mainly burrowers, with the result that little bedding
is left in these deposits, and their original deposition as channel-fill can only be surmised
from the occasional epifaunal shell complete enough to be identified. This environment
may correspond to that of Scarborough Beds (Farrow 1966), which also have an abun-
dant infauna, but we find no evidence of a depth-controlled distribution of annelid and
crustacean burrows.

The Epithyris beds (e.g. 2k, 3k) contain a rich epifauna (Tables 8 and 9) of Epithyris,
Modiolus , and other bivalves, with subsidiary echinoids; the infauna consists mainly of
Anisocardia, terebelloid worms, anomuran crustaceans (as indicated by the presence of
Favreina), and Aphanoptyxis, any of which may be abundant in some beds. This com-
munity lived on a stable substrate on the floor and sides of channels. Ager (1965) sug-
gests that terebratuloid morphology may be closely correlated to environment; he places
forms (such as Epithyris) having broad folds, an elongated beak, and a large foramen in
a shallow-water peri-reefal habitat, where the sediments include bioclastic calcarenites.
There is thus some approximate correspondence between the channel-living Epithyris
at Kirtlington and the habitat of other terebratuloids with a similar morphology.

Jones (1950) states that, in the Irish Sea at the present day, the Modiolus Community
occurs in deeper water than the littoral Myti/us Community; if the Jurassic Modiolus
lived in a similar environment, the channel floors of the White Limestone were covered
at low tide (text-fig. 5, p. 79).

Tables 8, 9, and 10 show the faunas collected from three Epithyris limestones, together
with their Oxford University Museum registration numbers. The distribution of epi-
faunal and infaunal species is given on the basis of Petersen’s (1913) classification, and
on Stanley’s (1968) description of Mesozoic bivalve adaptive radiations. The propor-
tions of each systematic group in the epifauna and infauna and the ratio between total
epifauna and infauna are given in Table 11; this also shows articulation ratios for
Epithyris, Modiolus, and Anisocardia. The articulation ratio is defined as the ratio of
articulated shells to our estimate of the total population; we obtained this last figure by
adding the number of articulated shells to half the total of single disarticulated valves.

The Epithyris beds in the White Limestone are channel deposits whose faunas are
significantly different from the bulk of the White Limestone in the predominance of
epifauna. Some of these channel deposits have a sharp base, e.g. beds 4b(l), 5c(l), and

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOGICAL STUDIES 75

6c(l), and appear to be lag deposits from which the fine material has been removed by
currents. Other Epithyris beds (e.g. le, 2i(2)) merge downwards into a bioturbated
deposit with an abundant infauna. It would appear that the base of the channel is some-
times blurred by the infauna living in the channel and burrowing into previously bio-
turbated material forming the sides and floor. A few beds (e.g. 2k) contain abundant
epifauna and infauna together; some infauna therefore lived in the channels as well as

TABLE 10

Faunal list for bed 3o with the total numbers collected for each item (in parentheses) and the Oxford

University Museum registration numbers.

Coeienterata

EPIFAUNA

Cyathophora pratti (Edwards)

(4) J28093-6

Thamnasteria lyelli (Edwards and Haime)

(6) J28097-102

lsastrea limitata (Michelin)

coral intermediate between lsastrea and

(5) J28I03-7

Thamnasteria

J28108

simple coral

J28143

Brachiopoda

EPIFAUNA

Epithyris oxonica , Arkell

whole shells (measured)

(37) J27000-36

„ ,, (unmeasured)

(11) J27037-47

single pedicle valves (measured)

(53) J27048-100

single valves (unmeasured)

(246) J27 101-346

Mollusca: Bivalvia

INFAUNA

Lucinacea Sphaeriola sp.

J28109

EPIFAUNA

Arcacea arcids

(8) J28110-17

cucullaeids

(3) J28118-20

Mytilacea Modiolus imbricatus J. Sowerby

whole shells

(4) J274 19-22

left valves

(18) J27347-64

right valves

(15) J27365-79

fragments

Lithophaga fabella (J. A. Eudes-

(38) J27380M17

Deslongchamps)

J 28 142

Pteriacea Costigervillia sp.

(2) J28121-2

Pteroperna sp.

J28126

Bakevellia waltoni (Lycett)

(3) J28123-5

Pectinacea pectinids

(12) J28 126-37

Limacea Lima cardiiformis J. Sowerby

(3) J28 138-40

Ostreacea Ostrea sp.

J2814I

Gastropoda

INFAUNA

? Natica

J28146

EPIFAUNA

Nil

Arthropoda

INFAUNA

Favreina sp.

J28227

Echinodermata

EPIFAUNA

spines

(2) J 28 144-5

in the tidal flats, though there is no direct evidence that they lived in exactly the same
areas as the epifauna. The absence of infauna in some of the White Limestone beds which
still have bedding preserved (e.g. 21, 2j, and 2e) may be compared with Newell’s (1959)
observation that, in regions of rapidly shifting oolitic substrate, the infaunal Tivela
Community is very sparse.

The Epithyris limestone in Profiles 1 and 2 (le, 2j, and 2k) extends for at least 40 m.
The collections of Epithyris , Modiolus , and Anisoeardia from this bed all have high
articulation ratios (Table 11). The field evidence suggests that this is a channel deposit,
where sedimentation, when it does occur, may be rapid. This model (text-fig. 5) fits with
the palaeontological evidence: high articulation ratios in three varied animals ( Aniso -
cardia is a burrower; Epithyris and Modiolus are epifaunal) suggest rapid burial; negative

76

PALAEONTOLOGY, VOLUME 12

skewed distributions (text-fig. 3) suggest little transportation; and the presence of many
hollow Epithyris suggests burial before the tissues had decayed.

Table 1 1 also shows that 89% of the collection from this limestone is epifaunal, and
that Epithyris and Modiolus are the dominant constituents, while the infauna consists

TABLE 11

Proportion of epifaunal and infaunal members of the faunas collected from beds 3o, 3k, and 2k, also
showing the articulation ratios for Epithyris and Modiolus for each collection.

No. of

% of epifauna

% of total

Articulation

specimens

or infauna

fauna

ratio

Bed 3o

EPIFAUNA

Epithyris

198

72-4

72-2 \

0-24

arcids

8

2-9

2-9

cucullaeids

3

11

M

Modiolus

41

14-9

14-9

010

Lithophaga

1

0-4

0-4

Costigervillia

2

0-7

0-7

>99-2

Pteroperna

1

0-4

0-4

Bakevellia

3

11

11

pectinids

12

4-4

4-4

Lima

3

1-1

11

Ostrea

1

0-4

0-4)

Total

273

INFAUNA

Natica

1

50

0-4

0-8

Sphaeriola

1

50

0-4

Total

2

Bed 3k

EPIFAUNA

Epithyris

39

41-5

30-75

0-69

arcaceans

5

5-3

3-9

Modiolus

25

26-6

19-7

0-29

Bakevellia

20

2L3

15-8

'74-0

Lima

2

2-1

1-6

Ostrea

1

10

0-8

Ataphrus

1

L0

0-8

trochid

1

10

0-89

Total

94

INFAUNA

Nucula

1

30

0-85

Anisocardia

22

66-7

17-3

0-22

(excluding very
small shells)

■26-0

? Corbis

3

9-1

2-4

Pseudotrapezium

1

30

0-8

Aphanoptyxis

4

12-1

3-2

Natica

2

61

1-6)

Total 33

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOGICAL STUDIES 77

table 11 continued

No. of

% of epifauna

% of total

Articulation

specimens

or infauna

fauna

ratio

Bed lej2k

EPIFAUNA

Epithyris

247

79-3

70-6N

0-57

Modiolus

54

17-3

15-4

0-72

Trichites

1

0-3

0-3

Bakevellia

2

0-6

0-6

89-1

Entolium

1

0-3

0-3

Lima

1

0-3

0-3

Ostrea

2

0-6

06

Exogyra

4

1-3

\-2)

Total

312

INFAUNA

Nucula

1

2-6

0-3^

Pterocardia

1

2-6

03

Anisocardia

26

68-4

7-4

10-9

0-67

Aphanoptyxis

7

18-4

20

Natica

3

7-9

0-9 J

Total 38

largely of Anisocardia and burrowing gastropods (Table 11). Terebelloid worms and
anomuran crustaceans, represented by Favreina faecal material (see Table 8), are also
present, though (as one animal produces thousands of faecal fragments) it is not prac-
ticable to count them.

The Forest Marble

(i) Oyster -Epithyris and Coral -Epithyris beds

The oyster -Epithyris marl (6e, 2n) passes laterally into the Epithyris limestone (3k,
4d), from which the fauna has been analysed (Tables 9, 11). Epithyris has high articula-
tion ratios in this bed, but Modiolus and Anisocardia have low ratios. Bed 3k differs
from bed 2k in that it does not clearly represent a channel (it passes laterally into a
marl, and it can be correlated throughout the quarry); consequently, it could have had
substantially slower rates of sedimentation. If the shells were exposed on the sea-floor
for some period after death, one might expect the Modiolus to disarticulate more rapidly
than Epithyris. The presence of drifted Anisocardia shows that sediments in which
these burrowers lived were being eroded close by, and the low articulation ratios are in
accord with the transportation of the shells after this erosion. At one point, many
dozens of small Anisocardia (less than 3 mm.) occurred in a cluster; it was not possible
to separate them from the matrix and no accurate count could be made. This clustering
may be due to current action, but we have no understanding of the mode of life of very
young Anisocardia.

Bed 3k shows considerable disturbance of the sediments; this may be linked with the
fact that the proportion of infauna in this bed is over twice that in bed 2k. The pro-
portions of individual genera in beds 2k and 3k are different (e.g. Epithyris is 30% in 3k
and 70% in 2k, Table 11), but the species composition of both beds is very similar,

78

PALAEONTOLOGY, VOLUME 12

except for the presence of arcaceans in bed 3k. Yonge (1961) suggests that arcaceans
prefer clean shallow- water substrates, with coarse shell gravel; their presence in bed
3k may thus be linked with a more stable substrate than that present in the channel
floor of bed 2k.

The Kirtlington coral -Epithyris bed may have formed in an environment similar to
the Persian Gulf channels. The coral -Epithyris bed is absent in Gibraltar Quarry
(477185), 1 1 miles south-west of the Kirtlington quarry, and in Lower Greenhill Quarry
(485178), li miles south of Kirtlington. It (or a similar bed at a similar horizon) is
present, however, at Shipton Cement Works (479175) half a mile further to the south-
west. It is thus clear that this coral-Epithyris bed has an irregular lateral occurrence,
which lends some support to the theory of a channel-controlled distribution.

Newell et al. (1959) have described coral environments in the Bahama Banks. The
branching forms at Kirtlington suggest that they did not grow in excessively turbulent
water, but at a depth of around 6 m. corresponding to the Plexaurid Community of
Newell et al. Vaughan (1916) has stated that for shoal-water corals of Florida and the
Bahamas there is a relation between the phenotypic nature of the coral mass and its
environment, especially in relation to turbulence. He found that branching corals
occurred in calmer water, and massive forms in more agitated conditions. The corals
present at Kirtlington have been assigned to the genera Isastrea , Thamnasteria, Cyatho-
phora , and Sty/ina; all of these genera can occur as massive hemispherical colonies,
but only Isastrea and Thamnasteria develop long (up to 60 cm.) cylindrical branches
(about 2 cm. in diameter, made up of 5-mm. polygonal corrallites). The coral -Epithyris
bed contains both massive and branching forms of these two genera; the branching
forms predominate. Hence we conclude that the immediate environment of the corals
was neither completely calm nor excessively turbulent. The abundance of ramose corals
suggests that they grew in a quiet environment.

In the Bahamas, Newell’s Plexaurid Community has a rock-pavement substrate, and
is thus associated with a very reduced infauna; the coral-Epithyris bed also has a poor
infauna; this may be an indication that the substrate was too hard for burrowers. Some
Anisocardia and Favreina are present, but the dominant Kirtlington coral -Epithyris
bed infauna consists of boring forms like Lithopliaga.

The fauna of the coral-Epithyris bed (3o) is dominantly composed of epifaunal species
(99-2%), and is very different from 2k and 3k in faunal composition (Tables 6, 10, and
1 1). The bulk of the shelly epifauna appears to have been transported into an area
where corals were growing. This transportation is indicated by: low articulation ratios
in Epithyris and Modiolus', normal distributions in both whole and single valves of
Epithyris (text-fig. 4); and many small shell fragments. The corals are associated with
a rich and diverse living fauna of bivalves such as the free-living, byssally attached, or
cemented pectinids, and Lima , which are much less abundant in beds 3k and 2k.

The indigenous reef epifauna is not easily separated from those shells brought in by
currents. Mujaji and Habe (1947) show that in some modern Japanese marine thanato-
coenoses there is an abundance of species. The richness of species in bed 3o is another
instance of a variety of animals living in slightly differing habitats being brought
together by subsequent transportation. Bed 3o is like the remainder of the Forest
Marble above bed 3k in the absence of Anisocardia', the substrate appears to have been
unsuitable for burrowers apart from Favreina and the occasional gastropod.

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOGICAL STUDIES 79
(ii) The remaining Forest Marble beds

The Forest Marble limestones, other than beds 3k and 3o and their equivalents,
have an abundant epifauna of oysters and pectinids (Tables 2, 3, 4, and 5). The
infauna is very reduced and few of these limestones show signs of bioturbation. We

(a)

low tide

(c)

Ya CORALS <) EP/THYR/S CS MODIOLUS

0 ANISOCARDIA i_i OYSTERS Q PECTENS

text-fig. 5. Interpretations of the environments represented by (a) the Epithyris limestone (bed 2k) :
Epithyris and Modiolus confined to channels with floors below low-tide level. Anisocardia also present.

(b) The oyster -Epithyris limestone and clay (beds 2n, 3k, 4d, and 6e) : oysters and Epithyris present
on muddy substrates; Epithyris, Modiolus and Anisocardia on limy substrates. All below low-tide level.

(c) The coral -Epithyris limestone (bed 3o): Epithyris and Modiolus transported into an area of more

stable substrate where corals are growing and support a reef epifauna including pectens.

are uncertain as to the precise form of shallow marine environment in which these beds
accumulated, but, as there is no evidence of inter-tidal conditions, we would assume
that there was slightly deeper water than during White Limestone times. In the case
of the oyster-Epithyris bed (2n, 4d, and 6e), both genera occur together and most shells
are complete; there is little doubt that they lived in the same area, though not neces-
sarily closely intermingled. This area must have been marine, and we consider that

80

PALAEONTOLOGY, VOLUME 12

all the limestone beds (most of which contain pectinids and other bivalves in addition
to oysters) were marine too.

The Forest Marble clays contain abundant lignite, and many of them also contain
oysters and other bivalves. Some of them, like the fimbriatus-waltoni Clay (2o, 31, 4e,
and 6f), may have been formed in very shallow water in which the large herbivorous
dinosaur Cetiosaurus oxoniensis Phillips could wade. The lignite could have come from
vegetation growing nearby which provided a food supply for the dinosaurs. But other
clays, some of which have a similar fauna to the Forest Marble limestones, may have
been laid down in deeper water. The freshwater ostracods in four of these clays may
have been derived from rivers flowing into the sea in this general area.

CONCLUSIONS

There are five broad lithological/faunal associations in the White Limestone and
Forest Marble at Kirtlington.

1. The bioturbated limestones of the White Limestone, which show a wide range of
sediment size from 5-cm. shells to microcrystalline calite; occasionally these may
retain traces of bedding (e.g. bed 21), but more usually the infauna has destroyed all
trace of the depositional structures. We agree with Klein (1965) that these were tidal
flats at the time of bioturbation, although the original sediments were probably deposited
in migrating channels. This is suggested by the remains of epifauna which can be
recognised in some less disturbed beds.

2. The Epithyris limestones, with or without Modiolus (e.g. beds le, 2k, 2i(2), and
6c), are often seen to have been deposited in channels (this is especially clear in Gibraltar
Quarry). It is thought that all these epifaunal assemblages in the White Limestone lived
in channels, which were cut in tidal flats, but were still holding water at low tide (text-
fig. 5). Bed 3k, at the base of the Forest Marble, is completely sub-tidal, and is not part
of any visible channel. It was laid down in a period of slow sedimentation, with inter-
mittent erosion of the sea floor, exposing the infauna to the influence of transporting
currents. The limestones pass laterally into oyster-Epithyris marls (beds 2n, 6e) where
some of the oysters are internally etched, which might be due to exposure at low tide;
the marl area may thus represent slightly shallower water than the limestone.

3. The Forest Marble limestones (excluding beds 3k and 3o and their equivalents)
consist dominantly of oyster shells and other epifauna; they can easily be distinguished
from the White Limestone by the scarcity of infauna and the lack of bioturbation.
Although channels are present in the Forest Marble of other Oxfordshire quarries, none
are clearly seen at Kirtlington, and there is no direct evidence of an inter-tidal environ-
ment. We think this epifauna lived in a shallow sub-tidal environment.

4. The coval-Epithyris bed (3o, 4i, and 6j) represents deposition on a stable substrate
on which corals up to a metre high could grow (text-fig. 5). The sedimentation rate for
this bed was very low, the currents were sufficient to transport brachiopods and bivalves,
but not powerful enough to damage slender cylindrical coral; the substrate was
unsuitable for burrowing bivalves. It is not possible to estimate any depth differences
between beds 3o and 3k, nor do we see exposures of the area where the Epithyris and
Modiolus were living before being drifted into the coral patches of bed 3o, but these
epifaunal shells contemporaneous with bed 3o might have lived in peri-reefal environ-
ments similar to bed 3k. Comparisons with the Persian Gulf and the Bahamas suggest

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOGICAL STUDIES 81

that this bed may have been deposited in a shallow but sheltered region. No indications
of channelling associated with bed 3o are visible in the field.

5. The Forest Marble clays are rich in lignite, and one (the fimbriatus-waltoni Clay,
beds 2o, 31, 4e, and 6f) has herbivorous dinosaur remains and freshwater and marine
ostracods. We conclude that fringing swamps existed in or close to an area with rich
vegetation. The fimbriatus-waltoni Clay contains caliche-like nodules, and the oyster-
Epithyris marl has some oysters with internally grooved shells; these are indicators that
the two basal clays of the Forest Marble may differ from the remainder in being inter-
tidal.

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sugden, w. 1963. The hydrology of the Persian Gulf and its significance in respect to evaporite deposi-
tion. Am. J. Sci. 261, 741-5.

and mckerrow, w. s. 1962. The composition of marls and limestones in the Great Oolite Series

of Oxfordshire. Geol. Mag. 99, 363-8.

thorson, g. 1950. Reproductive and larval ecology of marine bottom invertebrates. Biol. Rev., 25,
1-45.

vaughan, t. w. 1916. The results of investigation of the ecology of the Floridian and Bahaman shoal-
water corals. Proc. natn. Acad. Sci. U.S.A. 2, 95-100.
walne, p. r. 1961 . Observations on the mortality of Ostrea edulis. J. Mar. biol. Assoc. U.K. 41, 113-22.
weimer, r. j. and hoyt, j. h. 1964. Burrows of Callianassa major Say, geologic indicators of littoral and
shallow neritic environments. J. Paleont. 38, 761-7.
wilson, d. p. 1958. Some problems in larval ecology related to the localised distribution of bottom
animals. In a. a. buzzati-traverse (ed.), Perspectives in marine biology. University of California
Press, pp. 87-103.

worssam, b. c. and bisson, g. 1961. The geology of the country between Sherborne, Gloucestershire
and Burford, Oxfordshire. Bull. geol. Surv. G.B. 17, 75-1 15.

McKERROW, JOHNSON, AND JAKOBSON: PALAEOECOLOGICAL STUDIES 83

yonge, c. m. 1946. On the habits of Turritella communis Risso. J. Mar. biol. Assoc. U.K. 26, 377-80.
1961. Life and environment on the bed of the sea. Adv. Sci. 18, 383-90.

W. S. MCKERROW

Department of Geology and Mineralogy
Parks Road
Oxford

R. T. JOHNSON

Eleanor Roosevelt Institute for Cancer Research
University of Colorado Medical Center
Denver, Colorado
M. E. JAKOBSON

Department of Biology
Royal Free Hospital School of Medicine
8 Hunter Street
Brunswick Square
London, W.C. 1 .

Typescript received 22 June 1968

A METHOD OF STRATIGRAPHIC CORRELATION
USING EARLY CRETACEOUS MIOSPORES

by N. F. HUGHES Clfld J. C. MOODY-STUART

Abstract. Spores of the Cicatricosisporites group are used in correlation between the outcrop Hastings Beds
and the Lower Wealden of the Warlingham Borehole, Surrey. Published species are not used, and the fossils
selected are described instead in terms of biorecords and events , both of which terms are defined. There is a brief
discussion of the relationship of these biorecords to published taxa. The method of use of the fossils is chosen
to favour (a) correlation on a fine scale, (b) easy inclusion of extensions of the observations to refine the correla-
tions, and (c) storage and retrieval of essential data as free as possible from points of interpretation, which should
be separately labelled and stored. The material is presented in slightly extended form so that the method itself
may be criticized and improved. Some of the specific difficulties of handling Cicatricosisporites spores are
illustrated and discussed.

By far the most numerous fossils in the Lower Wealden rocks of southern England are
dispersed miospores, and we believe that there has been a failure hitherto to use them,
or other spores of similar age, successfully in any fine stratigraphic correlations (see
Hughes 1958, and several other authors). Spores have served to define fairly large time
divisions on the scale of an ‘Age (Stage)’, but this does not represent an improvement
on stratigraphy using any other type of (less common) fossil. It had become apparent to
us that much additional work was not yielding results in terms of stratigraphic refine-
ment, and we now believe that this was due to a failure of method rather than to any
lack of evolutionary manifestation in these plant-organ fossils. We have suggested a new
approach (Hughes and Moody-Stuart 19676) and we attempt here to develop it further.
As we have found it necessary to reject certain current practices as unprofitable, we wish
to avoid misunderstanding by stating briefly the reasons for this action, in a list of points
numbered for reference in discussion:

1. In accepting the stratigraphic approach implicit on the report of the Geological
Society of London’s Stratigraphical Code Subcommittee (George et al. 1967), and
developments from it (Hughes, Williams, Cutbill, and Harland 1967, 1968), we see
reference-points as the first essential for both precision and unambiguous communication.

2. An event (stratigraphic) is an item of geologic information relatable (or potentially
so) to the general evolutionary state of the earth, and based in a rock sample or in a
general attribute (to include metamorphism, etc.) of some named rocks.

3. The identification of events is artificial and arbitrary, being dependent mainly on
the accidents of collection. In stratigraphy of sedimentary sequences, an event is any
character raised from a rock sample that is as closely located as possible. The borehole
samples used in this paper are mainly located to 1 ft. in depth, which seems more than
adequate at present but may not be so in twenty years time. The average stratigraphic
spacing of events concerned with fossil information should be at most one-quarter (de
Jekhowsky 1958) and probably one-tenth of the general size of scale division that is
sought.

4. Stratigraphic correlation of a newly described ‘ event ’ (in a ‘ new ’ section), with a
standard (already described) reference scale of ‘events’, consists of a pair of decisions.

[Palaeontology, Vol. 12, Part 1, 1969, pp. 84-111, pi. 13-22.]

HUGHES AND MOODY-STUART: STRATIGRAPHIC CORRELATION 85

Each of the two similar decisions is: whether the newly described event represents a
time before or after a selected reference scale event. The ‘bracket’ so obtained may
be fine or coarse but is always theoretically capable of refinement, given new observa-
tions or interpretations. The correlation of whole rock sequences, however elaborately
expressed, consists essentially of these primary paired decisions.

5. Events cannot be equated in time, but only ordered. The purely mental process of
grouping events into some kinds of biostratigraphic zones, usually to achieve equation
between sequences, is equivalent to the employment of a blunt instrument in correlation
that cannot be operated successfully within the limits of the size range of its bluntness.

6. Stratigraphic zones are unacceptable to us as tools because (a) they cannot as
abstractions be closely enough defined, and ( b ) they are based on the idea of equation
in stratigraphy which is either too crude or is even wrong in concept. Excluded from this
criticism is the chron (George et al. 1967) which is simply a rock-defined minor time
division in a standard reference section.

THE PALAEONTOLOGIC PROBLEM

7. In predominantly non-marine strata such as the English Wealden, the frequently
occurring fossiliferous palynologic samples may well contain assemblages with species
from 25 distinct miospore ‘genera’. These species have been erected and expanded by
many authors on purely morphographic principles, usually with a reconnaissance
description in mind; as a result they tend to have relatively long ranges. They have
proved difficult to ‘split’ further on purely morphographic grounds, and because of
general palaeontologic tradition against the practice there has been a reluctance to
add any explicit stratigraphic limits to the diagnoses of the ‘splits’.

8. In studying other comparable palynologic problems for possible solutions, it is
difficult to assess the unpublished achievements in oil exploration. The successful
German technique used in the study of Tertiary Brown Coal is more akin to Pleistocene
work in its limited geographic and stratigraphic scale. Most of the many papers on the
West European Carboniferous do not appear to aim at or to achieve fine stratigraphy;
particularly interesting in this respect is the major work of Smith and Butterworth
(1967) which, however, is unusual in being restricted to the one facies group of the coals,
and also unusual in providing so much well-presented basic data, clear of its interpreta-
tion. Although much palynology is still in the reconnaissance phase of development, we
have not found any solution from study of work that is already further advanced.

9. There is clearly a temptation to abandon any accepted species concept (cf. Shaw
1964, p. 220) as being too ‘blunt’ (see para. 5 above), and to attempt some total descrip-
tion of the sample assemblage that could be compared with others by machine methods.
Although such description would be difficult to accomplish even on a ‘module’ basis
without detailed preliminary interpretation, the main factors that appear to rule it out
for the present are palynologic facies (see Hughes and Moody-Stuart 1 961a) and variable
preservation of miospores. The mere numbers of fossils available will eventually make
machine handling of data essential, but understanding, particularly of the chemical
aspects of preservation, is in our opinion insufficiently advanced to make this at all
profitable.

1 0. Behind such considerations is the usual economic problem in biologic descriptions.
Whatever observations are made in erecting a scheme, and whatever further work is

86

PALAEONTOLOGY, VOLUME 12

necessary to make use of it, must not involve more skilled or semi-skilled man-hours
than the information is judged to be worth now or in the immediate future.

PROPOSED METHOD

11. Since variation in land-life forms, at least since the Devonian period, is assumed
to have been discontinuous on the same basis as for observed recognition of extant
species, it seems wiser to use this assumption rather than to ignore it (as implied in
para. 9 above).

12. As a preliminary, then, to consideration of events for correlation, we intend to
make in each appropriate miospore group (taken to mean approximately the current
miospore genus) a set of fully documented 'biorecords', primarily for local use in our
standard stratigraphic succession (regional standard in the sense of George el al. 1967),
which will be the Warlingham Borehole. These will approximate to species as currently
used but will be outside the Rules of Nomenclature; they will instead be subject to special
rules that we devised for species (Hughes and Moody-Stuart 1967 b, pp. 348-9) but here
applied to biorecords, in that they can only ever be modified (emended) by use of topo-
type material.

13. A biorecord is defined as a conceptual taxon, based on specimens from one
sample or locality that are judged to have a normal distribution of continuous variation.
A palynologic biorecord has a basis in not less than lOOtopotype specimens. Should a
biorecord prove unsatisfactory in use, it can be replaced without formality by another
from the same or another sample; it can also overlap the variation of another to any
degree. There is no question of priority, only one of use or discard; each biorecord bears
a unique author's serial number.

14. We present here biorecords for all the kinds of Cicatricosisporites that we have
seen in the Lower part of the Wealden of the Warlingham No. 1 Borehole (Surrey,
England) from 2,040 to 1,740 ft. depth. Work on the Upper part of the Wealden, and
studies on other genera such as Aequitriradites, Trilobosporites , etc., are not yet complete.

15. The events used in this paper are thus composed solely of information on
Cicatricosisporites miospores. The occurrence of these spores in each event sample is
expressed as percentages of types that are judged by eye and by measurement as dis-
tinct, and are recorded (using measurements) by graded comparisons (see Hughes and
Moody-Stuart 19676, p. 353) with the appropriate biorecord.

16. Events, with some additional biorecord material, based on samples from the
coastal outcrop of the Fairlight Clay near Hastings are correlated with those of the
borehole regional standard. Correlation with a main marine standard succession is not
attempted in this paper.

17. An attempt has been made to ensure that all data generated here can be assessed
and stored without further attention from a palynologist. Both these arrangements and
the general method are described more fully than would normally be necessary in the
hope that the principles may be discussed.

18. Although it is only partly relevant to our stratigraphic purpose, we believe that
for dispersed spores our biorecord (based on topotype material only) gives a much better
opportunity than does any orthodox fossil species of an approach to the spores actually
produced by a once-living plant population. From our studies so far we are strongly of

HUGHES AND MOOD Y-STUART: STRATIGRAPHIC CORRELATION 87

the opinion that land plant evolution will, with the help of palynology, soon be
demonstrable in quite fine detail; the old view that land plants evolved slowly was
largely due to the obscuring effect of unthinking adherence by palaeontologists to a
Linnean system of nomenclature that had been devised and developed for living organisms
with verifiable genetic limits.

ESTABLISHMENT OF A BIORECORD

The biorecord is not in essence different from a palaeontologic species at the stage
of description by its originator, but differs in the use that can subsequently be made of
it. The process of selection of suitable material presents the same difficulties as with
species, but almost no literature search is obligatory, and no awkward description
priorities need be considered. In the current case, the sequence of work appears to be:

1 . Reconnaissance of as many samples of the standard sequence as possible to select
suitable samples for biorecords satisfying the following requirements: (a) adequate
preservation; (b) adequate ease of obtaining 100 specimens; (c) facies that is unlikely
to have modified significantly the part of the assemblage concerned, i.e. to have removed
part of the size variation; (<f) as early as possible in the stratigraphic ‘range’ of the
form concerned; ( e ) useful biorecord, i.e. spore type seen elsewhere. The difficulty is to
achieve these aims safely without too great an expenditure of time.

2. Using the selected sample, record the slide position of each specimen of Cicatrico-
sisporites and record its major character as follows:

(a) Well-preserved specimens of selected type, i.e. unambiguous specimens of bio-
record.

(b) Extreme specimens of biorecord, well preserved.

(c) Possible extreme specimens, poorly preserved.

(d) Unambiguous specimens of other types.

( e ) Well-preserved specimens that could be extremes of two or more types present.

(/) Rare specimens that could belong to the biorecord or to any other type present.

These may be aberrants, e.g. monolete, aborted, etc., or even specimens of other-
wise unrepresented ‘species’.

3. Make detailed measurements and analysis of first unselected 100 specimens from
categories 2 (a), ( b ), and (c), and test for homogeneity in the chief characters.

BIORECORDS CRET 26 23 GB SPOR

The following biorecords are set out with sample data and diagnosis in normal type
and intended for data storage; description, preservation, and distinction, etc., which are
in small type (not for storage), are items that are usually given for species and are possibly
helpful to other workers, but in theory if the stored data has been perfectly prepared
they should not be necessary. The title heading and reference line for a biorecord (e.g.

1 CICATR AT) consists of (a) a serial number which outside this paper would be
preceded by an identifier such as author initials, ( b ) an informal (but stored) classifica-
tion guide, and (c) an author’s working reference printed in italics to indicate that it is
a ‘non-search’ item. Holotypes are not mentioned in the text because they are not
necessary, but in case they are required later they are marked as designated specimens
in the relevant plate explanations.

88

PALAEONTOLOGY, VOLUME 12

1 AT

-=H

7 Cl

i—=

8 C2

1 —

9AP

text-fig. 1 . Diagram of the character ‘four adjacent muri and lumina’ for each of the biorecord spores,
X 2,000. The line in each case represents the mean diameter of the spore to the same scale.

HUGHES AND MOOD Y-STU ART: STRATIGRAPHIC CORRELATION

89

The heading of this section is in the form of a suggestion for data handling and storage ;
the figures ‘26 23’ stand for the time division ‘Tithonian’ to Hauterivian Ages/Stages,
both inclusive. The Ages/Stages are those used in the ‘Fossil Record’ (Harland et al.
1967), numbered consecutively back from Recent; and they may, we suggest, be used
for storage of data and for reference without hierarchical complications (see Hughes
et al. 1968).

The graded comparisons (cfA., cfB.) used throughout follow our previous scheme
(Hughes and Moody-Stuart 19676, p. 353).

1 CICATR AT

Plate 13, figs. 1-12; text-fig. 1

Record sample. Warlingham Borehole (* see p. 97 below), depth 1,998 ft. (see also
Event 3 CICATR); greenish-grey banded silty clay, general size of coarse fraction 45 p.
Preparation V067: 60 min. cold cone. HNQ3, shaken, mineral separation, short
centrifuging. Palynologic facies: spores compressed, little damage, little corrosion;
8% other pollen, 2% Classopol/is, 1% bisaccates, 29% other ‘ferns’ (inch 2% Tri/obo-
sporites), 59% Cicatricosisporites (compr. 13% AT, 41% biorecord 2 CICATR AF,
5% indet.); total fern spore size index 12:77:11; many spore-sized plant fragments.

Diagnosis (100 specimens; V067/l,3; 29 02 68). Miospore, trilete, gross maximum
diameter mean 44-5 / ± standard deviation 5-3 p (100); proximal face thin, plano-convex;
distal face convex. Laesura three-quarters radius, lips simple membraneous, height
4-5 p. Exine 1(2 p) 2-5 including murus (81), radial equatorial exine 1 -5(2-5 /x)4 (85).
Sculpture positive/negative (PI. 13, figs. 1,2): three interradial sets of sub-parallel muri,
height 0-5(M p) 1-5 (97), width 1 -0(1 -8 p)2-5 (100); four adjacent muri and lumina in
a width of 7(11-9 /la) 1 7, standard deviation 1-54 p, coefficient of variation 12-9%; distal
configuration, polar triangle with concave sides (PI. 13, fig. 5), radial lumen.

Description. Smooth concave contact area, maximum diameter 10(21 p)A0 (53 specimens). Ratio of
mean radial equatorial to normal exine thickness 1-2. Amb subtriangular, sides may be concave (PI. 13,
fig. 5) despite convex distal surface. Muri slightly sinuous at junctions that occur mainly in radial
equatorial areas. Thickness of interradial exine (excl. murus) 0-8( 1 -2 /a) 1 -5 (41); because of this thin
exine, folding and rupturing of exine are controlled by alignment of muri. In equatorial view, mural
sets curve distally between radial equatorial areas, due to distal configuration. Observed limits of gross
maximum diameter 32-60 p, coefficient of variation 12%. Specimens in polar aspect 47%, equatorial
29%.

Preservation and compression. Thin proximal face may rupture; splitting may occur along radial
lumen and adjacent laesura. Thin exine may fold between muri, thus reducing width of 4 muri and
lumina, and making equatorial amb concave. In some specimens regular ‘drillings’ widen murus
(PI. 13, fig. 9).

Distinction local. Biorecord 2 CICATR AF (from same sample) has negative sculpture and no radial
lumen. 3 CICATR AR has positive sculpture and wide lumina. 4 CICATR AW has wider muri.
Ruffordia goepperti (spores) Hughes and Moody-Stuart 1966 are larger, and have wider lumina.

2 CICATR AF
Plate 14, figs. 1-12; text-fig. 1

Record sample. Warlingham Borehole, depth 1,998 ft.; details as in biorecord 1 above.
Diagnosis (100 specimens; V067/1; 29 02 68). Miospore, trilete, gross maximum
diameter mean 42-8 p, standard deviation 5-6 p (100); contact areas unsculptured.

90

PALAEONTOLOGY, VOLUME 12

plano-convex, proximal face about 2-5 p thick (PI. 1 4, fig. 1 0) ; distal face convex. Laesura
two-thirds radius, lips simple, height 3-4 p. Exine (inch murus) 1-5(2 p)3 thick (99), radial
equatorial exine 1 -5(3-5 /x)6-5 (90), ratio radial/interradial 1-0(1 -7)2-6 (87 specimens).
Sculpture negative (canaliculate) distal and equatorial; straight parallel lumina form 3
interradial sets (of variable number) and alternating in the radial areas; lumen depth
(= murus height) 1-0(1 -2 p)2-0 (80); flat-topped murus 2-0(2-2 p) 3-0 wide (100); width
of 4 adjacent lumina and muri 9-0(13-1 /x) 1 8 (100), standard deviation 1-94 p, coefficient
of variation 14-8%; distal configuration triangle with straight sides (PI. 14, fig. 9), or
sub-parallel lumina (PI. 14, figs. 7, 8).

Description. Amb triangular. Maximum diameter of unsculptured area 9(19 yu,)30 (70 specimens).
Rigidity of spore due to relatively thick exine with narrow (1 p) lumina. Radius not crossed by lumina,
radial equatorial exine particularly rigid and may be slightly thickened. Muri have sharp rectangular
profile. Occasional tetrads seen and 1 monolete specimen. Observed limits of maximum diameter 26-
60 p, coefficient of variation 13%. Specimens in polar aspect 38%, equatorial aspect 34%.
Preservation and compression. When murus outline is not rectangular, this is probably due to exine
‘softening’ of edges of lumina (PI. 14, fig. 10).

Distinction local. Biorecords 1 CICATR AT and 4 CICATR AW have radial lumen. 9 CICATR 4Pis
larger in all dimensions.

3 CICATR AR
Plate 15, figs. 1-13; text-fig. 1

Record sample. Warlingham Borehole, depth 1,873 ft. 8 in.; medium grey silty clay,
general size of coarse fraction 20 p , little carbonate, much mica up to 10 p; plant frag-

EXPLANATION OF PLATE 13

Magnification x 1,000.

Figs. 1-12. Biorecord 1 CICATR AT. 1-3, Designated specimen, proximal aspect, low, mid, and high
focus; V067/1, OR 48-8 116-9. 4-5, Distal aspect, low and high focus; V067/1, OR 50-7 119.
6, Equatorial aspect; V067/3, OR 43-7 121-9. 7, Proximal aspect; V067/3, OR 45T 122-9. 8, Large
specimen, high focus; V067/1, OR 38-1 116-9. 9, Distal aspect, high focus; V067/1, OR 36-4

120-2. 10, Distal aspect, high focus; V067/3, OR 36-5 119-3. 11-12, Equatorial aspect, high and
low focus; V067/1, OR 55-2 116-4.

EXPLANATION OF PLATE 14

Magnification X 1,000.

Figs. 1-12. Biorecord 2 CICATR AF. 1-2, Designated specimen, proximal aspect, low and high focus;
V067/6, OR 48-5 1 12. 3, Proximal aspect, high focus; V067/1, OR 50-4 1 19-8. 4, Oblique aspect,
low focus; V067/1, OR 44-6 1 12-2. 5, Proximal aspect, high focus; V067/1, OR 50 119-8. 6-7, Dis-
tal aspect, low and high focus; V067/6, OR 33-7 127-7. 8, Distal aspect; V067/1, OR 39-8 122-5.
9, Distal aspect; V067/1, OR 37-3 121. 10, Equatorial aspect; V067/6, OR 55 120-4. 11, Oblique
aspect, low focus; V067/6, OR 50 1 23-1 . 12, Equatorial aspect, mid focus; V067/6, OR 19-1 117.

EXPLANATION OF PLATE 15

Magnification X 1,000.

Figs. 1-13. Biorecord 3 CICATR AR. 1, Distal aspect; Y528/5, OR 33 122-4. 2, Equatorial aspect;
Y528/2, OR 39-3 121-3. 3-4, Equatorial aspect, low and high focus; Y528/2, OR 27-9 113-4. 5,
Proximal aspect; Y528/5, OR 37-9 125. 6, Equatorial aspect; Y528/4, OR 39-3 117-3. 7, Oblique
aspect, high focus; Y528/2, OR 43-7 119-9. 8-9, Distal aspect, low and high focus; Y528/2, OR
38-7 114-6. 10-11, Distal aspect, low and high focus; Y528/4, OR 28-7 110-9. 12-13, Designated
specimen, proximal aspect, low and high focus; Y528/5, OR 27 117.

Palaeontology, Vol. 12

PLATE 13

10

12

HUGHES and MOODY-STUART, Early Cretaceous miospore biorecords

Palaeontology, Vol. 12

PLATE 14

HUGHES and MOODY-STUART, Early Cretaceous miospore biorecords

Palaeontology, Vol. 12

PLATE 15

HUGHES and MOODY-STUART, Early Cretaceous miospore biorecords

HUGHES AND MOODY-STU ART: STRATIGRAPHIC CORRELATION 91

meats, regular bedding. Preparation Y528: 30 min. cold cone. HN03, mineral separa-
tion. Palynologic facies: some fern spores in good condition, but full range of corrosion
and pale fragments, reworking suspected, many small wood fragments ; 17% other pollen,
33% Classopollis (pale), 7% bisaccates (pale), 30% other ‘ferns’, 13% Cieatricosisporites
(compr. 4-3% 3 C1CATR AR, 4-7% cf. AT/ A W, 1% or less cfA. 14 CICATR 48H and
cfA. 7 CICATR Cl); total fern spore size index 45:52:03.

Diagnosis (100 specimens; Y528/2,3,4; 10 01 68). Miospore, trilete, gross maximum
diameter mean 36-Op., standard deviation 5-45 p (100); proximal face plano-concave,
distal convex. Laesura medium long, lips simple membraneous 2-4 p high. Sculpture
positive, no radial murus. Exine (excl. murus) interradial 0-5(0-8 p)l-3 (70), and
radial 0-5(0-9 p)E4 (71). Distal and equatorial areas bear 3 interradial sets with 4(6)10
(84) sub-parallel muri of height 1 -1(1-6 p)3-2 (98), width 0-6( 1 - 1 p)2-0 (94); width of 4
adjacent muri and lumina 10-0(13-5 p)17-0 (99), standard deviation 2-09 p. Proximal
face unsculptured triangle (PL 15, fig. 12) of height 12(19 p)28 (71), distal configuration
symmetrical concave-sided polar triangle.

Description. Approximately 50% of specimens have sinuous and undulose muri, and in 20% muri
anastomose interradially. Polar views show 3 or 4 muri in profile crossing radial amb perpendicularly.
Eight specimens have muri flattened (PI. 15, tig. 1) interradially to apparent width 1 -0(2-0 p)3-2.
Observed limits of gross maximum diameter 24-5 p, coefficient of variation 15-1%; coefficient for
width of 4 muri and lumina 14-7%. Aspect of specimens, 16% distal, 18% proximal, 33% equatorial.

Preservation. Mural height in some specimens may have been reduced by corrosion.

Distinction local. Biorecord 1 CICATR HE has closer, lower, more numerous muri. 5 CICATR A2
is larger and has higher, straighter, more widely spaced muri. 14 CICATR 48H has negative sculpture,
thicker exine, wider muri. Ischyosporites spp. have more perfect and uniform distal mural reticulum.
Ruffordia goepperti (spores) are larger (mean 50 p), and have lower muri.

4 CICATR AW
Plate 16, figs. 1-12; text -fig. 1

Record sample. Warlingham Borehole, depth 1,945 ft.; medium grey silty clay, bedded,
general size of coarse fraction 20 p. Preparation V419: 25 min. cold cone. HNG3,
mineral separation, short centrifuging. Palynologic facies: many spores in good con-
dition, some pale and some corroded, Botryocoecus abundant; 32% other pollen, 19%
Classopollis, 14% bisaccates, 32% other ‘ferns’, 3% Cieatricosisporites (compr. 3%
4 CICATR A W, also present cfA. 1 CICATR AT, cfA. 3 CICATR AR, cfB. 7 CICATR
Cl); total fern spore size index 47:39:14.

Diagnosis (100 specimens; V419/1 ; 08 04 68). Miospore, trilete, gross maximum diameter
mean 43-3 p, standard deviation 5-58 p (100); proximal face plano-convex, distal con-
vex. Laesura medium long, lips simple membraneous 2-5 p high. Sculpture negative,
no radial murus. Exine thickness (inch murus), radial 2-0(3-7 p)12-0 (88), interradial
1 -4(2-3 p)5-6 (87). Three interradial sets of sub-parallel muri of height 1-0(1 -1 p)2-5 (79),
and width 1 -2(2-4 p)4-0 (100); width of 4 adjacent muri and lumina 10-0(13-4 p)19-0
(100); distal configuration symmetrical concave-sided polar triangle, proximal sculp-
tured.

92

PALAEONTOLOGY, VOLUME 12

Description. Gross maximum diameter limits 26-69 p, coefficient of variation 1 2-8% ; coefficient of
variation of width of 4 muri and lumina 34-5%. Radial exine thickening distinct in a few specimens
that could perhaps be separated. Aspect of specimens, proximal 22%, distal 19%, equatorial 24%;

1 monolete specimen seen.

Distinction local. Biorecord 1 CICATR AT is of the same size and configuration but has narrower muri.

2 CICATR TFhas no radial lumen. 3 CICATR AR has positive sculpture, thinner exine, and is smaller.

5 CICATR A2
Plate 17, figs. 1-11; text-fig. 1

Record sample. Warlingham Borehole, depth 1,843 ft.; medium grey silt, general size
of coarse fraction 100 /lx, much mica up to 50 p; plant fragments; disturbed, small
lenses. Preparation V016: 10 min. warm cone. HN03, shaken, mineral separation.
Palynologic facies: spores in good condition, fragments of unmacerated wood; 19%
other pollen, 7% ClassopoUis, 14% bisaccates, 40% other ‘ferns’, 20% Cicatricosis-
porites (compr. 1% 5 CICATR A2, 10% cf. AT/ AW, 5% 14 CICATR 48H, 2% cfA.

3 CICATR AR, also present cfA. 6 CICATR B5 ); total fern spore size index 25:53:22.

Diagnosis (100 specimens; V016/l,2,3,4; 29 02 68). Miospore, trilete, gross maximum
diameter mean 44-8 /x, standard deviation 6-38 p (100); proximal face plano-concave,
distal convex. Laesura medium length, lips simple membraneous low. Exine (excl.
murus) interradial 0-5(l-l p)\ -8 (71). Sculpture positive, radial lumen; distal and
equatorial areas bear 3 interradial sets each with 3(5)10 (96) sub-parallel muri of height
2-0(3-2 /x)5-5 (94), width 1 -5(2-7 /x)4-0 (89); width of 4 adjacent muri and lumina
12-0(20-0 ft)30-0 (90), standard deviation 6-7 yu.; distal configuration symmetrical
concave-sided polar triangle (PI. 17, fig. 2), with some muri coalescing interradially
(PI. 17, fig. 7); proximal unsculptured.

Description. Muri may fold down (PI. 17, fig. 3), increasing apparent width of murus up to 6 p, and
decreasing apparent height of murus and width of lumen, which is 0-5(2-5 p)10 (90). Murus broad-based
in section, making murus-width a somewhat uncertain measurement. Downfolding of exine (PI. 17,
fig. 9) between muri leads to highly variable ‘width of 4 muri and lumina’, coefficient of variation 33%.
Observed limits of gross diameter 32-59 p, coefficient of variation 14-2%. Aspect of specimens, 19%
equatorial, 29% proximal, 19% distal.

EXPLANATION OF PLATE 16

Magnification x 1,000.

Figs. 1-12. Biorecord 4 CICATR AW\ prep. V419/1. 1-2, Oblique proximal, low and high focus;

OR 44-4 115-9. 3, Oblique equatorial, OR 23-1 117-8. 4, Designated specimen, proximal; OR 32-2
122-5. 5, Distal aspect, high focus; OR 29-5 114-8. 6-7, Proximal aspect, low and high focus;
OR42-5 126-9. 8, Proximal aspect, low focus; OR 22-1 125-2. 9, Equatorial aspect; OR 37-1 1 16-2.
10-11, Monolete specimen, low and high focus; OR 28-8 115. 12, Proximal aspect, torn; OR 42-3
121-5.

EXPLANATION OF PLATE 17

Magnification x 1 ,000.

Figs. 1-11. Biorecord 5 CICATR A2. 1-2, Designated specimen, distal aspect, low and high focus;
V016/4, OR 38-4 122. 3, Distal aspect, high focus; V0 1 6/1 , OR 43-2 120-2. 4, Distal aspect;

V016/3, OR 23-3 113-1. 5, Distal aspect; V0 1 6/1 , OR 40-4 123. 6, Equatorial aspect, low focus;

V016/4, OR 43-7 128-6. 7, Distal aspect, high focus; V016/4, OR 34-3 112-8. 8, Proximal aspect;

V016/1, OR 40-3 109-8. 9, Equatorial aspect, low focus; V0 16/3, OR 31-1 110-7. 10-1 1, Proximal

aspect, low and high focus; V016/1, OR 24-3 111-5.

Palaeontology, Vol. 12

PLATE 16

HUGHES and MOODY-STUART, Early Cretaceous miospore biorecords

Palaeontology , Vol. 12

PLATE 17

HUGHES and MOODY-STUART, Early Cretaceous miospore biorecords

HUGHES AND MOOD Y-STUART: STRATIGRAPHIC CORRELATION

93

Distinction local. Biorecord 3 CICATR AR is smaller with lower and thinner muri. 7 CICATR Cl
(Cic. lucifer H. and M-S. 1967 b) has narrow-based muri and wider lumina, a radial murus, and distal
configuration of symmetrical straight-sided polar triangle. 6 CICATR B5 is larger with higher and
thicker muri, thicker exine and proximal sculpture. 15 CICATR A3 is larger in all dimensions.

6 CICATR B5
Plate 18, figs. 1-8; text-fig. 1

Record sample. Warlingham Borehole, depth 1,834 ft.; light medium grey siltstone, well
sorted with general size of coarse fraction 50^; lensing and disturbance throughout.
Preparation V017: twice warm cone. HN03 totalling 1 h., shaken, mineral separation,
short centrifuging. Palynologic facies: spores in fair condition, but many broken;
38% other pollen, 4% Classopollis , 14% bisaccates, 28% other ‘ferns’, 16% Cicatrico-
sisporites (compr. 4% 6 CICATR B5, 5% cfA. 5 CICATR A2, 4% cfA. 4 CICATR A W,
etc.); total fern spore size index 13:44:43.

Diagnosis (100 specimens; VO 1 7/1 ,2,3 ; 26 01 68). Miospore, trilete, gross maximum
diameter mean 88-3 /x, standard deviation 13-7 p (100); proximal face planar, distal
convex. Laesura medium long, lips simple, same height as muri. Sculpture posi-
tive. Exine (excl. murus) 2-5(4-2 p)6-0 (84) measured interradially is of even thickness,
giving an apparent total radial thickness 6-0(1 TO /x) 16-0 (95), including murus height
3 -2(5-7 p) 10-0 (77). Three interradial sets of 5(8-5)11 (78) sub-parallel muri occupy
proximal, equatorial and distal surfaces, and members of sets coalesce sub-radially
(PI. 18, fig. 8); murus width 2-2(34 p,)5-0 (84); width of 4 adjacent muri and lumina
23(33-4 p) 44 (94), standard deviation 5-05 p. Distal configuration symmetrical straight-
sided polar triangle.

Description. Radial lumen usually absent. ‘Drillings’ in muri (PI. 18, fig. 7) occur in 84% of specimens
and resulting distortion causes increased apparent murus width 3 0(5-2 p) 8 0 (92), but contrast Plate 18,
fig. 8. True murus height not always measurable (PI. 18, fig. 2) because of exine thickness which is
2 0(5-1 ju)7-2 (39); contrast with Plate 18, fig. 1. In distal configuration, only 2 specimens have sym-
metrical concave-sided polar triangle, and 2 specimens sub-parallel muri. Range of gross maximum
diameter 54-103 p, coefficient of variation 15-5%; coefficient for width of 4 muri and lumina 15-1%.
Specimens in equatorial aspect 9%, proximal 29%, distal 38%.

Preservation. Most specimens inflated, 25% show corrosion, 37% torn; stronger oxidation than usual
was necessary to clear sufficiently the opaque thick exine.

Distinction local. Biorecord 5 CICATR A2 is smaller, has unsculptured proximal face, and always has
radial lumen. 9 CICATR AP is smaller has negative sculpture, and will not be confused with B5 when
that spore is in good condition. 15 CICATR A3 has fewer, wider muri.

7 CICATR Cl
Text-fig. I

Record sample. Warlingham Borehole, depth 1,757 ft.; for all details see record of
Cicatricosisporites lucifer Hughes and Moody-Stuart (19676).

94

PALAEONTOLOGY, VOLUME 12

8 CICATR C2
Plate 19, figs. 1-1 1 ; text-fig. 1

Record sample. Warlingham Borehole, depth 1,740 ft. 6 in.; medium grey sandy silt,
general size of coarse fraction 30 p, mica flakes to 1 50 /x ; small plant fragments, thin
banding. Preparation V416: 25 min. cold cone. HN03, mineral separation, short
centrifuging. Palynologic facies: many spores in good condition, few pale and torn
specimens, little corrosion, medium and small unmacerated wood fragments; 18%
other pollen, 13% Classopollis (pale), 23% bisaccates (pale), 30% other ‘ferns’, 16%
Cieatrieosisporites (compr. 1% 8 CICATR C2, 5% cfA. 7 CICATR Cl, 5% cfA.
4 CICATR A W, 1% 9 CICATR AP, 1% 10 CICATR A5S, 1% cfA. 5 CICATR A2,
and others); total fern spore size index 08:50:42.

Diagnosis (100 specimens; V4 16/1,2,3,4,5,7, 8; 29 02 68). Miospore, trilete, gross maxi-
mum diameter mean 39-9 p, standard deviation 5-03 p (100); proximal face plano-
convex, distal convex. Laesura medium length, lips simple, 2-4 p high. Sculpture
negative (canaliculate), proximal, equatorial, and distal; straight parallel lumina form
3 interradial sets asymmetrically developed on distal face in 50% of specimens; flat-
topped murus (PI. 19, figs. 4, 5), width T2(l-7 /x)2-8 (99), and lumen depth 0-5(l-l
(34); width of 4 adjacent lumina and muri 7-0(9-9 fx)15 (99), standard deviation 2-67 p,
coefficient of variation 27T%. Interradial exine thickness (inch murus) 1 -3(2-2 /u,)3-0
(93); unsculptured elongate radial equatorial extensions with radial dimension
1 -2(4- 1 /x)6-5 (88), width in equatorial plane 2-5(6-4^x)13 (84) (PI. 19, figs. 6, 11), and
2(5)7 (71) members from each of 2 adjacent equatorial sets of lumina terminating at
base of extension; radial equatorial exine thickness 4-0(6-8 jtx)9-0 (98), ratio radial/
interradial 1 -7(3- 1)5-3 (93).

Description. Interradial amb convex. Observed limits of gross maximum diameter 29-52 p, coefficient
of variation 12-6%. 18% of specimens show unsculptured area 6-0(13-9 p)20. Only 5% of specimens
have radial extensions that are unusually wide or small. Distal configuration: straight-sided triangle
27%, concave-sided triangle 25%, sub-parallel muri 38% (73). Aspect of specimens, proximal 29%,
distal 31%, equatorial only 9% presumably because of presence of radial extensions.

EXPLANATION OF PLATE 18

Magnification of Fig. 8 x 1,000; all others X 500.

Figs. 1-8. Biorecord 6 CICATR B5. 1, Distal aspect, high focus; V017/2, OR 44-5 109-2. 2-3, Distal
aspect, low and high focus; V017/2, OR 39-2 111-9. 4, Proximal aspect; V017/2, OR 38-9 112.
5, Distal aspect; V017/3, OR 30-9 118-3. 6, Proximal aspect; V017/2, OR 31-2 119-7. 7, Oblique
showing drillings; V017/3, OR 41-9 123-8. 8, Designated specimen, proximal aspect; V017/3, OR
311 117-4.

EXPLANATION OF PLATE 19

Magnification X 1,000.

Figs. 1-11. Biorecord 8 CICATR C2. 1-2, Proximal aspect, low and high focus; V416/1, OR 20-4
118-2. 3, Proximal aspect; V416/4, OR 55-8 115. 4-5, Designated specimen, distal aspect, low and
high focus; V416/7, OR 51-4 1 16-3. 6, Distal aspect, low focus; V416/4, OR 57-3 114-8. 7, Equa-
torial aspect, high focus; V416/4, OR 38-8 1 14-6. 8, Distal aspect, low focus; V416/3, OR 22 115-1.
9-10, Distal aspect, low and high focus; V416/7, OR 35-4 123-2. 11, Proximal aspect, low focus;
V416/5, OR 46-5 123-2.

Palaeontology, Vol. 12

PLATE 18

HUGHES and MOODY-STUART, Early Cretaceous miospore biorecords

Palaeontology, Vol. 12

PLATE 19

HUGHES and MOODY-STUART, Early Cretaceous miospore biorecords

s

HUGHES AND MOODY-STUART: STRATIGRAPHIC CORRELATION 95

Preservation and compression. In natural compression, radial equatorial extensions twist readily on
relatively thin spore body; of 20 fractured specimens (= 20% of total), 18 were torn parallel to base
of extension. Corrosion often appears to affect radial extension but not spore body, and vice versa.

Distinction local. Biorecord 7 CICATR Cl has positive sculpture, and the radial extensions arise from
single mural intersections. 9 CICATR AP is larger, has thicker exine, wider muri, and sculptured radial
extension (if any). 13 CICATR C2L is larger in all dimensions.

9 CICATR AP
Plate 20, figs. 1-7; text-fig. 1

Record sample. Warlingham Borehole, depth 1,740 ft. 6 in.; all details given under
8 CICATR C2.

Diagnosis (100 specimens; V416/2,3,4,5,6; 29 02 68). Miospore, trilete, gross maximum
diameter mean 60-4^, standard deviation 8-9^ (100); proximal face plano-convex,
distal convex. Laesura medium length, flanked by deep lumen, lips simple, low (PI. 20,
figs. 2, 3). Exine thickness radial equatorial (inch murus) 4-0(9-0 p)\6-0 (98), interradial
2-5(4-5 yLt)7*5 (100), ratio radial/interradial 1-0(2-0)4-0 (98). Sculpture negative, radial
lumen always absent; proximal, equatorial, and distal surfaces bear 3 interradial sets
of regular sub-parallel lumina of depth 1 -2(2-4 /x)3-2 (37), 2-0(3-3 p)5D (99) apart; width
of 4 adjacent lumina and muri 12-0(16-7 /x)23-0 (100), standard deviation 4-4 p,
coefficient of variation 26-2% (PI- 20, fig. 6); lumina of adjacent sets do not coalesce;
distal configuration, symmetrical straight-sided polar triangle to sub-parallel.

Description. Observed limits of gross maximum diameter 45-83 p, coefficient of variation 14-7%. Of
spores with sub-parallel distal configuration, half had muri perpendicular (PI. 20, fig. 1) to a radius,
and half parallel to a radius. Equatorial aspect 21% of specimens, proximal 20%, and distal 24%.
Thick radial exine due to thickening of internal layers of exine; radial equatorial sculpture not modified.

Preservation. 50% of all specimens were torn, 25% showed corrosion (PI. 20, fig. 4), and 10% were
‘drilled’ (see description of biorecord 14 CICATR 48 H).

Distinction local. Biorecord 6 CICATR B5 is larger, with wider, deeper lumina (i.e. positive sculpture) ;
12 CICATR APP is larger. 8 CICATR C2 is smaller in all dimensions, and has unsculptured radial
equatorial extensions. 14 CICATR 48 H has exine of even thickness and radial lumen. Pelletieria valden-
sis (spores) are similar but larger (Hughes and Moody-Stuart 1966).

10 CICATR 45S
Plate 21, figs. 1-12; text-fig. 1

Record sample. Warlingham Borehole, depth 1,740 ft. 6 in.; all details given under
8 CICATR C2.

Diagnosis (100 specimens; V416/2,4,6,7,8; 29 02 68). Miospore, trilete, gross maximum
diameter mean 37-8 p, standard deviation 5-66 p (100 specimens); proximal face plano-
convex, distal very convex. Laesura medium short, lips simple membraneous, low.
Sculpture negative; not more than 1 radial lumen. Exine thickness (inch murus), inter-
radial 2-0(2-8 |u)3-9 (97), radial 2-0(2-9 p)4-\ (92). Proximal, equatorial, and distal
surfaces bear sub-parallel lumina, depth 0-5(1 -1 p) 2-1 (71), and 1 -5(2-2 p) 3-2 (100) apart;
width of 4 adjacent lumina and ‘muri’ 7-3( 11-5 /x) 1 6, standard deviation 1-78 p (100).
Proximal configuration of concentric triangles; equatorially 2 to 4 circular lumina that

96

PALAEONTOLOGY, VOLUME 12

may be truly continuous (11%; PI. 21, figs. 1, 2), or inter-finger in 1 radial area (47%;
PI. 21, fig. 6), or be broken by 1 radial lumen (42%); distal configuration sub-parallel.

Description. Spore appears spherical; this is supported by distribution of spore aspects, 36% polar
(11% proximal, 25% distal), 31% equatorial, 33% oblique. Sculpture may be asymmetrical. Coefficient
of variation 15 0% for gross diameter, 15-5% for width of 4 lumina and ‘muri’.

Preservation. Most specimens inflated; only 14% show any corrosion, but 31% are torn; this is similar
for other spores of this assemblage.

Distinction local. Schizaeopsis americana (spores) has circular lumina, but is larger and has smaller
sculptural elements. Biorecord 16 CICATR A5H is larger and has proximal configuration with lumina
of each interradial set parallel to one branch of laesura.

14 CICATR 48 H
Plate 22, figs. 1-12; text-fig. 1

Record sample. Sample H48/16 (TQ 88721288), prominent 6-ft. silt bed (upper part),
20 ft. above cliff base, 150 m. east of Cliff End Point, 4 miles east of Hastings; pale grey
silt, no lamination, few plant fragments. Preparation N016: 12 h. Schulze solution,
cold, not renewed; mineral separation. Palynological facies: spores in good condition,
plus small pale indet. fragments, cuticle, spore-masses, megaspores; 3% bisaccates,
82% other ‘ferns’, 15% Cicatricosisporites (compr. 13% cfA. 14 CICATR 48 H, 2%
cfA. 1 CICATR AT); total fern spore size index 09:43:48.

Diagnosis (100 specimens; NO 16/1; 29 02 68). Miospore, trilete, gross maximum
diameter mean 50-0 p, standard deviation 5-8 p (100 specimens); proximal face plano-
convex, distal convex. Laesura long to medium, lips simple membraneous. Sculpture

EXPLANATION OF PLATE 20

Magnification x 1 ,000.

Figs. 1-7. Biorecord 9 CICATR AP. 1-2, Designated specimen, proximal aspect, low and high
focus; V416/2, OR 32-8 1181. 3, Proximal aspect, high focus; V41 6/6, OR 49-3 120-2. 4, Extreme
specimen; V416/2, OR 45-7 122-8. 5, Proximal aspect, high focus; V416/6, OR 35-4, 111-6

6, Distal aspect, high focus; V416/6, OR 53-3 120-3. 7, Equatorial aspect; V416/4, OR 25-4 122-6.

EXPLANATION OF PLATE 21

Magnification X 1,000.

Figs. 1-12. Biorecord 10 CICATR A5S. 1-2, Designated specimen, distal aspect, low and high focus;
V416/8, OR 24-2 118-1. 3, Equatorial aspect, high focus; V416/8, OR 50-6 111 -4. 4-5, Equatorial
aspect, low and high focus; V416/7, OR 38-9 110-9. 6, Equatorial aspect; V416/6, OR 22-3 115-4.
7-8, Distal aspect, low and high focus; V416/6, OR 28-6 112-5. 9-10, Distal aspect, low and high
focus; V416/4, OR 29-6 121. 11-12, Distal aspect, low and high focus; V416/6, OR 22-8 118.

EXPLANATION OF PLATE 22

Magnification X 1 ,000.

Figs. 1-12. Biorecord 14 CICATR 48H\ N016/1. 1-3, Designated specimen, proximal aspect, low,

mid, and high focus; OR 27-4 111-3. 4, Distal aspect, high focus; OR 33-1 121-7. 5, Equatorial
aspect, low focus; OR 27-2 116-1. 6-7, Proximal aspect, mid and high focus; OR 33-4 120-6. 8,
Equatorial aspect, high focus; OR 26-9 116-2. 9, Distal aspect, high focus; OR 32-7 1 14-9. 10, Distal
aspect, low focus; OR 33-1 120-1. 11-12, Distal aspect, high and low focus; OR 29-5 126-6.

Palaeontology, Vol. 12

PLATE 20

HUGHES and MOODY-STUART, Early Cretaceous miospore biorecords

Palaeontology, Vo I. 12

PLATE 21

1 1

HUGHES and MOODY-STUART, Early Cretaceous miospore biorecords

Palaeontology, Vol. 12

PLATE 22

HUGHES and MOODY-STUART, Early Cretaceous miospore biorecords

)

HUGHES AND MOOD Y-STUART: STRATIGRAPHIC CORRELATION

97

negative, radial lumen always present (PI. 22, fig. 11) on two of the radial equatorial
areas. Exine (inch murus) of equal thickness in radial and interradial areas 2-5(4-8 fi)8-0
(96). Distal, equatorial, and proximal surfaces bear 3 interradial sets of 5(8)11 (98)
lumina each ; the narrow 0-4(0-9 p)2-0 (99) lumina of depth 1 -5(2-0 ,u)3-0 (86) are unevenly
spaced and may be discontinuous, but are about 2 0(3-4 p)5-0 (74) apart; width of 4
adjacent lumina and muri 13(16-8 /x)24, standard deviation 2-7 p (97). Proximal con-
figuration is unsculptured (PI. 22, figs. 8, 12) or with concentric triangles (PI. 22, fig. 2)
of 0(2)5 lumina (65); distal configuration symmetrical polar triangle, or sub-parallel.

Description. Distal triangle at meeting of lumen sets often has few irregular short lumina asymmetrically
disposed ; lumina have sharply defined and sometimes sinuous edges ; lines of ‘ drillings ’ midway between
2 lumina in many specimens. Laesura may be flanked by deep lumen (PI. 22, fig. 12). Observed limits
of gross maximum diameter 34-63 p, coefficient of variation 11-6%; coefficient for width of 4 lumina
and muri 16-9%. Aspect of specimens, equatorial 42%, proximal 7%, and distal 27%.

Preservation. No ordinary corrosion in this assemblage, so that ‘drillings’ (PI. 22, fig. 4) appear to be
characteristic of the species.

Distinction local. Biorecord 9 CICATR AP has no radial lumen, and may have internal thickenings.
4 CICATR A W is slightly smaller in all measurements except lumen width. 10 CICATR ASS is smaller
and differs in equatorial and distal configuration.

UNCOMPLETED BIORECORDS

It is clear from the study of the coarser-grained Fairlight Clay samples that further
Cicatricosisporites biorecords additional to those taken from the Warlingham Borehole,
are potentially available in the Hastings Beds, and will be needed for continuation with
other correlation. So that brief reference can be made at this stage, some are listed below.
Because they have not been properly established, comparison with them is not graded.

1 1 CICATR A WW:

12 CICATR APP:

13 CICATR C2L:

15 CICATR AS:

16 CICATR A5H:

4 AW, with very wide muri; has been seen in spore-masses.

larger than 9 AP, and earlier.

much larger than 8 C2, and much earlier.

larger than 5 A2.

larger than 4 AW, with characteristic proximal configuration,
and later.

RECORDING OF EVENTS

The location of the Warlingham Borehole is TQ 34765719, RTE 347 ft. above MSL;
the samples here described are sub-samples kindly supplied by the Institute of Geological
Sciences (UK), who hold the main collections and records of the borehole. The reference
file for the outcrop samples of the Fairlight Clay is a field note-book (NFH) deposited
in the Department of Geology, Cambridge.

SELECTED EVENTS
CRET 25 24 GB SPOR CICATR

This heading for events is again in the form of a suggestion for data storage (cf.
heading above, for biorecords). The figures ‘25 24’ indicate that the recorded events are
believed to be of Berriasian-Valanginian age, and are so arranged for ‘search’ purposes.

C 6289 H

98

PALAEONTOLOGY, VOLUME 12

Under the individual events we regard the calendar date of ‘observation’ given with
each item as essential data.

Warlingham Borehole

4, WM 1987 1 1-3. 28 02 68 C1CATR: 46% cfA. 1 AT, 23% cfA. 4 AW, 12% cfA. 3 AR,
6% cfA. 2 AF, 12% Contignisporites.

Sample. Medium grey siltstone, small scale cross-bedding; mica, bivalve shell frag-
ments, black indet. fragments; general size of coarse fraction 40 /x. Preparation
N044-5/12-16: 12 h. cold Schulze. Palynologic facies: 30% other pollen, 28%
Classopollis, 14% bisaccates, 23% ‘other ferns’, 2% Cicatricosisporites, 3% ‘plank-
ton’; large cuticle; fern spore size index 40:48:12.

5, WM1968/10. 27 02 68 CICATR: 38% cfA. 1 AT, 41% cfA. 4 AW, 12% cfA.
3 AR, 9% cfA. 2 AF.

Sample. Dark grey silty claystone; bivalve shell fragments; general size of coarse
fraction 20 /x. Preparation V484/3: 25 min. HN03, mineral separation. Palynologic
facies: 32% other pollen, 27% Classopollis, 4% bisaccates, 31% ‘other ferns’, 5%
Cicatricosisporites ; most of assemblage pale, corroded ; fern spore size index 38:48: 04.

7, WM 1957 j2. 06 03 68 CICATR: 60% cfA. 4 A W, 12% cfA. 1 AT, 21% cfA.
3 AR, 5% cfA. 2 AF.

Sample. Medium grey silty clay, laminated, with shell bands; general size of coarse
fraction 60 /x. Preparation V503/2: 25 min. HNOa cold. Palynologic facies: 34% other
pollen, 21% Classopollis, 8% bisaccates, 33% ‘other ferns’, 4% Cicatricosisporites',
wood, cuticle, Botryococcus ; fern spore size index 20:54:16.

10, WM1945. 29 03 68 CICATR: 42% 4 Biorecord AW, 28% cfA. 1 AT, 11% cfA.
3 AR, 9% cfA. 2 AF, 8% cfB. 5 A2, 2% cfB. 7 Cl.

Sample. Medium grey fissile silty clay; general size of coarse fraction 20 /x. Prepara-
tion V4 1 9/1 ,3 : 25 min. HNOa cold, mineral separation. Palynologic facies: 32%
other pollen, 19% Classopollis, 14% bisaccates, 32% ‘other ferns’, 3% Cicatrico-
sisporites', Botryococcus', fern spore size index 47:39: 14.

12, WM1941/4. 07 03 68 CICATR: 58% cfA. 4 AW, 19% cfA. 1 AT, 19% cfA. 3 AR,
4% cfA. 2 AF, +cfB. 7 Cl.

Sample. Medium grey laminated claystone with bivalve shells; general size of coarse
fraction 15 /x. Preparation V489/1 : 25 min. HN03 cold. Palynologic facies: 58% other
pollen, 6% Classopollis, 13% bisaccates, 17% ‘other ferns’, 6% Cicatricosisporites',
background assemblage pale, fern spores ‘softened’; fern spore size index 37:56:07.

14, WM 192418-9. 09 03 68 CICATR: 58% cfA. 4 AW, 20% 11 AWW, 8% cfA. 1 AT,
10% cfA. 3 AR, 2% cfB. 5 A2, 2% cfB. 6 B5, cf.2% 12 APP.

Sample. Grey silty claystone; ostracods; general size of coarse fraction 20 /x. Prepara-
tion V505/2: 25 min. HN03 cold. Palynologic facies: 21% other pollen, 8% Classo-
pollis, 13% bisaccates, 34% ‘other ferns’, 24% Cicatricosisporites', wood, background
assemblage pale except ferns; fern spore size index 35:51 : 14.

HUGHES AND MOOD Y-STUART: STRATIGRAPHIC CORRELATION 99

18, WM1915/2. 21 03 68 CICATR: 59% cfA. 4 AW, 8% cfA. 1 AT, 8% cfA. 11 AWW,
13% cfB. 5 A2, 5% cfA. 3 AR, 1% cfA. 12 APP, 1% cfA. 6 B5, +cfB. 7 Cl, 5%
Contignisporites.

Sample. Medium grey silty claystone, laminated; ostracods, pyrite; general size of
coarse fraction 25 p. Preparation V524/3: 20 min. HN03 cold, mineral separation.
Palynologic facies: 36% other pollen, 2% Classopollis, 15% bisaccates, 40% ‘other
ferns’, 7% Cicatricosisporites; wood, cuticle, spore-masses inaperturate pollen; fern
spore size index 38:53: 09.

26, WM1887. 26 03 68 CICATR: 56% cfA. 1 AT, 18% cfA. 4 AW, 9% cf. 11 AWW,
12% cfA. 3 AR, 3% cfA. 5 A2, 2% cfA. 7 Cl.

Sample. Medium grey siltstone, with irregular lensing; general size of coarse fraction
35 p. Preparation V493/1 : 25 min. HNQ3, cold. Palynologic facies: 47% other pollen,
12% Classopollis, 4% bisaccates, 33% ‘other ferns’, 4% Cicatricosisporites', fern
spore size index 56:41:03.

28, WM1878I10. 14 03 68 CICATR: 32% cfA. 4 AW, 7% cfA. 1 AT, 25% cfA. 14
48H, 14% cfA. 7 Cl, 21% cfA. 3 AR.

Sample. Medium grey siltstone, faintly laminated; general size of coarse fraction
70 p. Preparation V009-1/2: 5 min. HNQ3 cold, mineral separation. Palynologic
facies: 66% other pollen, 3% Classopollis, 8% bisaccates, 20% ‘other ferns’, 3%
Cicatricosisporites', cuticle; fern spore size index 61:31:08.

30, WM 1873 18. 14 02 68 CICATR: 36% cfA. 4 AW, 16% cfA. 1 AT, 24% Biorecord
3 AR, 12% cfA. 7 Cl, 9% cfA. 5 A2, 1% cfB. 9 AP, fragments cf. 6 B5.

Sample. Medium grey silty claystone, bedded with plant fragments; average size of
coarse fraction 20 p. Preparation: Y528/2-5: 30 min. HN03, mineral separation.
Palynologic facies: 32% other pollen, 11% Classopollis, 11% bisaccates, 36% ‘other
ferns’, 10% Cicatricosisporites', wood, many pale indet. spores ex count, small acri-
tarchs; fern spore size index 52:45:03.

33, WM1847. 04 04 68 CICATR: 54% cfA. 4 AW, 18% cfA. 1 AT, 12% cfA. 7 Cl, 7%
cfA. 5 A2, 6% cfA. 3 AR, 3% cfA. 6 B5, +cf. 9 AP.

Sample. Green silty clay, brown mottled; lensing, bioturbation; average size of
coarse fraction 65 p. Preparation: Y529/3: 30 min. HN03, mineral separation. Paly-
nologic facies: 30% other pollen, 3% Classopollis, 32% bisaccates, 25% ‘other ferns’,
10% Cicatricosisporites', fern spore size index 30:57:13.

36, WM1843. 20 02 68 CICATR: 47% cfA. 4 AW, 16% cfA. 1 AT, 15% cfA. 5 A2,
10% cfA. 7 Cl, 11% cfA. 3 AR, +cf. 9 AP.

Sample. Medium grey siltstone, lensed, disturbed; plant fragments, pyrite; general
size of coarse fraction 40 p. Preparation V016/3: 10 min. HNG3 shaken, mineral
separation. Palynologic facies: 34% other pollen, 5% Classopollis, 22% bisaccates,
24% ‘other ferns’, 15% Cicatricosisporites', wood; fern spore size index 32:53:15.

100

PALAEONTOLOGY, VOLUME 12

43, WM 18 1915. 15 05 68 C1CATR: 46% cfA. 4 AW, 8% cfA. 1 AT, 20% cfA. 5 A2,
8% cfA. 7 Cl, 10% cfA. 3 AR, 3% cfA. 8 C2, 2% cfA. 6 B5.

Sample. Medium dark grey shale; plant fragments; general size of coarse fraction
30 /x. Preparation V533/1.2: 25 min. HN03, mineral separation. Palynologic facies:
18% other pollen, 16% Classopollis, 15% bisaccates, 47% ‘other ferns’, 4% Cicatrico-
sisporites; wood, fungal spores; fern spore size index 35:58:07.

53, WM 174016. 19 01 68 CICATR: 29% cfA. 7 Cl, 25% cfA. 4 AW, 8% cfA. 1 AT,
11% cfA. 5 A2, 8% Biorecord 8 C2, 15% Biorecord 10 AJS, 2% Biorecord 9 AT,
2% cfA. 3 AR.

Sample. Medium grey siltstone, laminated; large mica; general size of coarse fraction
30 i~l. Preparation V4 1 6/1—8 : 25 min. HNOa, mineral separation. Palynologic facies:
21% other pollen, 14% Classopollis, 19% bisaccates, 38% ‘other ferns’, 8% Cica-
tricosisporites; wood, spinose acritarchs; fern spore size index 21:60:19.

Fairlight Clay outcrop, east of Hastings, Sussex

All samples from coast section (collected 1 952—6) ; descriptive reference points from
White (1928, fig. 5, p. 33), and stratigraphic subdivision from the same work (fig. 4,
p. 22) are listed below as FC (c), (d), etc.

61, HI 27; FC (a), Fairlight anticline west limb, 18 ft. below ‘Goldbury bed’ and 4 ft.
above HWM. 19 03 68 CICATR: 45% cfA. 1 AT, 30% cfA. 4 AW, 7% cfA. 2 AT,
14% cfB. 5 A2.

Sample. Buff blocky fine siltstone. Preparation V092/2: 30 min. HN03, mineral
separation. Palynologic facies: 20% other pollen, 5% Classopollis, 36% bisaccates,
36% ‘other ferns’, 3% Cicatricosisporites ; fern spore size index 17:46:37.

62, H41; FC (b) mid-high, shore-reefs Goldbury East. 20 03 68 CICATR: 57% cfA.
4 AW, 17% cfA. 1 AT, 6% cf. 1 1 A WW, 9% cfA. 2 AT, 3% cfB. 5 A2, 3% cfB. 7 Cl.

Sample. Buff-grey siltstone, bedded; plant fragments, wood. Preparation V163/1:
45 min. HNQ3, mineral separation. Palynologic facies: 25% other pollen, 38%
bisaccates, 33% ‘other ferns’, 4% Cicatricosisporites; wood, cuticle, spore-masses;
fern spore size index 14:50:36.

63, H58; FC (c), 15 ft. above ‘Goldbury bed’ at Goldbury Point. 26 03 68 CICATR:
63% cfA. 4 AW, 6% cf. 11 A WW, 6% cfA. 1 AT, 6% cfA. 5 A2, 4% cfB. 7 Cl,
3% cfB. 9 AT, 3% cfA. 3 AR, 3% cfB. 6 B5, +cf. 13 C2L.

Sample. Dark grey fine siltstone, unbedded; small plant fragments. Preparation
V 173/2 : 60 min. HN03, mineral separation. Palynologic facies: 20% other pollen,
1% Classopollis, 15% bisaccates, 50% ‘other ferns’, 14% Cicatricosisporites; cuticle,
megaspores, spore-masses; fern spore size index 19:45:36.

64, HI 29; FC (c), Lee Ness, 40 ft. above HWM. 29 03 68 CICATR: 54% cfA. 4 AW,
14% cf. 1 1 A WW, 1 1 % cfA. 1 AT, 1 1 % cfB. 5 A2, 2% cfA. 5 A2, 5% cfB. 7 Cl, +cf.
13 C2L.

Sample. Pale pink-grey blocky medium siltstone; plant fragments. Preparation

HUGHES AND MOOD Y-STUART: STRATIGRAPHIC CORRELATION 101

V169/2: 45 min. HNO:J, mineral separation. Palynologic facies: 15% other pollen,
3% ClassopoJlis, 26% bisaccates, 41% ‘other ferns’, 15% Cicatricosisporites; cuticle,
megaspore, spore-masses; fern spore size index 07:61 :32.

65, H128 ; FC (c) high, Lee Ness, 80 ft. above HWM. 21 03 68 CICATR: 40% cfA.

4 AW, 16% cfA. 1 AT, 10% cf. 1 1 A WW, 14% cfB. 7 Cl, 10% cfA. 5 A2, +cf. 2 AF.
Sample. Pale grey fine siltstone; plant fragments. Preparation V 1 68/1 : 45 min.
FlN03, mineral separation. Palynologic facies: 21% other pollen, 20% bisaccates,
46% ‘other ferns’, 13% Cicatricosisporites ; fern spores well preserved, cuticle and
other spores not; fern spore size index 02:43:55.

66, H71 ; FC (c), 250 yd. east of Warren Glen, 5 ft. above HWM. 28 03 68 CICATR:
57% cfA. 1 AT, 13% cfA. 4 AW, 7% cfA. 3 AR, 2% cfB. 5 A2, 15% cfA. 5 A2, 2%
cfB. 7 Cl, +cf. 9 AP.

Sample. Pale grey siltstone, blocky (not laminated). Preparation V165/2: 60 min.
HN03, mineral separation. Palynologic facies: 16% other pollen, 2% C/assopollis,
17% bisaccates, 62% ‘other ferns’, 3% Cicatricosisporites-, fern spore size index
49:40:11.

67, HI 18; FC (d), 100 yd. west of Warren Glen, at HWM in oblique bedding. 14 05 68
CICATR: 52% cfA. 4 AW, 8% cfA. 1 AT, 5% cfA. 3 AR, 17% cfA. 7 Cl, 8% cfA.

5 A2, 8% Contignisporites.

Sample. Pale grey fine siltstone, bedded. Preparation V592/1 : 20 min. HNQ3, mineral
separation. Palynologic facies: 27% other pollen, 3% Classopollis, 27% bisaccates,
38% ‘other ferns’, 5% Cicatricosisporites; fern spore size index 51 :44:05.

68, H73; FC (e), 100 yd. west of Warren Glen, 200 ft. above HWM, 2 in. below 5-ft.
sandstone. 02 04 68 CICATR: 36% cfA. 4 AW, 5% cfA. 1 AT, 5% cfA. 3 AR, 10%
cf. 17 AWL, 16% cf. 15 A3, 20% cf. 12 APP, 2% cfA. 7 Cl, 2% cf. 13 C2L.

Sample. Pale buff siltstone, unbedded; medium-size plant fragments. Preparation
BP391/1-3: 18 h. HNQ3 cold. Palynologic facies: 29% other pollen, 6% Classopollis,
30% bisaccates, 28% ‘other ferns’, 7% Cicatricosisporites; fern spore size index
20:40:40.

69, H87; FC (e), 75 yd. east of Ecclesbourne Glen, 6 ft. above HWM. 28 03 68
CICATR: 27% cfA. 1 AT, 13% cfA. 4 AW, 28% cfA. 3 AR, 20% cfA. 7 Cl, 9%
cfA. 5 A2, 2% cfA. 8 C2, 1% cfA. 9 AP.

Sample. Pink-grey coarse siltstone, bedded; plant fragments. Preparation V058/4-5:
20 min. Schulze, mineral separation. Palynologic facies: 31 % other pollen, 3% Classo-
pollis, 14% bisaccates, 43% ‘other ferns’, 9% Cicatricosisporites; cuticle, wood,
fungal spores; fern spore size index 41:43:16.

70, HI 17; FC (e) top, 200 yd. east of Ecclesbourne Glen, 10 ft. above HWM. 13 05 68
CICATR: 25% cfA. 1 AT, 23% cfA. 4 AW, 6% cfA. 3 AR, 22% cfA. 7 Cl, 6%
cfA. 5 A2, 7% cfA. 8 C2, 2% cfA. 9 AP, 2% cf. 15 A3, 4% cf. 18 ATT.

Sample. Pale buff-grey medium siltstone, unbedded. Preparation Y183/2: 30 min.

102

PALAEONTOLOGY, VOLUME 12

War ling ham
Borehole

1700' -i

Biorecords

V/arlingham

Events

Fairlight Clay

c , Biorecords

events

Hastings Beds
Outcrop

- 1740/6 8 C2.9AP, 10 A5S 5„

7 Cl

1

1

1

1

i

1

i

- 1819/5

6 B5

l

i

1

1

l

43-4

1

1

|

1 1
ooloo
1^1

5 A2, 15 A3

36 -|
33-.

1

- 1873/8

3 AR

1

30 -|

- 1878/10

28-1

- 1387

26 -I

- 1915/2

18-'

- 1924/8-9

11 AWW

14-1

- 1 94p4

- 12L5

4 AW

12 -
10 -1

- 1 95 7/2

7 -I

- 196 OhO

5 -

- 1987/1-3

1 AJ, 2 AF

4 — *

T

i

67-

I

68-
V ■

I

64

i

I

T |

I X

63 • . .
I

1

70

69’

I

14 48H-

17 AWL
12 APP

65 ■

13 C2L

A

S

H

D

O

W

N

62

i

A.

70 HH7
■ 69 H 87

.68 H 73
67 mje® 4-
66 H 71

•65 H 1 28
•64 H 1 29

■ 63 H58
62 H41 <Cb
u

.61 H127 ®

Base

not

seen

F

A

I

R

L

I

G

H

T

text-fig. 2. Diagram to show the correlation of each of ten selected Fairlight Clay samples by means
of events based on Cicatricosisporites miospores they contain, against a sequence of similar events from
the standard succession in the Warlingham Borehole.

HUGHES AND MOOD Y-STU ART: STRATIGRAPHIC CORRELATION 103

Schulze, mineral separation. Palynologic facies: 24% other pollen, 2% Classopollis,
23% bisaccates, 39% ‘other ferns’, 12% Cicatricosisporites; cuticle, wood; fern spore
size index 32:50:18. (Preparation C156 of Couper 1958 from this sample.)

STRATIGRAPHIC CORRELATION

As shown on the right of text-fig. 2, Hastings Beds samples giving events 61-70 can
be correlated with the local standard sequence in the Warlingham Borehole as follows:

61 EVENT H127\ Between events 5 WM1968/10 and 10 WM1945; on proportion
1 AT/ 4 AW it could lie between events 4 WM 1887 / 1-3 and 5, but 14% cfB. 5 A2
suggests proximity to 10; not later, on absence of 7 Cl.

62 EVENT H41: Between events 7 WM1957/2 and 12 WM1941 /4; presence of cfB.
7 C7, first appearance of cf. 11 AWW.

63 EVENT H58 : Between events 10 WM1945 and 18 WM1915/2; very high cfA.
4 A W , presence of cfB. 6 B5.

64 EVENT HI 29: Between events 14 WM1924/8-9 and 26 WM1887; high cfA. 4 AW,
and also cf. 11 AWW; no cf. 6 B5.

65 EVENT HI 28: Between events 18 WM 1915/2 and 26 WM1887; change in ratio cf.
1 AT I 4 AW, presence of cfA. 5 A2.

66 EVENT H71: Between events 18 WM1915/2 and 28 WM1878j 10; after the main
occurrence of cf. 1 1 AWW , high ratio cf. 1 AT / 4 AW as in events 24 WM1888/3-6
to 26 WM1887, and low cfB. 7 Cl.

67 EVENT HI 18: Between events 30 WM1873I8 and 33 WM1847; low cfA. 1 AT, but
no trace of cf. 8 C2.

68 EVENT H73: Between events 30 WM1873j8 and 36 WM1843; low cfA. 1 AT, high
cf. 15 A3 and others.

69 EVENT H87: Between events 36 WM1843 and 43 WM1819j5; low but definite
occurrence of cfA. 8 C2.

70 EVENT HI 17: Between events 43 WM 18 19/5 and 53 WM1740/6; similar fern spore
size index to 69 event, but stronger occurrence of cfA. 8 C2; pre-53 event as no occur-
rence of cfA. 10 A5S, but this long interval has not yet been analysed.

The result is a ten-event correlation of the samples from the exposed Fairlight Clay
of Hastings, Sussex, with the events from the Warlingham Borehole succession from
depth 1,968/10 ft. to 1,819/5 ft. Other events not here described in detail from the
borehole and outcrop, support the correlations. Only Cicatricosisporites spores have
been used, but other spores in the assemblages are expected to increase the precision of
correlation.

Although it seems probable that eventually much of the comparison can be done by
machine, we do not believe that we yet understand the possibilities well enough to take
advantage of that convenience. We admit to occasional use in both biorecords and events
of the traditional ‘comparative’ terms of description that are now insufficiently precise,
but this was due to lack of time rather than to intention.

INTERPRETATION OF CICATRICOSISPORITES SPECIMENS

Preservation. As shown in text-figs. 3 and 4, preservation changes can completely alter
the appearance of the main characters which must be used in identifying the biorecords

104 PALAEONTOLOGY, VOLUME 12

OPACITY

(Under-maceration)

Full

COMPRESSION
of Spore

SURFACE
COMPRESSION
(lumen closure)

LUMEN
OPENING
(from inflation)

MURUS

CORROSION

GENERAL

THINNING

(without corrosion)

1

SOFTENING
(without thinning)

'drillings'

COLOUR

Darker

y

yj

Lighter

Pale

Pale

y

y

GROSS

DIAMETER

yj

y/

Decrease

not

significant

Increase

not

significant

Slight
dec rease

J

Increase

y

SHAPE

CHANGE

V

Depends on
original
shape

Amb less
circular

Amb more
circular

yj

Tends to
compress

Irregular

folds

y

MURAL

PROFILE

(negative)

Obscures

—

Murus
top more
rounded

Increases
apparent
murus width

—

Decrease
murus width
and height

Distorts

irregularly

Decrease

murus

height

MURAL

PROFILE

(positive)

—

Muri

fold

down

Increase
apparent
murus width

—

—

Decrease

murus

height

Distorts

irregularly

Increase
murus width;
decrease height

WIDTH of
FOUR MURI
andLUMINA

Difficult

to

measure

May

decrease

Decrease

Increase

«/

yj

Decrease

or

increase

Slight

increase

INTER-
RADIAL
EXINE
THICKNESS
(excl. murus
if positive)

Increase 1 Increase

yj

Decrease

May

decrease

Decrease

Obscures
_ ?

decrease

y

RADIAL

EXINE

THICKNESS

Increase

Increase

May

increase

yj

y

Decrease

Decrease

v/

EXAMPLES

on

plates

6CICATR

B5

figs. 2,3

5CICATR
A2
fig. 3

10 CICATR
A5S
fig. 3

8 CICATR C2
figs. 9,10

1 CICATR AT
fig. 8

14 CICATR 48H
fig. 8

9 CICATR
AP

fig. 4

8 CICATR
C2
fig-7

3 CICATR
AR
fig. 5

6CICATR B5
fig. 7

8 CICATR C2
figs. 9, 10
14 CICATR 48H
fig. 4

text-fig. 3. Table of description of various preservation effects on selected Cicalricosisporites spore
characters, expressed as differences from the characters of the ‘ideally preserved' spore. ‘No difference’
is shown by a tick; ‘not applicable’ by a dash. Any apparent discrepancy between lines 4 and 5 of this
table (murus profile) and the corresponding illustrations in text-fig. 4, is due to abbreviation of the

wording in this table.

HUGHES AND MOOD Y-STUART: STRATIGRAPHIC CORRELATION

105

NEGATIVE
9 CICATR AP

- SCULPTURE

Preservational

effect

- POSITIVE
5 CICATR A2

Compression

Surface compression
(lumen closure)

General

thinning

Lumen
opening
(from inflation)

Softening

text-fig. 4. Diagrams of certain preservation effects on murus profile in an example of negative sculp-
ture (Biorecord 9 AP) and of positive sculpture (Biorecord 5 A2). Scale approximately X 2,000.

106

PALAEONTOLOGY, VOLUME 12

or species of this group. Some allowance can be made if the various preservation possi-
bilities are understood, but perhaps most important is confident rejection of unsatis-
factory specimens from a diagnosis. In some cases (e.g. Biorecord 3 CICATR AR in
30 WM1873/8 ) it has been necessary to make biorecords from relatively poorly preserved
material, and allowance for this is necessary throughout the use of this biorecord; it
can be seen that we have made less use of 3 AR than of some others. We hope that
increasing knowledge of the chemistry of sporo-pollenin and of its changes in diagenesis
will make possible the scientific expression of the course of exine degradation even to the
level at which it could be a useful tool in studying the depositional and post-depositional
history of sedimentary rocks. The effects of the preservational states on sculptural and
even structural features of Cicatricosisporites (text-figs. 3, 4) are not all mutually
exclusive and frequently occur superimposed in one specimen or assemblage, but may
not affect the entire specimen or assemblage.

Facies. The selection of data for supplementary description of events follows our earlier
paper (Hughes and Moody-Stuart 1967n); it is of course only suitable for these Early
Cretaceous samples from this special environment. The fern spore size index is based
on 100 specimens of all trilete spores divided into percentages of those falling into the
gross maximum diameter groups < 30 yu. : 30—50 /x : > 50 p. The figures for the event
30 WM 1873 /8 are 52:45:03, which are likely to represent an impoverishment of the
assemblage. However, from this sample, the biorecord 3 CICATR AR has an unusually
low gross maximum diameter mean of 36 p that is unlikely to have been affected; the
absence of cf. 8 C2 (a small spore) is probably stratigraphically significant but the lack
of cf. 9 AP and other larger spores may well not be.

Reworking. While this problem must always remain under observation, there are rela-
tively few specific precautions that can be taken. We believe that it is worth checking
for discontinuous preservation state in specimens being compared with a biorecord or
species, and very unusual palynologic facies should be carefully considered. In some
cases, however, where reworking seems certain from such criteria, it is clear that there
was only a short time difference and thus no stratigraphic difficulty.

SYSTEMATIC TREATMENT

Relatively little published work deals with spores of Berriasian-Valanginian age.
Some of our biorecords fall within the circumscription of published species that refer
in part or wholly to that time; as will be shown below, however, there are very many
minor problems of detail, as well as the major difficulties of stratigraphic use of such
species that are already validly published. We do not discuss post-Hauterivian species,
as in our opinion the evolutionary changes shown by the whole flora by Barremian time
provide adequate grounds for palynologic distinction. The principle works concerned
are by Bolkhovitina (1961), Doring (1965), and Burger (1966).

Genus cicatricosisporites Potonie and Gelletich 1933
Cicatricosisporites recticicatricosus Doring 1965
Remarks. Our biorecord 1 CICATR AT can be included here, and possibly also 2
CICATR AF, because a distinction of this nature has not previously been made. We
believe that C. sprumonti Doring 1965, although recorded as being larger, is also close

HUGHES AND M OOD Y-STU ART: STRATIGRAPHIC CORRELATION 107

to this species. Most other authors have placed all such spores in the now irrelevant
Eocene species C. dorogensis (Couper 1958, Bolkhovitina 1961, Pocock 1962), or in C.
mohrioides Delcourt and Sprumont 1955 (Lantz 19586, Burger 1966) that Delcourt et al.
(1963) regarded as too inadequately based for further use.

Unfortunately the state of preservation of Doring’s (1965) spores appears to be not
very good, and his measurements on all his spores appear to be up to 20% higher than
would be expected from work on spores of comparable age from other areas. His oxida-
tion time was not stated, and it was followed by KOH treatment also of unspecified
time; Smith and Butterworth (1967, p. 105) recorded serious swelling with the use of
KOH, particularly in material which may have been over-oxidized naturally or in the
laboratory.

The closest description to our 1 C1CATR AT is that given by Burger (1966) under
C. mohrioides , but in addition to the difficulty already mentioned about the holotype.
Burger apparently ignored the clear statement by Delcourt and Sprumont (1955) that
the measurement of 4 muri and lurnina is about 18 /z. This appears to be a case for a
new name if such taxonomy is to be continued.

Cicatricosisporites abacus Burger 1966

Remarks. Our biorecord 4 CICATR AW may be included here. The use of Anemia
exilioides (Mai.) Bolkhovitina by Yaroshenko (1965) and other Russians appears to be
similar but the illustrations are not good enough to make comparison certain. C. ster-
num van Ameroni 1965 was used by Burger (1966) for similar forms, but was an Upper
Cretaceous species and thus not relevant.

Cicatricosisporites globosus Doring 1965

Remarks. Our biorecord 1 1 CICATR A WW appears to belong here. Others, however,
may wish to combine the species with C. abacus Burger, over which it has priority of
name. C. globosus was unfortunately only illustrated by a single spore in an equatorial
view.

Cicatricosisporites ( Anemia ) sibirica (Kara-Murza) comb. nov.

Combination. This is made on principle to record our disagreement with the Russian
practice of loading the genera of extant plants with dispersed spore species which cannot
be satisfactorily compared with living whole plants.

Remarks. Our biorecord 3 CICATR AR may be included here, judging from a photo-
graph (Bolkhovitina 1961, pi. 17, fig. 2) rather than from a drawing in the same paper;
the age of the species was given as Valanginian. Samoilovich et al. (1961, p. 281 and
pi. xxiv, fig. 2) listed Mohria striata (Naum.) Bolkh. as a definite element of a Valan-
ginian assemblage; this looks very like our AR, but cannot be used as Bolkhovitina
(1961, p. 66) herself put it in synonymy with ‘ Pelletieria' tersa ( tersa is a Barremian or
later spore with some radial proximal muri). The description given by Groot and Penny
(1960, p. 230) under C. goepperti may include AR, but their new combination was
inadmissible because it placed the megafossil fern Ruffordia in synonymy; Kedves
and Sole de Porta (1963) followed their error. Brenner (1963) swept these spores into
synonymy with the Albian C. aralica (Bolkh.).

] 08

PALAEONTOLOGY, VOLUME 12

Cicatricosisporites crassistriatus Burger 1966
Remarks. Our biorecord 5 CICATR A2 is probably correctly placed here, but Burger’s
holotype (pi. 7, fig. 2) does show one radial murus although the description does not.
In our A2 occasional specimens may show one radial murus but they would be regarded
as extreme variants only, of a form that essentially lacks such a feature (see our dis-
tinction of C. lucifer Hughes and Moody-Stuart 19676, p. 352).

Cicatricosisporites grabowensis Doring 1965

Remarks. Our biorecord 6 CICATR B5 may well belong here, but the holotype preserva-
tion is not good and the diagnosis does not agree accurately. We have also examined
the description of C. angicanalis Doring which was, however, only based on 8 scattered
specimens. As the preservation of our B5 may also be unusual in a different way, it is
perhaps better to leave its attribution undetermined.

Cicatricosisporites myrtellii Burger 1966

Remarks. Our biorecord 10 CICATR AJS agrees in size and in equatorially circular
muri with this species. Burger (1966) described a spore which approaches this form and
could perhaps be combined with it, as C. striatus Rouse 1962; that name, however, is
not available owing to Mohria striata (Naum.) Bolkh. 1953, which is mentioned above
under C. sibirica.

Cicatricosisporites lucifer Hughes and Moody-Stuart 19676
Remarks. Our biorecord 7 CICATR Cl is the same as the record of this species. Most
authors have submerged such spores in the Senonian Appendicisporites tricornitatus
Weyland and Greifeld 1953 (Delcourt and Sprumont 1955, Couper 1958, Groot and
Penny 1960, Pocock 1962), or in A. macrorhyza (Mai.) Bolkh. (Bolkhovitina 1961,
pi. 15, figs. 7c, d only). Burger (1966) gave a recognizable description under the name
PlieateUa problematical but it is better to avoid this name as Doring (1965) re-combined
Cingulatisporites problematicus Couper 1958 into Contignisporites which is very close
morphologically to Cicatricosisporites.

Genus appendicisporites Weyland and Krieger 1953
Remarks. Although post-Hauterivian forms may truly fall in such a genus, we adhere
to our view that Valanginian spores with long appendages are only extreme forms of
Cicatricosisporites species (Hughes and Moody-Stuart 1966, p. 288; 19676, p. 353).

Appendicisporites jansonii Pocock 1962

Remarks. Our biorecord 9 CICATR A P may be included here on the basis of our views
on the genus, although it is not, of course, strictly according to Pocock’s diagnosis.
Burger (1966) used A. tricornitatus for such spores. Another earlier biorecord 12
CICATR APP agrees more closely in size with this species, as do Pelletieria valdensis
(spores) which we described in 1966.

Cicatricosisporites {Anemia) crimensis (Bolkh.) comb. nov.

Remarks. Our biorecord 8 CICATR C2 belongs here; see Bolkhovitina 1961 (p. 55,
pi. 15, fig. 8), and Samoilovich et al. 1961 (p. 75, pi. 19). Western authors have con-

HUGHES AND MOODY-STUART: STRATIGRAPHIC CORRELATION 109

sistently used the Senonian Appendicisporites tricornitatus for these spores (Couper
1958, Doring 1965); Doring (1965, pi. 12, figs. 5-7) figured a battered specimen with the
broken radial area that we find characteristic in the biorecord C2.

Stratigraphic range. The Russians record the range of this species as Hauterivian
onwards. Doring (1965) found it to be restricted to German Wealden G, which is Early
Valanginian, and our records are in agreement with this. Burger (1966) had no such
species, which suggests that perhaps his section may not have gone high enough to con-
tain them. Our separate earlier biorecord 13 C1CATR C2L, which is distinct and of a
much larger spore, may fall into Anemia pschekhaensis Bolkh. 1961 (pi. 15, fig. 9).

Results of systematic study

From the systematic discussion above it can be seen that in no case is the attribution
clear-cut and satisfactory both in taxonomy and in nomenclature. The inclusion in the
discussion of any post-Hauterivian taxonomy on a morphological basis only adds to
the confusion.

Ignoring the circumscriptions and names, however, it is clear that the Cicatricosis-
porites spore assemblages we have studied in Britain compare closely with those of
similar age from the Netherlands (Burger 1966) and Mecklenburg (Doring 1965), if not
also with those of the U.S.S.R. All of the spores they describe are recognizable in our
assemblages, and we have relatively few types that they do not indicate in any way. It
is even possible to suggest that Doring’s (1965) German Wealden A may be later than
he suggests in his table, and perhaps equivalent to about 1,940-1,920 ft. in the
Warlingham Borehole.

Further work in progress covers other British sections, and firmer correlation with
continental sections.

GENERAL CONCLUSIONS

1. The method used has evolved during the work, with the result that some minor
decisions, such as the sample selection for biorecords, could in future be improved
when starting with an agreed method; biorecords are of course not claimed as any new
invention, but rather as a planned convenience.

2. Events are intended to remain open for additional data; in cases of such addition
the event number could be modified by decimalized suffix with a new date.

3. It seems possible that there is some minor fault repetition (or even omission) in the
Wealden of the Warlingham Borehole, as there is in the Purbeck Beds below, and it
should become apparent through this form of analysis.

4. Neither the terms ( biorecord , event etc.) nor the precise arrangements used need
to remain unchanged. Criticism is invited (a) of method, and ( b ) of the execution.

5. We do not envisage this correlation method as more powerful than others over a
greater distance. Long-distance (inter-province) single-item biological correlation is a
pipe-dream; world-wide correlation will eventually be achieved by many consecutive
steps essentially of the kind envisaged here, although certain short cuts are not
precluded.

6. We believe from this study that although our scale of working approaches that of
plant ‘migration’ time, it is still well above it.

7. A usual criticism of this kind of work is that it presupposes biological (or earth)

110

PALAEONTOLOGY, VOLUME 12

evolution. It makes this assumption in general, but this does not invalidate the separate
investigation of evolution in detail.

8. The slightly extended presentation here is intended to draw attention to the data
storage need. Future publication level in this field may have to be ‘plates and diagnosis’,
or even ‘plates alone’, with the remainder advertised ‘on call’. An attempt has been
made to allow for data handling problems so far foreseen.

9. We believe that methods such as are presented here are necessary throughout
stratigraphic palaeontology. The clear separation of basic data from interpretation is as
essential in stratigraphy in the de-formalizing of the concept of zones, as it is in palaeon-
tology in the restriction of ‘Linnaean’ taxonomy and nomenclature to interpretative
functions alone.

Acknowledgement. 'We are grateful to members of the G. L. Seminar (1967) in the Department of Geology,
Cambridge, whose timely criticisms and suggestions were most helpful.

REFERENCES

bolkhovitina, n. a. 1961. Fossil and Recent spores of the family Schizaeaceae. Trudy geol. Inst. Acad.

nauk SSSR ., Moscow, 40, 1-176, 41 pi. (in Russian).
brenner, o. j. 1963. The spores and pollen of the Potomac Group of Maryland. Bull. Md. Dep. Geol.
Mines, Baltimore, 27, 1-215, 43 pi.

burger, d. 1966. Palynology of uppermost Jurassic and lowermost Cretaceous strata in the eastern
Netherlands. Leid. geol. Meded. 35, 209-76, 39 pi.

couper, R. a. 1958. British Mesozoic microspores and pollen grains. Palaeontographica, Stuttgart,
103B, 75-179, 17 pi.

delcourt, a. and sprumont, g. 1955. Les Spores et Grains de pollen du Wealdien du Hainaut. Mem.
Soc. beige Geol., n.s., 5, 1-73, 4 pi.

— dettmann, M. e., and hughes, N. f. 1963. Revision of some Lower Cretaceous microspores from
Belgium. Palaeontology, 6, 282-92, pi. 42-45.

doring, h. 1965. Die sporenpalaontologische Gliederung des Wealden in Westmecklenburg (Struktur
Werle). Geologie Jg. 14, Beih. 47, 1-118, 23 pi.

george, t. N. et al. 1967. Report of the Stratigraphical Code Sub-Committee. Proc. geol. Soc. Loud.
1638, 75-87.

groot, j. j. and penny, j. s. 1960. Plant microfossils and age of non-marine Cretaceous sediments of
Maryland and Delaware. Micropaleontology , 6, 225-36, 2 pi.
harland, w. b. et al. (eds.) 1967. The fossil record. London (Geological Society), xii + 828 pp.
hughes, N. f. 1958. Palaeontological evidence for the age of the English Wealden. Geol. Mag. 95, 41-9.

and moody-stuart, j. c. 1966. Descriptions of schizaeaceous spores taken from early Cretaceous

macrofossils. Palaeontology, 9, 274-89, pi. 43-47.

— 1967«. Palynological facies and correlation in the English Wealden. Rev. Palaeobot.

Palynol. 1, 259-68.

19676. Proposed method of recording pre-Quaternary palynological data. Ibid. 3, 347-58,

1 pi.

williams, d. b., cutbill, j. c., and harland, w. b. 1967. A use of reference-points in stratigraphy.

Geol. Mag. 104, 634-5.

1968. Hierarchy in stratigraphical nomenclature, ibid. 105, 78-9.

jekhowsky, b. de 1958. Methodes d'utilisation stratigraphique des microfossiles organiques dans les
problemes petroliers. Revue lnst.fr. Petrole, Paris, 13, 1391-1418, 3 pi.
kedves, m. and sole de porta, n. 1963. Comparacion de las esporas del genero Cicatricosisporites
R. Pot. y Gell. 1933 de Hungrla y Colombia. Boln Geol. Fac. Petrol. Univ. ind. Santander, 12, 51-76.
lantz, j. 19586. Etude palynologique de quelques echantillons mesozoiques du Dorset (Grande -
Bretagne). Revue Inst. fr. Petrole, Paris, 13, 917-43, 7 pi.
pocock, s. a. j. 1962. Microfloral analysis and age determination of strata at the Jurassic-Cretaceous
boundary in the Western Canada plains. Palaeontographica, Stuttgart, 111B, 1-95, 15 pi.

HUGHES AND MOOD Y-STU ART: STRATIGRAPHIC CORRELATION

samoilovich, s. r. et al. 1961. Pollen and spores of western Siberia; Jurassic to Palaeocene. Tr.

VNIGRI, Leningrad, 177, 352 pp., 141 pi. (in Russian).
shaw, A. b. 1964. Time in stratigraphy. McGraw-Hill.

smith, a. h. v. and butterworth, m. a. 1967. Miospores in the coal seams of the Carboniferous of
Great Britain. Spec. Paper Palaeont. 1, 1-324, 27 pi.
white, h. j. osborne 1928. The geology of the country near Hastings and Dungeness. Mem. Geol.
Surv. U.K., Sheets 320-1.

Yaroshenko, o. p. 1965. Spores and pollen complexes of Jurassic and Lower Cretaceous deposits of
northern Caucasus and their stratigraphic importance. Trudy geol. Inst. Acad, nauk SSSR., Moscow,
117, 1-108, 23 pi. (in Russian).

n. f. hughes

J. C. MOODY-STUART

Department of Geology
Sedgwick Museum

Typescript received 1 May 1968 Cambridge

THE OSTRACODA OF THE DORSET KIMMER1DGE

CLAY

by T. I. KILENYI

Abstract. Fifty-nine species of Ostracoda are recorded and figured from the Kimmeridge Clay of Dorset, the
type area of the Kimmeridgian Stage. Fifteen new species and one new subspecies are described. The classifica-
tion of some Jurassic ostracod genera is critically reviewed and the stratigraphical distribution of each recorded
species is given.

The best exposures of the Kimmeridge Clay in Dorset are found in two main areas
(text-fig. 1). The most complete section extends from the west side of Kimmeridge Bay
to Chapman’s Pool, a distance of some 6 miles, exposing a thickness of almost 1,100 ft.
(Arkell 1947). At the time of collecting the entire section was accessible except for a

N

text-fig. 1. Sketch map of the coast of south-east Dorset to show the outcrop of the Kimmeridge

Clay and important localities.

50-ft. gap in the Rhynchonella Marls (Rotunda Zone), which was obscured by landslips.
The section does not expose, however, the lower part of the Kimmeridge Clay, including
the Baylei, and Cymodoce, Mutabilis Zones and the lower portion of the Pseudomutabilis
Zone. These are accessible further to the west, between Osmington Mills and Shortlake
at a locality referred to in the text as ‘Black Head’ section. The section here is much
disturbed by landslips due to the soft nature of the shales. Arkell (1947) recorded at

[Palaeontology, Vol. 12, Part 1, 1969, pp. 112-160, pi. 23-31.]

T. I. KILENYI: OSTRACODA OF DORSET KIMMERIDGE CLAY 113

Black Head about 500 ft. of shales, extending as far up in the succession as the Pectina-
tus Zone. Only 180 ft. of this section was sampled, reaching up to and including the
basal 35 ft. of the Pseudomutabilis Zone, the rest being obscured by landslips and
mudflows.

Altogether 125 samples were collected, 106 from the Kimmeridge Bay — Chapman’s
Pool section and 19 from the Black Head section. In addition Dr. A. J. Lloyd was kind
enough to let me have ten washed samples from the Grandis, Wheatleyensis, and Pec-
tinatus Zones. Samples were collected at 10-ft. intervals, but where an obvious litho-
logical change occurred, an additional sample was taken. In the lowest three Zones the
sampling was carried out at much more frequent intervals (text-fig. 2). The stratigraphi-
cal horizon of each sample was determined by accurately measuring the vertical distance
from the nearest ‘stone band’ or other well-marked bed (Arkell 1947). About 1,000 g.
of each shale sample was washed. Some of the harder shales were extremely difficult
to break down and very harsh methods had to be employed. This may be responsible
for the almost complete lack of ostracods in the higher Pseudomutabilis, Gigas, and
Vimineus Zones.

The ostracod terminology is essentially that adopted in the Treatise, Part Q. Some
difficulty arises, however, in applying the hinge terminology, especially in some species
of Amphicythere where the hinge structure seems to be transitional between the types
described as paramphidont and schizodont in the Treatise (text-fig. 6).

The classification adopted here is basically that of the Treatise but with some signi-
ficant differences. Species of Schuleridea and Nodophthalmocy there are placed in the
family Schulerideidae (Schulerideinae Mandelstam 1959, raised to family status by Bate
1963). In the writer’s opinion this is justified by the distinct, fan-shaped arrangement of
the radial pore canals. The Treatise included Protocytherinae Ljubimova 1955 in the
family Progonocytheridae Sylvester-Bradley 1948. Bate (1963) raised Protocytherinae
to family status and this practice is followed by the writer. Mandelstamia is retained
in Loxoconchinae Sars 1925 (Neale and Kilenyi 1961; Kaye 1963).

Acknowledgements. The author would like to thank Dr. John W. Neale for constant advice and
encouragement throughout this study; Mr. L. F. Penny for the use of facilities in the Geology Depart-
ment, University of Hull; also Dr. F. W. Anderson, Dr. A. J. Lloyd, Dr. H. Malz, Mr. F. P. C. M. van
Morkhoven, and Dr. R. C. Whatley, for help received.

Abbreviations. The sample numbers are prefixed by letters referring to the ammonite zones according
to the following code: P. = Pictonia baylei; RC. = Rasenia cymodoce; RM. = R. mutabilis;
AU. = Aulacostephanus pseudomutabilis; G. = Gravesia gigas; SUV. = Subplanites vimineus;
SUG. = S. grandis; SUW. = S. wheatleyensis; PE. = Pectinatites pectinatus; PA. = Pavlovia
rotunda and P. pallasoides Zones. The letters DO. preceding the codes refer to samples received from
Dr. A. J. Lloyd.

In giving the dimensions of ostracod valves the following abbreviations are used throughout the text:
L, length; H, height; W, width; M/a, width of anterior margin. Dimensions are given in millimetres,
and are averages except in the case of numbered specimens.

Repository. All figured and described specimens are stored in the Geology Department, University
of Hull. Specimen numbers are indicated by the prefix HU.

C 6289

1

114

PALAEONTOLOGY, VOLUME 12

T 100ft

.50

J- 0

A pseudomutabilis

TV

AU. I-V

I

Rasenia mutabilis

Astarte

supracorallina

bed.

T 0
'7
6

RM. 1-10

3

1

Rasenia cymodo^e^

Pictonia baylei

1 3 .1 R C 1-3

3

text-fig. 2. Zonal classification of the Kimmeridge Clay (as in Arkell 1956) and the distribution of

samples throughout the section.

T. I. KILENYI: OSTRACODA OF DORSET KIMMERIDGE CLAY

115

SYSTEMATIC DESCRIPTIONS

Subclass ostracoda Latreille 1806
Order podocopida Muller 1894
Suborder platycopina Sars 1866
Genus cytherella Jones 1 849
CythereUa recta Sharapova 1939

Plate 23, figs. 1-5

1939 Cytherella ovalis Terquem var. recta Sharapova, p. 34, pi. 4, figs. 45, 46 (<J).
1955 Cytherella recta Sharapova; Ljubimova, p. 105, pi. 12, figs. 3 a, b G).

1955 Cytherella ukrainensis Ljubimova, p. 106, pi. 12, figs. 6a, b (9).

Material. 15 valves and carapaces. HU 2.J.2.1-15.

Dimensions {mm.).

L

H

W

$ Left valve

0-68-0-70

0-35

0 13

9 Right valve

0-69-0-70

0-43-0-44

0 14

cj Left valve

0-68

0-36

012

S Right valve

0-69

0-38

0 12

Occurrence. Baylei and Cymodoce Zones, P. 1, RC. 3.

Diagnosis. Large, sub-rectangular carapace with equally rounded anterior and posterior
ends. Right valve higher than left, overlapping it strongly ventrally and dorsally. Dorsal
margin straight, ventral slightly concave in middle. Sexual dimorphism strong.

Remarks. In the recent literature on Mesozoic ostracods a large number of species of
Cytherella have been described based on slight differences in the outline of the carapace.
In the author’s opinion a critical study would drastically reduce the number of species,
but at present only a few, obvious examples are included in the synonymy.

Genus cytherelloidea Alexander 1929
Cytherelloidea weberi Steghaus 1951
Plate 23, figs. 6, 7

1951 Cytherelloidea weberi Steghaus, p. 207, pi. 14, figs. 4-6, non figs. 3, 5.

1955 Cytherelloidea weberi Steghaus; Schmidt, p. 51.

1957 Cytherelloidea weberi Steghaus; Oertli, p. 650, pi. 1, fig. 11.

1959 Cytherelloidea weberi Steghaus; Oertli, p. 17, pi. 2, figs. 28, 29.

1960 Cytherelloidea weberi Steghaus, var. reticulata Donze, pp. 10, 11, pi. 1, figs. 3-6.
1962 Cytherelloidea weberi Steghaus; Klinger, Malz, and Martin, p. 168, pi. 25, fig. 21.
1964 Cytherelloidea weberi Steghaus; Glasshof, p. 52.

Material. 1 carapace. HU 2.J.4.1-2.

Dimensions (mm.). L H

Left valve 0-65 0-34

Right valve 0-69 0-37

Occurrence. Mutabilis Zone, RM. 6.

Diagnosis. Carapace quadrangular. Each valve has peripheral ridge which runs parallel
with edge of valve, equidistant from margin. Ridge may be interrupted antero-dorsally.
On posterior part of both valves two rounded ‘swellings’ occur in vertical superposition.

1 16

PALAEONTOLOGY, VOLUME 12

Median rib branches out from upper one, descends to middle of valve, where it turns
to run parallel with dorsal margin.

Remarks. The above diagnosis is based on the carapace found in the Dorset material.
Oertli (1957, p. 650) does not mention the posterior ‘swelling’, while Steghaus (1951,
pp. 207, 208) describes one.

Cytherelloidea paraweberi Oertli 1957

Plate 23, figs. 8, 9; text-fig. 5a

1951 Cytherelloidea weberi (pars) Steghaus, p. 207, pi. 14, figs. 3, 5, non figs. 4, 6.

1955 Cytherelloidea weberi Steghaus ( pars ?); Schmidt, p. 51.

1957 Cytherelloidea paraweberi Oertli, p. 651, pi. 1, figs. 12-15.

1959 Cytherelloidea paraweberi Oertli; Oertli, p. 18, pi. 2, figs. 26, 27.

1964 Cytherelloidea paraweberi Oertli; Glasshof, p. 52.

1966 Cytherelloidea paraweberi Oertli; Barker, p. 457, pi. 3, figs. 7-9; p. 485, pi. 9, figs. 1, 2.
Material. 2 valves. HU 2. J. 5. 1-2.

Dimensions (mm.). L H W

Right valve 0-57 0-28 0 09

EXPLANATION OF PLATE 23

All figures X 50.

Figs. 1-5. Cytherella recta Sharapova, Cymodoce Zone, RC. 3, Lower Kimmeridgian. 1, Right valve,
male, external view, HU 2.J.2.I. 2, Right valve, female, external view, HU 2.J.2.6. 3, Carapace,
male, dorsal view, HU 2.J.2.9-10. 4, Left valve, male, external view, HU 2.J.2.5. 5, Right valve,
female, transmitted light, HU 2.J.2.6.

Figs. 6, 7. Cytherelloidea weberi Steghaus, Mutabilis Zone, RM. 6, Lower Kimmeridgian. 6, Carapace,
dorsal view. 7, Carapace, left side, external view, HU 2.J.4.I.

Figs. 8, 9. Cytherelloidea paraweberi Oertli, Mutabilis Zone, RM. 9, Lower Kimmeridgian. 8, Right
valve, external view. 9, Right valve, dorsal view, HU 2J.5.1.

Figs. 10-13. Paracypris sp. C. Oertli, Baylei Zone, P. 1, Lower Kimmeridgian. 10, Right valve,
external view, HU 2.J.6.I. 11, Right valve, internal view, transmitted light, HU 2.J.6.I. 12-13,

Right valve, internal view, polarized light, HU 2.J.6. 1.

Figs. 14, 15. Paracypris sp. 1, Rotunda Zone, PA. 1, Upper Kimmeridgian. 14, Left valve, external
view, HU 2.J.8.I. 15, Left valve, internal view, transmitted light, HU 2.J.8.I.

Figs. 16-20. ? Paracypris problematica sp. nov., Rotunda Zone, PA. 21, Upper Kimmeridgian.
16, Right valve, female, external view, HU 2.J.7.2. 17, Left valve, female, external view, holotype,
HU 2. J. 1.1. 18, Right valve, male, external view, HU 2.J.7.3. 19, Left valve, male, external view,
HU 2.J.7.4. 20, Carapace, male, dorsal view, HU 2.J.7.5-6.

Figs. 21-33. Schuleridea triebeli (Steghaus), Baylei Zone, P. 2, Lower Kimmeridgian. 21, Right valve,
male, external view, HU 2.J.9.I. 22, Left valve, male, external view, HU 2.J.9.2. 23, Right valve,
female, external view, HU 2.J.9.7. 24, Left valve, female, external view, HU 2.J.1.32. 25, Right
valve, juvenile male, external view, HU 2.J.9.13. 26, Left valve, juvenile male, external view,

HU 2.J.9.12. 27, Right valve, juvenile female, external view, HU 2.J.9.15. 28, Left valve, juvenile
female, external view, HU 2. J. 9.16. 29, Left valve, male, with broad duplicature, transmitted light,
HU 2.J.9.18. 30, Carapace, female, dorsal view, HU 2. J. 9.20-21. 31, Left valve, male, with narrow
duplicature, HU 2.J.9.26. 32, Carapace, male, dorsal view, HU 2.J. 9.22-23. 33, Left valve, male,
internal view, HU 2.J.9.17.

Figs. 34, 35, 39. Schuleridea sp. 1, Wheatleyensis Zone, DO VW. 6, Middle Kimmeridgian. 34, Cara-
pace, left side, external view, HU 2.J.I.2. 35, Carapace, right side, external view, HU 2.J.I.2.
39, Carapace, dorsal view, HU 2.J. 1.2.

Figs. 36, 38. ? Schuleridea sp. 1, Wheatleyensis Zone, DO VW. 4, Middle Kimmeridgian. 36, Right
valve, female, external view, HU 3.J.I.5. 37, Left valve, female, external view, HU 3.J.I.4.
38, Left valve, male, external view, HU 3.J.I.7.

Palaeontology, Vo/. 12

PLATE 23

KILENYI, Kimmeridge Clay ostracods

T. I. KILENYI: OSTRACODA OF DORSET KIMMERIDGE CLAY

117

Occurrence. Mutabilis Zone, RM. 9.

Diagnosis. Similar to Cytherelloidea weberi except for peripheral ridge, which is con-
tinuous. Median rib curved.

Remarks. Oertli separated C. paraweberi from C. weberi on the basis of the presence of
a continuous peripheral ridge. Equally diagnostic, it seems, are the lack of posterior
‘swellings’ in C. paraweberi and different dorsal silhouette.

Suborder podocopina Sars 1866
Superfamily cypridacea Baird 1845
Family paracyprididae Sars 1923
Genus paracypris Sars 1866
Paracypris sp. C, Oertli 1957
Plate 23, figs. 10-13; text-fig. 5b
1957 Paracypris sp. C, Oertli, p. 653, pi. 1, fig. 24.

Material. 1 broken right valve. HU 2.J.6. 1.

Dimensions (mm.). L: 0 60; H: 0-24.

Occurrence. Baylei Zone, P. I .

Paracypris sp. 1
Plate 23, figs. 14, 15

Material. 2 left valves. HU 2.J.8.1-2.

Dimensions (mm.). L: 0 58; II : 0-26.

Occurrence. Base of Rotunda Zone, PA. 1 .

Description. Left valve elongated, greatest height near anterior end. Dorsal margin
strongly convex, ventral slightly concave. Posterior end terminates in sharp point.

Marginal areas relatively narrow, posterior duplicature slightly wider than anterior.
Inner margin and line of concrescence seem to coincide. Radial pore canals straight,
simple, numerous. Muscle scar pattern not seen.

? Paracypris problematica sp. nov.

Plate 23, figs. 16-20; text -fig. 5c
Holotype. A female left valve, HU 2J.1.1.

Paratypes. 23 valves, HU 2.J. 7.2-24.

Type locality and horizon. Hounstout Cliff, Kimmeridge, Dorset. Rotunda Zone, Upper Kimmerid-
gian.

Dimensions (mm.).

L

H

W

9 Left valve (holotype)

0-45

019

005

9 Right valve

0-44

018

004

S Left valve

0-44

0-17

005

c? Right valve

0-42

017

005

Occurrence. Rotunda Zone, PA. 21.

Diagnosis. Shape elongated, with pointed posterior end. Marginal areas extremely
narrow. Seven irregularly spaced muscle scars. Strong sexual dimorphism.

118

PALAEONTOLOGY, VOLUME 12

Description. Shell minute, anterior end rounded, posterior pointed. Dorsal margin
strongly convex, ventral straight. Left valve slightly larger than right, overlapping it
dorsally and ventrally. Valve surface smooth.

Marginal areas narrow, line of concrescence and inner margin seem to coincide.
Number and nature of radial pore canals not seen. No hinge structure observed.
Muscle scar pattern consists of 7 irregularly spaced scars, 6 together in two groups of
three and 1 anterior. Sexual dimorphism strong; presumed female valves much higher
posteriorly.

Remarks. The generic position of this species is doubtful. In shape it is closest to Para-
cypris , but it differs in the narrower marginal areas and the slightly different muscle
scar pattern. The genus Pontocypris has a similar shape and relatively narrow marginal
areas, but the muscle scars are definitely different, and in the case of Pontocypris always
constant. Macrocypris has a wide anterior margin with a broad inner lamella.

Superfamily cytheracea Baird 1850
Family schulerideidae Mandelstam 1959
Subfamily schulerideinae Mandelstam 1959
Genus schuleridea Swartz and Swain 1946
Schuler idea triebeli (Steghaus 1951)

Plate 23, figs. 21-33

1951 Haplocytheridea triebeli Steghaus, p. 214, pi. 15, figs. 27-29.

1955 Haplocytheridea triebeli Steghaus; Schmidt, p. 58, pi. 4, fig. 4; pi. 5, fig. 2.

1957 Schuleridea triebeli (Steghaus); Oertli, p. 654, pi. 1, figs. 25-29.

1958 Schuleridea triebeli (Steghaus); Bizon, p. 23, pi. 5, figs. 4-6.

1959 Schuleridea triebeli (Steghaus); Oertli, p. 25, pi. 3, figs. 87, 88.

1960 Schuleridea cf. triebeli (Steghaus); Lutze, p. 433, pi. 37, fig. 9.

1964 Schuleridea triebeli (Steghaus); Glasshof, pp. 40, 41.

Material 585 valves and carapaces. HU 2. J. 1.32, HU 2.J.9.1-584.

Dimensions (mm.).

L

H

W

M/a

$ Left valve

0-42-0-50

0-31-0-37

0 14

0-05

? Right valve

0-44-0-46

0-30-0-31

0 10

0-05

S Left valve

0-49-0-62

0-31-0-37

0 13

0-05

S Right valve

0-45-0-62

0-25-0-26

0-13

0-05

Occurrence. Baylei, Cymodoce, and Mutabilis Zones, P. 1,2, RC. 1-3, RM. 7, 9.

Diagnosis. Species of Schuleridea with very strong sexual dimorphism. Female carapace
with ovoid outline, tapering towards posterior, males elongated. Faint depression in
ocular region. Peripheral sulcus developed along anterior and posterior border. Overlap
of left valve very pronounced, especially in females.

Remarks. This is an extremely common species in the Upper Jurassic of western Europe,
ranging from the Mariae Zone (Lower Oxfordian) to the top of the Mutabilis Zone
(Lower Kimmeridgian). There seems to be a considerable variation in the forms
described from the various localities, especially in size and degree of sexual dimorphism.
The median element of the hinge has been described as smooth or finely denticulate;
the Dorset specimens seem to belong to the latter type. An unusual phenomenon was

T. I. KILENYI: OSTRACODA OF DORSET KIMMERIDGE CLAY

119

observed in a large population of S. triebeli from the Lower Kimmeridgian ; the width
of the duplicature was reduced by half in some specimens which in all other respects
conformed to the type. This is certainly not a variation as it is observed in the final instar
only, in both males and females.

Schuleridea sp. 1
Plate 23, figs. 34-39

Material. 30 valves and carapaces. HU 2.J.1.2, HU 3. J. 1.2-30.

Dimensions (mm.). L

Carapace 0 60-0-65

? Juvenile forms

$ (?) Left valve 0-45-0-48

$ (?) Right valve 0-45

S (?) Left valve 0-49

Occurrence. The larger, closed carapaces occur i
Wheatleyensis Zone.

H

W

0-40-0-42

0-30

0-30

01 2-0- 14

0-26

0 11-0-12

0-27

0 11

DO VW. 6, the smaller valves in DO VW. 4,

Description. Carapace ovoid, well rounded, without marked cardinal angles. Left valve
larger than right, overlapping it along dorsal and ventral margins. Contours of both
valves similar, right valve being slightly less high. Only closed carapaces found.

From slightly lower horizon similar, but smaller, forms were found, which may
represent earlier instar. These specimens have rather more angular appearance, and
since found as separate valves, characteristic hinge and duplicature of Schuleridea could
be observed. These smaller valves show sexual dimorphism, a feature not definitely
established in larger, closed carapaces. Smaller forms therefore included only tentatively
in Schuleridea sp. 1 .

Remarks. This form is close to S. triebeli but differs from it in the far less pronounced
overlap of the left valve and the outline of the right valve; the state of preservation does
not allow the establishment of a new species.

? Schuleridea sp. 2
Plate 24, fig. 1

Material. 1 right valve. HU 2. J. 10.1.

Dimensions (mm.). L H W M/a

Right valve 0-62 0-37 0 16 0-05

Occurrence. Top of Pectinatus Zone, DO PE. 11.

Description. In side view valve ovoid, slightly triangular, with rounded anterior, straight
dorsal and ventral margins. Posterior end more angular. Greatest height at prominent
anterior cardinal angle.

Surface finely punctate, and normal pore canals plainly visible. Inner margin and line
of concrescence coincide. About 25-30 anterior radial pore canals occur, arranged in
shape of fan. Hinge structure (owing to poor preservation) not seen clearly, but gives
impression that all positive hinge elements are in right valve.

Remarks. The number and arrangement of the radial pore canals are typical of Schuleri-
dea. The hinge structure would give the decisive identification.

120

PALAEONTOLOGY, VOLUME 12

Genus nodophthalmocythere Malz 1958

Nodophthalmocy there tripartita Malz 1958

Plate 24, figs. 2-7

1 958<:/ Nodophthalmocyther
Material. 24 valves and carapaces
Dimensions (mm.).

$ Left valve
9 Right valve
<S Left valve
<S Right valve

tripartita Malz, pp.
HU 2.J. 11.1-24.

125, 126, pi

L

H

0-48

0 31

0-47

0-28

0-54

0-30

0-54

0-28

1, figs. 1-8; pi. 3, figs. 25, 26.

W

012

012

013

013

Occurrence. Mutabilis Zone, RM. 6.

Diagnosis. Species of Nodophthalmocythere with upside down T-shaped median sulcus.
Two bulges in front and behind sulcus, and long one underneath. Eye tubercules
developed. Sexual dimorphism pronounced.

Remarks. This species was first described by Malz (1958u) from the Pseudomutabilis
Zone of the Black Head section, and he mentioned that it occurred with Exophthahno-
cy there fuhrbergensis Steghaus. N. tripartita is here recorded with E.fuhrbergensis, from
the middle of the Mutabilis Zone but no trace of it has been found in the Pseudo-
mutabilis Zone. It is very likely, therefore, that Malz’s horizon and locality corresponds
with the writer’s and not to the Pseudomutabilis Zone as first suggested.

Family cytherideidae Sars 1925
Subfamily cytherideinae Sars 1925
Genus galliaecytheridea Oertli 1957
Galliaecytheridea dissimilis Oertli 1957
Plate 24, figs. 8-20; text-figs. 3a, 5 d

EXPLANATION OF PLATE 24
All figures x 50, unless otherwise stated.

Fig. 1. ? Sclnderidea sp. 2, Pectinatus Zone, DO PE. 11, Upper Kimmeridgian. Right valve, external
view, HU 2.J.10.1.

Figs. 2-7. Nodophthalmocythere tripartita Malz, Mutabilis Zone, RM. 6, Lower Kimmeridgian.
2, Right valve, male, external view, HU 2.J.11.1. 3, Left valve, male, external view, HU 2.J.11.2.
4, Left valve, female, external view, HU 2.J.11.4. 5, Carapace, male, dorsal view, HU 2.J.11.5.
6, Left valve, male, internal view, transmitted light, HU 2. J. 11.9. 7, Left valve, male, anterior
margin, transmitted light, HU 2. J. 11.2, x85.

Figs. 8-14. Galliaecytheridea dissimilis Oertli, Cymodoce Zone, RC. 3, Lower Kimmeridgian. 8, Right
valve, male, external view, HU 2.J.12.1. 9, Left valve, male, external view, HU 2.J.12.2. 10, Right
valve, female, external view, HU2. J.12.6. 11, Left valve, female, external view, HU 2.J.12.4. 12, Left
valve, juvenile, external view, HU 2.J.12.5. 13, Carapace, female, ventral view, HU 2.J. 12. 10-11.

14, Right valve, female, dorsal view, HU 2. J. 12.12.

Figs. 15-20. Galliaecytheridea dissimilis Oertli, Pseudomutabilis Zone, AU. II, Lower Kimmeridgian.

15, Right valve, ? female, external view, HU 3.J.2.2. 16, Left valve, ? female, external view,

HU 2.J.I.3. 17, Left valve, ? male, external view, HU 3.J.2.4. 18, Right valve, ? female, internal
view, transmitted light, HU 3.J.2.2. 19, Carapace, ? female, ventral view, HU 3.J.2.7-8. 20, Left
valve, juvenile, external view, HU 3.J.2.3.

Figs. 21-27. Galliaecytheridea wolburgi (Steghaus), Mutabilis Zone, RM. 1, Lower Kimmeridgian.
21, Right valve, external view, HU 2. J. 13.1. 22, Left valve, external view, HU 2.J.13.2. 23, Cara-
pace, dorsal view, HU 2.J.13.8-9. 24, Carapace, ventral view, HU 2.J.13.8-9. 25, Right valve,
juvenile, external view, HU 2.J.13.5. 26, Left valve, juvenile, external view, HU 2.J.13.3. 27, Right
valve, juvenile, internal view, transmitted light, HU 2.J.13.5.

Palaeontology, Vol. 12

PLATE 24

^9^

25

26

27

KILENYI, Kimmeridge Clay ostracods

tf3

T. I. KILENYI: OSTRACODA OF DORSET KIMMERIDGE CLAY

121

1957 Galliaecytheridea dissimilis Oertli, p. 655, pi. 1, figs. 32-9; pi. 2, figs. 40-44.
1964 Galliaecytheridea dissimilis Oertli; Glasshof, pi. 4, figs. 8-11.

Material. 1,396 valves and carapaces. HU 2.J. 12.1—1 ,387, HU 3.J.1-9.

Dimensions (mm.). L

? Left valve 0-64-0-73

$ Right valve 0-63-0-71

<$ Left valve 0-67

S Right valve 0-64

H

W

M/a

0-45-0-52

0-20

0-06

0-36-0-40

0-16

0-07

0-46

0-21

0-39

0 16

Occurrence. Baylei, Cymodoce, Mutabilis, and Pseudomutabilis Zones, P. 1, RM. 2, RC. 1-3, AU. II.

Diagnosis. Left valve much larger than right and more rounded in side view. Dorsal
margin of left valve strongly convex, of right valve straight. Right valve posterior end
pointed. Surface smooth or finely punctate. Radial pore canals straight, simple, and
few. Sexual dimorphism occurs.

Remarks. The Dorset specimens are appreciably larger than the specimens described by
Oertli (1957) from the Paris basin, but sexual dimorphism is less prominent.

Galliaecytheridea wolburgi (Steghaus 1951)

Plate 24, figs. 21-27; text-figs. 3e, 5e

1951 Cyprideis wolburgi Steghaus, p. 213, pi. 14, figs. 24, 25; pi. 15, fig. 26.

1955 Cyprideis wolburgi wolburgi Steghaus; Schmidt, p. 58, pi. 2, figs. 25, 26.

1955 Cyprideis wolburgi minuta Schmidt, p. 58, pi. 2, figs. 27-30.

1957 Galliaecytheridea wolburgi (Steghaus); Oertli, p. 657, pi. 2, figs. 56-60; pi. 3, figs. 61-68.
1959 Galliaecytheridea wolburgi (Steghaus); Oertli, p. 14.

1964 Galliaecytheridea wolburgi (Steghaus); Glasshof, p. 39, pi. 4, figs. 1-3.

1 966a Galliaecytheridea wolburgi (Steghaus); Barker, p. 450, pi. 2, figs. 1-8.

Material. 347 valves and carapaces. HU 2.J. 13. 1-347.

Dimensions (mm.).

L

H

W

M a

Left valve

0-75

0-50

0 18

0-08

Right valve

0-74

0-40

0 16

0-06

Occurrence. Baylei, Cymodoce, and Mutabilis Zones, P. 2, RC. 1-3, RM. I, 2, 5, 9, 10.

Diagnosis. Carapace elongate, tapering posteriorly. Posterior cardinal angle about 45°.
Posterior end angular. Left valve overlapping dorsally and ventrally.

Remarks. Sexual dimorphism was not observed in the Dorset material.

Galliaecytheridea punctata sp. nov.
Plate 25, figs. 1-4; text-fig. 3c

Holotype. A left valve. HU 2.J.I.4.

Paratypes. 342 valves and carapaces. HU 3.J.3.1-342.

Type locality and horizon. Black Head, Dorset. Cymodoce Zone, Lower Kimmeridgian.

Dimensions (mm.).

L

H

W

M/a

Holotype

0-63

0-42

0 14

0-06

Left valve

0-55-0-64

0-39-0-42

0 14

0-06

Right valve

0-54-0-61

0-34-0-35

0 13

005

Occurrence. Pictonia and Cymodoce Zones, P. 1,2, RC. 1, 3.

122

PALAEONTOLOGY, VOLUME 12

Diagnosis. Species of Galliaecytheridea with ovoid shape, tapering strongly towards
posterior. Dorsal margin straight on both valves. Surface ornamented with small pits.
Radial pore canals straight, widening towards middle. Sexual dimorphism not present.

Description. Carapace ovoid, anterior rounded, posterior more angular, both valves
taper strongly towards posterior. Left valve much larger than right, overlapping it
dorsally and ventrally. Dorsal margin of both valves straight, ventral margin convex,
more so in left valve. In dorsal and ventral views carapace elliptical with greatest width
in middle. In side view greatest height one-third of length from anterior end. Posterior
end of valve often bears 1 or 2 spines.

Inner margin and line of concrescence coincide. Radial pore canals (10-15 anteriorly)
straight, widening towards middle. Surface of valve coarsely punctate with ends of
normal pore canals.

Hinge robust. Right valve has dentate anterior ridge with 6 strong denticles, smooth
median groove and posterior dentate ridge, slightly larger than anterior one. Denticles
on anterior element increase in size towards middle, third from front being largest while
most posterior one reduced to small rounded knob-like projection. In posterior element
size of denticles increases posteriorly. Left valve carries corresponding structure with
smooth median bar. Above bar is fairly wide accommodation groove.

Muscle scar pattern shows usual arrangement of 4 vertical scars with 2 anterior ones.
Lower 2 scars in vertical row usually bigger.

Remarks. G. punctata resembles the type species G. dissimilis but differs from it in the
structure of the hinge (terminal elements), shape of the radial pore canals, and surface
ornamentation.

EXPLANATION OF PLATE 25

All figures X 50.

Figs. 1-4. Galliaecytheridea punctata sp. nov., Cymodoce Zone, RC. 3, Lower Kimmeridgian.
1, Right valve, external view, HU 3.J.3.2. 2, Left valve, external view, holotype, HU 2.J.I.4.
3, Carapace, dorsal view, HU 3.J.3.6-7. 4, Left valve, external view, HU 3.J.3.3.

Fig. 5. Galliaecytheridea sp. 1, Mutabilis Zone, RM. 9, Lower Kimmeridgian, HU 2. J. 1.5. Left valve,
external view.

Figs. 6-12. Galliaecytheridea elongata sp. nov., Mutabilis Zone, RM. 8, Lower Kimmeridgian.
6, Right valve, ? male, external view, HU 3.J.5.2. 7, Left valve, ? female, external view, holotype,
HU 2.J.I.6. 8, Right valve, ? female, external view, HU 3.J.5.3. 9, Left valve, ? male, external view,
HU 3.J.5.4. 10, Carapace, ? male, ventral view, HU 3.J.5.6. 11, Left valve, ? female, internal view,
transmitted light, holotype, HU 2.J.I.6. 12, Right valve, ? male, internal view, transmitted light,
HU 3.J.5.2.

Figs. 13-19. Galliaecytheridea trapezoidalis sp. nov., Mutabilis Zone, RM. 8, Lower Kimmeridgian.
13, Right valve, female, external view, HU 3.J.7.2. 14, Left valve, female, external view, holotype,
HU 2. J. 1.8. 15, Right valve, male, external view, HU 3.J.7.3. 16, Left valve, male, external view,
HU 3.J.7.4. 17, Left valve, female, internal view, holotype, HU 2.J.I.8. 18, Right valve, female,
internal view, HU 3.J.7.2. 19, Carapace, male, dorsal view, HU 3.J.7.11-12.

Figs. 20-22. Galliaecytheridea malzi sp. nov., Baylei Zone, P. 1, Lower Kimmeridgian. 20, Right valve,
external view, HU 3.J.6.2. 21, Left valve, external view, holotype, HU 2.J. 1.7. 22, Carapace, dorsal
view, HU 3.J. 6.9-10.

Figs. 23-28. Galliaecytheridea confuudens sp. nov., Cymodoce Zone, RC. 2, Lower Kimmeridgian.
23, Right valve, female, external view, HU 3.J.8.7. 24, Left valve, female, external view, holotype,
HU 2.J.I.9. 25, Left valve, male, external view, HU 3.J.8.8. 26, Carapace, female, dorsal view,
HU 3. J. 8. 10-1 1 . 27, Right valve, female, dorsal view, HU 3.J.8.7. 28, Right valve, female, internal
view, transmitted polarized light, HU 3.J.8.7.

Palaeontology, Vol. 12

PLATE 25

25

28

KILENYI, Kimmeridge Clay ostracods

T. I. KILENYI : OSTRACODA OF DORSET KIM MERIDGE CLAY

123

Gcilliaecytheridea elongata sp. nov.
Plate 25, figs. 6-12; text-fig. 3 i

Holotype. A female (?) left valve. HU 2.J.I.6.

Paratypes. 26 valves and carapaces. HU 3.J.5.1-26.

Type locality and horizon. Black Head, Dorset. Mutabilis Zone, Lower Kimmeridgian.

Dimensions (mm.). L

Holotype 0-82

Left valve 0-72-0-82

Right valve 0-68-0-79

Occurrence. Mutabilis Zone, RM. 8.

H

0-43

0-37-0-43

0-34-0-40

W
0 16

011-0-16

0-10-0-14

M/a

0-06

Diagnosis. Species of Gal/iaecytheridea with very elongated carapace, dorsal and ventral
margins running parallel. Posterior end often bears postero-ventral spine. Left valve
overlaps right dorsally and ventrally. Surface finely punctate.

Description. Carapace very elongated. Left valve larger than right, overlapping it ven-
trally and dorsally. Carapace elliptical in dorsal view; greatest width at middle. Straight
dorsal and ventral margins run parallel. Anterior cardinal angle rounded, posterior
prominently angular. Anterior end rounded, posterior ends in blunt angle at mid-height.
Postero-ventral spine often present.

Surface smooth or finely punctate, with very numerous normal pore canals, covering
surface of valve densely. Slight depression developed in eye region.

Anterior duplicature broad, with strongly developed selvage running at moderate
distance from outer margin, inner margin and line of concrescence coincide. Radial
pore canals few, only about 7 or 8, straight, simple. Selvage lip narrow, more prominent
on right valve. Often 1 or 2 septae on inner side of duplicature.

Hinge follows usual hemimerodont structure found in Gal/iaecytheridea but very thin.
Denticles on anterior and posterior elements of right valve small, rounded, situated on
spindle-like, slightly curved ridge. 5 or 6 denticles and corresponding loculi in left
valve. Median element of right valve is wide smooth groove, occupying nearly whole
width of hinge margin. Bar on left valve slender and straight, accommodation groove
above it narrow.

Shell structure characterized by dense system of pits, round or sometimes more
angular. Sexual dimorphism doubtful. Some valves relatively higher than others and
may be considered females.

Gal/iaecytheridea ma/zi sp. nov.

Plate 25, figs. 20-22; text-figs. 3/;, 5/

Holotype. A left valve. HU 2.J.I.7.

Paratypes. 85 valves and carapaces. HU 3.J.6.22-86.

Type locality and horizon. Black Head, Dorset. Baylei Zone, Lower Kimmeridgian.

Dimensions (mm.).

L

H

W

M/a

Holotype

0-63

0-39

0 14

0-05

Left valve

0-61-0-64

0-38-0-42

0-14

0-05

Right valve

0-63

0-39

0 14

0-05

Occurrence. Baylei Zone, P. 1.

124

PALAEONTOLOGY, VOLUME 12

Diagnosis. Carapace tapering posteriorly. Posterior end rounded. Surface finely punctate.
Dorsal margin straight, ventral margin slightly convex. Radial pore canals few and thick.
Left valve higher than right. Teeth on right valve’s hinge very small. Sexual dimorphism
not apparent.

Description. Carapace ovoid. In dorsal and ventral view carapace elliptical, greatest
width around middle. Left valve larger than right, overlap being most prominent ven-
trally. Dorsal margin straight, ventral margin slightly convex, both margins converging
towards posterior end. Posterior cardinal angle marked, anterior rounded. In side view
greatest height one-third of length from anterior.

Surface smooth or finely punctate. Normal pore canals clearly visible on surface.
Eye depression not developed.

Marginal areas narrow, especially hinge margin. Inner margin and line of concres-
cence coincide. Radial pore canals straight, simple, relatively broad, about 6-8 anteriorly,
2-3 posteriorly.

Hinge rather delicate, denticles weakly developed on terminal ridges of right valve
as 4 or 5 rounded projections. Median groove on same valve smooth, shallow, rather
narrow. Median element on left valve smooth, narrow bar. Accommodation groove
present but hardly noticeable.

Muscle scar pattern shows oblique row of 4 scars, with 2 more in front. Upper
anterior scar larger than others, pear-shaped, pointing downwards.

Remarks. This species closely resembles G. punctata in many features but is more elon-
gated and its hinge is weakly developed (in contrast to the robust hinge of the latter).
Sexual dimorphism was not observed.

Galliaecytheridea trapezoidalis sp. nov.

Plate 25, figs. 13-19; text-figs. 3 f 5 g
Holotype. A female left valve. HU 2.J.I.8.

Paratypes. 30 valves and carapaces. HU 3.J.7.1-30.

Type locality and horizon. Black Head, Dorset. Upper part of Mutabilis Zone, Lower Kimmeridgian.

Dimensions (mm.). L

$ Left valve (holotype) 0-70

$ Right valve 0-68

S Left valve 0-66-0-73

S Right valve 0-69

Occurrence. Mutabilis Zone RM. 6, 8, 10.

H

W

M/a

0-44

0 13

0-05

0-38

0 12

0-06

0-37-0-44

0 12

0-36

0-11

Diagnosis. Species of Galliaecytheridea with trapezoidal outline. Straight margin between
posterior cardinal angle and posterior end. Hinge strongly developed, with prominent
teeth in right valve. Sexual dimorphism occurs.

Description. Carapace trapezoidal in side view, spindle-shaped in dorsal view. Left
valve larger than right, overlapping it ventrally and dorsally. Left valve dorsal margin
slightly concave, posterior cardinal angle marked, postero-dorsal margin straight or very
slightly concave. Posterior end angular, but rounded at extreme end. Ventral margin
convex. Right valve dorsal margin straight, posterior extremity angular, carrying

T. I. KILENYI: OSTRACODA OF DORSET KIMMEREDGE CLAY 125

upward-pointing spine. Sexual dimorphism fairly strong, female carapace being higher
and more rounded ventrally. Shell heavy, thick.

Surface of valve smooth. Normal pore canals fairly numerous. Slight depression
around ocular region. Marginal areas fairly narrow, except at strongly developed hinge
margin. Inner margin and line of concrescence coincide. About 10-12 simple, straight
radial pore canals occur on anterior margin.

Hinge in right valve consists of 2 terminal dentate ridges, both spindle-shaped, curved,
with 6 strong denticles on each. Anterior element larger than posterior. Median element
wide smooth groove, widest in anterior quarter of its length. In left valve median bar
narrow at posterior end, widening anteriorly. Same applies to accommodation groove.

Muscle scars follow usual pattern in Galliaecytheridea, but 2 anterior scars much
bigger than scars of vertical row.

Galliaecytheridea confundens sp. nov.

Plate 25, figs. 23-28; text-fig. 3 d
Holotype. A female left valve. HU 2.J.I.9.

Paratypes. 33 valves and carapaces. HU 3.J.8.2-34.

Type locality and horizon. Black Head, Dorset. Cymodoce Zone, Lower Kimmeridgian.

Dimensions (mm.).

L

H

W

Mia

Holotype

0-58

0-37

013

0-04

? Left valve

0-54-0-58

0-33-0-38

0 13

0-04

? Right valve

0-54

0-33

0 12

0-04

$ Left valve

0-58-0-61

0-31-0-34

0-11

0-04

<? Right valve

0-52-0-57

0-28-0-31

0 10

0-04

Occurrence. From Baylei to Pseudomutabilis Zones, P. 2, RC. 2, 3, RM. 2, AU. II.

Diagnosis. Short, rather tumid form. Dorsal margin straight, ventral slightly curved.
Posterior end rounded, postero-dorsal margin straight. Surface of valve smooth. Hinge
robust, teeth on right valve elevated. Sexual dimorphism pronounced.

Description. Carapace ovoid (?) or elongated (T). Left valve larger, overlapping right
dorsally and ventrally. Anterior end rounded, posterior more or less angular. Dorsal
margin straight, ventral slightly convex. Postero-dorsal part of margin straight also, and
spine often occurs postero-ventrally.

Surface smooth, ends of normal pore canals very conspicuous. Marginal areas
narrow, selvage hardly visible. About 12 radial pore canals, straight, equally spaced.

Hinge robust, strongly developed. Right valve terminal elements are prominent ridges
with 5 equally spaced denticles on each. Denticles strong, high. Median groove widens
towards middle, where it is exceptionally wide. Terminal elements on left valve equally
strongly developed, and median bar bent towards centre of valve. Accommodation
groove widest near anterior end.

Sexual dimorphism prominent, males being longer and less high than females.

Remarks. Specimens of this species vary considerably and it is not easy to delimit them
from similar forms. G. punctata is similar in shape but differs markedly in the hinge
structure (the median element is straight and narrow in G. punctata) and there is also a

126

PALAEONTOLOGY, VOLUME 12

great difference in the shape of the radial pore canals. G. malzi differs in hinge structure,
having a much more delicately built hinge.

GaUiaeeytheridea cf. mandelstami (Ljubimova 1955)

Plate 26, figs. 1-9; text-fig. 3 g

1955 Palaeocytheridea mandelstami Ljubimova, p. 42, pi. 4, figs. 4a, b.

Material. 75 valves and carapaces. HU 3.J.9.2-75, HU 2.J.1.10.

Dimensions {mm.).

L

H

W

M/a

Left valve

0-71-0-75

0-43-0-46

0 17-0 19

0-06

Right valve

0-70-0-72

0-38-0-40

0 16-018

0-06

Occurrence. Middle of Mutabilis Zone, RM. 6.

Diagnosis. Carapace high with marked posterior cardinal angle, ending in blunt point.
Surface finely punctate. Marginal areas broad. Sexual dimorphism doubtful.

Description. Carapace ovoid in side view, elliptical in dorsal view, greatest height and
width in middle. Left valve only slightly larger than right, two valves similar in shape.
Dorsal margin straight on both valves, ventral margin straight or slightly concave.
Marked posterior cardinal angle, postero-dorsal margin straight. Posterior ends in
blunt point.

Surface punctate, densely covered with system of small pits, size of which varies,
largest concentrated on middle of valve.

Duplicature wide, inner margin and line of concrescence coincide. Radial pore canals
straight, simple, few, only 6-8 anteriorly.

EXPLANATION OF PLATE 26

All figures X 50, unless otherwise stated.

Figs. 1-9. GaUiaeeytheridea cf. mandelstami (Ljubimova), Mutabilis Zone, RM. 6, Lower Kimmerid-
gian. 1, Right valve, ? female, external view, HU 3.J.9.2. 2, Left valve, ? female, external view,
HU 2.J.1.10. 3, Left valve, ? male, external view, HU 3.J.9.6. 4, Carapace, ? female, ventral
view, HU 3. J. 9. 8-9. 5, Left valve, juvenile, external view, HU 3.J.9.3. 6, Right valve, ? female,
internal view, transmitted light, HU 3.J.9.2. 7, Left valve, ? female, internal view, transmitted light,
HU 2.J.1.10. 8, Right valve, ? female, dorsal view, HU 3.J.9.4. 9, Left valve, ? female, dorsal view,
HU 3.J.9.5.

Figs. 10-13, 16, 17. GaUiaeeytheridea spinosa sp. nov., Rotunda Zone, PA. 11, Upper Kimmeridgian.
10, Right valve, female, external view, HU 3.J.10.3. 11, Left valve, female, external view, holotype,
HU 2. J. 1.11. 12, Right valve, female, internal view, HU 3. J. 10.3. 13, Left valve, female, internal
view, holotype, HU 2.J.1.11. 16, Right valve, male, external view, HU 3.J.10.5. 17, Left valve,
male, external view, HU 3. J. 10.4.

Figs. 14, 15, 18-20. GaUiaeeytheridea spinosa sp. nov., Rotunda Zone, PA. 21, Upper Kimmeridgian.
14, Right valve, female, external view, HU 3.J.10.10. 15, Left valve, female, external view, HU

3. J. 10.11. 18, Right valve, female, anterior margin in transmitted light, HU 3.J.10.22, X 125.

19, Left valve, female, dorsal view, HU 3.J.10.15. 20, Right valve, female, dorsal view, HU 3.J.10.15.

Figs. 21-26. ? GaUiaeeytheridea po/ita sp. nov., Pallasoides Zone, PA. 30, Upper Kimmeridgian.
21, Right valve, female, external view, HU 3.J.1 1.2. 22, Left valve, female, external view, holotype,
HU 2. J. 1.12. 23, Right valve, male, external view, HU 3. J. 1 1 .4. 24, Left valve, male, external view,
HU 3. J. 11.5. 25, Carapace, female, dorsal view, HU 3.J.1 1.7-8. 26, Carapace, female, ventral
view, HU 3. J. 11.7-8.

Palaeontology, Vol. 12

PLATE 26

KILENYI, Kimmeridge Clay ostracods

T. I. KILENYI: OSTRACODA OF DORSET K1MMERIDGE CLAY 127

Hinge in right valve consists of 2 terminal dentate ridges, connected with smooth
groove. Very long, curved anterior element, spindle-shaped, highly elevated, with 6
denticles. Width of middle 4 denticles greater than that of ridge itself. Posterior element
similar, but only 5 denticles. Median groove slightly curved. Special feature in left hinge
is wide edge between terminal sockets and inside of valve. Median bar in this valve
smooth, curving slightly inwards. Accommodation groove narrow.

text-fig. 3. Hinge structures in various species of Galliaecytheridea Oertli. Hinges are oriented with
the anterior end upwards. X 60. a, G. dissimilis Oertli. b, ? G. po/ita sp. nov. c, G. punctata sp. nov. d,
G. confundens sp. nov. e, G. wolburgi Steghaus./, G. trapezoidalis sp. nov. g, G. cf. mandelstami (Ljubi-
mova). It, G. malzi sp. nov. i, G. selongata sp. nov. j, G. postrotunda Oertli. k, G.fragilis sp. nov.

Muscle scars form usual pattern of Galliaecytheridea , but 2 anterior scars set well
apart from row of 4.

Sexual dimorphism doubtful; slightly more elongated specimens considered to be
males.

Remarks. The specimens seem to agree well with Ljubimova’s figures, but are slightly
smaller and more elongated. In many respects this species is reminiscent of the Upper
Kimmeridgian G. spinosa but the latter has a more angular appearance, and the
posterior end always bears a few spines. Its sexual dimorphism is also very pronounced,
in contrast to G. cf. mandelstami.

128

PALAEONTOLOGY, VOLUME 12

Gal/iaecytheridea spinosa sp. nov.

Plate 26, figs. 10-20

Holotype. A female left valve. HU 2. J. 1.11.

Paratypes. 387 valves and carapaces. HU 3. J. 10.2-388.

Type locality and horizon. Hounstout Cliflf, Kimmeridge, Dorset. Rotunda Zone, Upper Kimmeridgian.

Dimensions (mm.).

L

H

W

Holotype

079

0-45

0-20

$ Left valve

0-74-0-81

0-43-0-48

0 18-0-21

$ Right valve

0-71-0-77

0-38-0-42

0-17-0-19

<5 Left valve

0-89-0-95

0-44-0-46

0-20

<? Right valve

0-85-0-91

0-42-0-46

0 19

Occurrence. Rotunda and

Pallasoides Zones,

PA. 8, 10-13,

19, 21, 25.

Diagnosis. Species of Galliaecytheridea with extremely pointed posterior end. 2 or 3
little spines usually on posterior extremity. Sexual dimorphism very strong, males much
longer than females. Surface of valve pitted.

Description. Carapace ovoid (?) or elliptical (d'). In side view greatest height one-third
length from anterior end. Left valve larger than right, overlapping it dorsally and
ventrally. In dorsal view greatest width one-third distance from posterior end.

Anterior margin rounded; dorsal, postero-dorsal, andpostero-ventral margins straight.
Ventral part of valve gently rounded. Posterior end on both valves sharply pointed,
carrying 2-5 spines which point downwards. Often denticulation on anterior flange.

Surface ornamented with pits of varying sizes, largest occurring in central parts of
valve.

Duplicature wide, with inner margin and line of concrescence coinciding. Selvage
prominent, running some distance away from outer margin. Selvage lip wide, long.
Radial pore canals straight, thin, about 10-15 anteriorly, 2-6 posteriorly.

Hinge well developed, with 6 denticles on terminal elements of right valve. Median
element straight in both valves. Accommodation groove much wider on female valves.
Sexual dimorphism striking. Males 10-15% longer than females.

Remarks. See Galliaecytheridea cf. mandelstami (Ljubimova 1955).

? Galliaecytheridea polita sp. nov.

Plate 26, figs. 21-26; text-fig. 3 b

Holotype. A female left valve. HU 2. J. 1.12.

Paratypes. 58 valves and carapaces. HU 3. J. 11.2-59.

Type locality and horizon. Hounstout Cliff, Kimmeridge, Dorset. Pallasoides Zone, Upper Kimmerid-
gian.

Dimensions {mm.).

L

H

W

Holotype

0-70

0-44

0 18

9 Left valve

0-68-0-71

0-42-0-44

0 18

$ Right valve

0-67-0-69

0-38-0-39

0-16

cj Left valve

0-78

0-45

0-19

c? Right valve

0-77

0-40

0-17

Occurrence. Pallasoides Zone, PA. 29, 29/A, 30.

T. I. KILENYI: OSTRACODA OF DORSET KIMMERIDGE CLAY 129

Diagnosis. Carapace elongated. Left valve only slightly larger than right. Dorsal and
ventral margins straight and parallel. Posterior end rounded. Sexual dimorphism
pronounced.

Description. Carapace elongated, ovoid (?) or elliptical (T). Left valve only slightly
larger than right, overlapping it along ventral and dorsal margins. Dorsal margin straight
on both valves, ventral margin almost straight, with small convexity in middle. Postero-
dorsal margin straight in females but slightly convex in males. Posterior end of valves
is rounded angle, left valve ending more pointedly than right. In side view greatest
height of valves falls in middle. Sexual dimorphism very pronounced, males 10-12%
longer than females.

Surface of valve completely smooth. Faint depression around ocular region.

Hinge differs from usual arrangement in Galliaecytheridea in number and size of
denticles on right valve terminal elements. 7 denticles, decreasing in size towards
median element, which is smooth groove.

Duplicature and structure of valve not observed owing to infilling matrix in valves.

Remarks. ? G. polita differs from all the other species of the genus in lacking the peri-
pheral furrow along the anterior margin on the outside of the valve and it possibly
belongs to Paraschuleridea Swartz and Swain 1946. This genus was described from the
Upper Jurassic of the Western Interior of the United States. It lacks the peripheral
furrow of the anterior margin, as does ? G. polita , but the well-developed accommoda-
tion groove on the left valve is perhaps more typical of Galliaecytheridae.

Galliaecytheridea postrotunda Oertli 1957
Plate 27, figs. 5—14 ; text-figs. 3j, 5 h

1957 Galliaecytheridea postrotunda Oertli, pp. 656-7, pi. 2, figs. 45-55.
1959 Galliaecytheridea postrotunda Oertli; Oertli, p. 25, pi. 3, fig. 89.

1964 Galliaecytheridea postrotunda Oertli; Glasshof, p. 38, pi. 4, figs. 4-7.
1966(7 Galliaecytheridea postrotunda Oertli; Barker, p. 450, pi. 3, figs. 1-6.

Material. 19 valves and carapaces. HU 2.J. 14.1-19.

Dimensions {nun.).

L

H

W

Left valve

0-83

0 41

018

Right valve

0-82

0-39

018

Occurrence. Baylei Zone, P. 1.

Diagnosis. Carapace an elongate oval. Dorsal margin straight or slightly convex. Posterior
cardinal angle marked. Surface finely punctate. Hinge relatively narrow. Sexual dimor-
phism occurs.

Remarks. There are some differences between Oertli’s original description and the
specimens from Dorset. The anterior margin is dentate on Oertli’s specimens, whilst
the present material shows no traces of this. Sexual dimorphism is very doubtful in
the Dorset specimens, whereas according to Oertli it is very pronounced.

C 6289

K

130

PALAEONTOLOGY, VOLUME 12

GaUiaecytheridea fragilis sp. nov.

Plate 27, figs. 17-24; text-figs. 3k, 5/

Holotype. A left valve. HU 2.J.1.14.

Paratypes. 36 valves and carapaces. HU 3. J. 14.2-37.

Type locality and horizon. Black Head, Dorset. Cymodoce Zone, Lower Kimmeridgian.

Dimensions {mm.).

L

H

W

M/a

Holotype

0-64

0-35

Oil

006

Right valve

0-60

0-33

Oil

006

Occurrence. Baylei and Cymodoce Zones, P. 1, RC. 2, 3.

Diagnosis. Carapace elongated, fragile, tapering towards posterior. Both ends rounded.
Left valve slightly larger than right, overlap restricted to dorsal region and part of
anterior margin. Hinge weakly developed, teeth minute, rounded. No sexual dimor-
phism.

Description. Carapace elongated, with pronounced taper towards posterior. Left valve
slightly larger than right, overlapping it along dorsal and anterior margins. In dorsal and
ventral view carapace elliptical, greatest width around middle. Right valve shows slight
sulcus in middle. Two valves differ in shape, dorsal margin straight on left valve, slightly
arched on right. Both valves highest at anterior cardinal angle. Posterior end rounded
with several weakly developed spines postero-dorsally.

EXPLANATION OF PLATE 27
All figures x 50, unless otherwise stated.

Figs. 1-4. GaUiaecytheridea sp. 2, Cymodoce Zone, RC. 3, Lower Kimmeridgian. 1, Right valve,
? juvenile, external view, HU 3.J.12.2. 2, Left valve, ? juvenile, external view, HU 3.J.12.3.

3, Right valve, ? juvenile, external view, HU 3. J. 12.4. 4, Left valve, external view, HU 2.J.1.13.
Figs. 5-14. GaUiaecytheridea postrotunda Oertli, Baylei Zone, P. 1, Lower Kimmeridgian. 5, Right
valve, ? female, external view, HU 2. J. 14.1. 6, Left valve, ? female, external view, HU 2. J. 14.2.
7, Right valve, ? male, external view, HU 2.J.14.3, x40. 8, Left valve, ? male, external view,
HU 2.J.I4.4, x40. 9, Carapace, ? female, dorsal view, HU 2.J.14.9-10. 10, Carapace, ? female,
ventral view, HU 2. J. 14.9-10. 1 1, Left valve, ? female, internal view, transmitted light, HU 2.J.14.2.
12, Right valve, ? female, internal view, transmitted light, HU 2.J.14.1. 13, Left valve, ? female,
internal view, transmitted polarized light, HU 2.J. 14.2. 14, Right valve, ? female, internal view,
transmitted polarized light, HU 2. J. 14.1.

Figs. 15, 16. GaUiaecytheridea sp. 3, Rotunda Zone, PA. 11, Upper Kimmeridgian. 15, Right valve,
external view, HU 2.J.15.1. 16, Left valve, external view, HU 2.J.15.2.

Figs. 17-24. GaUiaecytheridea fragilis sp. nov., Cymodoce Zone, RC. 3, Lower Kimmeridgian.
17, Right valve, external view, HU 3.J.14.2. 18, Left valve, external view, holotype, HU 2.J.1.14.
19, Right valve, external view, HU 3.J.14.3. 20, Left valve, external view, HU 3.J.14.4. 21, Right
valve, juvenile, external view, HU 3.J.14.9. 22, Left valve, juvenile, external view, HU 3.J.14.10.
23, Carapace, dorsal view, HU 3. J. 14.7-8. 24, Carapace, ventral view, HU 3. J. 14.7-8.

Figs. 25, 26. ? Pyrocytheridea sp., Rotunda Zone, PA. 11, Upper Kimmeridgian. 25, Right valve,
external view, HU 2.J.16.1. 26, Left valve, external view, HU 2.J.16.2.

Figs. 27-29. Protocythere sigmoidea Steghaus, Rotunda Zone, PA. 21, Upper Kimmeridgian. 27, Left
valve, male, external view, HU 2.J.17.4. 28, Right valve, female, external view, HU 2.J.17.1.
29, Left valve, female, external view, HU 2.J.17.2.

Figs. 30-32. Protocythere rodewa/densis (Klingler), Baylei Zone, P. 1, Lower Kimmeridgian. 30, Right
valve, external view, HU 2.J.18.1. 31, Left valve, external view, HU 2.J.18.2. 32, Left valve, internal
view, transmitted light, HU 2.J.18.2.

Palaeontology, Vol. 12

PLATE 27

KILENYI, Kimmeridge Clay ostracods

T. I. KILENYI: OSTRACODA OF DORSET KIMMER1DGE CLAY 131

Surface of valve smooth, slight depression around ocular region. Normal pore canals
small but clearly visible.

Duplicature rather narrow. Selvage weakly developed, selvage lip scarcely noticeable.
Inner margin and line of concrescence coincide. 10 to 12 thin straight radial pore canals
on anterior margin.

Muscle scars as in other species of Galliaecytheridea, but upper anterior scars much
larger than others.

Hinge structure is ‘weak’ type of hinge found in some species of Galliaecytheridea,
e.g. denticles on right valve terminal elements small, rounded, also corresponding loculi
on other valve. Median element of left valve is bar which runs separate from inner edge
of hinge margin; no accommodation groove present. Median groove on right valve is
smooth and narrow.

Galliaecytheridea sp. 1
Plate 25, fig. 5

Material. 27 valves. HU 3.J.4.2-27, HU 2.J.I.5.

Dimensions (mm.). L H W

Left valve 0-75 0-45 0-22

Occurrence. Upper part of the Mutabilis Zone, RM. 9, 10.

Description. Carapace ovoid, both ends rounded. Left valve only slightly larger than
right, overlapping it ventrally. Dorsal margin straight on both valves, both cardinal
angles rounded. Ventral margin only very slightly convex in both valves.

Surface smooth, ends of numerous normal pore canals plainly visible. Marginal areas
broad, with inner margin and line of concrescence coinciding. Radial pore canals
straight, simple, about 10 on anterior and 5 on posterior margin. Selvage follows outer
margin closely. Hinge shows usual hemimerodont arrangement of Galliaecytheridea.

Remarks. This form is close to G. punctata in shape, but has a more rounded outline,
especially the posterior end, and the surface is smooth not punctate. There is also a
considerable difference in the hinge.

Galliaecytheridea sp. 2
Plate 27, figs. 1-4

Material. 25 valves. HU 3.J. 12.2-25, HU 2. J. 1.1 3.

Dimensions (mm.). L H XV

Left valve 0-59 0-34 0T4

Occurrence. Cymodoce Zone, RC. 3.

Description. Carapace elongate, tapering posteriorly. Left valve larger than right and
very different in shape, having convex ventral margin and greatest height at anterior
quarter of valve. Right valve much more elliptical in shape, tapering far less towards
posterior, more rounded.

Surface of valve smooth; end of wide normal pore canals conspicuous. About 12
radial pore canals on anterior.

Remarks. Only one adult specimen has been found, the rest being immature valves.
It is certainly different from other species of Galliaecytheridea , mainly in the outline of
the right valve.

132

PALAEONTOLOGY, VOLUME 12

Galliaecytheridea sp. 3

Plate 27, figs. 15, 16

Material. 60 valves and carapaces. HU 2J.15.l-60.

Dimensions {mm.).

L

H

W

Left valve

0-65-0-79

0-37-0-40

0-20

Right valve

0-64-0-73

0-35-0-37

0 18

Occurrence. Pectinatus and Rotunda Zones, PA. 1, 3, 6, 10-13, DO PE. 11.

Description. Carapace elongated, tapering posteriorly. Left valve overlaps right along
entire margin. Valves nearly identical in shape. Dorsal margin straight on both valves,
ventral margin slightly convex. Anterior end broadly rounded, posterior pointed down-
wards with single strong spine also pointing downwards. Posterior cardinal angle
prominent, postero-dorsal margin straight. Poor preservation of material prevented

EXPLANATION OF PLATE 28

All figures X 50.

Figs. 1-4. Protocythere nea/ei sp. nov., Pallasoides Zone, PA. 21, Lower Kimmeridgian. 1, Right
valve, external view, HU 3.J.15.2. 2, Left valve, external view, holotype, HU 2. J. 1.15. 3, Left
valve, dorsal view, holotype, HU 2. J. 1.15. 4, Right valve, dorsal view, HU 3.J.15.2.

Figs. 5-7. Cytheropteron sp., Wheatleyensis Zone, DO VW. 2, Middle Kimmeridgian. 5, Left valve,
female, external view, HU 2.J.20.1. 6, Left valve, male, external view, HU 2.J.20.2. 7, Left valve,
female, dorsal view, HU 2.J.20. 1.

Figs. 8-11. Cytheropteron aquitanum Donze, Wheatleyensis Zone, DO VW. 7, Middle Kimmeridgian.
8, Carapace, right side, external view ; 9, Carapace, left side ; 1 0, Carapace, anterior view ; 11, Cara-
pace, dorsal view, HU 2. J. 1.16.

Figs. 12, 13. Exophthalmocythere fuhrbergensis Steghaus, Mutabilis Zone, RM. 6, Lower Kimmerid-
gian. 12, Left valve, external view, HU 2.J.19.2. 13, Left valve, external view, HU 2.J.19.3.

Figs. 14-17. Eocytheropteron decoration Schmidt, Baylei Zone, P. 1, Lower Kimmeridgian. 14, Right
valve, external view, HU 2.J.21.1. 15, Left valve, external view, HU 2 J. 2 1.2. 16, Right valve, dorsal
view, HU 2.J.21.1. 17, Left valve, dorsal view, HU 2. J. 2 1.2.

Figs. 18-24. Procytheropteron sp. 1, Baylei Zone, P. 1, Lower Kimmeridgian. 18, Left valve, male,
external view; 19, Left valve, male, internal view, HU 2.J.1.18. 20, Left valve, female, internal
view, transmitted light, HU 2.J.1.17. 21, Right valve, female, HU 3.J.16.7. 22, Left valve,

female, external view, HU 2. J. 1.1 7. 23, Right valve, female, external view, HU 3.J.16.6. 24, Left
valve, female, external view, HU 3.J.16.8.

Fig. 25. Orthonotacythere interrupta Triebel, Mutabilis Zone, RM. 2, Lower Kimmeridgian. Right
valve, external view, HU 2.J.22.1.

Figs. 26-9. Orthonotacythere interrupta Triebel, Mutabilis Zone, RM. 7, Lower Kimmeridgian.
26, Right valve, external view, HU 2.J.22.3. 27, Left valve, internal view, transmitted light,

HU 2.J.22.4. 28, Left valve, external view, HU 2.J.22.6. 29, Left valve, external view, HU 2.J.22.4.

Figs. 30, 31. Orthonotacythere sp., Rotunda Zone, PA. 6, Upper Kimmeridgian. 30, Right valve,
external view, HU 3.J.30.1. 31, Left valve, external view, HU 3.J.30. 1.

Figs. 32-9. Orthonotacythere pustulata sp. nov., Rotunda Zone, PA. 21, Upper Kimmeridgian.
32, Right valve, external view, HU 3.J.18.6. 33, Left valve, external view, holotype, 2.J.1.19.

34, Right valve, external view, HU 3. J. 18.3. 35, Left valve, external view, HU 3.J.18.4. 36, Right
valve, external view, HU 3.J.18.2. 37, Left valve, external view, HU 3.J.18.4. 38, Right valve,
juvenile, external view, HU 3.J.18.5. 39, Left valve, juvenile, external view, HU 3.J.18.7.

Figs. 40-43. ? Acrocythere inornata sp. nov., Rotunda Zone, PA. 13, Upper Kimmeridgian. 40, Right
valve, external view, HU 3.J.19.2. 41, Left valve, external view, holotype, HU 2.J.1.20. 42, Right
valve, juvenile, external view, HU 3.J.19.3. 43, Left valve, juvenile, external view, HU 3 .J.19.4.

Palaeontology, Vol. 12

PLATE 28

KILENYI, Kimmeridge Clay ostracods

T. I. KILENYI: OSTRACODA OF DORSET K1MMERIDGE CLAY 133

observation of internal structures of valve; one left valve, however, showed typical
hinge of Galliaecytheridea.

Subfamily eucytherinae Puri 1954
Genus pyrocytheridea Ljubimova 1955
? Pyrocytheridea sp.

Plate 27, figs. 25, 26

Material. 7 valves. HU 2.J.16.1-7.

Dimensions (mm.).

L

H

W

Left valve

0-53

0-28

0-10

Right valve

0-51

0-26

0-10

Occurrence. Rotunda Zone, PA. 11.

Description. Carapace elongated, tapering strongly towards posterior end. Both valves
end in slightly blunted point. In dorsal view, carapace elliptical, greatest width at middle.
Valves seem to be equal in size, shape nearly identical, right valve slightly more angular
at anterior cardinal angle and at posterior end. Greatest height of valves at anterior
cardinal angle. Dorsal margin straight. Surface of valve smooth.

Details of interior structure of valves not discernible owing to bad state of preserva-
tion, although duplicature seems to be very narrow.

Remarks. Species of Pyrocytheridea have a similar shape, and they occur at about the
same horizon in the Upper Jurassic of the Ural region of the U.S.S.R. Unfortunately
the typical hinge structure of Pyrocytheridea could not be seen and therefore the identi-
fication is queried.

Subfamily loxoconchinae Sars 1925
Genus mandelstamia (mandelstamia) Ljubimova 1955
Mandelstamia ( Mandelstamia ) rectilinea Malz 1958

Plate 29, figs. 1-6; text -figs. 4a, b

1958 Mandelstamia rectilinea Malz, p. 38, pi. 11, figs. 58-63.

1961 Mandelstamia rectilinea Malz; Neale and Kilenyi, pp. 440-2, pi. 71, figs. 1-4, 6.

1964 Mandelstamia rectilinea Malz; Glasshof, p. 48.

Material. 52 valves and carapaces. HU 2. J. 1.21, HU 3.J.20.2-52.

Dimensions (mm.).

L

H

W

Mia

Left valve

0-66-0-73

0-38-0-40

0 16

0-06

Right valve

0-67-0-72

0-39-0-40

0 16

0-06

Occurrence. Mutabilis Zone, RM. 5, 6.

Diagnosis. Species of Mandelstamia (M.) with oblong shape. Valves about equal in size.
Posterior end sometimes higher than anterior. Dorsal margin straight, ventral concave.
Valve surface ornamented by pits, larger on anterior part of valve.

Mandelstamia (M.) triebeli Kilenyi 1961
Plate 29, figs. 9, 10; text-figs. 4c, d, 5k

1961 Mandelstamia triebeli Kilenyi; Neale and Kilenyi, pp. 442-3, pi. 71, figs. 5, 9, 10, 14, 15.
Material. 513 valves and carapaces. HU 2.J.1.22, HU 3.J.21. 2-513.

134 PALAEONTOLOGY, VOLUME 12

Dimensions (mm.).

L

H

W

M/a

Left valve

0-55-0-61

0-30-0-35

0-15-0-17

0-05

Right valve

0-57-0-64

0-32-0-36

0-15-0-17

0-05

Occurrence. Mutabilis and Pseudomutabilis Zones, RM. 1, 2, 5, 6, 9, AU. II, IV.

Diagnosis. Species of Mandelstamia ( M .) in which valves are equal in size, carapace
tapering towards posterior end. Anterior end rounded, posterior cardinal angle more
or less prominent; dorsal margin straight, ventral convex. Marginal areas broad.

Mandelstamia ( M .) angulata Kilenyi 1961

Plate 29, figs. 11-16

1961 Mandelstamia angulata Kilenyi; Neale and Kilenyi, pp. 443-4, pi. 71, figs. 11, 12, 16-18.
Material. 56 valves and carapaces. HU 2.J.1.23, HU 3.J.22.2-56.

Dimensions (mm.).

L

H

M/a

Left valve

0-42-0-45

0-25-0-27

0-03

Right valve

0-42-0-44

0-22-0-23

0-03

Occurrence. Baylei and Cymodoce Zones, P. 1, RC. 3.

EXPLANATION OF PLATE 29

All figures x 50, unless otherwise stated.

Figs. 1-6. Mandelstamia (M.) rectilinea Malz, Mutabilis Zone, RM. 6, Lower Kimmeridgian. 1, Right
valve, external view, HU 3.J.20.2. 2, Left valve, external view, HU 3.J.20.3. 3, Left valve, external
view, HU 2. J. 1.21. 4, Carapace, dorsal view, HU 3. J. 20.7; 5, Left valve, central part in transmitted
light, x 150; 6, Left valve, central part in polarized light, X 150.

Figs. 7, 8. Mandelstamia ( Xeromandelstamia ) sp. 1. Kilenyi, Rotunda Zone, PA. 1, Upper Kimmerid-
gian. 7, Right valve, external view, HU 3.J.30.1. 8, Left valve, external view, HU 3.J.30.2.

Figs. 9, 10. Mandelstamia (M.) triebe/i Kilenyi, Mutabilis Zone, RM. 6, Lower Kimmeridgian.
9, Right valve, external view, HU 3.J.21.2. 10, Left valve, external view, HU 2.J.1.22.

Figs. 11-16. Mandelstamia (M.) angulata Kilenyi, Cymodoce Zone, RC. 3, Lower Kimmeridgian.
11, Right valve, ? male, external view, HU 3.J.22.2. 12, Left valve, ? female, external view,
HU 2.J.1.23. 13, Right valve, male, HU 3.J.22.7. 14, Left valve, male, external view, HU 3.J.22.8.
15, Carapace, female, dorsal view, HU 3.J.22.10-1 1. 16, Carapace, female, ventral view, HU

3.J.22.10-1 1.

Figs. 17, 18, 21. Monoceratina sp. 2, Rotunda Zone, PA. 9, Upper Kimmeridgian. 17, Right valve,
external view, HU 2.J.26.1. 18, Left valve, external view, HU 2.J.26.2. 21, Carapace, dorsal view,
HU 2.J.26.1-2.

Figs. 19,20. Monoceratina sp. 2, Rotunda Zone, PA. 21, Upper Kimmeridgian. 19, Right valve,
external view, HU 2.J.26. 1. 20, Left valve, external view, HU 2.J.26.2.

Figs. 22-24. Monoceratina sp. 1, Rotunda Zone, PA. 3, Upper Kimmeridgian. 22, Right valve, external
view, HU 2.J.25.1. 23, Left valve, external view, HU 2.J.25.2. 24, Carapace, dorsal view, HU
2.J.25.1-2.

Figs. 25, 26. Amphicythere confundens Oertli, Cymodoce Zone, RC. 2, Lower Kimmeridgian. 25, Right
valve, external view, HU 2.J.27.1. 26, Left valve, juvenile, HU 2.J.27.4.

Figs. 27-32. Amphicythere pennyi sp. nov., Baylei Zone, P. 1, Lower Kimmeridgian. 27, Right valve,
female, external view, holotype, HU 2. J. 1.26. 28, Right valve, female, external view, HU 3 J.24.6.
29, Left valve, male, external view, HU 3.J.24.3. 30, Carapace, female, dorsal view, HU 3.J.24.10-1 1 .
31, Left valve, female, dorsal view, HU 3.J.24.8. 32, Right valve, female, dorsal view, HU 3.J.24.12.

Fig. 33. Mandelstamia ( Xeromandelstamia ) maculata Kilenyi, Grandis Zone, SUG. 5, Middle Kim-
meridgian. Carapace, female, dorsal view, HU 2 J. 1.24.

Palaeontology, Vol. 12

PLATE 29

KILENYI, Kimmeridge Clay ostracods

T. I. KILENYI: OSTRACODA OF DORSET KIMMER1DGE CLAY 135

Diagnosis. Small species of Mandelstamia (M.) with pointed posterior end. Dorsal
margin of right valve convex, that of left valve straight. Left valve slightly rounded
posteriorly, right valve pointed. Sexual dimorphism doubtful.

Subgenus mandelstamia (xeromandelstamia) Beutler and Griindel 1963
Mandelstamia ( Xeromandelstamia ) maculata Kilenyi 1961
Plate 29, fig. 33; text-figs. 4 e,f

1961 Mandelstamia maculata Kilenyi; Neale and Kilenyi, pp. 444-6, pi. 71, figs. 19-25.
Material. 89 valves and carapaces. HU 2.J.1.24, HU 3.J.23.2-89.

Dimensions (mm.).

L

H

W

Mia

9 Left valve

0-72

0-40-0-41

0 17

008

$ Right valve

0-72

0-42

017

007

S Right valve

0-86

0-45

0-18

0-07

Occurrence. Grandis Zone, SUG. 3, 5, 8.

text-fig. 4. Hinge structures in species of Mandelstamia Ljubimova. Hinges are oriented with the
anterior end upwards. X 60. a, M. rectilinea Malz. b, same, dorsal view, c, M. triebeli Kilenyi. d, same,
dorsal view, e, M. (X.) maculata Kilenyi. /, same, dorsal view.

Diagnosis. Carapace elongated, tapering posteriorly. Anterior end rounded, posterior
more angular. Ventral margin of right valve strongly concave, that of left valve straight,

136

PALAEONTOLOGY, VOLUME 12

ventral side of valves overhanging ventral margins to form sort of ala. Surface covered
with equally dispersed pits. Hinge of right valve has following structure: anterior element
is minute, oval-shaped ridge with 4 small rounded projections, middle 2 of which are
larger than others. Median element wide, smooth groove, ending on both sides in
rounded pit slightly deeper than groove itself. Posterior element like anterior, but smaller.
Left valve terminal elements are oval-shaped sockets with 3 or 4 faint loculi in them.
Median element lies in middle of contact margin and consists of smooth bar, both ends
thickened, slightly projecting. Marginal areas relatively broad with few straight, simple
pore canals. Sexual dimorphism very pronounced.

Mandelstamia (X.) sp. 1, Kilenyi 1961

Plate 29, figs. 7, 8

1961 Mandelstamia sp. 1, Kilenyi; Neale and Kilenyi, p. 446, pi. 71, figs. 7, 8, 13.
Material. 23 valves. HU 3.J.30.1-23.

Dimensions {mm.).

L H

W

M/a

Left valve

0-50 0-32

016

004

Right valve

0-48 0-28

015

004

Occurrence. Pectinatus and Rotunda Zones, DO PE 11, PA. 1

, 3.

Diagnosis. Shape like M. maculata but with the hinge more advanced towards the hemi-
merodont type, the terminal teeth being more markedly dentate. The median ridge on the
left valve is straight and has no terminal widening. Radial pore canals few.

EXPLANATION OF PLATE 30

All figures X 50, unless otherwise stated.

Figs. 1-8. Amphicythere sphaerulata sp. nov., Cymodoce Zone, RC. 1, Lower Kimmeridgian. 1, Right
valve, female, external view, HU 3. J.26.2. 2, Left valve, female, external view, holotype, HU 2.J. 1.28.
3, Right valve, male, external view, HU 3.J.26.3. 4, Left valve, male, external view, HU 3.J.26.4.
5, Left valve, male, dorsal view, HU 3.J.26.4. 6, Right valve, male, dorsal view, HU 3.J.26.3.
7, Left valve, female, internal view, holotype, HU 2.J.1.28. 8, Right valve, female, internal view,
HU 3. J.26.2.

Figs. 9, 10. Macrodentina (M.) sp. 1, Mutabilis Zone, RM. 9, Lower Kimmeridgian. 9, Right valve,
female, external view, HU 2.J.30.1. 10, Left valve, female, external view, HU 2.J.30.2.

Figs. 11-19. Macrodentina (M.) cicatricosa Malz, Cymodoce Zone, RC. 3, Lower Kimmeridgian.
11, Right valve, female, external view, HU 2.J.29.1. 12, Left valve, female, external view,

HU 2.J.29.2. 1 3, Right valve, male, external view, HU 2.J.29.5. 14, Left valve, male, external view,
HU 2.J.29.6. 15, Carapace, male, dorsal view, HU 2.J.29.20-1. 16, Carapace, female, dorsal view,
HU 2.J.29. 16-17. 17, Left valve, female, hinge median element, X175; 18, Right valve, female,
hinge anterior element, x 175; 19, Right valve, hinge posterior element, x 175.

Figs. 20-27. Macrodentina ( Polydentina ) proclivis striata subsp. nov., Pseudomutabilis Zone, AU. IV,
Lower Kimmeridgian. 20, Right valve, female, external view, HU 2.J.30.1. 21, Left valve, female,
external view, holotype, HU 2. J. 1.36. 22, Right valve, male, external view, HU 2.J.30.2. 23, Left
valve, male, external view, HU 2.J.30.3. 24, Carapace, female, dorsal view, HU 2.J. 30.8-9. 25,
Carapace, female, ventral view, HU 2.J. 30.8-9. 26, Carapace, male, dorsal view, HU 2.J.30.6-7. 27,
Carapace, male, ventral view, HU 2.J.30.6-7.

Palaeontology , Vol. 12

PLATE 30

KILENYT, Kimmeridge Clay ostracods

T. I. KILENYI: OSTRACODA OF DORSET KIMMER1DGE CLAY

137

Subfamily Uncertain
Genus dicrorygma Poag 1962
Subgenus dicrorygma (orthorygma) Christensen 1965
Dicrorygma ( Orthorygma ) kimmeridgensis (Kilenyi 1965)
Plate 31, figs. 22-31

1957 Cytherideinarum ? sp. 1, Oertli, p. 661, pi. 3, figs. 86-91.

1965 Oertliana kimmeridgensis Kilenyi, pp. 573-4, pi. 79, figs. 1-12; text-fig. 1.

Material. 101 valves and carapaces. HU 2.J.31.1, HU 3.J.29. 1-100.

Dimensions (nun.).

L

H

W

M/a

$ Left valve

0-36-0-38

0-20-0-21

0-08

003

$ Right valve

0-35-0-37

0-18-0-20

0-07

0-03

Left valve

0-43-0-45

0-21-0-23

0-08

0-04

<3 Right valve

0-43-0-45

0-20-0-22

0-07

0-03

Occurrence. Mutabilis Zone, RM. 9.

Diagnosis. Carapace elliptical, anterior end rounded, posterior slightly pointed. Valves
subequal, left slightly larger. Surface of valves slightly punctate. Radial pore canals
relatively thick in middle, narrowing suddenly near both ends. Sexual dimorphism
strong.

Remarks. D. (O.) kimmeridgensis is distinguished from D. (G.) maior Christensen 1965
by its almost straight ventral margin, lacking the marked antero-ventral concavity of the
dorsal margin in the latter species.

Dicrorygma ( Orthorygma ) sp. 1 (Kilenyi 1965)

Plate 31, figs. 32, 33

1965 Oertliana sp. 1, Kilenyi, pp. 574-5, pi. 79, figs. 13-16.

Material. 39 valves. HU 2.J.34.1-39.

Dimensions (mm.). L H

Left valve 0-45 0-24

Right valve 0-44 0-23

Occurrence. Rotunda Zone, PA. 1, 6, 11, 13.

Diagnosis. Elongate, almost oblong-shaped carapace. Valves equal in size. Surface very
finely punctate, almost smooth. No eye depression.

Indet. gen. A. sp. 1

Plate 31 , figs. 20, 21

Material. 2 valves (1 destroyed). HU 2.J.1.25 (left valve).

Dimensions (mm.). L H

Left valve 0-54 0-30

Right valve 0-54 0-30

Occurrence. Cymodoce Zone, RC. 3.

Description. Carapace ovoid, valves similar in shape. Anterior broadly rounded, posterior
blunt. Surface of valves covered by rather irregular system of thick ribs, knobs, and

138

PALAEONTOLOGY, VOLUME 12

bulges. Semicircular dorsal rib starts from posterior cardinal angle, first rising slightly
above dorsal margin, then turning back and ending on lateral part of valve at about its
mid-point. Second dorsal rib starts from just below first and runs across valve, apparently
ending on antero-ventral side without reaching margin. Third rib ventral, roughly follow-
ing ventral margin. Between these ribs, bulges and knobs occur apparently without
definite pattern.

Inner margin and line of concrescence coincide. Only few radial pore canals, 7 at
most, straight, simple, widest at their middle. Selvage only weakly developed.

Hinge lophodont, with very small drop-shaped terminal teeth and wide, smooth
median groove in right valve.

Muscle scars arranged in oblique row of 4 scars with 1 additional scar level with top
one of row.

Remarks. Indet. gen. A. sp. 1. resembles species of Wolburgia Anderson 1966 in shape
and surface ornamentation. There are, however, differences in the hinge and duplicature.
Wolburgia has denticulate terminal hinge elements and a narrow vestibule is present,
whereas in Indet. gen. A. sp. 1, the hinge teeth are definitely smooth and the inner
margin and line of concrescence coincide. Since only 3 species of Wolburgia have been

EXPLANATION OF PLATE 31

All figures X 50, unless otherwise stated.

Figs. 1-5. Macrodentina ( Polydentina ) parvcipunctata sp. nov., Mutabilis Zone, RM. 5, Lower Kim-
meridgian. 1, Right valve, external view, HU 3.J.28.3. 2, Left valve, external view, holotype,
HU 2.J.1.30. 3, Left valve, dorsal view, HU 3.J.28.4. 4, Left valve, external view, HU 3.J.28.4.
5, Left valve, internal view, HU 3.J.28.4.

Figs. 6-11, 17, 18. Macrodentina ( Polydentina ) prociivis proclivis Malz, Pseudomutabilis Zone, AU. II,
Lower Kimmeridgian. 6, Left valve, male, external view, HU 2.J.32.1. 7, Left valve, female, ex-
ternal view, HU 3. J. 27.2. 8, Right valve, female, external view, HU 2. J. 1.29. 9, Right valve, male,

external view, HU 3.J.27.3. 10, Left valve, male, external view, HU 3.J.27.4. 11, Carapace, male,
dorsal view, HU 3. J. 27. 6-7. 17, Left valve, female, internal view, HU 2.J.1.29. 18, Right valve,
female, internal view, HU 3.J.27.2.

Figs. 12-16, 19. Macrodentina (M.) maculata Malz, Mutabilis Zone, RM. 9, Lower Kimmeridgian.
12, Right valve, female, external view, HU 2.J.31.1. 13, Left valve, female, external view, HU

2.J.31.2. 14, Right valve, male, external view, HU 2.J.31.4. 15, Left valve, male, external view,
HU 2.J.31.5. 16, Carapace, male, dorsal view, HU 2.J.31.8-9. 19, Carapace, female, dorsal view,
HU 2. J. 3 1.6-7.

Figs. 20, 21. Indet. gen. A. sp. 1, Cymodoce Zone, RC. 3, Lower Kimmeridgian. 20, Right valve,
external view, (destroyed). 21, Left valve, external view, HU 2. J. 1.25.

Figs. 22-31. Dicrorygma {Orthorygma) kimmeridgensis (Kilenyi), Mutabilis Zone, RM. 9, Lower
Kimmeridgian. 22, Right valve, female, external view, HU 3.J.29.17. 23, Left valve, female,

external view, HU 2.J.31.1. 24, Left valve, male, external view, HU 3.J.29.7. 25, Right valve,
male, external view, HU 3. J. 29.6. 26, Left valve, male, external view, HU 3. J. 29.2. 27, Right valve,
female, external view, HU 3.J. 29.22. 28, Right valve, male, external view, HU 3.J.29.17. 29, Right
valve, ? male, external view, HU 3.J.29.23. 30, Right valve, female, external view, HU 3.J.29.3.

31, Right valve, male, internal view, transmitted light, HU 3.J.29.15, X 125.

Figs. 32, 33. Dicrorygma (Orthorygma) sp. 1 (Kilenyi), Rotunda Zone, PA. 13, Upper Kimmeridgian.

32, Right valve, ? male, external view, HU 2.J.34.1. 33, Left valve, ? male, external view, HU
2.J.34.3.

Fig. 34. Indet. gen. B. sp. 1 , Rotunda Zone, PA. 11, Upper Kimmeridgian. Left (?) valve, external view,
HU 2.J.35.1.

Palaeontology , Vol. 12

PLATE 31

32

33

KILENYI, Kimmeridge Clay ostracods

T. I. KILENYI: OSTRACODA OF DORSET KIMMERIDGE CLAY

139

described, all from the Purbeck-Wealden beds, the assignment of this form to Wolburgici
would be premature.

Family protocytheridae Ljubimova 1955
Subfamily protocytherinae Ljubimova 1955
Genus protocythere Triebel 1938
Protocy there sigmoidea Steghaus 1951

Plate 27, figs. 27-29

1951 Protocythere sigmoidea Steghaus, p. 219, pi. 15, figs. 42-45.

1955 Protocythere sigmoidea Steghaus; Klingler, pi. II, figs. 11 a-d.
1955 Protocythere sigmoidea Steghaus; Schmidt, p. 59.

1957 Protocythere sigmoidea Steghaus; Oertli, p. 661, pi. 3, figs. 92-94.
1959 Protocythere sigmoidea Steghaus; Oertli, p. 31, pi. 4, fig. 126.

1964 Protocythere sigmoidea Steghaus; Glasshof, p. 45.

Material. 12 valves and carapaces. HU 2.J.17.1-12.

Dimensions {mm.).

L

H

W

M/a

$ Left valve

0-62

0-36

0-20

008

$ Right valve

0-63

0-34

019

008

S Left valve

0-70

0-36

0-22

008

S Right valve

not found

Occurrence. Rotunda Zone, PA. 19, 21.

Diagnosis. Species of Protocythere in which median rib joins dorsal rib at posterior end,
and ventral rib at anterior end. Result is sigmoidal surface ornament. Surface is smooth.
Duplicature broad. Sexual dimorphism strong.

Remarks. According to Steghaus (1951), Schmidt (1955), and Oertli (1957) the median
element of the left valve hinge is denticulate. In the rather poorly preserved specimens
from Dorset the bar appears to be smooth.

Protocythere rodewaldensis (Klingler 1955)

Plate 27, figs. 30-32; text-fig. 5 j

1955 Pleurocythere ? rodewaldensis Klingler, p. 198, pi. 10, figs. I Oa-c ; pi. 11, fig. 10 d.
1955 Protocythere ? n. sp. Schmidt, p. 59, pi. 2, fig. 33.

1957 Protocythere rodewaldensis (Klingler); Oertli, p. 662, pi. 3, figs. 95-97 .

1959 Protocythere rodewaldensis (Klingler); Oertli, p. 31, pi. 4, fig. 127.

1964 Protocythere rodewaldensis (Klingler); Glasshof, p. 46.

Material. 4 valves. HU 2 J. 18.1-4.

Dimensions {mm.), (females?)

L

H

W

M/a

Left valve

0-52

0-32

017

008

Right valve

0-55

0-29

013

008

Occurrence. Baylei Zone, P. 1.

Diagnosis. Surface ornamentation of 3 main ribs. Median rib starts from posterior
cardinal angle and joins ventral rib antero-ventrally. Additional fine rib runs parallel
with anterior margin. Eye tubercle well developed. Surface of valve reticulate.

140

PALAEONTOLOGY, VOLUME 12

Remarks. The sexual dimorphism mentioned by Klingler (1955), was not observed in
the Dorset material and it is very likely that only female valves were represented.

a b c

d

e f

g hi j k l

text-fig. 5. Muscle scar patterns (right valves), X 250. a, Cytherelloidea paraweberi Oertli. b, Parcicypris
sp. C. Oertli. c, ? Paracypris problematica sp. nov. d, Galliaecytheridea dissimilis Oertli. e, G. wolburgi
(Steghaus)./, G. malzi sp. nov. g, G. trapezoidalis sp. nov. h, G. postrotunda Oertli. i, G.fragilis sp. nov.
j, Protocythere rodewaldensis (Klingler). k, Mandelstamia triebeli Kilenyi. /, Amphicythere sphaerulata

sp. nov.

Protocythere nealei sp. nov.

Plate 28, figs. 1-4

Holotype. A female left valve. HU 2. J. 1.1 5.

Paratypes. 8 valves. HU 3.J. 15.2-9.

Type locality and horizon. Hounstout Cliff, Kimmeridge, Dorset. Pallasoides Zone, Upper Kimmeridgian.

Dimensions (min.).

L

H

W

Mia

Holotype

0-58

0-34

015

006

Right valve

0-60

0-30

015

006

Occurrence. Pallasoides Zone, PA. 21.

Diagnosis. Species of Protocythere with following surface ornamentation: dorsal and
median ribs joined together at posterior end. Median rib branches out from dorsal rib
near posterior cardinal angle where a characteristic knob-like structure is found which
projects above dorsal margin of valve when viewed from side. Valve surface reticulate.
Hinge hemimerodont, delicate. Sexual dimorphism doubtful.

Description. Carapace triangular, highest at anterior cardinal angle. Left valve slightly
larger than right, but as only separate valves found, degree of overlap not observed.
In dorsal view valves alike, roughly triangular in shape. Greatest width about one-fifth
distance from posterior end.

T. I. KILENYI: OSTRACODA OF DORSET KIMMERIDGE CLAY 141

Valves similar in shape, but left valve higher at anterior cardinal angle, and its anterior
end less rounded. Dorsal margin straight on both valves. Cardinal angles more marked
on right valve, as edge of terminal sockets in left valve form two half-circles, giving more
rounded appearance to cardinal angles. Postero-dorsal margin very short, concave, more
conspicuous on left valve. Posterior end more or less a rounded right-angle. Ventral
margin straight on both valves. Sexual dimorphism doubtful; some valves somewhat
longer and less high than others and probably males.

Surface ornamented by system of 3 quasi-horizontal ribs between which surface is
reticulate; ‘secondary’ ribs may occur. Three main ribs form main ornamentation.
Upper one starts from posterior part of valve, just in front of posterior cardinal angle.
Here knob-like protuberance occurs, usually more strongly developed on left valve,
protruding above dorsal margin in side view. Rib itself runs parallel with dorsal margin
for about half its length and then for short distance leaves dorsal margin, forming semi-
circular depression, rejoining dorsal margin at anterior cardinal angle. Rib continues
round anterior margin, joining ventral rib. This runs parallel with dorsal rib, becoming
very prominent towards its posterior end, where it ends abruptly. On left valve these
2 ribs seem to join at their posterior ends. Median rib branches out from dorsal one
at posterior cardinal angle, where protuberance occurs, and from this point forms a
straight line to exact centre of valve, where it turns upwards and joins dorsal rib near
anterior. Faint ‘secondary’ rib (crest) branches out from median rib near centre of
valve and joins anterior part of ventral rib. Exact structure of rib system best observed in
transmitted light. In side view all 3 ribs are highest at their posterior end and slope
gradually towards anterior, ventral rib being highest of 3.

Duplicature broad. Line of concrescence coincides with inner margin; radial pore
canals straight, thin, few.

Hinge delicate; consists of 2 terminal dentate ridges connected with long, straight,
apparently smooth groove (right valve). Five denticles on terminal elements. Com-
plementary arrangement of left valve has 2 elongate, loculate sockets and straight
smooth bar.

Remarks. P. nealei resembles P. rodewaldensis (Klingler 1955) but is easily distinguish-
able from it by its more angular appearance and the ornamentation of the valves.

Family cytheruridae Midler 1894
Genus cytheropteron Sars 1865
Cytheropteron aquitanum Donze 1960

Plate 28, figs. 8-1 i

1960 Cytheropteron aquitanum Donze, p. 21, pi. 4, figs. 48-51.

Material. 1 carapace. HU 2. J. 1.1 6.

Dimensions {mm.).

L

H

W

Left valve

0-59

0-35

019

Right valve

0-57

0-33

015

Occurrence. Wheatleyensis Zone, DO VW. 7.

Diagnosis. Species of Cytheropteron with inflated ventral border and strongly developed
alae.

142

PALAEONTOLOGY, VOLUME 12

Cytheropteron sp.

Plate 28, figs. 5-7

Material. 2 valves. HU 2.J.20.1-2.

Dimensions (mm.). L H

$ Left valve 045 0-28

<S Left valve 048 026

Occurrence. Wheatleyensis Zone, DO VW. 2, 4.

Description. Species of Cytheropteron with flat wing-like alae. Four ribs on surface of
valve, none of them very marked. First connects anterior cardinal angle with posterior
part of ala. Second and third arch to dorsal margin from anterior and posterior parts.
Fourth runs vertically in middle of valve. Longer, vertically more compressed valves are
considered males.

Genus eocytheropteron Alexander 1933
Eocytheropteron decoration (Schmidt 1954)

Plate 28, figs. 14-17

1954 Cytheropteron (C.) decoration Schmidt, p. 82, pi. 5, figs. 1, 2; pi. 6, figs. 16-18.

1955 Cytheropteron (C.) decoration Schmidt; Schmidt, p. 59.

1957 Eocytheropteron ? decoration (Schmidt); Oertli, p. 663, pi. 4, figs. 109-1 12.

Material. 8 valves. HU 2.J.21.1-8.

Dimensions (mm.).

L

H

W

M/a

Left valve

0-46

0-28

014

003

Right valve

0-41

0-25

015

003

Occurrence. Baylei Zone, P. 1.

Diagnosis. Carapace bud-shaped, posterior end pointed. Surface ornamented with fine
vertical ribs radiating from centre of dorsal margin, ventral part of valve bearing few
longitudinal ribs. Hinge on the right valve consists of 2 terminal dentate ridges with
6 denticles each connected with smooth median bar. Accommodation groove present on
left valve.

Remarks. There seems to be some difference between Schmidt’s and Oertli’s figures, the
Dorset specimens being closer to the latter. The sexual dimorphism mentioned by
Schmidt is not apparent in the Kimmeridge material.

Genus procytheropteron Ljubimova 1955
Procytheropteron sp. 1
Plate 28, figs. 18-24

Material. 25 valves. HU 3J.16.1-18, HU 3.J.17.1-5, HU 2.J. 1.17-18.

Dimensions (mm.).

L

H

W

M/a

? Left valve

0-42

0-24

Oil

005

$ Right valve

0-40

0-23

Oil

005

o Left valve

0-48

0-22

Occurrence. Baylei Zone, P. 1,2.

T. I. KILENYI: OSTRACODA OF DORSET KIMMERIDGE CLAY 143

Remarks. Species of Procytheropteron with ventral longitudinal ridges and with irregu-
larly spaced tubercles and short ridges on upper half of valve. This form will be described
as a new species of Procytheropteron by R. C. Whatley in his forthcoming study of
Oxfordian-Corallian ostracods.

Genus orthonotacythere Alexander 1933
Orthonotacythere interrupt a Triebel 1941

Plate 28, figs. 25-29

1941 Orthonotacythere interrupta Triebel, p. 394, pi. 4, figs. 31, 32.

1955 Orthonotacythere interrupta Triebel; Schmidt, p. 60.

1957 Orthonotacythere interrupta Triebel; Oertli, p. 666, pi. 4, figs. 127-130.

1960 Orthonotacythere interrupta Triebel var. reticulosa Donze, p. 23, pi. 5, figs. 56-59.

1964 Orthonotacythere interrupta Triebel; Glasshof, p. 43.

Material. 19 valves. HU 2.J.22.1-19.

Dimensions {mm.). L H

$ (?) Left valve 0-40 0-24

? (?) Pvight valve 0-40 0-24

S (?) Left valve 0-49 0-26

d (?) Right valve 0-47 0-27

Occurrence. Cymodoce and Mutabilis Zones, RC. 3, RM. 2, 7, 9.

Diagnosis. Species of Orthonotacythere with well-developed median furrow in middle of
valve. Surface strongly reticulate except in furrow. Two characteristic ridges present, one
running straight from postero-dorsal part of valve to middle, other from anterior
cardinal angle, joining first one in knob-like protuberance near ventral edge.

Remarks. The specimens from Dorset are rather badly preserved, but they show the
definite specific characteristics, especially the smooth median furrow and the prominent
lateral ribs which border the furrow. Specimens from the lower part of the Mutabilis
Zone (RM. 2) are larger than specimens from the top part of the Zone (RM. 7 and 9).
The sexual dimorphism mentioned by Triebel (1951) and Oertli (1957) is not very
prominent or convincing in the Dorset material. The different sized specimens which are
regarded as belonging to different sexes were not found in the same sample.

Orthonotacythere pustulata sp. nov.

Plate 28, figs. 32-39

Holotype. A left valve. HU 2.J.1.19.

Paratypes. 54 valves and carapaces. HU 3.J. 18.2-55.

Type locality and horizon. Hounstout Cliff, Kimmeridge, Dorset. Rotunda Zone, Upper Kimmeridgian.

Dimensions (mm.).

L

H

W

M/a

Holotype

0-55

0-30

0-10

0-06

Left valve

0-49-0-56

0-25-0-30

0-08-0- 11

0-06

Right valve

0-48-0-55

0-25-0-28

0-08-0-11

0-05

Occurrence. Pectinatus, Rotunda, and Pallasoides Zones, DO PE.

11, PA. 1, 2, 21.

Diagnosis. Species of Orthonotacythere with elongate carapace. Posterior part of valve
reticulate, anterior covered with irregularly spaced bulges. Median furrow on central

144 PALAEONTOLOGY, VOLUME 12

part of valve is present but not so prominent as in O. interrupta Triebel. Sexual dimor-
phism not apparent.

Description. Carapace elongate, more or less angular. Valves nearly same size, left
slightly larger. Valves differ only slightly in shape. Dorsal margin straight on both
valves, cardinal angles marked, with exception of posterior one in right valve, which
is rounded. Posterior end pointed at slightly above mid-height, slightly higher on left
valve than on right. Ventral margin convex, running to posterior end without forming
an angle.

Surface ornamentation very complex, with great range of variation. Three main ele-
ments in ornamentation, a coarse reticulation, bulges, and ribs. Ventral, longitudinal
rib occurs on every valve. Another constant feature is faint median furrow which
divides surface of valve into two separate parts. Bulges occur irregularly, one or two
prominent ones usually near ocular region, and fairly constant bulge appears postero-
ventrally forming end of ventral rib. On most valves large swelling occurs postero-
dorsally, near posterior cardinal angle. Surface of valve coarsely reticulate, reticulation
being more prominent on posterior half of valve.

Inner margin and line of concrescence coincide. Other details not observed.

Hinge rather long but narrow, hemimerodont type, with smooth median element.
Right valve hinge consists of 2 terminal, dentate ridges and straight, wide, smooth
groove as median element. Five denticles on each terminal element, their size gradually
decreasing towards median groove. Left valve shows corresponding loculate socket —
smooth bar — loculate socket arrangement. No accommodation groove.

Sexual dimorphism may be present but owing to small number and different
stratigraphical position of specimens, could not be established.

Or thonotacy there sp.

Plate 28, figs. 30, 31

Material. 1 carapace. HU 3.J.30.1.

Dimensions (mm.). L‘. 0-64; H\ 0-32.

Occurrence. Rotunda Zone, PA. 6.

Description. Relatively large form. Dorsal margin straight, ventral margin curves
upwards reaching dorsal margin without an angle. Surface strongly ornamented with
reticulation and spines.

Genus acrocythere Neale 1960
? Acrocythere inornata sp. nov.

Plate 28, figs. 40-43

Holotype. A left valve. HU 2. J. 1.20.

Paratypes. 13 valves HU. 3. J. 19.2-14.

Type locality and horizon. Hounstout Cliff, Kimmeridge, Dorset. Rotunda Zone, Upper Kimmerid-
gian.

T. I. KILENYI : OSTRACODA OF DORSET KIMMERIDGE CLAY

145

Dimensions (mm.).

L

H

W

Mia

Holotype

0-66

0-32

0 12

0-05

Left valve

0-56-0-66

0-26-0-32

0-10-012

0-05

Right valve

0-56-0-64

0-26-0-31

0-10-0-12

0-05

Occurrence. Rotunda Zone, PA. 11, 12, 13.

Diagnosis. Species of Acrocythere with smooth valve surface. Caudal process well
developed.

Description. Carapace elongated, tapering slightly towards posterior end. Valves equal
in size. Dorsal margin straight in both valves, anterior end rounded. Middle portion of
ventral margin concave, more conspicuously on right valve. Both cardinal angles
strongly angular. Postero-dorsal margin concave on both valves forming a caudal
process, and posterior part pointed at mid-height. Surface of valve smooth.

Inside of valve, owing to bad preservation, not suitable for examination. Inner margin
and line of concrescence seem to coincide, while hinge definitely of simple merodont
type, although further details not discernible.

Remarks. This species is placed tentatively in the genus Acrocythere on the basis of the
shape of the carapace. Neale (1960) separated Acrocythere from Orthonotacythere on
the absence of a central sulcus and on the position of the posterior end of the shell, which
is markedly dorsal in the latter and at mid-height in the former. The smooth surface of
the valve is certainly unknown in other species of Acrocythere but the outline of the shell,
and especially the position of the caudal process, agrees very well with Acrocythere.

Family bythocytheridae Sars 1926
Genus monoceratina Roth 1928
Monoceratinci sp. 1
Plate 29, figs. 22-24

Material. 1 carapace. HU 2J.25.l-2.

Dimensions (mm.). L \ 0 44; H\ 0 18; W: 0 20.

Occurrence. Rotunda Zone, PA. 3.

Description. Carapace quadrangular. Left valve slightly larger than right. Anterior end
rounded, posterior end beak-like, protruding. Dorsal margin straight, ventral margin
slightly concave in middle. Ventral side of valve forms weakly developed ala.

In dorsal and ventral view carapace oval-shaped, with greatest width slightly posterior
of middle. Both ends appear compressed in this view, posterior end being more drawn
out than anterior. Surface of valve reticulate.

Monoceratina sp. 2
Plate 29, figs. 17-21

Material. 3 carapaces. HU 2J.26.l-6.

Dimensions (mm.). L: 0-55; H\ 0-27; 1 V: 01 4.

Occurrence. Rotunda and Pallasoides Zones, PA. 9, 21.

Description. Carapace quadrate, posterior half triangular. Anterior end rounded. Dorsal
margin straight, valves ending in blunt point. Ventral margin convex, and from its middle

C 6289

L

146

PALAEONTOLOGY, VOLUME 12

curves upwards to posterior end. In dorsal view carapace oval-shaped, posterior end
rather drawn out. Two valves about equal in size. Valve surface has ornamentation of
small pits, giving punctate appearance. Alae do not seem to be developed.

Family brachycytheridae Puri 1954
Genus amphicythere Triebel 1954
Amphicythere confundens Oertli 1957

Plate 29, figs. 25, 26; text -figs. 6 a, b

1957 Amphicythere (A.?) confundens Oertli, pp. 674-5, pi. 8, figs. 219-226.
non 19586 Amphicythere (A. ?) confundens Oertli; Malz, p. 33, pi. 11, figs. 55, 56.
1959 Amphicythere (A.?) confundens Oertli; Oertli, p. 37, pi. 6, figs. 164-165.
1964 Amphicythere confundens Oertli; Glasshof, p. 32.

Material. 19 valves and carapaces. HU 2.J.27.1-19.

Dimensions (mm.).

L

H

W

Left valve

0-76

0-44

016

Right valve

0-76

0-42

016

Occurrence. Cymodoce Zone, RC. 2.

Diagnosis. Species of Amphicythere with weakly developed paramphidont hinge and
slight ocular depression.

Remarks. The paramphidont nature of the hinge is clearly demonstrated in the speci-
mens and therefore they can safely be included in Amphicythere. The hinge, however
does not completely correspond with that of the type species {Amphicythere semisulcata
Triebel 1954) as the median bar appears to be smooth in the Dorset specimens and denti-
culate as in A. semisulcata.

Amphicythere pennyi sp. nov.

Plate 29, figs. 27-32; text-figs. 6c, d

19586 Amphicythere (A.) cf. confundens Oertli; Malz, pp. 33-4, pi. 11, figs. 55, 56.
Holotype. A female right valve. HU 2.J.1.26.

Paratypes. 74 valves and carapaces. HU 3.J.24.1-74.

Type locality and horizon. Black Head, Dorset. Baylei Zone, Lower Kimmeridgian.

Dimensions (mm.).

L

H

W

M/a

Holotype

0-66

0-45

0-25

007

$ Left valve

0-65

0-45

0-25

007

$ Right valve

0-66

0-44

0-24

007

S Left valve

0-77

0-45

0-25

007

S Right valve

0-78

0-44

0-25

007

Occurrence. Baylei and Cymodoce Zones, P. 1,2, RC. 3.

Diagnosis. Species of Amphicythere with following characteristics; hinge strongly
paramphidont with especially conspicuous antero-median socket in right valve, broad
marginal areas with 12 straight radial pore canals anteriorly. Sexual dimorphism
strong. Valve surface densely pitted.

T. T. KILENYI: OSTRACODA OF DORSET KIM MERIDGE CLAY 147

Description. Carapace elongate-ovoid. Two valves about equal in size, left valve little
higher than right. Anterior end rounded, as is posterior end of left valve. Posterior end
of right valve drawn out, extreme end rounded. Dorsal margin straight, both cardinal
angles marked. Ventral margin gently rounded, in middle ventral side of valve strongly
convex, overhanging ventral margin. Surface of valve coarsely pitted; slight depression
in ocular region.

Inner lamella well developed, inner margin and line of concrescence coinciding. Sel-
vage strongly developed and wide, forming rather prominent selvage lip on ventral side.
Radial pore canals simple, straight, widest at their base; 12 on anterior margin and 3 or
4 on posterior.

Hinge strongly paramphidont. Right valve hinge consists of 4 elements, anterior one
a bipartite ridge, bearing 3-4 small rounded denticles followed by large conical tooth.
Antero-median element is deep, elongated pit continuing in median groove, which
is smooth, straight, wide, tapering posteriorly. Posterior dentate ridge carries 5-8
denticles, centre one largest. Anterior element of left valve is loculate socket, its posterior
end characterized by large single socket for receiving corresponding tooth on other valve.
Antero-median element is smooth conical boss, continuing in smooth, straight bar
(median element). Posterior part of hinge is elongated loculate socket with 5-8 loculi.

Muscle scar pattern consists of oblique row of 4 equally sized scars with 2 rounded
anterior scars, upper of two being the larger. Sexual dimorphism strong, males about
15% longer than females.

Remarks. A. pennyi is close to A. confundens Oertli 1957, but differs in its more rounded
outline and the strongly paramphidont hinge.

Amphicythere sphaerulata sp. nov.

Plate 30, figs. 1-8; text-figs. 51, 6 e,f
Holotype. A female left valve. HU 2. J. 1.28.

Paratypes. 73 valves and carapaces. HU 3.J.26.2-74.

Type locality and horizon. Black Head, Dorset. Cymodoce Zone, Lower Kimmeridgian.

Dimensions (mm.).

L

H

W

M/a

Holotype

0-62

0-38

0-20

0-05

$ Left valve

0-60-0 -63

0-37-0-40

0-20

0-05

? Right valve

0-59-0-61

0-35-0-37

0 19

0-05

S Left valve

0-66-0-68

0-34-0-36

0-18

0-06

A Right valve

0-64-0-69

0-33-0-35

0-18

0-06

Occurrence. Cymodoce Zone, RC. 1.

Diagnosis. Species of Amphicythere with bean-shaped carapace. Hinge strong, with
large antero-median socket on left valve. Corresponding tooth on left valve high,
rounded. Sexual dimorphism strong, males longer and less high than females.

Description. Carapace bean-shaped, ovoid. Left valve larger than right, overlapping it
along entire margin, except posterior part. In dorsal view carapace oval in shape, greatest
width at middle. In side view carapace highest at middle, left valve much higher
than right. Anterior end rounded on both valves. Dorsal and ventral margins convex.

148

PALAEONTOLOGY, VOLUME 12

Postero-dorsal margin more or less straight, meeting dorsal margin in an angle to form
posterior cardinal angle. Posterior end rounded, but has somewhat angular appearance.

Surface of valve finely punctate, eye depression slightly developed.

Inner lamella relatively broad, inner margin and line of concrescence coinciding.
Selvage only weakly developed, but forms wide selvage lip on both valves. Radial pore
canals simple, straight, about 10 on anterior margin. Often fine septae ornament inner
part of inner lamella.

text-fig. 6. Hinge structures in species of Amphicythere Triebel. a, A. confundens Oertli. b, same, dorsal
view, c, A. pennyi sp. nov. d, same, dorsal view, e, A. sphaendata sp. no v. /, same, dorsal view.

Hinge very unusual paramphidont type. Right valve anterior element is bipartite
ridge with 3 small teeth and 1 large one. Ridge probably more accurately described as
lobate than dentate. Antero-median element is large, deep, circular pit, continuing in
median element, a smooth groove. Posterior element is dentate ridge with 4 triangular
denticles. In left valve anterior element is elongate, oval-shaped socket with 3 to 4
loculi, posterior part of socket a separate deep pit. Antero-median element is high,
bilobate boss and its continuation is smooth wide median bar. Posterior element is
loculate socket. This description does not accord with any accepted hinge types; it is
perhaps a transitional form between schizodont and paramphidont.

Muscle scar pattern usual oblique row of 4 scars with 1 anterior scar. Presence of
second anterior scar doubtful. Sexual dimorphism pronounced, males more elliptical,
less high, longer than females.

T. I. KILENY1: OSTRACODA OF DORSET KIMMERIDGE CLAY

149

Remarks. A. sphaerulata is easily distinguished from all other species of Amphicythere
by its elliptical shape and extremely robust hinge.

Genus macrodentina Martin 1940
Macrodent ina ( Macrodentina ) cicatricosa Malz 1958

Plate 30, figs. 1 1-19

19586 Macrodentina ( M .) cicatricosa Malz, pp. 17-18, pi. 5, figs. 70-75.

Material. 826 valves and carapaces. HU 2.J.29.1-826.

Dimensions {mm.).

L

H

W

M/a

$ Left valve

0-62-0-69

0-41-0-43

0-18-0-20

0-06

$ Right valve

0-62-0-66

0-39-0-41

0 17-019

0-06

S Left valve

0-80

0-44

0 19

0-06

d Right valve

0-80

0 41

0 19

0-06

Juvenile forms (left valves)

Instar 8

0-51-0-58

0-30-0-39

„ 7

0-42-0-49

0-26-0-32

„ 6

0-34-0-40

0-20-0-25

„ 5

0-28

0 18

Occurrence. Baylei and Cymodoce Zones, P. 1, RC. 1-3.

Diagnosis. Relatively small species of Macrodentina s. str. with straight and sloping
dorsal margin. Posterior end pointed. Two ventral longitudinal ribs not very conspicuous,
in dorsal view not visible at all. Central vertical rib broadens out suddenly at centre of
valve into knob-like bulge. Sexual dimorphism very pronounced.

Macrodentina ( Macrodentina ) macuiata Malz 1957
Plate 31, figs. 12-16, 19

1953 Macrodentina retirugata Martin; Steghaus, p. 41.

1957 Macrodentina cf. retirugata Martin; Martin and Weiler, pp. 126-8.
1957 Macrodentina macuiata Malz, p. 250.

1957 Macrodentina macuiata Malz; Malz, p. 218, pi. 1, fig. 2.

19586 Macrodentina (M.) macuiata Malz; Malz, p. 25, pi. 8, figs. 10-20.

Material. 103 valves and carapaces. HU 2.J. 31. 1-102, HU 2.J.32.1.

Dimensions {mm.).

L

H

W

M/a

? Left valve

0-55

0-32

0 14

007

$ Right valve

0-55

0-28

0 14

0-07

A Left valve

0-63

0-32

0 15

0-06

$ Right valve

0-63

0-28

0 15

0-06

Occurrence. Mutabilis Zone, RM. 9.

Diagnosis. Oblong-shaped form with rounded posterior end. Surface ornamentation
strongly reticulate, irregular, with sharp bars separating pits. Sexual dimorphism strong.

Remarks. The specimens from Dorset exhibit a hinge structure which is much closer to
hemimerodont than paramphidont and on this basis the species should be included in
the subgenus Polydentina. In all other respects, however, there is complete agreement
between the Dorset specimens and Malz’s material, except in size, the former being

150

PALAEONTOLOGY, VOLUME 12

about 12% shorter. On this basis the Dorset specimens are considered as juvenile forms
probably belonging to the pre-adult instar, and this explains the more hemimerodont
nature of the hinge. Malz (1956, 1 958Z>) demonstrated that in the ontogeny of Macro-
dentina ( M .) the juvenile instars have a hemimerodont hinge.

Macrodentina ( M .) sp. 1
Plate 30, figs. 9, 10

Material. 6 valves. HU 2.J.30.1-6.

Dimensions (nun.).

L

H

W

Mia

Left valve

0-62

0-38

017

007

Right valve

0-60

0-34

017

007

Occurrence. Mutabilis Zone, RM. 9.

Diagnosis. Carapace elongate-trapezoid. Surface rather regularly reticulate. Vertical
ribs less prominent than in other species.

Description. Shape of valve similar to that of M. ( M .) cicatricosa Malz 1958, but more
elongated. Main difference is in surface ornamentation. Vertical ribs less prominent; on
lateral side longitudinal ribs developed, producing net-like pattern.

Hinge like that of M. (M.) cicatricosa , although antero-median element of right valve
more like a pessular tooth.

Subgenus polydentina Malz 1958
Macrodentina ( Polydentina ) proclivis proclivis Malz 1958

Plate 3 1 , figs. 6-11, 17, 18

19586 Macrodentina ( Polydentina ) proclivis Malz, p. 33, pi. 5, figs. 76-80.

Material. 40 valves and carapaces. HU 2.J.1.29, HU 3.J.27.1-39, HU 2.5.32.1.

Dimensions (mm.).

L

H

W

Mfa

$ Left valve

0-52-0-59

0-35

0 16

0-04

$ Right valve

0-52-0-57

0-33

0-14

0-03

3 Left valve

0-59

0 31

0-11

0-04

3 Right valve

0-60

0-31

Oil

004

Occurrence. Pseudomutabilis Zone, AU. II.

Diagnosis. Small species of Macrodentina ( Polydentina ) with pointed posterior end.
Surface almost uniformly pitted, vertical or longitudinal ridges inconspicuous.

Remarks. Malz (19586) described M. ( P .) proclivis proclivis from the Cymodoce Zone of
the Black Head section. This discrepancy may be attributed to the frequent landslips in
this area which make sampling very difficult at times.

Macrodentina ( Polydentina ) proclivis striata subsp. nov.

Plate 30, figs. 20-27

Holotype. A female left valve. HU 2.J.1.36.

Paratypes. 62 valves. HU 2.J.30.1-62.

Type locality and horizon. Black Head, Dorset. Pseudomutabilis Zone, Lower Kimmeridgian.

T. I. KILENYI: OSTRACODA OF DORSET KIMMERIDGE CLAY

151

Dimensions (nun.).

L

H

W

M/a

$ Left valve (holotype)

0-56

0-36

015

005

$ Right valve

0-56

0-32

015

005

d Left valve

0-59

0-32

014

005

cJ Right valve

0-58

0-30

014

005

Occurrence. Pseudomutabilis Zone, AU. IV.

Diagnosis. Subspecies of Macrodentina {Polydentina) proclivis having same outline and
internal characteristics but different surface ornamentation. Vertical and ventral longi-
tudinal ribs well developed and together with pitting give reticulate appearance to valve.
Weak sexual dimorphism.

Description. Shape and internal characteristics as for Macrodentina (P.) proclivis pro-
clivis. Surface strongly reticulate with well developed vertical ribs radiating from antero-
dorsal part of valve. Slight broadening on central rib, which branches out into 2
separate ribs under the broadening. On lateral part of valve longitudinal ribs fairly well
developed, combination of two rib systems producing square-shaped pits, most con-
spicuous on central part of valve. On ventral part of valve about 6 strongly developed
longitudinal ridges present; second from dorsal side strongest, giving the ventral ‘edge’
of valve in dorsal view. Between first and second ribs (counting dorsally), still some trace
of vertical ribs and so pits appear, but remainder of ventral ribs run on completely
smooth surface.

Macrodentina ( Polydentina ) parvapunctata sp. nov.

Plate 31, figs. 1-5

Ho/otype. A left valve. HU 2. J. 1.30.

Paratypes. 13 valves. HU 3.J.28. 1—13.

Type locality and horizon. Black Head, Dorset. Mutabilis Zone, Lower Kimmeridgian.

Dimensions (mm.).

L

H

W

M/a

Holotype

0-77

0-44

0-20

006

Left valve

0-74

0-45

0-20

006

Right valve

0-72

0-40

019

006

Occurrence. Mutabilis Zone, RM. 5, 6.

Diagnosis. Elongate carapace, strongly tapering towards posterior. Tapering much more
conspicuous in right valve, consequently valves differ strongly in shape. Surface of valve
has ornament of sparsely spaced pits. Sexual dimorphism not apparent.

Description. Carapace elongated, strongly tapering towards posterior end. Left valve
larger than right, overlapping it mainly along ventral margin. Dorsal margin straight in
both valves, posterior end of left valve blunt, that of right valve strongly pointed. In
side view ventral edge of valve overhangs ventral margin. Valve highest at anterior
cardinal angle, about one quarter of length from anterior end.

In dorsal view carapace elliptical, greatest width at middle. Flat carina developed on
both ends, especially anterior. Surface of valve has ornament of more or less rounded
pits, on lateral parts only, ventral part of valve smooth. Pits arranged in vertical rows,
ribs between rows absent or only very weakly developed.

Inner margin and line of concrescence coincide, inner lamella broad. Selvage strong.

152

PALAEONTOLOGY, VOLUME 12

wide. Radial pore canals not discernible. Hinge robust, typically hemimerodont. Right
valve terminal elements carry 6 very strongly developed denticles, median element is
smooth, narrow groove. Corresponding structure in left valve consists of 2 terminal
sockets and smooth, straight median bar. Jn side view bar equally high at both ends.

Family Uncertain

Genus exophthalmocythere Triebel 1938
Exophthalmocy there fuhrbergensis Steghaus 1951

Plate 28, figs. 12, 13

1951 Exophthalmocythere fuhrbergensis Steghaus, p. 220, pi. 15, figs. 46-48.

1955 Exophthalmocythere fuhrbergensis Steghaus; Schmidt, p. 59.

1955 Exophthalmocythere tricornis Ljubimova, p. 87, pi. 10, figs. 2a, b.

1957 Exophthalmocythere fuhrbergensis Steghaus; Oertli, pp. 662-3, pi. 3, figs. 98-100.

1958 Exophthalmocythere fuhrbergensis Steghaus; Malz (19586), pp. 39-40, pi. 11, figs. 10a, b.
1964 Exophthalmocythere fuhrbergensis Steghaus; Glasshof, p. 48.

Material. 17 valves and carapaces. HU 2.J.19.1-17.

Dimensions (mm.). L H

9 Left valve 0-75 0-40

9 Right valve 0-77 0-38

c? Left valve 0-78 0-41

S Right valve O il 0-44

Occurrence. Mutabilis Zone, RM. 6, 9.

Diagtwsis. Species of Exophthalmocythere with 4 tubercles, 2 of them near dorsal
margin (anterior one the eye tubercle), 2 others near ventral margin. Occasionally
1 more tubercle appears centrally. Sexual dimorphism may occur.

Remarks. Steghaus’s and Oertli’s figures correspond with the young specimens from
Dorset and it is very likely that all specimens of these authors are young moults. Exoph-
thalmocythere tricornis (Ljubimova 1955), from the Lower Volgian of the Ural region,
corresponds in every respect with E. fuhrbergensis Steghaus 1955. The fifth tubercle,
not mentioned by either of the above authors, may be found only on adult carapaces.
Sexual dimorphism is not mentioned by Steghaus, but in the Dorset material it seems
fairly convincing.

Indet. gen. B. sp. 1
Plate 31, fig. 34

Material. 1 (?)left valve. HU 2.J.35.1.

Dimensions (mm.). L: 0-60; H: 0-23; W\ O il.

Occurrence. Rotunda Zone, PA. 1 1 .

Description. Left valve (?) very elongated, javelin-shaped. Dorsal margin straight,
anterior end rounded. Ventral margin convex, drawn out posterior end pointing down-
wards. Greatest height just posterior of middle. Surface of valve smooth.

Inner lamella broad, line of concrescence and inner margin do not appear to coincide
anteriorly. Radial pore canals straight, probably quite numerous. Contact margin
narrow, no hinge structure observed.

T. I. KILENYI: OSTRACODA OF DORSET KIM M ERTDGE CLAY

153

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154

PALAEONTOLOGY, VOLUME 12

text-fig. 8. Stratigraphical distribution of Ostracoda in the Kimmeridge Clay (2),

T. I. KILENYI: OSTRACODA OF DORSET KIMMERIDGE CLAY

155

Remarks. As no hinge or muscle scars were observable the taxonomic position is
unknown and the orientation of the valve is doubtful.

STRAT1GRAPHICAL DISTRIBUTION

Many of the Upper Jurassic marine ostracod species are long ranging forms, and only
a limited number of species have vertical ranges comparable with those of ammonites.
Some of these long ranging forms occur intermittently, giving the impression of zonal
significance if only a limited vertical range is explored. For example, Galliaecytheridea
postrotunda appears to be restricted to the Baylei Zone of the Lower Kimmeridge Clay,
yet it has been found by Whatley (1965) in the Plicatilis and Pseudocordata Zones, and
by Barker (1966a) in the Portland Sand. Since ecological factors play an important part
in the distribution of the benthonic ostracods the vertical range of a species does not
necessarily coincide with its life span.

The distribution of ostracods in the Kimmeridge Clay of Dorset is very uneven; most
of the species described were found in the Lower Kimmeridge Clay of the Black Head
section, where the Baylei, Cymodoce, and Mutabilis Zones are especially rich in ostra-
cods. The Pseudomutabilis, Grandis, Gigas, Vimineus, and Wheatleyensis Zones of the
type section (Kimmeridge Bay to Chapman’s Pool) are almost completely barren of
ostracods, although this is largely due to the lithology of the rocks (paper and hard
shales). The Pectinatus and Rotunda Zones contain ostracods in large numbers, a com-
pletely new assemblage, far less rich in both individuals and species than the fauna of the
Lower Kimmeridge Clay.

TABLE 1

Total number of
species

Number of typically
L. Kimmeridgian
species

Number of typically
U. Kimmeridgian
species

Of the 21 genera found in the Dorset Kimmeridge Clay 16 occur in the Dorset
Oxfordian as well (Whatley 1965) but only 7 continue into the Portlandian (Barker
1966a, b). A very close relationship exists between the fauna of the Upper Oxfordian
(Corallian) and the Lower Kimmeridgian, as illustrated by Table 1.

The following conclusions can be drawn from Table 1 :

1. From their maximum in the Upper Oxfordian there is a marked and progressive
reduction in the number of ostracod species towards the end of the Jurassic. This decline
is further accentuated by the establishment of fresh-brackish water conditions in the
Purbeck.

2. The base of the Kimmeridgian is not very distinctly reflected in changes in the
ostracod faunas. The most conspicuous feature is the extinction of Lophoeythere, an

(Data from Whatley (1965) and Barker (1966a, b).)

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156

PALAEONTOLOGY, VOLUME 12

extremely prolific genus in the Callovian and Oxfordian. Only two genera make their
first appearance in the Lower Kimmeridgian : Exophthalmocy there and Nodophthalmo-
cy there.

3. Two major faunal breaks exist within the Kimmeridge Clay. The first occurs
between the Lower and Upper divisions, which have 36 and 21 species respectively, and
only 1 species common to both. This sharp difference between Lower and Upper Kim-
meridgian faunas is accentuated by the intervening ostracod-barren beds. The second
faunal break is between the Upper Kimmeridgian and the Portlandian.

Stratigraphically important species

(a) Species restricted to one ammonite Zone

Paracypris sp. C. Oertli .......

Amphicythere sphaerulata sp. nov. .....

Exophthalmocythere fuhrbergensis Steghaus ....

Macrodentina (M.) parvapunctata sp. nov. ....

Macrodentina (M.) maculata Malz .....

Galliaecytheridea cf. mandelstami (Ljubimova)

Galliaecytheridea trapezoidalis sp. nov. .....

Galliaecytheridea e/ongata sp. nov. .....

Nodophthalmocy there tripartita Malz .....

Mandelstamia (X.) maculata Kilenyi .....

? Paracypris problematica sp. nov. .....

Galliaecytheridea spinosa sp. nov. .....

Protocythere nealei sp. nov. ......

? Acrocythere inornata sp. nov. ......

Galliaecytheridea polita sp. nov. ......

Baylei

Cymodoce

Mutabilis

Grandis

Rotunda

Pallasoides

( b ) Species with restricted vertical range
Cytherella recta Sharapova .
Cytherelloidea weberi Steghaus
Galliaecytheridea dissimilis Oertli
Galliaecytheridea punctata sp. nov.
Galliaecytheridea malzi sp. nov. .
Galliaecytheridea confundens sp. nov.
Galliaecytheridea fragilis sp. nov.
Mandelstamia ( M .) rectilinea Malz
Mandelstamia (M.) triebeli Kilenyi
Mandelstamia (M.) angulata Kilenyi
Dicrorygma ( O .) kimmeridgensis (Kilenyi)
Protocythere rodewaldensis (Klingler) .
Eocytheropteron decoration (Schmidt) .
Orthonotacy there interrupt a Triebel
Orthonotacythere pustulata sp. nov.
Amphicythere confundens Oertli .
Amphicythere pennyi sp. nov.
Macrodentina (M.) cicatricosa Malz
Macrodentina ( P.) proclivis proclivis Malz

Baylei-Cymodoce
Plicatilis-Mutabilis
Cautisnigrae-Pseudomutabilis
Pseudocordata-Cymodoce
Plicatilis— Baylei

Pseudocordata-Pseudomutabilis

Pseudocordata-Cymodoce

Cautisnigrae-Mutabilis

Cautisnigrae-Pseudomutabilis

Cordatum-Cymodoce

Cautisnigrae-Mutabilis

Pseudocordata-Baylei

Cautisnigrae-Baylei

Plicatilis-Mutabilis

Pectinatus-Rotunda

Cautisnigrae-Cymodoce

Pseudocordata-Cymodoce

Cautisnigrae-Cymodoce

Plicatilis-Pseudomutabilis

( c ) Long ranging species

Galliaecytheridea wolburgi (Steghaus)
Galliaecytheridea postrotunda Oertli
Protocythere sigmoidea Steghaus .
Cytheropteron aquitanum Donze .

Corallian-Portlandian

Corallian-U. Kimmeridgian
Callovian-U. Kimmeridgian

T. I. KILENYI: OSTRACODA OF DORSET KIMMERIDGE CLAY

157

The ostracod fauna of the Lower Kimmeridge Clay shows a close affinity to faunas
described from the equivalent beds of the Paris basin (Oertli 1957) (12 species common
to both localities), NW. Germany (Steghaus 1951; Schmidt 1954, 1955; Klingler, Malz,
and Martin 1962) (9 species). A lesser degree of similarity is found to faunas of the
Swiss Jura (Oertli 1959) (8 species) and the lie d'Oleron, SW. France (Donze 1960)

S ENGLAND

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text-fig. 9. The correlation of the Upper Jurassic in western Europe (after Arkell 1956

and Oertli 1957).

(2 species). In spite of this close similarity of Lower Kimmeridgian ostracod faunas in
western Europe only a few species show more or less identical and restricted vertical
ranges and are thus useful zonal fossils. The author considers the following species to
belong to this category:

1 . Exophthahnocythere fulwbergensis Steghaus occurs in Dorset in the higher Mutabilis
Zone, in the Paris basin in the ‘middle part of the Lower Kimmeridgian’, and in NW.
Germany in the ‘Middle Kimmeridgian’ (text-fig. 9). In all the localities the vertical
range is very short and identical.

2. CythereUoidea weberi Steghaus is a widespread species, occurring in all the five
above-mentioned localities. It marks the Lower Kimmeridgian up to and including the
Mutabilis Zone in Europe, whereas in Dorset it extends down to the Plicatilis Zone.

3. Eocytheropteron decorcitum (Schmidt). In Dorset it ranges from the Plicatilis to the
Baylei Zone, in NW. Germany and the Paris basin it is confined to the Lower and Middle

158

PALAEONTOLOGY, VOLUME 12

Kimmeridgian (in the continental sense), and in the Swiss Jura its range extends into the
Lower ‘Portlandian’ (? Gigas Zone).

4. Protocythere rodewaldensis (Klingler) characterizes the basal Kimmeridgian in
NW. Germany, the Paris basin, and in the Swiss Juras. In Dorset it is confined to the
Corallian-Kimmeridgian border (Pseudocordata-Baylei).

5. Galliaecytheridea dissimilis Oertli is characteristic of the Upper Corallian (Pseudo-
cordata Zone) and the whole of the Lower Kimmeridgian in Dorset and in the Paris
basin.

6. Amphicythere confundens Oertli ranges from the Cautisnigrae to the Cymodoce
Zone in Dorset, with similar ranges in NW. Germany and in the Paris basin.

One constant feature appears in the comparison of the vertical ranges of these
ostracod species, namely the somewhat earlier appearance of each of these in England
compared with the continent, which suggests an easterly migration direction.

EVOLUTIONARY TRENDS

Most Mesozoic marine ostracods evolve at comparatively slow rates and successive
lineages can rarely be established. Some trends are, however, discernible in the Kim-
meridge Clay faunas. A common tendency, not confined to the Kimmeridgian, is seen in
the evolution of the hinge structure, which tends to become progressively more complex.
This is clearly shown in Mandelstamia (text-fig. 4). In the Corallian-Lower Kimmerid-
gian the hinge is a simple lophodont type with undifferentiated terminal elements. The
Upper Kimmeridgian Mandelstamia ( Xeromandelstamia ) shows a more complex hinge;
first the terminal elements divide into 3 or 4 denticles and later the ends of the median
element tend to broaden and deepen, the hinge now approaching the paramphidont
type. The same tendency towards more complex hinges appears in Protocythere. Upper
Jurassic species of this genus have either smooth or finely denticulate/loculate median
elements whereas in Cretaceous species the median element is always coarsely denti-
culate.

In Galliaecytheridea a definite trend towards the development of a caudal process can
be detected. In early species (up to the Baylei Zone) there is no sign of a caudal process
(e.g. G. dissimilis). In the Mutabilis and Pseudomutabilis Zones a slight elongation of the
posterior end is evident ( G . trapezoidaiis). In G. spinosa (Rotunda Zone) a caudal process
is present, and the Portlandian G. credonensis Barker exhibits a well drawn out caudal
process.

REFERENCES

anderson, f. w. 1966. New genera of Purbeck and Wealden Ostracoda. Bull. Brit. Mus. (Nat. Hist.),
Geol. 11, no. 9, 435-6.

arkell, w. j. 1933. The Jurassic System in Great Britain. 681 pp., 41 pi. Oxford.

1947. The Geology of the Country around Weymouth, Swanage, Corfe and Lulworth. Mem.

geol. Surv. G.B. 386 pp.

1956. Jurassic geology of the world. 806 pp., 46 pi. Edinburgh.

barker, d. 1966<7. Ostracods from the Portland Beds of Dorset. Bull. Brit. Mus. (Nat. Hist.), Geol.
11, no. 9, 447-57.

19666. Ostracods from the Portland and Purbeck Beds of the Aylesbury District. Ibid. 460-87.

T. I. KILENYI: OSTRACODA OF DORSET KIMMERIDGE CLAY

159

bate, R. h. 1963. Middle Jurassic Ostracoda from North Lincolnshire. Ibid. 8, no. 4, 176-219.
bizon, j. j. 1958. Foraminiferes et ostracodes de l'Oxfordien de Villers-sur-Mer (Calvados). Rev. Inst,
franc. Petr. 13, 3-45.

1960. Sur quelques ostracodes du Lias du Bassin Parisien. Rev. Micropaleont. 2, 203-11.

blake, j. f. 1875. On the Kimmeridge Clay of England. Quart. J I geol. Soc. Loud. 31, 196—
233.

Christensen, o. b. 1965. The ostracod genus Dicrorygma Poag 1962 from Upper Jurassic and Lower
Cretaceous. Dawn. geol. Unders. II, ser. 90, 1-21.

donze, p. 1960. Les formations du Jurassique terminal dans la partie nord-ouest de Tile d’Oleron
(Charente-Maritime). Ann/s. Univ. Lyon, C12, 5-30.

1962. Contribution a l’etude paleontologique de l'Oxfordien superieur de Trept (Isere). III.

Ostracodes. Trav. Lab. geol. Univ. Lyon, N.S., no. 8, 125-42.
glasshof, h. 1964. Ostracoden-Faunen und Palaogeographie im Oxford NW.-Europas. Palaont. Z.
38, 28-65.

grundel, j. 1963. In beutler, g. and grundel, j. Die Ostrakoden des unteren Keupers im Bereich
des Thiiringer Beckens. Freiberger Forsch-ft. C164, 33-92.
jones, t. r. and sherborn, c. d. 1888. On some Ostracoda from the Fullers-earth Oolite and Bradford
Clay. Proc. Bath nat. Hist. Fid. Cl. 6, no. 3, 249-78.
kaye, p. 1963. The interpretation of the Mesozoic ostracod genera of the family Cytherideidae Sars
1925. Rev. Micropaleont. 6, 23-40.

kilenyi, t. i. 1965. Oert/iana , a new ostracod genus from the Upper Jurassic of North-West Europe.
Palaeontology, 8, 572-6.

klingler, w. 1955u. Mikrofaunistische und stratigraphisch-fazielle Untersuchungen im Kimmeridge
und Portland des Weser-Aller-Gebietes. Geol. Jb. 70, 167-246.

1955A Nachtrag. Ibid. 575-6.

1956. Zur Gliederung des oberen Malm in Nordwestdeutschland. Erdol und Kohle, 9, 578-9.

malz, h. and martin, g. p. r. 1962. Malm NW. Deutschlands. In Leitfossilien der Mikro-

paldontologie, Gebriider Borntraeger, Berlin.

ljubimova, p. s. 1955. Ostracoda of the Middle Mesozoic formations of the Central Volga area and
the Obshchij Syrt. Trudy vses. neft.-nauch. issled. geol. Inst. ( VNIGRI .) N.s. 84, 3-189 (in Russian).

1956. Triassic and Jurassic ostracods of the eastern district of the Ukraine. In Microfauna of the
U.S.S.R., N.s. 8, Trudy vses. neft.-nauch. issled. geol. Inst. (VNIGRI.) 98, 533-89 (in Russian).
lloyd, a. j. 1959. Arenaceous foraminifera from the type Kimmeridgian (Upper Jurassic). Palaeon-
tology, 1, 298-320.

1962. Polymorphinid, miliolid and rotaliform foraminifera from the type Kimmeridgian. Micro-
paleontology, 8, 369-83.

lutze, g. f. 1960. Zur Stratigraphie und Palaontologie des Callovien und Oxfordien in Nordwest-
Deutschland. Geol. Jb. 77, 391-532.

malz, h. 1956. Zur Ontogenetischen Entwicklung des Schlosses bei Macrodentina-Arten (Ostrac.).
Senckenberg. leth. 37, 535-41, pi. 1, 2.

1957. Macrodentina maculata n. sp. ein stratigraphisch- wichtiger Ostracod im Oberen Malm.

Ibid. 38, 250.

1958u. Nodophthalmocythere n. gen. (Ostrac., Ob. Jura), nebst einer Abgrenzung gegen ahnliche

Gattungen. Ibid. 39, 119-33.

19586. Die Gattung Macrodentina und einige andere Ostracoden-Arten aus dem Oberen Jura von

NW. Deutschland, England und Frankreich. Abh. Senckenb. naturforsch. Ges. 497, 1-67.
Mandelstam, m. i. 1960. In orlov, j. a. (ed.). Fundamentals of palaeontology. (8) Arthropoda, Trilobita
and Crustacea. 515 pp., 17 pi. (in Russian).

martin, g. p. r. and weiler, w. 1957. Das Aldorfer Otholiten-' Pilaster’ und seine Fauna (Mittlerer
Miinder Mergel). Senckenberg. leth. 38, 211-49.

moore, r. c. (ed.). 1961. Treatise on invertebrate paleontology, Pt. Q. Arthropoda 3. Geol. Soc. Amer.
and University of Kansas Press.

neale, j. w. 1960. Marine Lower Cretaceous Ostracoda from Yorkshire, England. Micropaleontology,
6, 203-24.

1962. Ostracoda from the type Speeton Clay (Lower Cretaceous) of Yorkshire. Ibid. 8, 425-84.

160

PALAEONTOLOGY, VOLUME 12

neale, j. w. and kilenyi, t. i. 1961. New species of Mandelstamia (Ostracoda) from the English
Mesozoic. Palaeontology, 3, 439-49.

oertli, n. j. 1957. Ostracodes du Jurassique superieur du Bassin de Paris (Sondage Vernon 1). Rev.
Inst.frang. Petr. 12, 647-95.

1959. Malm-Ostrakoden aus des schweizerischen Juragebirge. Denkschr. schweiz. naturf. Ges.

83, 1-44.

1963 a. Mesozoic Ostracod faunas of France. Leiden.

- 19636. Fossile Ostracoden als Milieuindikatoren. Fortschr. Geol. Rhein/d Westf. 10, 53-66.

brotzen, f. and bartenstein, h. 1961. Mikropalaontologisch-feinstratigraphische Untersuchung

der Jura-Kreide-Grenzschichten in Siidschweden. Arsb. Sverig. Geol. Unders. 55 (3), Ser. C. 579, 1-24.
peterson, j. a. 1954. Jurassic Ostracoda from the ‘Lower Sundance’ and Rierdon formation. Western
Interior United States. J. Paleont. 28, 153-76.

schmidt, c. 1954. Stratigraphisch wichtige Ostracoden im ‘Kimmeridge’ und tiefsten ‘Portland’
NW. Deutschlands. Palaont. Z. 28, 81-101.

1955. Stratigraphie und Mikrofauna des Mittleren Malm im nordwest-deutschen Bergland. Abb.

Senckenb. naturf Ges. 491, 1-76.

sharapova, e. 1 939. Some data on the Ostracoda of the Upper Jura and the Cretaceous from the region
of St. Ozinki. Trans. Geol. Oil. Inst. Ser. A., fasc. 116, 1-93.
steghaus, h. 1951. Ostracoden als Leitfossilien in Kimmeridge der Olfelder Wietze und Fuhrberg bei
Hannover. Palaont. Z. 24, 201-24.

1953. Uber die Moglichkeit einer Gliederung des Weiss-Jura von Dalum. Ber. naturf Ges. Freiburg

i. B. 43, 39-46.

swartz, f. m. and swain, f. m. 1946. Ostracoda from the Upper Jurassic Cotton Valley group of
Louisiana and Arkansas. J. Paleont. 20, 362-73.

sylvester-bradley, p. c. 1956. The structure, evolution and nomenclature of the ostracod hinge. Bull.
Brit. Mus. (Nat. Hist.), Geol. 3, 1-21.

triebel, e. 1951. Einige stratigraphisch-wertvolle Ostracoden aus dem hoheren Dogger Deutschlands.
Abh. senckenb. naturforsch. Ges. 485, 87-102.

1954. Malm-Ostracoden mit amphidontem Schloss. Senckerberg. leth. 35, 3-16.

and bartenstein, h. 1938. Die Ostracoden des deutschen Juras, 1. Monoceratina- Arten aus dem

Lias und Dogger. Senckenbergiana, 20, 502-18.

whatley, r. c. 1964. The ostracod genus Progonocythere in the English Oxfordian. Rev. Micropaleont.
7, 188-194.

1965. Callovian and Oxfordian Ostracoda of Gt. Britain. Unpublished Ph.D. thesis. University

of Hull.

T. I. KILENYI

Department of Geology
Sir John Cass College
Jewry Street
London, E.C.3

Typescript received 6 March 1968

THE ORDOVICIAN TRIMERELLID BRACHIOPOD
EODINOBOLUS FROM SOUTH-EAST ONTARIO

by b. s. norford and h. miriam steele

Abstract. Obolus canadensis Billings, Obolellina magnifica Billings, and Dinobolus erectus Wilson are redescribed.
The species are Wilderness (early Caradoc) in age. Rowell recently assigned all three species to Eodinobolus and
chose Obolellina magnifica as the type species. The internal structures of the three species are described from
silicified material. A hypothesis is presented for the mechanics of the opening and closing of the shell and requires
articulation about a poorly defined hinge that is analogous in its position to that of the Class Articulata.

The internal morphology of trimerellid brachiopods is very poorly known for the
interiors of most described species are known only from internal moulds that poorly
display the features of the posterior regions of the thick shells. The discovery of a sili-
cified Dinobolus in northern British Columbia (Norford 1960) revealed an unusual form
of articulation. The present contribution is part of a continuing attempt to find well
preserved material of the various trimerellid genera, to fully describe the internal mor-
phology in the family, and to assess the relations of the family to the rest of the phylum.

Three species of trimerellid brachiopods have been described from the Fourth Chute
of the Bonnechere River and from Paquette Rapids on the Ottawa River, both in Ren-
frew County, south-east Ontario. All three species, Obolus canadensis Billings, Obolel-
lina magnified Billings, and Dinobolus erectus Wilson were recently placed in the genus
Eodinobolus Rowell with O. magnifica chosen as the type species (Rowell 1963). The
internal features were not adequately described although the type specimens of all three
species are silicified.

Several large blocks of limestone were collected by the present authors and G. W.
Sinclair from a thin stratigraphic interval at the Fourth Chute. The blocks, when etched,
provided more than 300 trimerellid brachiopods.

Acknowledgements. The authors are greatly indebted to G. W. Sinclair for his guidance in the course
of the field work, his aid in the placing of the collecting locality within the stratigraphic framework of
the Ordovician rocks of the Ottawa Valley, and his critical reading of the manuscript. E. Thorpe took
the photographs of the coarsely silicified material.

GEOLOGICAL SETTING

The Bonnechere outlier is one of several small outliers of Palaeozoic sediments on the
Precambrian Shield in Renfrew County. At Fourth Chute, the Bonnechere River has
cut a deep gorge through limestones that dip gently to the north and has exposed a
section about 40 ft. thick (Kay 1942, more than 37 ft.; Barnes 1967, 33 ft.).

The specimens of Eodinobolus were collected from outcrops on both sides of the river
at the top of the gorge and are from the uppermost 10 ft. of beds exposed at Fourth
Chute (GSC. Locality 73484). Except for two shells of E. canadensis , all the valves of
Eodinobolus are disarticulated and most are broken. The thick posterior regions of the

[Palaeontology, Vol. 12, Part 1, 1969, pp. 161-71, pis. 32, 33.]

C 6289 M

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PALAEONTOLOGY, VOLUME 12

platforms of the brachial valve of E. mcignificus are common as separate fragments.
These are strong remnants of shells that were broken by wave action or by the winnow-
ing of vigorous currents. The limestones at the collecting locality are yellowish-brown
calcarenites with abundant biogenic fragments. Clear calcite is present both as cement
and as fine stringers. Residues insoluble in hydrochloric acid contain common fine
quartz sand and light brown clay-size material. Flattened ropey masses of impure chert
are common and silicified fossils are locally abundant in layers and pockets.

Resistant thick beds of similar rock to that of the collecting locality form most of the
section at the Fourth Chute but chert is only common in the uppermost beds. Three
minor intervals of very thinly bedded, very pale grey limestones are present within the
sequence. Kay (1942, pp. 595-6, 601, 604) recognized 37 ft. of Chaumont beds in the
lower part of the gorge and assigned the overlying beds that include the present collecting
locality to the Rockland Formation. Recently Barnes (1967, p. 216) continued Kay’s
usage but referred the basal beds of the section to the Lowville Formation. Wilson (1946,
pp. 10, 16- 17) assigned collections from Fourth Chute to the Leray-Rockland beds of the
Ottawa Formation. Fossils are only abundant at the top of the gorge and these collec-
tions can be assumed to be from the same uppermost beds as Locality 73484. Satterly
(1945) mapped the rocks as Ordovician without attempting assignment to a formation.
Application of the term Chaumont in the Ottawa Valley is not widely accepted and the
Rockland Formation should probably be used for the whole sequence at Fourth Chute
(Sinclair, personal communication).

The blocks of rock of the fossil collections were selected primarily for specimens of
Eodinobolus and the following fauna recovered by etching may not be completely
representative of the fauna of the beds.

Eodinobolus canadensis (Billings), E. erectus (Wilson), E. magnificus (Billings), Eichwaldia subtri-
gonalis Billings, E. tricenaria (Conrad), Idiospira panderi (Billings), Oepikina sp., Rafinesquina sp.,
Strophomena sp., Ctenodonta nasuta (Hall) sensu Salter, C. logani Salter, Cyrtodonta sp., Lyrodesma
acuminatum Ulrich sensu Wilson, Tancrediopsis ‘ abrupt a ’ (Billings), T. contractu (Salter), ‘ Cycloceras ’
cylindratum Foerste, Michelinoceras sp., ‘ Spyroceras' sp., Richardsonoceras sp., Ectomaria pagoda
(Salter), Eunema strigi/lata Salter, Helicotoma planulata Salter, Hvolithes sp., Hormotoma sp., Lopho-
spira perangulata (Hall), Maclurites logani (Salter), ? Trochonema sp., Tropidodiscus (?) argo (Billings),
Receptaculites sp., stromatoporoid, Calapoecia sp., Lambeophyllum sp., Streptelasma sp., bryozoans,
echinoderm fragments.

Many of these species are also found at Paquette Rapids, Ontario and Quebec (Kay
1942, pp. 602-3), where about 20 ft. of the Rockland Formation are exposed in another
small outlier. The holotype and para types of Eodinobolus magnificus were collected at
Paquette Rapids. The Fourth Chute and Paquette Rapids faunules are coeval and are
within the Wilderness Stage of Cooper (1956, pp. 8-9). The Wilderness largely corre-
sponds to the Black River interval of earlier usage and can be correlated within the lower
part of the Caradoc Stage of the Welsh Borderland.

The specimens of Eodinobolus are coarsely silicified but very fragile. Adherent adventi-
tious material is difficult to remove without damaging the shells. Fortunately many
specimens are available and composite descriptions of the morphology of the species
are possible. All known specimens of the species are in the collections of the Geological
Survey of Canada, Ottawa, except for four specimens of Eodinobolus magnificus that are
in the United States National Museum, Washington.

NORFORD AND STEELE: BRACHIOPOD EODINOBOLUS

163

SYSTEMATIC PALAEONTOLOGY
Phylum BRACHIOPOD A

Family trimerellidae Davidson and King 1872
Genus eodinobolus Rowell 1963

1963 Eodinobolus Rowell, pp. 37-9.

1965 Eodinobolus Rowell; Rowell, p. H274.

Type species. Obolellina magnified Billings 1872, from the Rockland Formation at Paquette Rapids on
the Ottawa River, Ontario and Quebec.

Diagnosis. (Rowell 1963, p. 37); ‘Early trimerellids. Elongate oval to transversely oval in
outline. Gently biconvex. Pseudo-interarea of ventral valve relatively low, triangular.
Muscle platforms in both valves approximately diamond shaped in outline, very low,
particularly in the dorsal valve, solid, not elevated anteriorly or excavated. Median
ridges poorly developed or absent. Ventral beak solid.

Differs from all later trimerellids in the poor development of the muscle platforms.’

Discussion. Rowell discovered that the genus Obolellina was a junior objective synonym
of Rhynobolus and essentially proposed Eodinobolus to provide a valid generic name for
several early trimerellid species that had been previously assigned to Obolellina. The
present authors have studied only the three species from the Rockland Formation.
Published descriptions of the other species assigned to Eodinobolus (Rowell 1963, p. 39)
lack sufficient detail of internal morphology to allow fruitful comparison with the type
species of the genus. The pedicle valves of the three Rockland species are broadly
similar but the brachial valve of canadensis is strikingly different from those of magnificus
and erectus. The differences may warrant generic differentiation but proposal of new
genera of trimerellid brachiopods seems to be premature when so little is known of the
morphology of the existing genera. For the present, canadensis is retained within
Eodinobolus.

The terminology used in the description of the species is based, with minor modifica-
tions, on the usage evolved by Davidson and King (1874), Norford (1960), and Rowell
(1965). Several scars can be differentiated on the interiors of the valves and are assumed
to be the sites of muscle attachment. The pattern of scars is much better known than in
Dinobolus or any other genus of the family but the relations between the scars of the
two valves cannot yet be unequivocally demonstrated.

Opening and closing of shell. The mechanics of opening and closing of the shell in
the trimerellid brachiopods are not fully understood. The form of the forward edge of the
homeochilidial plate of the brachial valve of Eodinobolus and of the cardinal socket of the
pedicle valve would not have allowed any lateral movement of the valves relative to each
other, although some forward and rearward sliding might have been possible. A small
amount of movement perpendicular to the commissure seems very likely. Simple dorsal-
ventral movement of the whole brachial valve towards and away from the pedicle valve
may be postulated. Closing of the shell would be achieved by contraction of all the
muscles, but the problem of a mechanism of opening the shell cannot be readily resolved.

A hypothesis of opening and closing of the shell by means of rotation of the brachial
valve about a static axis is shown by text-fig. 2. Eodinobolus canadensis is illustrated
because the pseudo-interarea of its brachial valve is less modified and reduced than those

164

PALAEONTOLOGY, VOLUME 12

of E. magnificus and E, erectus. A likely axis would be between the antero-lateral corners of
the propareas of the pedicle valve; in the brachial valve, the corresponding line would
lie near the rear parts of the postero-lateral grooves (points a in text-fig. 2). With such
an interpretation, the valves could be opened by the contraction of a set of three muscles
lying behind this line and pulling directly between the valves (text-fig. 2b). These muscles
were attached to the pedicle valve at the front of the median part of the cardinal socket
and to a pair of short scars lying lateral to the rear of the cardinal buttress; this pair is
not discernible in the type species but can be seen in E. canadensis and E. erectus (text-figs.
Id, f). In the brachial valve, these muscles were attached to three scars just in front
of the forward edge of the homeochilidial plate. A less likely possibility is that the scars
in the pedicle valve belong to minor muscles and that the set in the brachial valve are
those of adductors rooted somewhere on the platforms of the pedicle valve. In either
case the valves could be closed by the contraction of muscles attached to the large scars
on the muscle platforms and pulling directly between the valves. A slight rearward gape
was probably present between the edge of the homeochilidial plate and the cardinal
socket when the shell was closed (text-fig. 2a). This gape would be closed when the valves
were open (as in E. magnificus , PI. 32, fig. 1 1 ) and it is difficult to imagine a functional
pedicle passing between the valves. In the valve-open position (text-fig. 2b), the concave
homeodeltidium would closely mould the main part of the homeochilidial plate and the
umbo of the brachial valve. The brachial valve of E. canadensis has a longer pseudo-
interarea than the other two species and, as would be expected from the hypothesis, the
pedicle valve has a deeper and more concave homeodeltidium. This form of articulation
would not be very different from that of the Articulata but in that class the hinge con-
sists basically of a pair of specialized hinge teeth in the pedicle valve and corresponding
sockets in the brachial valve. The corresponding sites in the pedicle and brachial valve
of Eodinobolus show no such specialization and one can assume that the articulation
was inefficient and the amount of possible movement small. However, the approximate
location at which one would look for a tooth and socket articulation is the site of the
rear parts of a pair of deep grooves in both valves, postero-lateral to the platforms.
Possibly these grooves accommodated a pair of strong muscles that acted as the actual
pivots of the valves.

This hypothesis is tenable for the three described species of Eodinobolus and probably
also for the Silurian Dinobolus cf. D. conradi (Hall) from northern British Columbia
(Norford 1960, 1962). However, it can only be regarded as tentative until other genera
of the trimerellids are as well known as Dinobolus and Eodinobolus. The various genera
of the family have many bizarre features in common and it is reasonable to assume that
they all opened and closed their shells in the same manner.

Eodinobolus magnificus (Billings, 1872)

Plate 32, figs. 1-26; text -figs. 1a, b

1858« Obo/us canadensis Billings (pars), fig. 19.

18586 Obolus canadensis Billings (pars); Billings, fig. 19.

1872 Obolellina? magnifica Billings, pp. 329-30, fig. 8.

1874 Dinobolus magnificus (Billings); Davidson and King, pp. 126, 164, pi. 19, fig. 8.

1875 Dinobolus magnificus (Billings); Nicholson, p. 18 ( non fig. 6a).

1946 Dinobolus magnificus (Billings); Wilson, p. 17, pi. 1, figs. 26, 27.

NORFORD AND STEELE: BRACHIOPOD EO DINOBOLUS

165

1956 Obolellina magnified Billings; Cooper, pp. 231-2, pi. 13, figs. 1-3; pi. 24, fig. 25.

1963 Eodinobolus magnificus (Billings); Rowell, pp. 37, 39.

1965 Eodinobolus magnificus (Billings); Rowell, p. H274, fig. 169, 3 a-c.

Material. Holotype GSC 1 161, a brachial valve collected by Billings from Paquette Rapids. Paratypes,
all from Paquette Rapids: GSC 1 161a, the apical part of a shell, fragments of both valves preserved,
GSC 1161b, 1161c, 1 161 d, all brachial valves. USNM 116800a, 116800b, 116800c, 1 1 6800d, and two
other valves, collected by G. W. Sinclair from GSC Loc. 77101, an old quarry in the Rockland
Formation on the south side of the Bonnechere River, a mile below Eganville. 87 brachial valves and
40 pedicle valves from GSC Loc. 73484 at Fourth Chute, including GSC 22930-41.

text-fig. 1. Diagrams of the internal features of Eodinobolus ; magnifications X 1|. a, b. The type species
Eodinobolus magnificus (Billings), brachial valve and pedicle valve, c, d. Eodinobolus canadensis
(Billings), brachial valve and pedicle valve, e, f. Eodinobolus erectus (Wilson), brachial valve and pedicle
valve; platform and cardinal buttress shown in text-fig. If based on developments in a small specimen

(GSC 22942).

Description. Shell thick, large, biconvex with brachial valve probably about twice as
deep as pedicle valve. Outline suboval with flattened front, slightly wider than long,
greatest width at about mid-length. Anterior commissure very faintly uniplicate, lateral
commissures plane. Ornament of widely spaced growth-lines on exteriors, rare specimens
show growth-lines on interiors of valves; numerous closely spaced faint growth-lines
visible on pseudo-interareas of large individuals.

Pedicle valve shallow, greatest depth a little behind mid-length, beak small, slightly
incurved, apical angle of shell about 100-115°. Pseudo-interarea large, moderately long,
orthocline, gently concave, with depressed concave homeodeltidium indistinctly set off
from the bordering propareas, except in a few large individuals ( PI. 32, fig. 18). Pair of

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PALAEONTOLOGY, VOLUME 12

widely divergent grooves limit propareas, very indistinct in most specimens but marked
in some (PI. 32, fig. 18). No pedicle opening. The front half of the homeodeltidium in the
sole specimen in which both valves are preserved (PI. 32, figs. 8-11) bears what may be
the remnants of a low semiconical plate or pair of plates, the base of which abuts against
the beak of the brachial valve in the interpreted valve-open position (text-fig. 2b and
PI. 32, fig. 1 1), but would have been apart from it in the valve-closed position (text-fig.
2a). This structure might be interpreted as a pedicle sheath but appears to be cut off
from the shell’s interior by the homeochilidial plate of the brachial valve (PI. 32, fig.

1 1). No other pedicle valves show any traces of this structure. Hinge plate low, indistinct,
without umbonal chambers, posterior part without a cardinal buttress but with a short
shallow wide depressed transverse area, the cardinal socket (PI. 32, figs. 14, 15, 19).
Platform wide, reaching forward to about mid-length, resting directly on floor of valve;
very faint in small specimens, indistinct in those of average size, but distinct and with
thickened posterior regions in large specimens (PI. 32, figs. 15, 18); front and lateral
margins gently rounded; front half of platform with low median septum corresponding
in position to cardinal buttress and dividing a pair of broad shallow scars. No distinct
scars visible on floor of valve outside front part of platform, a pair of deep grooves
border postero-lateral parts of platform.

Brachial valve wider than long, moderately deep, greatest depth just behind mid-
length; beak minute. Pseudo-interarea almost obsolete, rear margin of valve basically
consisting of a strong high gently curved transverse edge (of the extremely short homeo-
chilidial plate) articulating with the cardinal socket of the pedicle valve, together with
a pair of small depressed transverse areas behind and outside the edge (PI. 32, figs. 7,
22). Set of three shallow impressions present on hinge plate in front of homeochilidial
plate (PI. 32, figs. 21, 22, 26), lateral pair wider and slightly further forward than median
impression, which itself may be axially divided. Platform strongly developed, longer than
wide, resting directly on valve floor, extending forward well beyond mid-length, with
rounded but irregular lateral and front margins, rear parts of platform greatly thickened
in large specimens (PI. 32, figs. 23-6). Front third of platform bears seven raised septa
separating muscle scars (PI. 32, figs. 7, 22, 26). Inner two pairs of lateral septa curve

EXPLANATION OF PLATE 32

All figures natural size. All specimens from the Rockland Formation of south-east Ontario and unless
otherwise indicated, from GSC Loc. 73484, Fourth Chute of the Bonnechere River.

Figs. 1-26. Eodinobolus magni ficus (Billings). 1-3. External, rear, and lateral views of the holotype
brachial valve (GSC 1161); from Paquette Rapids. 4. 5. Lateral and external views of a large brachial
valve (GSC 22930). 6, 7. Rear and internal views of a brachial valve (GSC 22931). 8-1 1. Brachial,
lateral, rear, and front views of a fragmentary paratype (GSC 1161a) in which the two valves are
still in living position; from Paquette Rapids. In fig. 11, the brachial valve is above and the front
edge of its homeochilidial plate rests directly in contact with the cardinal socket on the floor of the
pedicle valve; an unetched piece of limestone is present on the left side of the specimen. 12-14.
External, lateral, and internal views of a pedicle valve (GSC 22932). 15. Internal view of a large
pedicle valve (GSC 22933). 16. External view of a small pedicle valve (GSC 22934). 17-19. Internal
views of small, large, and medium-sized pedicle valves (GSC 22935, 22936, 22937). 20, 21 . Internal
views of the rear part of a brachial valve (GSC 22938); strongly tilted in fig. 21. 22, 26. Internal
views of medium-sized and large brachial valves (GSC 22939, 22940). 23-5. Rear, internal, and
external views of a detached muscle platform (GSC 22941) from a brachial valve.

Palaeontology, Vol. 12

PLATE 32

NORFORD and STEELE, Eodinobolus

NORFORD AND STEELE: BRACHIOPOD EODINOBCLUS

167

axially to join with median septum and form an anterior limit to platform. Outer pair
trend almost straight, but forward ends twist laterally just before dying out. Inner pair
of scars very small, second pair much larger and more pronounced, outer pair long and
narrow, a further pair of scars may be present outside outermost platform septa. Rear
of platform bears a very deep narrow axial trench that starts abruptly some distance in
front of homeochilidial plate and gradually fades away before mid-length of platform;
this trench is normally pronounced but is faint in some specimens (PI. 32, figs. 20, 25).
Platform bounded postero-laterally by a pair of deep grooves. Low raised area trends
forward a short distance from central part of front of platform. A few specimens show
faint coarse pits just in front of shoulders of valve.

Discussion. Variation within the species seems to be primarily related to growth. Most
large specimens have greatly thickened platforms, brachial pseudo-interareas, and
shoulders of valves.

Eodinobolus canadensis (Billings, 1858)

Plate 33, figs. 1-28; text-figs, lc, d, 2

1858o Obolus canadensis Billings, pp. 189-90, figs. 20-3 (non fig. 19).

18586 Obolus canadensis Billings; Billings, pp. 441-2, figs. 20-3 ( non fig. 19).

1863 Obolus canadensis Billings; Logan et al., p. 942, fig. 15a-c, non d.

1871 Obolellina canadensis (Billings); Billings, p. 222.

1872 Obolellina canadensis (Billings); Billings, pp. 327-8, figs. 1-5.

1874 Dinobolus canadensis (Billings); Davidson and King, pp. 126, 162-3, pi. 19, fig. 7.

1946 Dinobolus canadensis (Billings); Wilson, p. 16, pi. 1, fig. 24.

1956 Obolellina canadensis (Billings); Cooper, p. 230, pi. 24, fig. 24.

1963 Eodinobolus canadensis (Billings); Rowell, p. 39.

Material. Holotype GSC 1 150, a complete specimen collected by Billings from the Fourth Chute of the
Bonnechere River, the same locality and almost certainly the same horizon as GSC Loc. 73484.
Paratypes GSC 1150b, 1150c, 1 1 50d, brachial valves, and 1150a, a small complete specimen; all from
the same locality as the holotype. 89 brachial valves and 128 pedicle valves from GSC Loc. 73484 at
Fourth Chute, including GSC 22943-56.

Description. Shell thick, biconvex with depth of pedicle valve about two-thirds that of
brachial valve. Outline suboval, large shells slightly longer than wide, small shells
equidimensional, greatest width just in front of mid-length. Anterior commissure
rectimarginate, lateral commissures plane. Ornament of widely spaced growth-lines on
exterior; numerous closely spaced faint growth-lines on pseudo-interareas.

Pedicle valve shallow, greatest depth at about mid-length; small, strongly incurved
beak, apical angle of shell about 85-105°. Pseudo-interarea large, long, gently anacline,
concave; with prominent concave homeodeltidium that is distinctly set off from border-
ing propareas. Pair of widely divergent shallow grooves limiting propareas on pseudo-
interareas, situated about midway between homeodeltidium and lateral margins (PI. 33,
figs. 24, 25). No pedicle opening. Hinge plate thick, without umbonal chambers, sup-
ported by very low coarse cardinal buttress that tapers and becomes indistinct forward
without quite reaching front of platform. Rear part of hinge plate bears a wide shallow
depressed transverse area, the cardinal socket (PI. 33, figs. 24, 27). Platform wide, reach-
ing beyond mid-length, resting directly on floor of valve, with almost straight antero-
lateral margins, front medianly thickened and elevated, and in front of platform, a low

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PALAEONTOLOGY, VOLUME 12

text-fig. 2. Hypothesis for opening and closing of shell of Eodinobolus canadensis (Billings), involving
relaxation and contraction of muscles and rotation about an axis through aa and perpendicular to the
plane of the diagram ; a (unspecialized hinge area in each valve) ; p, pedicle valve ; b, brachial valve ;
m, muscle; o, gape; magnification about X 3. a. Shell closed, note possible small gape at rear of shell in
shell-closed position; shell can be opened by contraction of muscles to rear of aa and relaxation of
large muscles on muscle platforms in front of aa. b. Shell open; shell can be closed by contraction of
large muscles on muscle platforms in front of aa and relaxation of muscles to rear of aa.

EXPLANATION OF PLATE 33

All figures natural size. All specimens from GSC Loc. 73484, Rockland Formation, Fourth Chute

of the Bonnechere River, south-east Ontario.

Figs. 1-28. Eodinobolus canadensis (Billings). 1-4. Brachial, pedicle, lateral, and rear views of a para-
type (GSC 1150a). 5-7. Brachial, lateral, and rear views of the holotype (GSC 1150). 8, 10-12.
External views of pedicle valves (GSC 22944, 22946, 22947, 22945). 9. External view of a brachial
valve (GSC 22943). 13-15. Rear, internal, and tilted internal views of a brachial valve (GSC

22948). 16, 22. Internal and lateral views of a brachial valve (GSC 22949). 17-20. Internal views of
brachial valves (GSC 22952, 22951, 22956); fig. 18 is a tilted view of the specimen shown in fig. 17.
21, 23. Rear and internal views of a brachial valve (GSC 22950). 24-6. Internal, tilted internal, and
lateral views of a pedicle valve (GSC 22953). 27, 28. Internal views of pedicle valves (GSC 22954,
22955); fig. 28 shows a tilted valve.

Figs. 29-37. Eodinobolus erectus (Wilson). 29-32. Lateral, internal, front, and external views of a
brachial valve (GSC 22957). 33, 34. Internal views of the rear parts of two fragmentary pedicle
valves (GSC 22958, 22959). 35. Internal view of a small pedicle valve (GSC 22942). 36, 37. Internal
and lateral views of the holotype pedicle valve (GSC 6301).

Palaeontology , Vol. 12

PLATE 33

NORFORD and STEELE, Eodinobolus

NORFORD AND STEELE: BR ACHIOPOD EODINOBOLUS 169

broad median elevation trending a short distance forward on floor of valve (PI. 33, figs.
27, 28). One pair of large longitudinally striated scars on main part of platform, divided
by cardinal buttress; second small transverse pair of depressions at rear of platform, just
in front of hinge plate (PL 33, figs. 25, 27); third narrow longitudinal pair of depressions
lie outside rear half of platform and are bounded laterally by a pair of shoulders on
floor of valve, rear ends of these shoulders lie just outside fronts of grooves that
limit propareas on pseudo-interareas (PI. 33, figs. 24, 25).

Brachial valve longer than wide, greatest depth at about mid-length; beak small.
Pseudo-interarea of moderate size, just anacline of orthocline, with prominent convex
homeochilidial plate that anteriorly slopes towards pedicle valve and becomes very
broad, culminating in a strong wide forward edge that articulates with cardinal socket
of pedicle valve; outer parts of pseudo-interarea narrow. Three transverse impressions
on hinge in front of homeochilidial plate ( PI. 33, figs. 14, 17, 23): medium scar at a higher
level on hinge than lateral pair, relatively deep; lateral pair shallow and slightly further
forward. Platform strongly developed, much longer than wide, resting directly on floor
of valve, extending well beyond mid-length, with almost straight postero-lateral margins
(a couple of specimens show thickened growth-lines on platform marking previous
positions of postero-lateral margins), front strongly thickened and elevated with a
median elevation trending forward before it (PI. 33, figs. 17, 20). Front half of platform
with pair of large muscle scars separated by small median pair (PI. 33, figs. 16, 20).
Faint pair of scars on rear of platform (PI. 33, figs. 14, 20), which is thickened and
bounded by a pair of postero-lateral grooves and without an axial trench. Another pair
of depressions that seem to trend into these grooves, lies outside front half of platform
and is bounded laterally by a pair of shoulders on floor of valve ( PI. 33, figs. 14, 15, 17).

Discussion. As in E. magnificus, large specimens of E. canadensis show thickening of the
posterior region of the shell and of the platforms. The brachial valve is very different
from that of E. magnificus , the pedicle valve primarily differs by being deeper and by having
a more incurved beak and a proportionally longer and more concave pseudo-interarea.

Eodinobolus erect us (Wilson, 1946)

Plate 33, figs. 29-37; text-figs. 1e, f

1946 Dinobolus erectus Wilson, p. 17, pi. 1, fig. 25.

1963 Eodinobolus erectus (Wilson); Rowell, p. 39.

Material. Holotype GSC 6301, a pedicle valve described from the Fourth Chute of the Bonnechere
River, the same locality and almost certainly the same horizon as GSC Loc. 73484. 10 brachial valves
and 26 pedicle valves from GSC Loc. 73484 at Fourth Chute, including GSC 22942, 22957-9.

Description. Shell large, thick in large individuals, subequally biconvex. Outline sub-
oval, longer than wide, greatest width in front of mid-length. Lateral commissures plane,
anterior commissure faintly uniplicate. Ornament of widely spaced growth-lines on
exterior; closely spaced faint growth-lines on pseudo-interareas of large individuals.

Pedicle valve shallow, greatest depth in front of mid-length; beak small, pointed,
slightly incurved, apical angle of shell about 75-85°. Lateral and anterior profiles very
gently convex with steeper slopes close to commissures in large valves. Pseudo-interarea
large, very long, orthocline, very gently concave, with depressed homeodeltidium that
is distinctly limited from propareas in most specimens (PI. 33, figs. 33, 34) but not in the

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PALAEONTOLOGY, VOLUME 12

holotype (PI. 33, fig. 36); pair of grooves limiting propareas barely discernible. No
pedicle opening. Hinge plate low, indistinct, supported by low very broad cardinal
buttress that can only be distinguished for a short distance forward (PI. 33, fig. 34) except
in a few small specimens. Rear part of hinge plate with a short depressed transverse area,
the cardinal socket. Platform low, indistinct, resting directly on floor of valve. Pair of
small transverse scars in front of cardinal socket, separated by broad cardinal buttress.

Brachial valve wider than long, greatest length at about mid-length; beak minute.
Pseudo-interarea almost obsolete; rear margin of valve basically consists of a strong
high curved transverse edge (of the homeochilidial plate); a pair of small transverse
depressed areas behind and outside this edge correspond to rest of pseudo-interarea.
Indistinct impressions on hinge in front of homeochilidial plate. Platform low, longer
than wide, resting directly on floor of valve, extending forward beyond mid-length
(PI. 33, fig. 30). Front half of platform with at least five raised rounded septa delimiting
muscle scars; inner pair of scars very small, second pair large, any outer pair of scars
that may be present are not well shown by available material. Rear of platform with
deep narrow axial trench that starts abruptly some distance in front of homeochilidial
plate and gradually fades forward. A pair of deep grooves form postero-lateral corners
of platform.

Discussion. Wilson described the species from a single exceptionally large pedicle valve
(PI. 33, fig. 36). The specimen seems to be part of a gerontic individual and has numer-
ous closely spaced coarse growth lamellae adjacent to the commissures. Study of these
growth lamellae reveals that the commissures began to contract during the final stages
of growth although the thickness of the individual continued to increase. The internal
features are poorly shown in the holotype but the platform is very thick, the cardinal
buttress is obscure, and its position is the site of a shallow median groove between the
lateral portions of the thickened platform; probably these are all features of old age.

Study of all the disarticulated specimens of Eodinobolus collected by the authors from
Fourth Chute allows discrimination of three forms of brachial valve and three forms of
pedicle valve. Fortunately two articulated specimens of E. canadensis from Fourth
Chute and one of E. magnificus from Paquette Rapids demonstrate which valves belong
to these species.

The remaining form of pedicle valve has an elongate interarea that indicates relation
to the holotype of E. erectus although none of the pedicle valves approaches the holotype
in size. The present description of the pedicle valve of E. erectus is primarily based on the
smaller specimens. The valve more closely resembles that of E. canadensis than that of
E. magnificus and has a similar outline in front of the hinge, but the valve is less deep,
the platform is less strongly developed, the beak is less incurved, the pseudo-interarea
less concave, the grooves on the propareas are very indistinct, the pseudo-interarea has
a more pointed apex, is much longer, and thus is proportionally narrower.

The third form of brachial valve is assumed to belong to E. erectus. It is very different
from that of E. canadensis but is very similar to that of E. magnificus except that it is more
elongate. This factor is reflected by a more narrow outline, by protrusion of the anterior
commissure further forward, and by the rear margin and the homeochilidial plate being
less transverse and more curved. The platform is less strongly developed than in
E. magnificus.

NORFORD AND STEELE: BRACHIOPOD EODINOBO LUS

171

The apparent similarity of the pedicle valve of E. erectus to that of E. canadensis in
contrast to the close relation of the brachial valve to that of E. magnificus is puzzling, but
the pedicle valve may have been conservative in the trimerellidsand the similarity may be
primarily due to the similar outline of the two species.

REFERENCES

barnes, c. R. 1967. Stratigraphy and sedimentary environments of some Wilderness (Middle Ordo-
vician) limestones, Ottawa Valley, Ontario. Canadian J. Earth Sci. 4, 209-44.
billings, E. 1858a. Report for the year 1857. Geol. Surv. Canada , Kept, of Progress for 1857, 147-92.

18586. New genera and species of fossils from the Silurian and Devonian formations of Canada.

Canadian Naturalist and Geologist , 3, 419-44.

1871. On some new species of Palaeozoic fossils. Ibid., N.s. 6, 213-22.

1872. On the genus Obo/ellina. Ibid., n.s. 6, 326-33.

cooper, g. a. 1956. Chazyan and related brachiopods. Smithson, misc. Coll. 127.
davidson, t. and king, w. 1872. Remarks on the genera Trimerella, Dinobolus, and Monomerella. Geol.
Mag. 9, 442-5.

1874. On the Trimerellidae, a Palaeozoic family of the Palliobranchs or Brachiopoda.

Q. Jl. geol. Soc. Loud. 30, 124-73.

kay, g. m. 1942. Ottawa-Bonnechere graben and Lake Ontario homocline. Bull. geol. Soc. Am. 53,
584-646.

logan, w. e., Murray, a., hunt, t. s., and billings, e. 1863. Geology of Canada: Geological Survey
of Canada, report on progress from its commencement to 1863. Geol. Surv. Canada.

Nicholson, H. A. 1875. Report upon the palaeontology of the Province of Ontario. Toronto.
norford, b. s. I960. A well-preserved Dinobolus from the Sandpile Group (Middle Silurian) of northern
British Columbia. Palaeontology, 3, 242-4.

1962. The Silurian fauna of the Sandpile Group of northern British Columbia. Bull. geol. Surv.

Can. 78.

rowell, a. j. 1963. Some nomenclatural problems in the inarticulate brachiopods. Geol. Mag. 100,
33-43.

1965. Inarticulata. In moore, r. g. (ed.). Treatise on invertebrate paleontology, Part H, Brachio-
poda. H260-H296. University Kansas Press.

satterly, j. 1945. Mineral occurrences in the Renfrew area. Ontario Dept. Mines, Ann. Rept. 53 (3),
Map 53b (1944).

wilson, a. e. 1946. Brachiopoda of the Ottawa Formation of the Ottawa-St. Lawrence Lowland.
Bull. geol. Surv. Can., 8.

b. s. norford

Geological Survey of Canada
3303, 33rd Street
Calgary, N.W.

Alberta

H. MIRIAM STEELE
Kline Geology Laboratory
Yale University
New Haven
Connecticut

Typescript received 16 October 1967

THE PALAEONTOLOGICAL ASSOCIATION

COUNCIL 1968-9

President

Professor Alwyn Williams, The Queen’s University, Belfast
Vice-President

Dr. W. S. McKerrow, University Museum, Oxford
Treasurer

Dr. C. Downie, Department of Geology, The University, Mappin Street, Sheffield, 1

Membership Treasurer

Dr. A. J. Lloyd, Department of Geology, University College, Gower Street, London, W.C. 1

Secretary

Dr. J. M. Hancock, Department of Geology, King’s College, London, W.C. 2

Assistant Secretary

Dr. W. D. I. Rolfe, Hunterian Museum, The University, Glasgow, W. 2

Editors

Mr. N. F. Hughes, Sedgwick Museum, Cambridge
Dr. Gwyn Thomas, Department of Geology, Imperial College, London, S.W.7
Dr. I. Strachan, Department of Geology, The University, Birmingham, 15
Professor M. R. House, The University, Kingston upon Hull, Yorkshire
Dr. R. Goldring, Department of Geology, The University, Reading

Other members of Council

Dr. F. M. Broadhurst, The University, Manchester
Mr. M. A. Calver, Geological Institute of Sciences, Leeds
Dr. C. B. Cox, King’s College, London
Mr. D. Curry, Eastbury Grange, Northwood, Middlesex
Dr. Grace Dunlop, Bedford College, London
Dr. G. F. Elliott, 60 Fitzjohn Avenue, Barnet, Herts.

Dr. A. Hallam, University Museum, Oxford
Dr. Julia Hubbard, King’s College, London
Dr. J. D. Hudson, The University, Leicester
Dr. R. P. S. Jefferies, British Museum (Natural History), London
Dr. J. D. Lawson, The University, Glasgow
Dr. A. H. Smout, British Petroleum Company, Sunbury-on-Thames
Professor H. B. Whittington, Sedgwick Museum, Cambridge

Overseas Representatives

Australia : Professor Dorothy Hill, Department of Geology, University of Queensland, Brisbane

Canada'. Dr. D. J. McLaren, Institute of Sedimentary and Petroleum Geology, 3303-33rd Street
NW., Calgary, Alberta

India : Professor M. R. Sahni, 98 The Mall, Lucknow (U.P.), India

New Zealand: Dr. C. A. Fleming, New Zealand Geological Survey, P.O. Box 368, Lower Hutt

West Indies and Central America: Mr. John B. Saunders, Geological Laboratory, Texaco Trinidad,
Inc., Pointe-a-Pierre, Trinidad, West Indies

Western U.S.A. : Professor J. Wyatt Durham, Department of Paleontology, University of California,
Berkeley 4, Calif.

Eastern U.S.A. : Professor J. W. Wells, Department of Geology, Cornell University, Ithaca, New
York

PALAEONTOLOGY

VOLUME 12 • PART 1

CONTENTS

Faunal realms and facies in the Jurassic. By A. hallam 1

Upper Maestrichtian planktonic Foraminifera from Galicia Bank, west of
Spain. By b. M. funnell, j. k. friend, and A. t. s. ramsay 19

A new species of Coelopleurus (Echinoidea) from the Miocene of Malta. By

G. ZAMMIT-MAEMPEL 42

Technique for scale modelling of cephalopod shells. By j. A. chamberlain, jr. 48

Palaeoecological studies in the Great Oolite at Kirtlington, Oxfordshire. By

W. S. MCKERROW, R. T. JOHNSON, and M. E. JAKOBSON 56

A method of stratigraphic correlation using early Cretaceous miospores. By

N. F. HUGHES and J. C. MOODY-STUART 84

The Ostracoda of the Dorset Kimmeridge Clay. By t. i. kilenyi 112

The Ordovician trimerellid brachiopod Eodinobolus from south-east Ontario.

By B. s. norford and h. miriam steele 161

PRINTED IN GREAT BRITAIN AT THE UNIVERSITY PRESS, OXFORD
BY VIVIAN RIDLER PRINTER TO THE UNIVERSITY

VOLUME 12 • PART 2

Palaeontology

AUGUST 1969

PUBLISHED BY THE
PALAEONTOLOGICAL ASSOCIATION
LONDON

Price £3

THE PALAEONTOLOGICAL ASSOCIATION

The Association was founded in 1957 to further the study of palaeontology. It holds
meetings and demonstrations, and publishes the quarterly journal Palaeontology.
Membership is open to individuals, institutions, libraries, etc., on payment of the
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There is no admission fee. Institute membership is only available by direct appli-
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tion at educational institutions recognized by the Council; on first applying for
membership, they should obtain an application form from the Membership
Treasurer. All subscriptions are due each January, and should be sent to the Member-
ship Treasurer, Dr. A. J. Lloyd, Department of Geology, University College,
Gower Street, London, W.C. 1, England.

COUNCIL 1969-70

President : Professor Alwyn Williams, The Queen’s University, Belfast

Vice-Presidents: Dr. W. S. McKerrow, Department of Geology, Oxford
Dr. C. Downie, The University, Sheffield

Treasurer : Dr. J. M. Hancock, Department of Geology, King’s College, London, W.C. 2

Membership Treasurer : Dr. A. J. Lloyd, Department of Geology, University College, Gower

Street, London, W.C.2

Secretary: Dr. W. D. I. Rolfe, Hunterian Museum, The University, Glasgow, W. 2

Editors

Mr. N. F. Hughes, Sedgwick Museum, Cambridge
Dr. Gwyn Thomas, Department of Geology, Imperial College, London, S.W.7
Dr. Isles Strachan, Department of Geology, The University, Birmingham, 15
Professor M. R. House, The University, Kingston upon Hull, Yorkshire
Dr. R. Goldring, Department of Geology, The University, Reading, Berks.

Other members of Council

Dr. F. M. Broadhurst, Manchester
Dr. L. R. M. Cocks, London
Dr. C. B. Cox, London
Mr. D. Curry, Northwood
Dr. A. Hallam, Oxford
Dr. Julia Hubbard, London
Dr. J. D. Hudson, Leicester

Dr. W. J. Kennedy, Oxford

Dr. J. D. Lawson, Glasgow

Dr. E. P. F. Rose, London

Dr. C. T. Scrutton, London

Dr. V. G. Walmsley, Swansea

Professor H. B. Whittington, Cambridge

Overseas Representatives

Australia: Professor Dorothy Hill, Department of Geology, University of Queensland, Brisbane
Canada: Dr. D. J. McLaren, Institute of Sedimentary and Petroleum Geology, 3303-33rd Street
NW., Calgary, Alberta

India: Professor M. R. Sahni, 98 The Mall, Lucknow (U.P.), India

New Zealand: Dr. C. A. Fleming, New Zealand Geological Survey, P.O. Box 368, Lower Hutt
West Indies and Central America: Mr. John B. Saunders, Geological Laboratory, Texaco Trinidad,
Inc., Pointe-i-Pierre, Trinidad, West Indies

Western U.S. A. : Professor J. Wyatt Durham, Department of Paleontology, University of California,
Berkeley 4, Calif.

Eastern U.S. A. : Professor J. W. Wells, Department of Geology, Cornell University, Ithaca, New York

© The Palaeontological Association, 1969

A NEW SPECIES OF BABINKA (BIVALVIA) FROM
THE LOWER ORDOVICIAN OF OLAND, SWEDEN

by HELEN SOOT-RYEN

Abstract. A new species of the genus Babinka Barrande, 1881, Babinka oelandensis is described from the
Lower Ordovician (Upper Ontikan) of Oland, Sweden. Previously, only the type species of Babinka, B. prima
Barrande, 1881, was known from the Barrandian area, Central Bohemia, and the Montagne Noire region in
southern France.

While examining a collection of Ordovician bivalves from Oland, Sweden, on loan
from the State Museum of Natural History, Stockholm (subsequently abbreviated
SMNH when referring to specimens), I recognized five specimens which seem to
belong to the genus Babinka Barrande, 1881.

The specimens come from the old collections of the museum and unfortunately the
stratigraphic position is not known with certainty. In 1948 and 1949 members of the
Palaeontological Institute of the University of Uppsala, led by Dr. Harry Mutvei,
made a detailed study of some Ordovician outcrops on Oland. During this survey,
specimens of bivalves from accurately located horizons were collected but unfortunately
no specimens of Babinka were among these. During a visit to the Musee National
d’Histoire Naturelle in Paris in 1967, I found in the collections of l'lnstitut de Paleon-
tologie a specimen from Cessenon, Montagne Noire region which appears to be Babinka
prima. As the specimen has not previously been figured and as it is much better preserved
than those figured from the same region by Thoral (1935), it is added here for com-
parison with the specimens from Oland.

Acknowledgements. I wish to thank Dr. Harry Mutvei of the Swedish State Museum of Natural
History, for the loan of material. Also I am grateful to Mr. J. Sornay, Sous-Directeur of l’lnstitut de
Paleontologie of the Musee National d’Histoire Naturelle in Paris for allowing me to borrow and
illustrate the French specimen. I am much indebted to Dr. A. Lee McAlester, Yale University, who has
willingly answered my many questions through correspondence. My thanks are especially due to
Dr. David L. Bruton, Palaeontological Museum, Oslo, who has discussed the contents of this paper
with me and given me numerous helpful suggestions. He has also taken the photographs and corrected
the English.

Genus Babinka Barrande, 1881
Type species. Babinka prima Barrande, 1881; by monotypy.

Remarks. Only the type species B. prima was previously known. It is recorded from the
Sarka beds (of Llanvirn age, see Havlicek and Vanek, 1966) of the Barrandian area,
central Bohemia, and from the Montagne Noire region, southern France (Thoral, 1935;
Dean, 1966). According to Dean, Thoral’s material probably came from Lower Arenig
strata. One specimen in the Museum in Paris referred by me to B. prima (PI. 34, figs. 6,
7, 8), is labelled ‘Schistes de Boutory’, Cessenon (Le Foulon), departement de l’Herault.
According to W. T. Dean (personal communication) this specimen is almost certainly

[Palaeontology, Vol. 12, Part 2, 1969, pp. 173-7, pi. 34.]

C 6508

N

174

PALAEONTOLOGY, VOLUME 12

from what Dean calls the Couches de Landeyran inferieures in his paper of 1966.
These beds belong to the extensus zone of the Arenig series. Dean (1966) has a record of
B. primal from the Couches du Landeyran superieures which is the horizon overlying
the Couches inferieures but is still of extensus zone age.

The Bohemian material has been restudied by McAlester (1965) who also confirmed
the identification of Thoral’s material.

Babinka oelandensis sp. nov.

Plate 34, figs. 1-5

Holotype. SMNH Mol 3869, internal mould with some shell attached.

Type locality and horizon. Halludden, Oland, Sweden. Probably Expansus Limestone, Upper Arenig
(Hunderum substage BIua).

Material. Halludden, Oland, 4 specimens: SMNH Mo 13869, Mo 13876, Mo 13929, Mo 13937. Hun-
derum, Oland, 1 specimen: SMNH Mol 3861.

Description. Shell of medium size, ellipsoidal, equivalve, extended slightly anteriorly,
apparently closed. Beaks small, prosogyral, placed in the middle of the dorsal margin.
Lunule short, pear-shaped, bordered by distinct ridges. Ligamental area flattened, on
the internal mould bordered by two distinct keels. Ligament not observed. Anterior
dorsal margin describes a slight curve; posterior dorsal margin slanting, almost straight;
ventral margin evenly rounded. Sculpture consists of fine concentric growth lines and
very fine radial elements.

Adductor scars prominent. Between the anterior and posterior adductor is a row of
approximately 8 small, pedal scars which are irregular and often undifferentiated. The
anterior pedal muscle scars are more dorsally placed than the posterior ones so that
the row of scars represent a slanting curve. Below the pedal scars is a row of approxi-
mately 8 very small scars which are most clearly seen on the holotype (PI. 34, fig. 1 ).

Pallial line distinct, non-sinuate; below the actual line there is a 2-3 mm. wide sulcus
on the internal mould. Hinge and teeth not well displayed but grooves in the internal
mould suggest a bidental hinge.

Measurements of the holotype. Length 240 mm.; height 200 mm.; diameter 90 mm.

EXPLANATION OF PLATE 34

Figs. 1-5. Babinka oelandensis sp. nov. 1, Holotype. SMNH Mol 3869, lateral view of internal mould
of left valve showing muscle scars. Length of specimen 24-0 mm., X 2-7. 2, SMNH Mol 3929, lateral
view of internal mould of left valve. Length of specimen 24 0 mm., X 2-7. 3, Same specimen as
fig. 2, lateral view of the exterior of the right valve, x2-7. 4, SMNH Mol3879, lateral view of
internal mould of left valve. Length of specimen 20-5 mm., x2-7. 5, SMNH Mol 3937, dorsal view
showing lunule and escutcheon. Length of specimen c. 17 0 mm., X 3 -5. All specimens from 1 Expansus
limestone, Halludden, Oland, Sweden.

Figs. 6-8. Babinka prima Barrande, 1881. Musee de Paris, B. 995. 6, Silicon-rubber cast of right
valve showing the hinge, X 5. 7, Lateral view of internal mould of right valve showing muscle scars.
Length of specimen 25-5 mm., x2-5. 8, Silicone-rubber cast of same specimen as fig. 7. Lateral
internal view, x 2-5. Couches du Landeyran inferieures, Le Foulon, Departement of Herault,
S. France.

Photographs taken by Dr. David L. Bruton. Specimens painted with diluted ‘Opaque’ and then

whitened with ammonium chloride.

Palaeontology , Vol. 12

PLATE 34

-v 4*&

SOOT-RYEN, Babinka oelandensis sp. nov

H. SOOT-RYEN: A NEW SPECIES OF BABINKA

175

Discussion. Four of the five specimens of Babinka oelandensis retain part of the shell
material, and it is possible to see on all of them very fine lines perpendicular to the
growth-lines. These radial elements have also been observed by McAlester (1965, p. 243).

B. oelandensis differs from B. prima in having more prominent umbones and more
distinct umbonal slopes. The pedal muscle scars in B. oelandensis are placed more
dorsally than in B. prima in which they occur approximately level with the adductor
scars. In the new species the pedal scars describe a slanting curve, the most anteriorly
placed scars having the more dorsal position. In B. prima the row of pedal scars lie on
a more or less straight line between the adductor scars, and are more prominent and
distinct (cf. PI. 34, figs. 7, 8). In B. oelandensis, however, they are not as prominent and

are often undifferentiated with makes it difficult to count their number with certainty.
In one specimen (PI. 34, fig. 2) the pedal muscle scars seem to form a continuous row
and give the appearance of a string of pearls. The small muscle scars below the pedal
scars can be seen on two specimens (PI. 34, figs. 1, 2). On the holotype they can only be
seen below the pedal scars number 5-7 (counted from the anterior side). In one specimen
of B. prima , McAlester (1965, p. 243, pi. 28, figs. 9-11, text-fig. 1) observed the smaller
scars below the 3rd to the 7th of the pedal scars. In another specimen from Oland the
small muscle scars seem to form a continuous row below the entire row of pedal scars
(PI. 34, fig. 2). McAlester (1965, p. 236) after comparison with the recent Monoplaco-
phoran mollusc, Neopilina galatheae Lemche 1957, suggests that these small scars
represent the site of attachment of the gills, a suggestion that seems quite feasible.

Vokes (1954) appears to have been the first to draw attention to the similarities in
muscular arrangement between Babinka and Monoplacophoran molluscs. He concluded
that Babinka and Monoplacophoran molluscs might be close to an ancestral molluscan
type and that Babinka might well have occupied an ancestral position in the phylogeny
of Pelecypoda as a whole. This hypothesis has later been further developed by Horny
(1960) and McAlester (1964, 1965). Horny established the new order Diplacophora, for
Babinka. McAlester (1964, 1965) came to the interesting conclusion that Babinka was
a probable evolutionary link between the bivalve superfamily Lucinacea and some

ped.

a odd

text-fig. 1. Sketch showing the arrangement of the muscle scars in Babinka
oelandensis sp. nov. a.add. anterior adductor scar, p.add. posterior adductor
scar, ped. pedal muscle scars, g. possible gill muscle scars.

176

PALAEONTOLOGY, VOLUME 12

Monoplacophora-like ancestral mollusc, a view strongly opposed by Chavan (1966).
The dorsal hinge aspect ( PI. 34, fig. 5) is reminiscent of many typical lucinaceans.

Unfortunately the material from Oland does not provide an answer to these problems.
However, the present author does not regard Bcibinka as an especially primitive bivalve,
although it has to be admitted that the regular arrangement of the pedal muscle scars
in B. prima is a striking feature. Multiple pedal muscular attachment as such, is not
uncommon, even in recent forms (cf. McAlester 1965, p. 234). The irregular arrange-
ment and variation of the pedal muscle scars of B. oelandensis adds to the confusion
concerning the evolution of Babinka.

In addition to Babinka , the material from Oland contains around 100 other bivalve
specimens many of which belong to the Modiolopsidae and Cvrtodontidae. This material
will be described in the future.

Remarks on stratigraphy. The material studied is from the old collections made by
G. Holm and G. Rettig and is labelled ‘Gra Vaginatkalk’. Four specimens are from
Halludden and one from Hunderum but in each case the stratigraphic position is not
known with certainty. Jaanusson (1960, p. 342) has shown that Holm’s ‘grey Vaginatum
Limestone’ includes three different stratigraphic divisions viz., in ascending order, the
Langevoja substage ( Lepidurus limestone), Hunderum substage ( Expansus limestone),
and the lowermost part of the Valaste substage (Lowermost Raniceps limestone) of the
Upper Ontikan limestone sequence of Oland. However, according to Jaanusson, the
bulk of Holm’s fossil material was collected from the Expansus limestone and a lesser
amount from the Raniceps limestone. It would appear from the matrix of the present
material that the Expansus limestone is the more likely horizon.

Skevington (1963) has shown that on Oland, the boundary between the graptolite
zones Didymograptus hirundo and D. bifidus roughly coincides in the shelly facies, with
the junction between the zones of Asaphus expansus and A. raniceps and thus, in terms
of the British succession, B. oelandensis is of Upper Arenig Age. The possibility that the
species is slightly younger can, however, not be excluded.

REFERENCES

barrande, j. 1881. Systeme silurien chi centre de la Boheine, 6, classe des Motlusques, ordre des
Acephales. Prague and Paris. 342 pp. pi. 1-361. 4 vols.
chavan, a. 1966. Remarques sur l’origine des Lucinacea (Mollusques Pelecypodes). C.r. Seanc. Soc.
geol. Fr. 1966, fasc. 4, 163^1.

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, no. 6, 245-353, pi. 1-21.

horny, r. 1960. On the phylogeny of the earliest pelecypods ( Mollusca). Vestn. geol. Ust. 35, p. 479-82.
mcalester, a. l. 1964. Transitional Ordovician bivalve with both Monoplacophoran and Lucinacean
affinities. Science, 146, no. 3649, p. 1293-4.

1965. Systematics, affinities and life habits of Babinka, a transitional Ordovician lucinoid bivalve.

Palaeontology, 8, 231-46, pi. 26-8.

havlicek, v. and vanek, j. 1966. The Biostratigraphy of the Ordovician of Bohemia. Sb. geol. ved.
palaeont. rada P. 8, 1-69, pi. 1-16.

ruzicka, b. and prantl, f., 1960. Genotypy nekterych barrandovych rodu staroprvohornich mlzu
(Pelecypoda). [Types of some Barrande’s Pelecypods (Barrandian).] Cds. ndrod. Mus. oddil ph'ro-
dovedny. cislo 1, 48-55 [in Czech with English summary].

H. SOOT-RYEN: A NEW SPECIES OF BABIN KA

177

skevington, d. 1963. Graptolites from the Ontikan Limestones (Ordovician) of Oland, Sweden. I:
Dendroidea, Tuboidea, Camaroidea, and Stolonoidea. Bull. geol. inst. Uppsala. 42, no. 6, 1-62.
thoral, m. 1935. Contribution a l’etude paleontologique de l'Ordovicien inferieur de la Montagne
Noire. These. Fac. Sci. Univ. Paris. 1541(A), 2° these. Montpellier, 1935.
vokes, h. e. 1954. Some primitive fossil pelecypods and their possible significance. J. Wash. Acad. Sci.
44, no. 8, 233-6.

HELEN SOOT-RYEN
Palaeontological Museum
University of Oslo

Typescript received 3 July 1968 Oslo, Norway

LOWER DEVONIAN HEX A GONA RIA (RUGOSA) FROM
THE ARMORICAN MASSIF OF WESTERN FRANCE

by S. E. SORAUF

Abstract. Three species of cerioid colonial Rugosa are described from the Siegenian and Emsian rocks of
western France. Hexagonaria namnetensis and H. venetensis appear related to the H. hexagona and H. quadri-
gemina lineages respectively. H. sp. cf. longiseptata, characterized by broad tabularium and few dissepiments is
very close to H. longiseptata from the Upper Devonian of Russia. Angles formed by septal trabeculae with
intercorallite walls and with the margin of the tabularium are demonstrably useful in determining relationships
within the genus.

Only rarely are massive colonial disphyllid corals found in rocks older than Middle
Devonian. The occurrence of such forms in Lower Devonian rocks of the Armorican
Massif of western France has long been known (Barrois 1889). They have also been
reported from Australia; in the Garra Formation regarded as Emsian by Strusz (1965,
p. 522), and in the Lilydale Limestone, the Coopers Creek Limestone, and the Loyola
Limestone, which have recently been dated as early Siegenian by Philip and Pedder on
the basis of their conodont faunas (1967, p. 797). The massive corals of western France
are assignable to the genus Hexagonaria , but the taxonomic position of the Australian
species has been questioned. Philip and Pedder note that ‘ Acervularia’ chalkii and
‘ Cyathophyllum ’ approximans from the Lower Devonian of Australia ‘may resemble
Hexagonaria (or what is generally held to be Hexagonaria), but differ in the diffuse
nature of the peripheral part of many of their septa’ (1967, p. 796). The species under con-
sideration in the present report are Hexagonaria namnetensis ( Barrois 1889), H. venetensis
(Barrois 1889), and H. sp. cf. longiseptata Bulvanker 1958. H. namnetensis occurs in the
Nehou Limestone (Siegenian) of the Cotentin Peninsula of Normandy, and H. nam-
netensis, H. venetensis, and H. sp. cf. longiseptata are found in the Erbray and Angers
limestones (Emsian) near the city of Angers in the Loire Valley (see text-fig. 1).

A. Bigot (1928) has summarized the presence of Lower Devonian limestones in the
Baubigny area of the Cotentin Peninsula of Normandy (text-fig. 1). The two most fos-
siliferous outcrops are seen in the road cut at the village of Roquelles and nearby in the
quarry of Baubigny. At Roquelles, beds of highly fossiliferous limestones are seen inter-
calated with shales. The limestones contain Hexagonaria namnetensis, Favosites punc-
tata, lamellar and branching Pachypora and Alveolites , and many stromatoporoids
(Bigot 1928, p. 40). In the quarry of Baubigny, the transition is seen between the inter-
bedded limestone and shale of the Nehou Limestone and gray massive limestones, with
stromatoporoids and corals, apparently a near-reef facies (p. 40). The Nehou Limestone
is considered by Dangeard (1951, p. 61) to be middle Siegenian in age.

In the portion of the Armorican Massif bordering the Loire Valley, the limestones of
Angers and Erbray are regarded as Emsian in age (Peneau 1928, p. 86; Lardeux 1965,
personal communication). These Emsian limestones are referred to as the Calcaires
d’Angers et d’Erbray. The rocks are fossiliferous, with a varied fauna, in the vicinity

[Palaeontology, Vol. T2, Part 2, 1969, pp. 178-88. pis. 35-36.]

J. E. SORAUF: DEVONIAN HEXAGONARIA FROM FRANCE

179

text-fig. 1. Outline map of the northern portion of the Armorican Massif of north-western
France. Devonian rocks are shown in black. Corals described in this report are from areas
near Nehou in the north, and near Erbray, and near Angers in the south.

of Angers. Farther to the north-west in the Angers Basin, the Erbray Limestone at
Erbray was considered by Barrois to be developed in a reefal facies (1889, p. 2).

The following abbreviations are used: MNHNF, Musee National d’Histoire Naturelle de France
(Paris); McVN, Musee Communal de la Ville de Nantes.

Family disphyffidae Hill 1939 (sensu Strusz, 1965)

Genus hexagonaria Giirich 1896

Hexagonaria namnetensis (Barrois 1889)

Plate 35, figs. 1-6, and Plate 36, fig. 6
1889 Acervularia namnetensis Barrois, p. 40, pi. 1, fig. la, lb, lc.

Diagnosis. Species of Hexagonaria with 24-30 attenuate to slightly dilated septa, and
diameter of tabularium varying from 3 to 3-5 mm. in mature specimens. Dissepimen-
tarium with on average 4-5 rows of globose dissepiments progressively sloping inward,
and tabularium with variable development of complete flat or sloping tabulae or with
development of axial flat-topped and periaxial series of tabulae.

Description , type specimen (MCVN). The type specimen of Hexagonaria namnetensis
(Barrois) shows the essential features of the species.

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PALAEONTOLOGY, VOLUME 12

In transverse section the specimen is characterized by fairly large mature corallites
with multi-sided, irregular polygonal shape in cross-section and immature corallites
which generally have a sub-triangular cross-section at one stage of their development
(PI. 35, figs. 1, 5). The mature individuals display attenuate to slightly dilated septa,
clearly differentiated into first and second orders. First order septa extend into the tabu-
larium, reaching b to § of the way from the edge of the dissepimentarium to the axis of
the corallite. The second order septa extend only a short distance into the tabularium.
In 9 mature corallites, the total observed range in diameter of tabularium (D,) is from
3-2 to 4T mm., and the range in total number of septa (n) is 28-32. The mean values are
3-55 mm. for D, and 28-9 for //.

In longitudinal section the specimen is characterized by largely complete tabulae
with varying geometry. Some are more or less flat, some slope across the tabularium,
and some are arched. In several corallites, a definite tendency toward development
of an axial series of tabulae is apparent (pi. 35, fig. 3).

The dissepimentaria clearly show periodic variations in growth, with bands of smaller,
more numerous dissepiments alternating with bands of few and larger ones (PI. 35, fig. 3).
In the zones of small dissepiments, there are generally 4-5 rows of inflated dissepiments,
while in the other bands, as few as one or two dissepiments may occupy the entire
width of the dissepimentarium (PI. 35, fig. 3). The dissepiments typically bend pro-
gressively inward and slope towards the tabularium at a high angle at the inner border
of the dissepimentarium, as is noted on the left side of Plate 35, fig. 3. However, low
reflexing of the dissepimentarium is commonly noted (as in the corallite on the right-
hand side of the same figure).

The fine structure of the specimen is characterized by truly cerioid walls, with epitheca
seen in cross-section as a dark line between two layers of prismatic calcite. The fine
structure of the septa is typically seen to have trabeculae in longitudinal section approach-
ing parallel with the intercorallite wall, and making an angle of approximately 40° with
the outer margin of the tabularium.

Description. Hexagonaria namnetensis is marked by a relatively small number of septa,
with first order septa reaching to, or almost to the axis of the corallite. Little septal
dilatation is noted in the majority of corallites, but a few (PI. 35, fig. 5) do have this
characteristic quite well developed. The corallites as seen in transverse section (PI. 35,
figs. 1, 2, 5) depart greatly from equilateral polygons, probably the result of vigorous
budding throughout the colony. The buds rapidly develop 18-20 septa, having attained
this number by the time epitheca is fully developed between mother and daughter coral-
lites. In adult corallites, the total number of septa, here labeled n, showed a range of
22-35 in 64 individuals of 4 colonies. Means for 4 colonies vary from 24-0 to 29-3 («).

EXPLANATION OF PLATE 35

Figs. 1, 3, 4, 5. Hexagonaria namnetensis (Barrois); Holotype, MCVN. I, transverse, X 2. 3, longi-
tudinal, X 3. 4, longitudinal, x4. 5, transverse, x4. Emsian, Erbray Limestone near Erbray.

Figs. 2, 6. Hexagonaria namnetensis ( Barrois); MNHNF B44224. 2, transverse, X 5. 6, longitudinal,
x 6. Siegenian, Nehou Limestone, from Roquelles, Normandy.

Figs. 7, 8. Hexagonaria venetensis ( Barrois) ; Holotype, Collection Lebesconte, MCVN. 7, transverse,
x2. 8, transverse and oblique, x2. Emsian, Erbray Limestone near Erbray.

Palaeontology , Vol. 12

PLATE 35

SORAUF, Hexagonaria

J. E. SORAUF: DEVONIAN HEXAGONARIA FROM FRANCE

181

Diameter of tabularium varied from 24 to 4-1 mm., with colony means of from 2-8
to 3-6 mm.

In longitudinal section the species shows width of tabularium in mature specimens
approximately of the width of the total corallite, (PI. 35, fig. 4) although recently
budded mother corallites show a resultant lessening in width of the affected side. The

0°

text-fig. 2. Trabecular angles in Hexagonaria namnetensis and H. sp. cf. longiseptata.
a illustrates the method of determining angle W between the intercorallite wall and
septal trabeculae, and angle T, the angle between the margin of the tabularium and
septal trabeculae, b shows the distribution of readings of W and T for 28 corallites of
H. namnetensis. c shows distribution of readings for 7 corallites of H. sp. cf. longi-
septata. Pertinent statistics are shown in Table 1 .

dissepimentaria are filled with 4-7 rows of dissepiments, and as rate of growth changed
there were as many as 7 rows of small dissepiments or as few as 4 rows of larger dissepi-
ments. The horizontal lines of dissepiments are ordinarily oriented nearly perpendicular
to the corallite wall, gradually bending downward as the tabularium is approached, but
commonly being noticeably reflexed (as in PI. 35, fig. 6). Such reflexing has been noted
in disphyllids (Strusz 1965), and should not be confused with reflexing associated with
tight fans of branching septal trabeculae such as those in PhiJlipsastraea.

182

PALAEONTOLOGY, VOLUME 12

The tabularium is typically filled with arched tabulae with globose accessory tabellae
present periaxially. Where thin-sections strike the exact centre of a corallite it can
be noted that long, irregular tabulae are present without, or with few accessory plates.
Near septa are seen strongly arched tabulae and tabellae.

The fine structure of the intercorallite walls is 3-layered, showing a central layer of
very fine-grained dark calcite (epitheca) between moderately thick prismatic layers of
clear fibrous calcite with fibres oriented perpendicular to the epitheca.

text-fig. 3. Budding sequence in Hexagonarici namnetensis. The black-line drawings were prepared
directly from photographs of acetate peel prints of serial sections. Fig. 3 a is the un-budded corallite,
and figs. 36-3A illustrate the serial development of the daughter corallite. Magnification is x4.

The septa are unitrabecular (Kato 1963, p. 588). Text-fig. 2 demonstrates that the
angle made by septal trabeculae and epitheca is generally less than 22°, while the angle
made by septal trabeculae and the outer margin of the tabularium shows a maximum
inclination of 34-75 (convex upward arrangement).

Blastogeny. Text-fig. 3 illustrates a typical series of sections through a budding sequence
in H. namnetensis. The budding encountered within this species was always the type
referred to as lateral by Jull (1965, p. 206). Terminology employed here for growth
stages is that of Smith (1945, p. 7).

(a) Hystero-brephic stage. This stage of development begins with the formation of

J. E. SORAUF: DEVONIAN HEX AGON ARIA FROM FRANCE 183

a concavity in the upper margin of several septa, so that they appear to be broken in the
outer dissepimentarium. As Rozkowska (1960, p. 15) reported for Hexagonaria laxa ,
budding takes place in the furthest corner from the axis. In the case of H. nanmetensis ,
the septa initially ‘broken’ are one first-order and two adjacent second-order septa.
At the same time, there appears to be a thickening of dissepimental calcite in the area
later to become the new intercorallite wall. Very early thin septal processes develop
from dissepimental folds, as in the right side of text-fig. 3d at 0-30 mm.

As seen in text-fig. 3e (0-35 mm.), the primary development of corallite shape takes
place by the lateral appearance of additional calcite, and interruption of pre-existing
septa on both sides of the protocorallite, as illustrated by text-figs. 3 g, 3 /?, and 3/.
Epitheca is not noted in the new intercorallite wall until quite late in its development.
(Here not until section shown in text-fig. 3/, at 0-95 mm.)

(b) Neanic stage. All text-figures beginning with 3//, and extending to include 3 j are
considered as belonging to the neanic stage of H. nanmetensis , until the tabularium is
completely developed. The corallite then has the majority of the characteristics of the
species.

Once the wall develops epitheca, septa are quickly inserted, and first and second order
septa are established. In the drawings presented in text-fig. 3, it is suggested that the
septa labelled / is the cardinal or counter-cardinal, and that the septa seen joined to the
end of this septum in text-fig. 3 h are the alar or counter-lateral septa, depending on
the identity of the first. Exact identification of these septa is not deemed possible in this
sequence, as almost all septa added later are inserted in the quadrant between the alar
and the counter-lateral septa, thus furnishing no means of differentiating alar from
counter-lateral.

The tabularium, first clearly shown in text-fig. 3j, expands, so that it is typically
developed in text-fig. 3k (3-35 mm.), outlined by several closely spaced dissepiments as
seen in the plane of the sections, due to the development of a calicinal pit, with steeply
inclined dissepiments present along the walls of this pit.

Remarks. H. nanmetensis belongs to the group of species that includes H. hexagona
(Goldfuss); species that are characterized by adorally convex septal trabeculae, pro-
gressive axially sloping dissepiments, dilated septa, and the tendency toward develop-
ment of long first-order septa and axial and periaxial series of tabulae (Sorauf 1967,
p. 24). This group has been referred to as the Hexagonaria hexagona lineage by Stumm
(1948, p. 12). It would appear that the Siegenian and Emsian species, H. nanmetensis ,
is closely related to the ancestor of the Frasnian species, H. hexagona.

Rozkowska proposed the genus Marisastrum for those cerioid corals placed by her in
the Phillipsastraeacea on the basis of their ‘ fan-like disposition of trabeculae and presence
or absence of horse shoes . . .’ (1965, p. 261). It must be assumed that Marisastrum is
thus characterized by the presence of tight fans of branching septal trabeculae such as
those found in Phillipsastrea and also in Marisastrum sedgwicki , as figured by Roz-
kowska (1965, p. 263, fig. 2). Scrutton (1967, p. 267) placed forms with slightly reflexed
calices and broad open fans of the ‘disphylloid’ type (Strusz 1965, p. 524), with forms
more closely allied to Phillipsastrea and other genera characterized by tight fans (with
branching trabeculae) and a strong tendency toward reflexing of the calicinal platform.
In the opinion of this writer, such a grouping is inadmissable. Hexagonaria hexagona at

184

PALAEONTOLOGY, VOLUME 12

times displays such reflexing (Sorauf 1967, p. 10, fig. 4-1 a) and even development of
a very slight amount of fanning of septal trabeculae of the ‘disphylloid’ type described
by Strusz. Thus, H. namnetensis is treated as a species closely related to H. hexagona.

Horizon and distribution: H. namnetensis occurs in the Siegenian Nehou Formation of the Cotentin
Peninsula of Normandy at Les Roquelles, and in the Emsian Erbray Limestone near Erbray in the
Angers Basin in the southern Arniorican Massif.

Hexagonaria venetensis (Barrois 1 889)

Plate 35, figs. 7 and 8

1889 Acervularia venetensis Barrois; p. 41, pi. 1, fig. 2a, 2b, 2c.

Diagnosis. Species of Hexagonaria with large corallites, large diameter of tabularia
(4-8 mm.), numerous attenuate septa (34-40), and first order septa only somewhat longer
than second order, leaving major part of tabularium free of septa. Dissepimentarium
typical for genus and tabularium filled with rather complete sloping or flat tabulae.

Description , type specimen. ( Collection Lebesconte, MCVN.) In transverse view, the
type specimen is characterized by a broad open tabularium with a large number of
attenuate septa (PI. 35, fig. 7). In 5 mature corallites observed, the diameter of tabularium
(D,) varied between 5-7 and 6-5 mm., with a mean value of 5-9 mm. The number of septa
(n) in the same corallites varied between 39 and 45, with the mean value of 42.

Both first and second order septa are attenuate, being thickest at their periphery.
Second order septa are quite long, extending a short distance into the tabularium. First
order septa extend only slightly further, leaving fully f of the tabularium free of septa.
Crowding of dissepimental intersection lines at the inner margin of the dissepimentarium
is not well developed, and as a result there is no or little development of an ‘inner wall’
around the tabularium.

In longitudinal view, the dissepimentaria are characterized by irregularity of size and
shape of dissepiments (PI. 35, fig. 8). As shown in this figure, there may be as many as
5 or 6 rows of dissepiments, or a lesser number of very large dissepiments may fill the
dissepimentarium. Shapes vary, as some are flattened, some arched, and some more or
less irregular. There is no well-marked change in orientation of the dissepiments in the
inner dissepimentarium as in many species of Hexagonaria. The tabularium is marked
by the presence of sloping or down-warped, flat-bottomed tabulae, almost all complete
and fairly widely spaced, with few accessory tabellae.

The fine structure of the walls shows clearly a thin dark line of epitheca in the centre
of the walls, with layers of prismatic calcite on each side. The attenuate septa do not
give the impression of being ‘inserted’ in the fibrous layer, as is commonly true in other
similar species. The septal fine structure is rather typical for species with attenuate septa.
The septal trabeculae make a high angle with the intercorallite wall, and do not make
an appreciably higher angle with the tabularium margin. In the one place in the type
specimen of H. venetensis where septal trabeculae could be closely examined, the angle
between septal trabeculae and wall is 63° and between septal trabeculae and margin of
tabularium is 68°. These numbers are not considered definitive, as only the one reading
was possible.

J. E. SORAUF: DEVONIAN HEX AGON ARIA FROM FRANCE 185

Remarks. In cutting the type specimen of Hexagonaria venetensis , it was necessary to
avoid altering the external appearance of the specimen as figured by Barrois. Thus,
instead of standard transverse and longitudinal thin sections, each turned out to be
somewhat oblique, as shown in Plate 35, figs. 7 and 8. Nevertheless, the specimen is
described in terms of transverse and longitudinal views.

Hexagonaria venetensis , with its complete tabulae, broad dissepimentarium, large
number of septa, and structure of septal trabeculae would seem to be related to such
species as H. quadrigemina of the Givetian of Belgium and Germany.

Horizon. H. venetensis was described by Barrois from the Erbray Limestone (Emsian) of Erbray (1889).
Other specimens have not been available for study.

Hexagonaria sp. cf. longiseptata Bit I ranker
Plate 36, figs. 1-5

cf. 1958 Hexagonaria longiseptata Bulvanker; p. 182, pi. lxxxix, figs. 2a, 2b, pi. xciii, figs, la, lb.

Diagnosis: Species of Hexagonaria characterized by small number (generally 26-30) of
attenuate septa reaching into broad tabularium. Dissepimentarium poorly developed,
occupying minor part of corallite and composed of 2-3 rows of dissepiments. Tabulae
variously developed; in some individuals being complete and subhorizontal, in others
largely incomplete and steeply inclined, and arched in still others.

Description. In transverse section (PI. 36, figs. 1, 3) the species is characterized by irregu-
larity in polygonal outline of corallites, a small number of attenuate to slightly dilated
septa, and a broad tabularium accentuated by a narrow dissepimentarium with few
dissepiments. Four specimens show a grand mean diameter of tabularium ( D, ) of 2-85
mm. and a grand mean number of septa (n) of 26-3 for 68 corallites (N). The total
observed range for mature corallites is from 2-2 to 3-5 mm. for D, and from 22 to 32 for
n. The figures given above are dependent somewhat on the subjective decision as to
which corallites are mature.

The septa are generally attenuate, being thickest near their point of insertion in the
corallite wall. They are characterized by second order septa which extend only to the
outer border of the tabularium, while the first order septa reach well into the tabularium,
extending almost to the axis of the corallite or slightly withdrawn from this position.
There is never any joining or swirling of septa in the axial region. In a number of coral-
lites there is slight dilatation of septa in the inner dissepimentarium. Recrystallization
of the specimens makes this feature difficult to ascertain precisely. However, dilatation
of septa is certainly not characteristic of the species.

The narrow dissepimentarium is seen in transverse section to occupy only the outer
of the corallite and to be composed of generally 2-3 dissepiments (PI. 36, figs. 1, 3).
The intersection of dissepiments in the plane of the thin-section outlines the broad
tabularium clearly.

In longitudinal section this narrow dissepimentarium is more strikingly displayed
(PI. 36, figs. 2, 4). The dissepimentarium rarely has more than 4 rows of dissepiments,
and more commonly has only 2 or 3 rows, and occasionally only one. In a number of
corallites the dissepiments are strongly inclined axially and rather flattened in shape

186 PALAEONTOLOGY, VOLUME 12

(PI. 36, fig. 2), while in others, they are more nearly horizontal in attitude and more
globose in shape.

The tabularia are variable in the configuration of contained tabulae. In some (PI. 36,
fig. 4), tabulae are rather evenly spaced, complete, and sub-horizontal to gently sloping,
while others (PI. 36, fig. 2) are characterized by incomplete, irregular, steeply sloping
tabulae, and still others are filled with evenly spaced, arched tabulae which show a
tendency toward development of axial and periaxial series of tabulae.

The fine structure of the intercorallite walls is typical for cerioid disphyllids, three-
layered in nature, with dark, thin epitheca sandwiched between two layers of fibrous
calcite. The fine structure of septa (PI. 36, fig. 5) shows septal trabeculae making angles
of 20-58° with the intercorallite wall and angles of 40-70° with the inner margin of the
dissepimentarium.

Remarks. This species is assigned a taxonomic position very close to Hexagonaria longi-
septata Bulvanker. Without a larger collection of coralla from the Lower Devonian of
France and the opportunity to study the type specimen of Bulvanker, the two species
cannot be regarded as identical with certainty. The specimens from the St. Barthelemy
quarry are in most characteristics identical to H. longiseptata Bulvanker (1958, p. 182,
pi. lxxix, fig. 2a, b). The species are closely similar in size, length of septa, presence of
attenuate septa, diameter of tabularium, configuration of tabulae, spacing of tabulae,
configuration, and number of dissepiments, and in septal fine structure. The main dif-
ference between H. longiseptata as described by Bulvanker and H. sp. cf. longiseptata
from St. Barthelemy is in number of septa. Bulvanker reports a total of 20 septa (1958,
p. 182), while the French species is characterized by 26-34 septa. Bulvanker did not
mention limits of variation in septal number for her species. An additional marked
difference between the two occurrances is in the age of enclosing strata. H. longiseptata
occurs in Upper Devonian rocks (D3) in the Kuznetsk Basin of Russia.

Horizon. Hexagonaria sp. cf. longiseptata was collected from the Angers Limestone of Emsian age in
the Fours a C/iaux quarry in St. Barthelemy, a suburb of Angers.

SEPTAL FINE STRUCTURE

The septal fine structure of the three species described herein shows two variations
commonly seen in the genus Hexagonaria , and allows recognition of relationships of these
species with other, well-known species of the genus. The species are characterized by
unitrabecular septa, with their configuration seen in longitudinal section as either
parallel or convex (Kato, 1963, p. 584).

EXPLANATION OF PLATE 36

Figs. 1-5, Hexagonaria sp. cf. H. longiseptata Bulvanker. 1, MNHNF B44225, transverse. 2,
MNHNF B44226, longitudinal. 3 and 4, MNHNF B44227, transverse and longitudinal, all x 5,
and all from Emsian, Angers Limestone, Fours a Chaux Quarry, St. Barthelemy. 5, MNHNF B44226,
longitudinal view of septum showing septal trabeculae making angle of 20° with intercorallite wall
and 63° with margin of tabularium, x26.

Fig. 6. Hexagonaria namnetensis (Barrois); MNHNF B44224, longitudinal, view of septum with
adorally convex septal trabeculae paralleling intercorallite wall and making angle of 47° with margin
of tabularium, x 18.

Palaeontology , Vol. 12

PLATE 36

SO RAUF, Hexagonaria

J. E. SORAUF: DEVONIAN HEXAGON ARIA FROM FRANCE

187

Hexagonaria namnetensis is characterized by septa with trabeculae that are convex
(PL 36, fig. 6). Table 1 shows statistics of angles measured on longitudinal sections of
septa, as shown in text-fig. 2. H. hexagona from the Frasnian of Belgium has similar
configuration of septal trabeculae.

TABLE 1

Statistics and parameters, Hexagonaria namnetensis and Hexagonaria sp. cf. longiseptata,

septal fine structure

Hexagonaria Hexagonaria cf.

namnetensis longiseptata

Angle W

Angle T

Angle W

Angle T

Number of septa examined

28

28

7

7

Mean value
Standard deviation

10-4°

50-0°

35-1°

52-5°

(using N-l)

61°

8-5°

1 2°

9-3°

Standard error, mean

1-2°

1-6°

4-5°

3-5°

Standard error, deviation

0-8°

1-1°

3-2°

2-5°

Confidence interval for mean
99%

7-5-13-3°

46-54°

20-9-49-3°

41-5-63-5

95%

8-4-12-4°

47-3-52-8°

26-3-43-9°

45-7-59-3'

Confidence interval for

deviation

99%

8-4-1 2-4°

47-2-52-8°

25-1-45-1°

44-7-60-3

95%

90-11-8°

48-1-51-9°

28-9-41-3°

47-7-57-5'

Implied relationships are discussed under remarks in the species description.

As noted above, only one reliable reading of trabecular angles could be made on the type
specimen of Hexagonaria venetensis , with an angle of 63° between the intercorallite wall
and septal trabeculae immediately adjacent to it, and 68° between the inner margin of the
dissepimentarium and septal trabeculae.

Hexagonaria sp. cf. longiseptata is characterized by high angles between septal trabe-
culae and intercorallite walls, as shown in Table 1 and text-fig. 2.

As shown in this figure, septal fine structure, and especially angles formed by septal
trabeculae and inter-corallite walls and the inner edge of the dissepimentarium constitute
a useful criterion in delineating some groups within the genus Hexagonaria. In general,
species with the adoral convexity in septal trabeculae are characterized by dissepiments
that progressively slope inwards toward the tabularium and by septa that are commonly
dilated in the inner dissepimentarium. Although H. namnetensis does not show marked
dilatation of septa, it would be included with this group. Species with more closely
parallel septal trabeculae and high wall angles tend towards having attenuate septa and
less change in attitude of dissepiments from one part of the dissipimentarium to another.
Both Hexagonaria venetensis and H. sp. cf. longiseptata appear to fall into this group.
Although numerical values listed above are not based on statistically valid numbers
of readings, the limited variability of these readings suggests that such trabecular angles
may well prove to be one more valid characteristic to be employed in defining and differ-
entiating species.

188

PALAEONTOLOGY, VOLUME 12

Acknowledgements. This paper grew out of conversations and correspondence between the writer and
Dr. H. Lardeux of the Musee National d’Histoire Naturelle in Paris. Dr. Lardeux kindly arranged
for the loan of type specimens described in this paper, and aided the writer in numerous ways.

Madame Baudouin-Bodin, curator of the Musee d’Histoire Naturelle in Nantes kindly consented
to allow the loan of type specimens in her care. Dr. J. Poncet of the University of Caen loaned speci-
mens for study from the Lower Devonian of Normandy. Mr. V. Jindrich of the Geological Survey of
Czechoslovakia helped with photography and prepared serial sections of budding sequences while
at the S.U.N.Y. at Binghamton. This manuscript was critically read by Dr. C. T. Scrutton of the British
Museum (Natural History), and by Dr. John Jell of the University of Queensland. I wish to thank
each for their aid.

REFERENCES

barrois, c. 1889. Faune du Calcaire d’Erbray. Mem. Soc. Geol. Nord, 3, 1-348, pi. 1-18.
bigot, a. 1928. Reunion Extraordinaire de la Societe Geologique et Mineralogique de Bretagne en
Basse Normandie. Bull. Soc. geol. min. Bretagne, 7, 39-41.
bulvanker, e. z. 1958. Devonskie chetryrekhluchevye korally okrain Kuznetzkogo basseyna. Vses.

nauchno-issled. geol. Inst. Leningrad, 1, 1-212, pi. 1-93.
dangeard, L. 1951. La Normandie. Geol. Regionale de la France, 7, 1-230.

hill, d. 1939. The Devonian Rugose Corals of Lilydale and Loyla, Victoria. Proc. roy. Soc. Viet. 51,
219-56, pi. 13-16.

jull, r. k. 1965. Corallum Increase in Lithostrotion. Palaeontology, 8, 204-25.
kato, m. 1963. Fine Skeletal Structures in Rugosa. J. Fac. Sci. Hokkaido Univ. (4), 11, 571-630, pi. 1-3.
peneau, J. 1928. Etudes Stratigraphiques et Paleontologiques dans le Sud-Est du Massif Armoricain.
Bull. Soc. Sci. nat. Ouest, 8, 1-267.

philip, g. m. and pedder, a. E. H. 1967. The Age of the Lilydale Limestone (Devonian), Victoria.
J. Paleont. 41, 795-8.

rozkowska, m. 1960. Blastogeny and Individual Variations in Tetracoral Colonies from the Devonian
of Poland. Acta palaeont. pol. 5, 3-64.

1965. Marisastridae N. Fam. and Marisastrum N. Gen. (Devonian Corals). Acta paleont. pol.

10, 261-6.

scrutton, c. t. 1967. Marisastridae (Rugosa) from south-east Devonshire, England. Palaeontology,
10, 266-79, pi. 40-43.

smith, s. 1945. Upper Devonian Corals of the Mackenzie River Region, Canada. Spec. Pap. Geol.
Soc. Amer. 59, 1-126, pi. 1-35.

sorauf, 3. e. 1967. Massive Devonian Rugosa of Belgium. Univ. Kansas Paleont. Contrib. 16, 1-41.
strusz, o. l. 1965. Disphyllidae and Phacellophyllidae from the Devonian Garra Formation of New
South Wales. Palaeontology, 8, 518-71, pi. 72-8.

stumm, e. c. 1948. Lower Middle Devonian Species of the Tetracoral Genus Hexagonaria of East-
Central North America. Cont. Mas. Paleont. Univ. Michigan, 7, 7 — 49, pi. 1-14.

J. E. SORAUF

Department of Geology
State University of New York at Binghamton
Binghamton, New York 13901

Typescript received 5 July 1968

BENTHONIC FORAMINIFERA FROM THE
M AESTRICHTIAN CHAFK OF GAFICIA BANK,

WEST OF SPAIN

by M. J. FISHER

Abstract. Benthonic foraminifera associated with a planktonic foraminiferal assemblage of Upper Maestrich-
tian age are described. The assemblages are from a chalk fragment dredged from a non-magnetic seamount,
Galicia Bank, off the western coast of Spain. Three new species, Anomalinoides hyphalus , Nuttallides galiciensis,
and Nuttallinella lusitanica are described, and one new name, Neoeponides hillebrandti for Eponides whitei
Hillebrandt is proposed. The assemblage is compared with those previously described from the Tethyan realm.

Funnell (1964) and Funnell, Friend, and Ramsay (1969) have recorded an Upper
Maestrichtian assemblage of planktonic foraminifera from a chalk fragment dredged
from Galicia Bank, a non-magnetic seamount off the Spanish coast. This paper describes
the associated benthonic foraminifera from the same sample, D. 3804.1., which was
obtained from the top of the seamount, at a depth of between 650 and 700 m., and at
42° 36' N., 11° 35' W. {fide Black, Hill, Laughton, and Matthews 1964).

The 354 benthonic foraminifera obtained from this sample have been assigned to
52 species, which, with the exception of the three new species described, have all been
previously recorded from Upper Cretaceous or Lower Tertiary horizons. The complete
list is given in Table 1. Of the 39 species positively identified and previously recorded,
7 have not been recorded from horizons younger than the Maestrichtian, 24 have been
recorded from both Maestrichtian and Palaeocene horizons, 7 have been recorded from
the Palaeocene but not from the Maestrichtian, and one, Buliminella grata Parker and
Bermudez has been recorded from the Eocene or Oligocene of California, Cuba, and
Trinidad. Beckmann (1960), however, suggested that B. grata may be identical with
B. beaumonti Cushman and Renz. If this is so, then the lower range of B. grata should
be extended into the Lower Danian, where B. beaumonti was recorded by von Hille-
brandt (1962) from the Reichenhall-Salzburg basin; this would be more in agreement
with the ranges of the other non-Maestrichtian species.

Of the seven species restricted to Upper Cretaceous horizons, Brizalina incrassata
(Reuss), Pyramidina szajnochae (Grzybowski), and Pseudouvigerina crist at a (Marsson)
have been recorded from numerous localities, and can therefore be regarded as reliable
stratigraphic indices. Pseudouvigerina rugosa Brotzen and Lenticulina pseudovortex
(Marie) are much more restricted geographically, and have been recorded from com-
paratively few localities; Verneui/ina convexa Olszewski and Heterostome/la mexicana
Cushman have only been recorded from the Belemnitella mucronata zone of the Polish
chalk, and from the Mendez Shale of Mexico respectively. These last four species are
considered to be of rather doubtful stratigraphic value.

None of the seven Palaeocene species are accepted stratigraphic indices; only
Valvalabamina scrobiculata (Schwager) and Eponides lotus (Schwager) are widely dis-
tributed geographically, and potentially useful in this context. Neoeponides hillebrandti
nom. nov. and Gaudryina limbata Said and Kenawy have both been recorded from the

[Palaeontology, Vol. 12, Part 2, 1969, pp. 189-200.]

C 6508

o

190

PALAEONTOLOGY, VOLUME 12

TABLE I

Stratigraphical and Geographical Distribution of Recorded Species

Hap/ophragmoides sp.

Spiroplectammina dentata (Alth)

Spiroplectommina cf S spectabi/is (Grzybowski)
Trocham m ina sp.

VerneuiHna convexa Olszewski
V. karreri Said 8 Kenowy
Gaudryino cf. G laevigata Franke
G.Umbata Said 8 Kenawy
Heterostomella mexicana Cushman
Arenobulimina frankei (Brotzen)

Dorothia trochoides (Marsson)

Martinottie/to alabamensi s (Cushman)

Nodosaria cf. N.vetascoensis Cushman
Neoflabellina rugoso (D'Orbigny)

Lenticuhna navicula (D'Orbigny)

L pseudovortex (Marie)

L.rotutata (Lamarck)

Lageno apicutata ( Reuss)

Guttu/ina communis (D’Orfcigny)

Butimina cf B midwayensis Cushman 8 Parker
Praebutimina reussi (Morrow)

Pyromidma szojnochae (Grzybowski)
Bulimmella grata Parker 8 Bermudez
Pseudouvigerina crist at a (Marsson)

P. rugosa Brotzen

Orthokarstenia cf O.ctarki (Cushman 8 Campbell)
Bot/vina oedum / Brotzen
Brizatina incrossata ( Reuss)

Arogoma monitifera (Galloway 8 Morrey)

A ouezzonens/s (Rey)

Guadrimorphma cf. Q at/omorphinoides (Reuss)
Gtobocass i du h na sp.

Lama rck i no ruguiosa Plummer

Aster/gerina z\Acrassaformis Cushman 8 Siegfus

Nuttattides gaticiensis sp nov.

Nuttattinetta t us i tonic a sp. nov.

Vatvatabamina aegypti aca ( Le Roy)

V tenticuto (Reuss)

V scrobiculato (Schwager)

Nonionetta robusta Plummer
Put tenia jarvisi Cushman
Neoeponides h ittebrandti nom nov.

Eponides lotus (Schwoger)

Govetinetto vombensis (Brotzen)

Gyroidinoides girardanus (Reuss)

G g/obosus (Hogenow)

G octocomeratus (Cushman 8 Hanna)

Stensiomo esnehensis Nakkady
Anomalinoides hyphatus sp nov.

A.vetascoens is (Cushman)

Osongutario vetascoensis (Cushman)

Rotatia hermi Hillebrandt

% of Population

Mexico

U S. Gulf Coast

Trinidad

N W Europe

s.a e.

Central Europe

N Alps

Egypt

N. Spain

<1

<1

|

C2

C'

C7

P5

P8

C4

<1

<1

C

<1

C - Pe

<1

<1

P5

p8

8

C2

<1

C7 P

2

C - P9

c

C. P

P5

C4

1

P3

<1

1

C - P9

C? P3

c

C

C

C - P8

1

P2

C2

c

C- P8

<1

c6

2

c2

C- P'

c7

C- P8

<1

c2

C- P'

c

C. P5

c8

1-5

P9

p3

C* P

P5

<1

<1

c9

c2

C'

C6

C

? p5

p8

<1

c?

c6

C

c

C4

1-5

T

T

? p5

<1

c2

C'

c7

C

<1

c7

<1

<1

C9 P

? p5

8

c9

c2

c'

c7

C

c

c8

C4

<1

p

<1

C- P

C-P

P5

C4

<1

<1

<1

p3

T

<1

45

6

1

p

3 5

c

c2

C-P'

c6

C

P8

4

p

? p

P

p

<1

c2

p

p5

c

<1

p-

C- P1

c

p5

<1

p9

p5

<1

? p

p

P

p5

p

3

C- P9

c

P5

c4

<1

c2

T1

p5

c8

2-5

P9

c2

0

1

"D

c7

c

c. P5

p8

3

T1

c7. P

p

p5

4 5

c

C- p

c4

215

7

P9

C - P

c. P5

<1

p5^

P'

c

C. P5

1

P5

c4

Key

C = Cretaceous t

P= Paleocene 5

T = Tertiary younger thanP 6

? = doubtful identification 7

source of information 1 fide Beckmonn, I960 8

2 11 Cushman , 1946 »

3 11 Cushman , 1951

Herm ,1965
Hillebrandt, 1962
Hofker, 1957
Hofker, 1966
Said 8 Kenowy, 1956
White, 1928-9

M. J. FISHER: BENTHONIC FORAMINIFERA

191

Reichenhall-Salzburg Basin, and from the Tampico embayment, Mexico, and Sinai
respectively. Nakkady (1959, p. 457) suggested that G. limbata is conspecific with G.
pyramidata Cushman, which has been recorded from Upper Cretaceous and Palaeocene
localities in Mexico, North America, Egypt, North-west and Central Europe, etc. G. limbata
can therefore be only tentatively regarded as a typical Palaeocene species. The records
of the remaining three species, Martinottiella alabamensis (Cushman), Aragonia monili-
fera (Galloway and Morrey), and Valvalabamina aegyptiaca (LeRoy) restrict their
occurrences to the Clayton Formation of the U.S. Gulf States, the ‘Upper Cretaceous’
(= Globorotalia pseudobulloides (Plummer) sub-zone) of Tabasco, Mexico, and the
Esna Shale of Egypt respectively. Lamarckina rugulosa Plummer, which, on the evidence
of Table 1 might appear to be restricted to the Palaeocene, has been recorded from the
Maestrichtian (Redbank Formation) of New Jersey by Olsson (1960).

The benthonic assemblage has therefore a rather indeterminate Maestrichtian-
Palaeocene aspect, for which at least two possible interpretations may be suggested.

Beckmann (1960) indicated that in Trinidad the benthonic fauna, unlike the associated
planktonic fauna, continues across the Cretaceous-Tertiary boundary with compara-
tively few modifications. Thus it is possible that the ranges of the nominally Palaeocene
species should be extended to include the uppermost Maestrichtian.

An alternative explanation is that the Palaeocene species are contaminants in a Mae-
strichtian assemblage. Referring to the planktonic forms, Funnell (1964, p. 422) stated
that ‘The post-Maastrichtian (probable Mid-Tertiary, and Upper Tertiary to Recent)
contaminants were probably introduced into the chalk via very narrow burrows or
borings’. Black (1964) also suggested that the burrowing of mud-feeding organisms was
more likely to have accounted for the thorough mixing of Upper Cretaceous and Middle
Eocene coccoliths in this sample, than redeposition of eroded Cretaceous forms. He
regarded this last process as improbable in such an exposed position as the shallower
parts of the seamount. It would also appear an unlikely explanation for the composition
of the benthonic assemblage when the ratio of exclusively Palaeocene to potentially
older individuals (i.e. 1 :9) is considered.

The apparent absence of Palaeocene planktonic foraminifera from the sediment might
be thought to favour the totally Maestrichtian assemblage interpretation, but this effect
might also be produced by the rarity of lowest Tertiary planktonic foraminifera in the
vicinity, leaving only Palaeocene benthonics to contaminate the previously deposited
Maestrichtian. Neither of the two interpretations suggested is entirely satisfactory
and clearly this question cannot be resolved on the evidence at present available.

Although the assemblage is perhaps numerically insignificant, its geographically
isolated position encourages any attempt at palaeoecological or palaeogeographical
correlation. Comparatively little information is available on these aspects of micro-
palaeontology, but in common with other faunal groups the areal distribution of
certain foraminiferal assemblages in the Upper Cretaceous has been interpreted in terms
of Boreal and Tethyan faunal realms. Wicher (1953; 1956) and Bettenstaedt and Wicher
(1955) indicated that the northern limits of the warm water Globotruncana populations
exhibit a southward trend throughout the Upper Cretaceous, interrupted only by spora-
dic incursions into the higher latitudes of the Boreal realm. This southward migration
was apparently reversed in the Upper Maestrichtian ( casimirovensis zone), when nomin-
ally Tethyan forms established themselves in the Boreal realm. Bettenstaedt and Wicher

192

PALAEONTOLOGY, VOLUME 12

do not make it entirely clear whether the indigenous Boreal species were displaced
further northward or whether there was an intermixing of faunas across the Boreal-
Tethyal boundaries; nor do they indicate what palaeoclimatic significance their terms
‘Boreal’ or ‘Tethyal’ have in the Upper Maestrichtian, although Wicher (1953) had
proposed that the northward migration of Pseudotextularia elegcins (Rzehak) in the
casimirovensis zone could have been related to the introduction of a contemporary
warm-water mass. Bettenstaedt and Wicher (p. 497) made one further interesting point:
‘When considering the whole fauna the difference of facies between Tethys and Boreal
is in most cases of greater importance than the distance of localities.’ This had already
been stressed by Wicher (1949) when he attempted to correlate the Upper Cretaceous
succession of the Tampico Embayment with that of Eurasia, and by Keller (1939).

From his detailed study of the Upper Cretaceous of Russia and Europe, Keller con-
cluded that there were two major micro-faunas corresponding to two climatic zones.
The first of these, the northern zone, is typified by the sediments of the Russian platform;
the second, the southern zone, by the calc-marl and flysch facies of the Crimean-
Caucasian geosynclinal region. The foraminifera of the northern and southern zones
are essentially dissimilar, and within the southern zone those of the calc-marl facies can
be readily distinguished from those of the flysch facies, by the greater proportion of
planktonic foraminifera in the latter. Keller’s northern zone may be equated with the
Boreal of Bettenstaedt and Wicher, and his southern zone with their Tethyal.

Geographically the benthonic foraminifera from Galicia Bank have affinities with
those previously described from the Mexican Gulf coasts, from North-west and Central
Europe, and from Egypt. Of the eighteen previously described species, which individually
comprise 1% or more, and collectively 55-5% of the benthonic population (see Table
1), fifteen have been recorded from the Americas and fifteen from Europe and Egypt:
three are apparently restricted to the New World, and three to the Old World. These
geographically restricted species are generally those that have been recorded from one
or two localities, and are therefore also stratigraphically restricted. Thus Heterostomella
mexicana Cushman and Martinottiella olabamensis (Cushman) are restricted to the
Americas, and Valvalabamina aegyptiaca (LeRoy) to Egypt. Rotalia hermi Hillebrandt,
recorded from the Reichenhall-Salzburg Basin (von Hillebrandt 1962) and North-west
Spain (Herm 1965) and Stensioina esnehensis Nakkady, originally described from the
Egyptian Esna shales (Nakkady 1950) and subsequently recorded from the Upper
Maestrichtian of Germany, Denmark and Belgium (Hofker 1956, 1960, 1962, 1966)
and of North-west Spain (Herm 1965) are more widespread, although restricted to the
Old World. Triimper (1968) suggested that 5. esnehensis may be synonymous with S.
pommerano Brotzen, which is very widely distributed in Eurasia, but which has not
been found in America. The possible conspecificity of Buliminella grata Parker and Ber-
mudez and B. beaumonti Cushman and Renz, and the consequent extension of the
geographical range of B. grata has already been mentioned (p. 189).

The majority of the benthonic species occur in assemblages from areas formerly
occupied by Tethys' sensu Bettenstaedt and Wicher (1955), corresponding with Keller’s
(1939) southern zone, and two, Pyramidina szajnochae (Grzybowski) and Aragonia
ouezzanensis (Rey) were considered by Bettenstaedt and Wicher to be restricted to the
Tethyan zone. The planktonic/benthonic ratio of the Galicia Bank assemblage is
19:1, which compares closely with the ratios from flysch sediments (e.g. the Tampico

M. J. FISHER: BENTHONIC FORAMIN1FERA

193

embayment; the Reichenhall-Salzburg Basin). There is, however, no evidence of associa-
tion with a local flysch facies; the nearest flysch of comparable age outcropping on the
north coast of Spain in Guipuzcoa Province, nearly 800 km. to the east. Nevertheless
the Upper Maestrichtian microfauna of these flysch deposits is very similar to that of
Galicia Bank, not only in terms of planktonic/benthonic ratios, but also in terms of the
number of species in common.

It would appear that the similarities between the Galicia Bank and ‘ flysch ’ assemblages
are not the result of similar sedimentological histories, although some of the factors that
determined the components of flysch microfaunas may also have been operative in the
area of Galicia Bank during the deposition of the Maestrichtian chalk. One plausible
palaeoecological interpretation of this assemblage is that it is representative of an
essentially Tethyan calc-marl facies, but under the influence of an open ocean environ-
ment, resulting in the high proportion of planktonic individuals.

Any attempt to interpret this assemblage definitively either palaeoecologically or
stratigraphically is restricted by the limited amount of material available. Subsequent
oceanographic investigations may therefore resolve some of the problems which have
been outlined.

SYSTEMATIC DESCRIPTIONS

Only new species and those with new specific, or combinations of, names are considered; the other
species are well documented elsewhere (see, for example, the references cited in the key to Table 1.

Genus martinottiella Cushman 1933
Martinottiella alabamensis (Cushman) 1940

1940 Listerella laevis Cushman, p. 54, pi. 9, fig. 8. [non] Listerella laevis Finlay 1939, p. 97,
pi. 14, fig. 79.

1947 Schenckiella alabamensis Cushman, p. 51, pi. 8, fig. 10.

Remarks. The genus Schenckiella Thalmann 1942 has been suppressed as a junior
synonym of Martinottiella ( fide Loeblich and Tappan 1964): S. alabamensis Cushman
is therefore included in the genus Martinottiella.

Genus pyramidina Brotzen 1948
Pyramidina szajnochae (Grzybowski) 1 896

1896 Verneuilina szajnochae Grzybowski, p. 287, pi. 9, fig. 19. [fide de Klasz and Knipscheer
1954, q.v.].

1929 Bulimina limbata White, p. 48, pi. 5, fig. 9.

1944 Reussella californica Cushman and Goudkoff, p. 59, pi. 10, figs. 3-5.

1946 Bulimina limbata White; Cushman, p. 124, pi. 52, fig. 5.

1946 Reussella limbata (White); Keller, p. 93, pi. 1, fig. 11.

1951 Reussella szajnochae (Grzybowski); Noth, p. 65, pi. 7, fig. 7.

1954 Reussella szajnochae szajnochae (Grzybowski); de Klasz and Knipscheer, p. 605, pi. 45,

figs. 1-13; tab. p. 605.

1955 Reussella szajnochae (Grzybowski); Bettenstaedt and Wicher, p. 502, figs. 11-18.

1957 Reussella szajnochae (Grzybowski); Hofker, p. 214, fig. 262.

1959 Reussella szajnochae (Grzybowski); Liszkowa, p. 69, pi. 3, figs. 3-5; pi. 9, fig. 2.

1959 Reussella szajnochae californica Cushman and Goudkoff; Olvera, p. 83, pi. 2, figs. I, 2.

1961 Reussella szajnochae (Grzybowski); Scheibnerova, p. 41, pi. 3, fig. 1.

1964 Reussella szajnochae (Grzybowski); Martin, p. 91, pi. 12, fig. 4.

1965 Reussella szajnochae szajnochae (Grzybowski); Herm, p. 323.

194

PALAEONTOLOGY, VOLUME 12

Remarks. Loeblich and Tappan (1964) suggested that the genus Pyramidina should
include those Upper Cretaceous species formerly referred to Reussella Galloway 1933
that have finely perforate walls and simple tooth-plates. Verneuilina szajnochae Grzy-
bowski is here included in the genus Pyramidina.

Bettenstaedt and Wicher (1955) considered P. szajnochae to be restricted to ‘Tethys’.
Hofker (1957) and Liszkowa (1959) subsequently recorded the species from Northern
Germany and Poland respectively; both these areas are within the Boreal zone as defined
by Bettenstaedt and Wicher. P. szajnochae appears to be a useful index species in the
Upper Cretaceous.

Genus brizalina Costa 1856
Briza/ina incrassata (Reuss) 1851

1851 Bolivina incrassata Reuss, p. 45, pi. 5, fig. 13.

1929 Bolivina incrassata Reuss; White, p. 43, pi. 4, fig. 19.

1946 Bolivina incrassata Reuss; Cushman, p. 127, pi. 53, figs. 8-11.

1951 Bolivina incrassata Reuss; Noth, p. 64, pi. 9, fig. 8.

1953 Bolivina incrassata Reuss; Le Roy, p. 20, pi. 10, figs. 4, 5.

1955 Bolivina incrassata Reuss gigantea (Wicher 1949); Bettenstaedt and Wicher, p. 502,

fig. 11-19.

1956 Bolivina incrassata Reuss; Said and Kenawy, p. 144, pi. 4, fig. 19.

1957 Bolivina incrassata Reuss; Hofker, p. 228, figs. 282-286, 288, 291, 292.

1958 Bolivina incrassata Reuss; Bieda, p. 45, fig. 15.

1961 Bolivina incrassata Reuss; Scheibnerova, p. 42, pi. 3, fig. 3.

1963 Bolivina incrassata Reuss; Kaptarenko-Cernousova et al., p. Ill, pi. 27, fig. 7.

1964 Bolivina incrassata Reuss; Martin, p. 90, pi. 11, fig. 14.

1965 Bolivina incrassata incrassata Reuss; Herm, p. 333, text-figs. 12, 13.

1966 Bolivina incrassata Reuss; Hofker, p. 39, pi. 5, fig. 42; p. 59, pi. 10, figs. 90, 91.

Remarks. Brizalina as emended by Loeblich and Tappan (1964) includes those species
formerly placed in Bolivina d’Orbigny 1839 that lack retral chamber processes or crenu-
lations. B. incrassata, lacking both retral processes and crenulations, is here referred to
the genus Brizalina.

This is a common and widespread species recorded from numerous Upper Cretaceous
localities, and regarded as a useful index microfossil. Wicher (1949) stated that the larger
form of this species, ‘var. gigantea which includes the Galicia Bank specimens, is
restricted to the Maestrichtian.

Genus nuttallides Finlay 1939
Nuttallides galiciensis sp. nov.

Text-fig. I a-c

Holotype. Slide 1 208c/.

Material. 16 specimens. Dimensions of figured specimen and average dimensions (in brackets): max.
diameter 0-275 (0-275) mm.; min. diameter 0-25 (0-25 ) mm.; thickness 0T5 (0125) mm.

Diagnosis. An unequally biconvex species with flattened umbilical boss, and trochospiral
coiling. Septal walls mono-lamellar; well-developed tooth-plate.

Description. Test trochoid, lenticular in section, unequally biconvex, with distinctly
flattened umbilical boss. Periphery acute or sub-acute, with narrow poreless keel,
crenulate. Umbilical side involute, inflated; umbilicus closed by translucent plug.

M. J. FISHER: BENTHONIC FORAMINIFERA

195

Spiral side a low cone, showing up to three previous whorls, though earlier whorls
often indistinct. 8-1 1 chambers in final whorl: sutures curved, sigmoid, flush or slightly
depressed between later chambers on umbilical side; straight, flush, and oblique on
spiral side. Aperture rather variable although with distinct lip, extending along base of
apertural face from umbilical boss to an indentation parallel to plane of coiling in
apertural face near periphery. Wall radial, perforate; septal walls mono-lamellar.
Tooth-plate structure well developed, extending as high ridge from behind indentation
in apertural face to face of penultimate chamber, where it is attached to area formerly
occupied by apertural lip.

text-fig. 1. Nut tall ides galiciensis sp. nov. a, umbilical side; b, edge view; c, spiral side. X 150.

Remarks. This species is very similar in many respects to N. trumpyi (Nuttall) but differs
in its smaller size, more numerous chambers, and smaller umbilical plug.

Genus nuttallinella Belford 1959
NuttallineUa lusitanica sp. nov.

Text-fig. 2 a-c

Holotype. Slide 1209.

Material. 20 specimens. Dimensions of figured specimen and average dimensions (in brackets): max.
diameter 0-4 (0-3 ) mm.; min. diameter 0-375 (0-275) mm.; thickness 0-225 (0-2) mm.

Diagnosis. Unequally biconvex, trochospiral species with mono-lamellar septal waffs,
and well-developed tooth-plate with folded upper margin.

Description : Test trochospiral, unequally biconvex, lenticular in section. Periphery acutle
with a rarely preserved poreless keel. Umbilical side involute, convex, with 7-9 chambers
in final whorl, and very narrow umbilicus, usually partially closed by chambers of fina,
whorl; spiral side flattened or slightly convex, showing up to 3 whorls. Sutures fairly
distinct, curved, slightly sigmoid on umbilical side, usually slightly depressed near peri-
phery, sometimes thickened near umbilicus; on spiral side straight, oblique, and flush.
Wall smooth, finely perforate; septal walls mono-lamellar. Aperture slit-like, at base of
apertural face, and extending from near periphery to umbilicus. A well-developed, ridge-
like tooth-plate with folded upper margin extends diagonally across floor of chamber
from near peripheral edge of apertural face to near the umbilicus on penultimate aper-
tural face.

196

PALAEONTOLOGY, VOLUME 12

Remarks. This species has the well-developed folded tooth-plate that Belford (1958)
considered diagnostic of the genus Nuttallina Belford 1958 ( non Dali 1871) = Nuttal-
linella Belford 1959. It is similar to N. coronula Belford, but differs in its generally
unequally biconvex test, larger number of chambers in the final whorl, and less well-
developed umbilicus.

text-fig. 2. Nuttallinella lusitanica sp. nov. a, umbilical side; b, edge view; c, spiral side x 100.

Genus valvalabamina Reiss 1963
Va/va/abamina aegyptiaca (Le Roy) 1953

1953 Valvulineria aegyptiaca Le Roy, p. 53, pi. 9, figs. 21-23.

1956 Valvulineria aegyptiaca Le Roy; Said and Kenawy, p. 147, pi. 4, fig. 45.

Remarks. See V. scrobiculata (Schwager).

Valvalabamina scrobiculata (Schwager) 1883

1883 Anomalina scrobiculata Schwager, p. 129, pi. 29, fig. 18.

1931 Planulina scrobiculata (Schwager); Galloway and Morrey, p. 346, pi. 39, fig. 8.

1932 [?] Valvulineria scrobiculata (Schwager); Cushman and Ponton, p. 70, pi. 9, fig. 5.

1953 Valvulineria scrobiculata (Schwager); Le Roy, p. 53, pi. 9, figs. 18-29.

1954 Anomalina ( Anomalina ?) scrobiculata Schwager; Vassilenko, p. 61, pi. 3, fig. 5.

1956 [non] Valvulineria scrobiculata (Schwager); Said and Kenawy, p. 147, pi. 4, fig. 42.

1959 Valvulineria scrobiculata (Schwager); Nakkady, p. 460, pi. 2, fig. 5.

Remarks. Reiss (1963) selected Rotcilina lentieula Reuss as the type species for the genus
Valvalabamina. Basically Valvalabamina differs from Valvulineria Cushman 1926 in
having a calcitic, granular wall structure, and an umbilical plate-like extension of the
apertural lip which is almost completely fused with the chambers of the last whorl.
V. aegyptiaca and V. scrobiculata both have granular, mono-lamellar walls and fused
umbilical ‘plates’; they are consequently referred to the genus Valvalabamina.

Genus neoeponides Reiss 1960
Neoeponides hillebrandti nom. nov.

1928 Rotalia cf. partschiana (D'Orbigny); White, p. 288, pi. 38, fig. 10.

1936 [non] Eponides whitei Brotzen, p. 167, pi. 12, figs. 5-8.

1962 Eponides whitei von Hillebrandt, p. 106, pi. 8, fig. 11.

Material. 1 specimen well preserved. Dimensions. Diameter 0-25 mm.; thickness 0T5 mm.

M. J. FISHER: BENTHONIC FORAMINIFERA

197

Diagnosis (from von Hillebrandt 1962, p. 106). ‘Eine neue Art der Gattung Eponides mit
folgenden Besonderheiten : Umbilikalseite nahezu plan, Spiralseite stark gewolbt,
Nabelpfropf gekornelt, Miindung extraumbilikal — interiomarginal in einer Bucht
liegend. (Holotypus: Slg. Miinchen Prot. 1341).’

Description. Text trochoid, planoconvex. Umbilical side almost flat, involute; spiral side
cone-shaped, evolute, showing 4 previous whorls; periphery acute with small keel.
Chambers distinct, 10 in the final whorl. Sutures limbate, straight, almost radial on
umbilical side; almost straight, sharply oblique on spiral side. On umbilical side sutures
thicken towards umbilicus, and merge into large granular umbilical boss. Wall granular
in appearance, perforate. Aperture simple; low arch beneath depression in apertural
face, extending into area of umbilicus.

Remarks. E. whitei Hillebrandt 1962 is pre-occupied by E. xvhitei Brotzen 1936 and a
new name, Neoeponides hi/lebrandti nom. nov., is proposed for von Hillebrandt’s species.
The morphological characters of this species are consistent with those described for the
genus Neoeponides Reiss, and although no sections are available, this species is here
assigned to that genus.

Genus anomalinoides Brotzen 1942
Anomalinoides hyphalus sp. nov.

Text-fig. 3 a-c

1928 [?] Planulina dayi var.; White, p. 302, pi. 41, figs. 4, 5.

Holotype. Slide 1210.

Material. 76 specimens. Dimensions of figured specimen and average dimensions (in brackets): max.
diameter 0-4 (0-275) mm.; min. diameter 0-325 (0-225) mm.; thickness 0-225 (0-2) mm.

Diagnosis. Planoconvex-biconvex species with reversed trochospiral coiling. Umbilical
area modified by flap-like extensions of chambers of last whorl; septal walls bilamellar.

Description. Test reversed trochospiral, involute, unequally biconvex-planoconvex;
periphery subacute to rounded. Chambers distinct, up to 12 in final whorl. Spiral side
convex, smooth, non-punctate, with transparent umbo through which previous whorls
may be seen. Umbilical side flat or slightly convex, almost completely involute, deep
umbilicus obscured by triangular flap-like extensions of later chambers, and by a some-
times imperfectly developed umbilical plug. Sutures curved, transparent, limbate, flush
on spiral side; curved, limbate, raised, especially near centre of umbilical side. Umbilical
side coarsely but sparsely punctate, especially in depressed areas between sutures.
Aperture a low arch at base of apertural face, and extending between chambers where
sutures have been excavated. Septal walls bilamellar.

Remarks. This species is very similar to A. ve/ascoensis (Cushman) but differs primarily
in lacking the distinct depressions between the sutures on the umbilical side. Similarities
are also apparent between this species and Gavelinella vombensis (Brotzen). However
the latter is always trochospiral, and there are no intermediate forms between the
reversed trochospiral forms described here and the forms described as G. vombensis.

198

PALAEONTOLOGY, VOLUME 12

The variants of Planulina dayi White described by White (1928, p. 302, pi. 41, figs. 4, 5)
appear to be similar to these forms, especially in the modification of the sutures on the
umbilical side.

text-fig. 3. Anomalinoides hyphalus sp. nov. a, umbilical side; b, edge view; c, spiral side x 100.

Anomalinoides velascoensis (Cushman) 1925

1925 Anomalina velascoensis Cushman, p. 21, pi. 3, fig. 3.

1928 Planulina velascoensis (Cushman); White, p. 303, pi. 41, fig. 7.

1946 Anomalina velascoensis Cushman; Cushman, p. 156, fig. 7.

1951 [?] Planulina velascoensis (Cushman); Noth, p. 80, pi. 7, fig. 14.

1959 [?] Anomalina velascoensis Cushman; Morgiel, p. 138, pi. 14, fig. 11.

1961 [?] Planulina velascoensis Cushman; Scheibnerova, p. 52, pi. 11, fig. 4.

1962 Gavelinella velascoensis (Cushman); von Elillebrandt, p. 102, pi. 8, figs. 3, 4.

Remarks. Cushman (1925, 1946) assigned this species to the genus Anomalina d'Orbigny
1826, but was at the time unaware of the internal arrangement of the chambers. Cush-
man’s ‘spiral thickening' on the ‘dorsal side’ is in fact an umbilical plug on the ventrum.
This species has a convex spiral side, and a concave or flattened umbilical side, the early
whorls on the spiral side being obscured by the partially involute later whorls, and by
secondary implacement of calcite on the umbo. The chamber arrangement is reversed
trochoid, and the aperture umbilical-extra-umbilical. These characters serve to dis-
tinguish the species of Anomalinoides from those of Gavelinella Brotzen 1942 and
Planulina d'Orbigny 1826.

Acknowledgements. The author would like to thank Mrs. J. K. Friend, Dr. J. Hofker and Dr. Z. Reiss
for their advice during the preparation of this work, and Dr. B. W. Funnell for critically reading the
manuscript. The project was financed by an N.E.R.C. research grant.

Holotypes, figured specimens and hypotypes have been deposited in the Sedgwick Museum,
Cambridge.

REFERENCES

beckmann, J. p. 1960. Distribution of benthonic Foraminifera at the Cretaceous-Tertiary boundary
of Trinidad (West Indies). Proc. 21st Int. geol. Congr., sect. 5, 57-69, fig. 1-17.
belford, d. j. 1958. The genera Nuttallides Finlay, 1939, and Nuttallina, n. gen. Contr. Cushman Fdn
foramin. Res. 9 (4), 93-8, pi. 18, 19.

1959. Nuttallinella, a new name for Nuttallina Belford, 1958 (non Nuttallina Dali, 1871). Ibid.

10 (1), 20.

bettenstaedt, f. and wicher, c. a. 1955. Stratigraphic correlation of Upper Cretaceous and Lower
Cretaceous in the Tethys and Boreal by the aid of microfossils. Proc. 4th W/d Petrol. Congr., Sect.
HD, Pap. 5, 493-516, pi. 1-5.

M. J. FISHER: BENTHONIC FORAMIN1FERA 199

bieda, e. 1958. Index Foraminifers and the age of the Mielnik Chalk (Eastern Poland). Biul. Inst. Geol.
121, 17-89, pi. 20 (Polish with English summary).

black, m. 1964. Cretaceous and Tertiary coccoliths from Atlantic seamounts. Palaeontology, 7, 306-16,
pi. 50-53.

— hill, m. n., laughton, a. s., and Matthews, D. H. 1964. Three non-magnetic seamounts off the
the Iberian Coast. Q. Jl. geol. Soc. Lond. 120, 477-517, pi. 37-44.

brotzen, f. 1936. Foraminifera aus dem schwedischen untersten Senon von Eriksdal in Schonen.

Arsb. Sver. geol. Unders., 30 (3), ser. C, no. 396, 1-206, pi. 1-14.
cushman, J. a. 1925. Some new Foraminifera from the Velasco Shale of Mexico. Contr. Cushman Lab.
foramin. Res. 1(1), 18-22, pi. 3.

1940. Midway Foraminifera from Alabama. Ibid. 16 (3), 51-73, pi. 9-12.

— 1946. Upper Cretaceous Foraminifera of the Gulf Coastal Region of the United States and
adjacent areas. Prof. Pap. U.S. geol. Surv. 206, 1-241, pi. 1-66.

1947. A supplement to the monograph of the foraminiferal Family Valvulinidae. Spec. Pubis.

Cushman Lab. 8a, 1-69, pi. 1-8.

and goudkoff, p. p. 1944. Some Foraminifera from the Upper Cretaceous of California. Contr.

Cushman Lab. foramin. Res. 20 (3), 53-64, pi. 9, 10.

and ponton, g. m. 1932. An Eocene foraminiferal fauna of Wilcox Age from Alabama. Ibid.

8 (3), 51-72, pi. 7-9.

funnell, b. m. 1964. Studies in North Atlantic geology and palaeontology: 1. Upper Cretaceous.
Geol. Mag. 1 01, 421-34.

friend, j. k., and ramsay, a. t. s. 1969. Upper Maestrichtian Planktonic Foraminifera from

Galicia Bank, west of Spain. Palaeontology, 12, 19-41, pi. 1-5.
galloway, j. j. and morrey, m. 1931. Late Cretaceous Foraminifera from Tabasco, Mexico.
J. Paleont. 5, 329-55, pi. 37-40.

herm, d. 1965. Mikropalaontologisch-stratigraphische Untersuchungen im Kreideflysch zwischen Deva
und Zumaya (Prov. Guipuzcoa, Nordspanien). Z. dt. geol. Ges. 115, 277-348.
hillebrandt, a. von. 1962. Das Paleozan und seine Foraminiferenfauna im Becken von Reichenhall
und Salzburg. Abh. bayer. Akad. I Viss. 108, 1-182, pi. 1-15.
hofker, j. 1956. Die Pseudotextularia-ZonQ der Bohrung Maasbtill I und ihre Foraminiferen-Fauna.
Paldont. Z. 30, 59-79, pi. 5-10.

1957. Foraminiferen der Oberkreide von Nordwestdeutschland und Holland. Beih. geol. Jb.

27, 1-464.

1960. The Foraminifera of the lower boundary of the Danish Danian. Meddr dansk geol. Foren.

14, 212-42.

1962. Correlation of the Tuff Chalk of Maestricht (type Maestrichtian) with the Danske Kalk of

Denmark (type Danian), the stratigraphic position of the type Montian, and the planktonic foramini-
feral faunal break. J. Paleont. 36, 1051-89.

1966. Maestrichtian, Danian and Paleocene Foraminifera: the Foraminifera of the type-

Maestrichtian in South Limburg, Netherlands, together with the Foraminifera of the underlying
Gulpen Chalk and the overlying calcareous sediments; the Foraminifera of the Danske Kalk and
the overlying greensands and clays as found in Denmark. Palaeontographica, Suppl. Bd. 10, 1-376,
pi. 1-86.

kaptarenko-cernousova, o. k., golyak, l. m., zernetskii, b. f., kraeva, e. ya., and lipnik, e. s.
1963. Atlas kharakternikh foraminifer yury, mela i paleogena platformennoi chasti Ukrainy. Trudy
Inst. geol. nauk, Kiev, ser. strut, paleont. 45, 1-200, pi. 1-47.
keller, b. m. 1939. Foraminifery verchnemelovych otlozheny S.S.S.R. Trudy neft. geol.-razv. Inst.
Ser. A. 116, 7-27, pi. 1, 2.

1946. The foraminifera of the Upper Cretaceous deposits in the Sotchi region. Byu/I. mosk.

Obskch. Ispyt. Prir., 51, Otdel geol. 21(3), 83-108, pi. 1-3 (Russian with English summary).
klasz, i. de, and knipscheer, h. c. g. 1954. Die Foraminiferenart Reussella szajnochae (Grzybowski):
ihre systematische Stellung und regionalstratigraphische Verbreitung. Geol. Jb. 69, 599-610, pi. I.
le roy, l. w. 1 953. Biostratigraphy of the Maqh Section, Egypt. Mem. geol. Soc. Am. 54, 1-73, pi. 1-14.
liszkova, J. 1959. Microfauna from beds with exotics at Bachowice. Biul. Inst. geol. 131, 39-110,
pi. 1, 3-9 (Polish with English summary).

200 PALAEONTOLOGY, VOLUME 12

loeblich, a. R. jr. and tappan, h. 1964. Treatise on invertebrate paleontology, ed. r. c. moore. Part C.
Univ. Kansas Press.

martin, l. 1964. Upper Cretaceous and Lower Tertiary Foraminifera from Fresno County, California.
Jb. geol. Bundesanst., Wien, Sond. 9, 1-128, pi. 1-16.

morgiel, j. 1959. The microfauna of the Babice clays. Biul. Inst. geol. 131, 111-47, pi. 10-14 (Polish
with English summary).

nakkady, s. e. 1950. A new foraminiferal fauna from the Esna Shales and Upper Cretaceous Chalk,
of Egypt. J. Paleont. 24, 675-92, pi. 89, 90.

- 1959. Biostratigraphy of the Um Elghanayem Section, Egypt. Micropaleontology, 5, 453-72,
pi. 1-7.

noth, r. 1951. Foraminiferen aus Unter- und Oberkreide des osterreichischen Anteils an Flysch,
Flelvitikum und Vorlandvorkommen. Jb. geol. Bundesanst., Wien, Sond. 3, 1-91, pi. 1-9.

olsson, r. k. 1960. Foraminifera of the latest Cretaceous and earliest Tertiary age in the New Jersey
Coastal Plain. J. Paleont. 34, 1-58, pi. 1-12.

olvera, y. e. 1959. Foraminiferos del Cretacico Superior Tampico Tuxpan. Boln Asoc. Mex. Geol.
Petrol. 11, 63-134, pi. 1-9.

reiss, z. 1960. Structure of so-called Eponides and some other rotaliiform Foraminifera. Bull. geol.
Surv. Israel, 29, 1-28, pi. 1-3.

1963. Reclassification of perforate Foraminifera. Ibid. 35, 1-111, pi. 1-8.

reuss, a. e., 1851. Ueber die fossilen Foraminiferen und Entomostraceen der Septarienthone der
Umgegend von Berlin. Z. dt. geol. Ges. 8, 49-92, pi. 3-7.

said, r. and kenawy, a. 1956. Upper Cretaceous and Lower Tertiary foraminifera from northern
Sinai, Egypt. Micropaleontology, 2, 105-73, pi. 1-7.

scheibnerova, v. 1962. Microfauna of the Middle and Upper Cretaceous of the Klippen Belt of West
Carpathians in Slovakia. Ada geol. geogr. Univ. Comenianae Bratislava, Geol. 5, 1-108, pi. 1-14
(Czech with English summary).

schwager, c. 1883. Die Foraminiferen aus den Eocaenablagerungen der libyschen Wiiste und Aegyp-
teus. Palaeontographica, 30, 80-153, pi. 24-29.

trumper, e. 1968. Variationsstatistische Untersuchungen an der Foraminiferen-Gattung Stensioeina
Brotzen. Geologie, 59, 1-103.

vassilenko, v. p. 1954. Anomalinidy. In: Iskopayemyye foraminifery SSSR. Trudy vses. neft. nauchno-
issled. geol.-razv. Inst., N.s. 80, 1-283, pi. 1-36.

white, m. p. 1928-1929. Some index Foraminifera of the Tampico embayment area of Mexico, Part I.
J. Paleont. 2, 177-215, pi. 27-29; Part II, ibid. 2, 280-317, pi. 38-42; Part III, ibid. 3, 30-58, pi. 4, 5.

wicher, c. a. 1949. On the age of the higher upper Cretaceous of the Tampico embayment area in
Mexico, as an example of the worldwide existence of microfossils and the practical consequences
arising from this. Glas. Muz. srp. Zend., Ser. A., 2, 76-105, pi. 2-8.

1953. Mikropaliiontologische Beobachtungen in der hoheren borealen Oberkreide, besonders

in Maastricht. Geol. Jb. 68, 1-26.

1956. mit einem Beitrag von F. Bettenstaedt: Die Gosau-Schichten im Becken von Gams (Oster-

reich) und die Foraminiferengliederung der hoheren Oberkreide in der Tethys. Palaont. Z. 30,
Sonderheft, 87-136, pi. 12, 13.

M. J. FISHER

Robertson Research Company Ltd.
Llanddulas
Abergele
Denbighshire

Typescript received from author 20 August 1968

UPPER SILURIAN AND LOWER DEVONIAN SPORE
ASSEMBLAGES FROM THE WELSH
BORDERLAND AND SOUTH WALES

by j. b. richardson and t. r. lister

Abstract. A reconnaissance of some Wenlockian, Ludlovian, Downtonian, and Dittonian strata from type and
other sections in England and Wales revealed a variety of spore assemblages dominated by small, trilete, azonate,
retusoid, sculpturally varied spores. The spore sequence is described. In the Welsh Borderland sections two
striking changes occur in spore assemblage composition; (a) at the Ludlovian-Downtonian boundary, and
( b ) between the Downtonian and Dittonian ; available evidence suggests that these vertical changes are essentially
time-controlled whereas environmental effects are mainly reflected in the relative abundance of spores to acri-
tarchs and other marine microfossils. Assemblages from South Wales are generally poorly preserved and there-
fore only limited comparisons are possible with the Welsh Borderland sequences. Published data on comparable
horizons from other areas is limited but shows essentially the same sequence of spores in late Silurian and early
Devonian strata as that shown here, thus emphasising the stratigraphic significance of these results. The
potential usefulness of spores and microplankton for linking vertebrate-zoned continental strata with inverte-
brate-zoned marine sequences is emphasized.

Forty-nine different types of spore are described, two genera Streelispora and Svnorisporites , twenty species,
and four varieties are regarded as new.

Apreliminary study of Upper Silurian and early Devonian strata from England and
Wales has revealed the presence in many of these rocks of abundant well-preserved
spores and microplankton. The main sections studied in the area are the type Ludlovian
section at Ludlow (Shropshire), the comparable section near Millichope (Shropshire), and
Downtonian from the Ludford Lane and Downton Gorge sections. In addition to the
Ludlow area. Upper Silurian and Lower Devonian strata have been studied at Gorsley
Common and Perton Lane (Herefordshire), Usk (Monmouthshire), Cwm Dwr and
Sawdde Valley (Carmarthenshire), and Lreshwater East (Pembrokeshire). Material has
been obtained also from probable Temeside shales, Long Mountain (Shropshire), and
Dittonian strata. Brown Clee Hill (Shropshire). All the localities investigated are listed
in the appendix at the end of the paper.

One of the authors (T. R. L.) is engaged in a study of the microplankton and has
been responsible for extraction and study of the Silurian material from Ludlow, Milli-
chope and Usk. Richardson has studied Lower Devonian strata from Ludlow, Long
Mountain, Brown Clee Hill and Upper Silurian and Lower Devonian strata from Gors-
ley, Downton Gorge and Lreshwater East. Both authors have collected and studied
material from the Cwm Dwr and Sawdde Valley sections.

In general, preservation of spores is good and occasionally excellent in the Welsh
Borderland samples especially in the Downtonian and Dittonian, and is poor in south-
west Wales. Spores have not been found in many of the samples processed from the
Sawdde, Cwm Dwr, and Lreshwater East sections and identification of spores when
present is difficult because they are carbonized and poorly preserved. Consequently only
general comparisons are possible at this stage with the type Ludlovian-Downtonian
assemblages. Nevertheless there are some indications that even in this area spores may
eventually provide significant stratigraphic contributions.

[Palaeontology, Vol. 12, Part 2, 1969, pp. 201-252, pis. 37-43.]

202

PALAEONTOLOGY, VOLUME 12

Acknowledgements. Both authors are grateful for financial support from the Natural Environment
Research Council. J. B. R. is indebted to the late Professor J. H. Taylor for help, support and encourage-
ment, and to the technical staff of King’s College Geology Department. T. R. L. thanks Professor L. R.
Moore for research facilities, Dr. C. Downie for discussion Dr. J. H. Shergold who supervised sampling
in the Millichope area, and the Director of the Institute of Geological Sciences for permission to
publish. Both authors thank Mr. R. V. Melville for his constructive criticism.

SILURIAN MIOSPORES FROM THE WELSH BORDERS

Miospores are present in small numbers throughout the Ludlow succession of the type
areaandarealwaysassociatedwithabundantacritarchs,chitinozoa,and scolecodonts;they
form less than 1% of most assemblages rarely figuring in counts of 200-300 individuals.
Of the fifty-six samples examined from the Ludlow succession thirty-seven yielded spores.

The Ludlovian spore succession from the type area is shown in Table 1. Supplement-
ary information has been obtained from a sequence collected from the Millichope-
Diddlebury area (stratigraphic control supplied by Dr. J. H. Shergold) and the spore
sequence from this area is presented in Table 2. Spores were also recovered from the
Wenlock Shale and Upper Llanbadoc Beds of Usk and from the Eltonian (probably
Middle Eltonian) of Ledbury (see Table 3).

table 1. Distribution of spores through the Ludlovian and Lower Downtonian of the type area, Ludlow, Shropshire. W.L., Wenlock
Limestone; L.E.B., and U.E.B., Lower, Middle, and Upper Elton Beds; L.B.B., and U.B.B., Lower, and Upper Bringewood

Beds; L.L.B. and U.L.B., Lower and Upper Leintwardine Beds; L.W.B. and U.W. B., Lower and Upper Whitcliffe Beds; D.C.S., Downton

Castle Sandstone Group. Silurian samples have the prefix LD (Appdx. A)

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

203

DEVONIAN

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| A chulus var. inframurinatus

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| cf. Streelispora granulata

| Retusotriletes sp A

| Apiculiretusispora synorea

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Spore Species

204

PALAEONTOLOGY, VOLUME 12

Nature of the record. The Ludlovian spore record is fragmentary and undoubtedly a
somewhat imperfect record of the true Ludlovian spore flora. Despite intensive search
several of the 15 components recorded are represented either by single specimens, or
by only two or three specimens. The scant record is undoubtedly a function primarily
of the long distance of the Ludlow region from the Ludlovian shore lines, and it is reason-
able to suppose that a near-shore or limnic sequence would yield a far more abundant
spore flora of appreciably greater diversity. This is to a certain extent indicated by the

table 2. Distribution of spores through the Wenlockian and Ludlovian of the Millichope-Diddlebury
area Shropshire. W.S., Wenlock Shale; U.C.B., Upper Coalbrookdale Beds; T. B., Tickwood Beds;
other abbreviations as for Table 1. All samples have the prefix MD (Appdx. A)

Spore Species

Horizon

ws

ueb tb

WL

LEB

MEB

UEB

L B B

UBB

LIB

LWB

UWB

Sample N°.

41

40

38

8

9

12

14

5B

6

16B

19

17

3B

24

26

30

31

33

34

? Arehaeozonotriletes cf.

divellomedium

X

9

?

Ambitispori tes dilutus

s . s.

X

X

X

Ambit isporites cf dilutus

X

X

X

X

X

X

?

Am. cf. avitus

X

A. chulus var. chulus

X

X

X

X

X

A. chulus var. inframur

n a t us

?

X

X

X

X

X

cf. Synor i spori tes verrucatus

X

Retusot r i 1 etes cf. warringtonii

X

X

X

X

X

X

?

?

cf. Sy nor i s po ri t e s down lonen isis

X

X

? Apiculiretusispora sp

D

X

evidence from Usk which, according to the present palaeogeographic reconstruction
(Holland and Lawson 1963) lay fairly close to the Ludlovian shore-line. Large numbers
of spores were recovered from both the Wenlock Shale sample and the sample from the
Upper Llanbadoc beds (Lower Leintwardine) (spores totalled approximately 90% and
20% respectively of the total assemblage). Neither of these assemblages, however, despite
their richness of numbers, exhibited any greater diversity of spore types, which suggests
that the total recorded spore flora is more representative than might at first be thought.
The Millichope-Diddlebury sequence (Table 2) little more than confirmed the main
Ludlow succession, adding only ? Arehaeozonotriletes cf. divellomedium Chibrickova
1959 and the spiny tetrad ? Apiculiretusispora sp. D (single specimen).

This evidence suggests that although continuity of the record would certainly be
improved by examination of further successions the number of spore types would not
be greatly increased. It seems important to establish this point before any fair comparison
of the Ludlovian with the Downtonian spore flora is attempted.

Stratigraphic interpretation. This can only be tentative in view of the discontinuous
nature of the record. Nevertheless some of the vertical changes appear to be evolutionary,
rather than an artefact of the imperfect record or a product of facies control. Thus in
the Wenlock Shale all the spores seen were smooth, simple triradiate types. The Wenlock

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

205

Limestone heralds the appearance of the atypical Ambitisporites dilulus (Hoffmeister)
comb. nov. i.e. A. cf. dilutus with raised laesurae, and the sculptured form cf. Synori-
sporites verrucatus sp. nov. makes its entry. A. chulus var. nanus var. nov. and A. chulus
var. inframurinatus var. nov. also appear for the first time but are thinner walled than
the specimens from higher horizons. These give way to somewhat more typical forms in
the Lower Elton Beds though they still tend to be small in size with narrow borders and
relatively thin distal hemispheres. In the Upper Elton Beds and higher in the succession
the latter have wider zones of equatorial thickening and thick-walled distal hemispheres,
and more sculptured forms appear.

table 3. Spores present in two samples from the Usk Inlier, and one from Ledbury.

W.S., Wenlock Shale; U.L.B., Upper Llanbadoc Beds; E.B., Elton Beds

Ledbury

Usk

E.B.

IV.S.

U.L.B.

Retusotriletes cf. minor

X

—

—

Archaeozonotriletes chulus var. inframurinatus

X

—

X

A. chulus var. nanus

X

X

X

A. chulus var. chulus

—

—

X

Ambitisporites dilutus s.s.

—

X

—

A. cf. dilutus

—

—

X

Retusotriletes cf. warringtonii

—

X

X

DEVONIAN MIOSPORES FROM THE WELSH BORDERLAND

In contrast to the underlying Silurian, spores are frequently abundant in Devonian
strata from South Wales and the Welsh Borderland. Preservation is generally good in the
Welsh Borderland (Shropshire and Herefordshire) but relatively poor in samples
examined from Carmarthenshire and Pembrokeshire. For the purposes of this paper the
base of the Devonian in the Welsh Borderland is taken at the Ludlow Bone Bed at
Ludford Lane, Ludlow, and its equivalents elsewhere. Consequently the Downtonian
is included within the Devonian.

Downtonian

Samples (see Table 4) from the Downton Castle Sandstone Group, Ludford and
Downton Gorge (Shropshire), Gorsley Common and Perton Lane (Herefordshire), and
?Temeside Shales, Wallop Hall quarry. Long Mountain (Shropshire), have all yielded
abundant well-preserved spores. In contrast Downtonian equivalents in the Cwm Dwr
section (Capel Horeb quarry) have so far yielded only poorly preserved spores. The only
other samples yielding spores of approximately this age in South Wales are those of the
Lower Red Marl Group on the north side of Freshwater East but these contain assemb-
lages in which most of the spores are carbonized.

Localities in the Welsh Borderland at Ludlow, Gorsley, Perton Lane, and Long Moun-
tain have yielded essentially the same spore assemblages; those at Gorsley and Ludlow
are practically identical. At the Perton Lane and Long Mountain localities several of
the rarer species have not been found but most of the species which are common at the
other two localities occur (Table 4). All the assemblages from the Lower Downtonian

C 6508

P

206 PALAEONTOLOGY, VOLUME 12

form a pronounced contrast with those from the Wenlockian and Ludlovian (Tables
1 and 5).

table 4. Comparison between Basal Downtonian assemblages from Gorsley, Ludlow, Perton
Lane, and ? Temeside Shales, Long Mountain (Shropshire)

Ludlow

Ludford

Lane

Downton

Gorge

Gorsley

Perton

Lane*

Long

Mountain*

Retusotri/etes dubius

7

7

X

—

—

R. cf. warringtonii

X

X

X

X

X

R. warringtonii

X

X

X

X

—

R. cf. minor

X

X

X

X

X

R. sp. A

X

X

X

—

—

Apicidiretusispora spicula

X

X

X

—

A. synorea

X

X

X

X

X

A. sp. A

X

X

X

—

—

A. sp. C

X

—

X

—

—

? Dictyotriletes sp. B
( Dictyotidium )

X

X

cf. Streelispora granulate

X

X

X

—

—

Synorispori tes do wn tone ns is

X

X

X

—

—

S. tripapillatus

X

X

X

X

X

S. verrucatus

X

X

X

X

X

Emphanisporites micrornatus

7

—

7

—

—

E. cf. micrornatus

X

—

X

—

X

E. cf. neglectus

X

X

X

X

—

A. chains var. chulus

X

X

X

X

X

A. chulus var. inframurinatus

X

' X

X

—

—

A. chulus var. nanus

X

X

X

7

X

? A. cf. divellomedium

X

X

X

7

—

? A. dubius

X

—

X

7

—

Cymbosporites echinatus

X

X

X

X

X

C. verrucosus

X

X

X

X

X

? Perotrilites sp. A

X

—

X

—

X

Other acid resistant microfossils

Acritarchs

X (D)

X (D)

X (D)

X

—

Chitinozoa

X

X

—

—

—

Hoegispheres

X

X

—

—

—

Scolecodonts

X

X

—

—

—

(D) = decreasing rapidly upwards in proportion to spore content.
* = based on a single sample.

Changes at the Ludlow Bone Bed

At the Ludlovian-Downtonian boundary there is a sharp facies change from deposits
representing open-sea conditions to those of near-shore-beach (Allen and Tarlo 1963).
Paralleling this change there is a significant change in the relative abundance of spores to
acritarchs. In the Silurian, spores generally constitute less than 1% of most assemblages
and they are associated with abundant acritarchs, chitinozoa, and scolecodonts. In the
basal Downtonian at Ludlow and Gorsley, however, acritarchs decrease rapidly upward

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

207

in the succession in relation to the spores. At Ludlow for instance the following have
been recorded from above the Ludlow Bone Bed (P = Present):

Acri-
Spores tarchs

LU 3 (5 ft. 10 in.-6 ft. above LBB) 70% 12%

LU 2 (4 ft. 10 in. -5 ft. above LBB) 51% 36%

LU 1 (0-4 in. above LBB) 11% 81%

Hoegi-

Indeter-

Chitinozoa

Scolecodonts

spheres

minate

—

—

—

18%

— -

—

P

13%

P

P

P

8%

Since acritarchs and chitinozoa are often abundant in holomarine, and absent from
fluviatile and fresh water, environments, these changes suggest a transition from marine
to brackish water. The same conclusion was reached by Allen and Tarlo (1963, p. 135)
based on sedimentological studies. No acritarchs have so far been seen in the Temeside
shales, but only one sample from this group has yielded microfossils.

As well as the increase in the relative abundance of the spores there is also an increase
in variety. Twenty-four different types of spore have been recorded from the Downtonian

table 5. Comparison between Upper Whitcliffe and Basal Downtonian assemblages,

Linton Quarry, Gorsley Common

Species

Silurian

Upper

Whitcliffe

Beds

Devonian
Lower
Down ton
Castle Sst. Gp.

Retusotriletes cf. warringtonii

X

X

Dictyotriletes sp. B (Dictyotidium)

X

X

A. chulus var. inframurinatus

X

X

Retusotriletes dubius

— -

X

R. cf. minor

—

X

R. sp. A

—

X

Apiculiretusispora spicula

—

X

A. synorea

—

X

A. sp. A

—

X

A. sp. C

—

X

cf. Streelispora granulata

—

X

Synorisporites do wntonensis

—

X

S. tripapillatus

—

X

S. verrucatus

—

X

Emphanisporites micrornatus

—

X

E. cf. micrornatus

—

X

E. cf. neglectus

—

X

A. chulus var. chulus

—

X

A. chulus var. nanus

—

X

1 A. cf. divellomedium

—

X

? A. dubius

- — -

X

Cymbosporites echinatus

—

X

C. verrucosus

—

X

? Pe rot r Hites sp. A

—

X

Acritarchs

x (A)

x (D)

Chitinozoa

X

—

Hoegispheres

X

—

Scolecodonts

X

—

(A), greater than 80% of the spore-acritarch content.

(D), decreasing rapidly upward

in relation to the spore content.

208

PALAEONTOLOGY, VOLUME 12

belonging to eight spore genera. In contrast fifteen different spore species and forms are
recorded in the Wenlock and Ludlovian belonging to six spore genera.

Genera recorded in the Wenlockian and Ludlovian are Retusotriletes, Ambitisporites ,
Archaeozonotriletes, Apiculiretusispora; and possible representatives of two new genera
(cf. Synorisporites verrucatus and cf. Streelispora). There is also a form which is doubt-
fully referred to the genus Dictyotriletes (? Dictyotriletes sp. B).

In the Downtonian on the other hand Ambitisporites has not been found and in
addition to those mentioned above further genera present are Emphanisporites (rare
forms with fine proximal ribs), Cymbosporites (patinate forms with spinose and verru-
cate sculpture), and IPerotrilites (spores with two clearly separated membranes). Pero-
trilites has a structural organization so far not seen in the Silurian and one which is rare
in the Downtonian.

Perhaps the greatest contrast between the Wenlockian-Ludlovian and Downtonian
assemblages is the increase in the number of sculptured forms. No sculptured forms
have so far been found in the Wenlock Shales. In the Wenlock Limestone so far only a
single specimen has been found with verrucate sculpture. In the succeeding Ludlovian,
verrucate, murinate, granulate, and apiculate sculpturing has been found but specimens
with any sculpture at all are rare and the majority of forms found in any one sample
are smooth walled. The Downtonian on the other hand contains abundant sculptured
spores, and verrucate, murinate, granulate, and apiculate types of sculpturing are all
relatively common.

Dittonian assemblages

A sample from the ‘ Psammosteus ’ Limestone Group (Downtonian/Dittonian junction
near Newport, South Wales) was described by Chaloner and Streel (1968) and has been
re-examined. Although the preservation is relatively poor, this assemblage shows several
of the species important in the succeeding Ditton Group but lacks the most characteris-
tic species of the Downtonian.

A feature of importance is that the genus Emphanisporites becomes much more
common. In the Downtonian the presence of proximal ribs is a rare and poorly developed
feature. In the ‘ Psammosteus ’ Limestone Group, many more spores of this type occur.
However, the presence of proximal ribs still appears to be an ‘unstable’ character since
in spores which are otherwise identical there are some that have fine proximal ribs and
others that do not.

Two distally smooth-walled types of Emphanisporites (E. cf. neglectus Vigran 1964
and E. epicautus sp. nov.) occur in the ‘ Psammosteus ’ Limestone; they are referred to
E. rotatus McGregor 1961 by Chaloner and Streel (1968), who record that of their five
common species E. rotatus constitutes 23% of the spore assemblage. However, this
may be a somewhat high figure since the preservation is relatively poor and Emphani-
sporites is an easily recognizable spore type.

From the Ditton Group an assemblage approximately 800ft. above the 'Psammosteus'
Limestone, has yielded abundant well-preserved spores which have helped in interpreting
the poorer assemblage from the ‘ Psammosteus ’ Limestone Group. Six species and
varieties are found here which are not recorded in the ‘ Psammosteus ’ Limestone Group.
In addition five other forms represented by relatively few specimens are identified only

text-fig. 2. Rangjescribed by Chaloner and Streel (1968) and re-examined,

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

209

to generic level; they represent new species but too few specimens have been found.
Emphanisporites is abundant and a variety of forms with distal sculpture occur.

COMPARISONS BETWEEN DOWNTONIAN AND DITTONI AN

ASSEMBLAGES

The range chart (text-fig. 2) shows distinct differences between the Downtonian and
Dittonian assemblages. Species of the genera Cymbosporites , Synorisporites , Perotrilites ,
and particularly Emphanisporites show the greatest contrasts. Only rare specimens of
Emphanisporites with smooth or apiculate distal surfaces occur in the Downtonian,
whereas in the Dittonian specimens of this genus are relatively common and show greater
variety. The genera Acinosporites and Che/inospora, and several other distinctive species,
e.g. Retusotri/etes cf. triangulatus Streel 1967, and Streelispora newportensis (Chaloner
and Streel) comb, nov., have not been found in the Downtonian and are most common
in the Ditton Group.

GENERAL CONSIDERATIONS

In the Welsh Borderland succession Silurian of open marine facies is followed by
Downtonian marginal-marine to fluviatile facies, and Dittonian fluviatile facies. Such
facies differences will obviously affect the nature and composition of spore assemblages.
Since most trilete spores were probably produced by land vascular plants nearness to
the shore, mouths of rivers, etc., will be reflected by spore abundance and possibly
variety. However, there is some evidence that the main changes between the Ludlovian,
Downtonian, and Dittonian spore assemblages are not facies controlled. Three lines of
evidence are considered important in this respect: (a) the nature of the spore record,
( b ) the Usk samples, and (c) comparisons with spore-pollen distribution patterns in
modern sediments.

Nature of the spore record. A consideration of the spore record as a whole, and in par-
ticular the number of spore taxa through the Silurian and early Devonian, provides some
evidence that the facies effects are slightly distorting a general evolutionary pattern.

table 6. Total number of spore taxa (present paper) through the Silurian and
early Lower Devonian. Upper Llandoverian record from Hoffmeister (1959)

Genera

Species, etc.

Sculptured

forms

Dittonian (Lower

11

29

21

and Middle)
Downtonian

8

24

13

Ludlovian

6

15

6

Wenlockian

4

8

1

Upper Llandoverian

1

2

0

Most of these trilete spores probably represent the spores of land vascular plants
although some algae produce spores in tetrads and bryophytes have trilete spores. No
indisputable trilete spores have been found in pre-Silurian strata, and the earliest
authenticated record of vascular plants is also from the Silurian. The spores gradually
increase in variety through the Wenlock, Ludlow, Downtonian, and Dittonian

210

PALAEONTOLOGY, VOLUME 12

(Table 6) and some of this is clearly due to evolutionary changes rather than for instance
distance from source areas and preservation factors.

The Usk samples. The evidence from the Silurian of Usk supports this general contention,
for there although the relative abundance of spores is much greater than in the Silurian
from other areas, the variety of spores is comparable with the Silurian assemblages from
Ludlow and Millichope where spores form less than 1% of the spore/microplankton
assemblages.

Comparison with palynological studies of recent sediments. Work on modern spore dis-
tribution patterns in clastic sediments shows that to a certain extent they reflect plant
distribution (Muller 1959, Hopping 1967) and sedimentary distribution patterns, since
water rather than wind is the dominant transporting agent (Muller 1959, Tschudy 1964,
Groot et al. 1966, Groot 1966, Traverse and Ginsburg 1966, 1967). Consequently spore
distribution patterns in the late Silurian and early Devonian are likely also to reflect these
factors although clearly the plants were very different and nothing is known of their
ecology. The only vascular plants known were very small (fragmentary axes of Cook-
sonia up to 6-5 cm.; Obrhel 1962) free-sporing pteridophytes. However, most of the
differences in spore species between the Ludlovian, Downtonian, and Dittonian do not
seem to be explicable on the basis of ecological or other contemporaneous factors.
This is suggested by comparisons between data from the present study and samples
from comparable environments on the Orinoco delta (Muller 1959), summarized in
Table 7. They show that in spite of differences there is a much greater similarity between
the contemporaneous pollen assemblages from various environments of the Orinoco
region than between those from comparable environments in the Silurian-Devonian
of the Welsh Borderland. This can clearly be seen from the comparisons in the species
which are common to other environments. In all cases there are many more species which
are common to other environments in the Recent sediments than within the sequence
of the Welsh Borderland.

However, certain resemblances include the paucity of spore species in holomarine
environments from the Orinoco delta and in the Ludlovian. In the latter this is doubtless
related partly to evolutionary factors, but that it is partly due to spore distribution
factors can be seen from the fact that certain spore species, e.g. cf. Streelispora granulata
sp. nov. and Apiculiretusispora synorea sp. nov. have a rather sporadic distribution and
also because Upper Ludlovian assemblages are less varied than assemblages from above
and below. Further, this paucity of spore species in the Upper Ludlovian does not appear
to be related to post-depositional preservation factors since many of the Upper Ludlovian
rocks examined contain beautifully preserved microplankton.

COMPARISONS BETWEEN SOUTH WALES AND THE
WELSH BORDERLAND

Ludlovian. The best spore assemblage found was in the Upper Cwm Clyd Beds (Sawdde
Gorge), included R. cf. warringtonii sp. nov., A. chulus vars. inframurinatus var. nov.,
chulus var. nov., and nanus , var. nov., Amb. cf. dilutus (Hoffmeister) comb, nov., and
Retusotriletes sp. The specimens of var. inframurinatus have very thick inframuri and
resemble forms in the Bringewood and Lower Leintwardine Beds. Further Amb. cf.

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

21 1

dilutus has not been recognized with certainty above this horizon. These findings agree
with previous suggestions of a Lower Leintwardine age for these beds ( Potter and Price
1965) but cannot at this stage be regarded as proof of such an age. The assemblage
contains abundant acritarchs and chitinozoans which have yet to be studied. The relative
abundance of the spores is interesting for as at Usk there is no greater variety than at
comparable Ludlovian levels.

table 7. Comparisons between spore data from the Welsh Borderland with that from comparable
environments in Recent deposits from the Orinoco Delta (Muller 1959)

Orinoco Delta

Silurian j Devonian

Holomarine
Near shore (but not

85%

1

22%

Ludlovian

opposite river mouths)

43%

13%

Downtonian

Fluvio-marine

48 %J

Delta (channel)

Delta (mud flats, lagoons)

45% 1
45% J

11%

Dittonian

(a) Percentage of species present which are common to all other deposits
in the Orinoco Delta and the Silurian/Devonian respectively.

Near shore

48%)

| 26%

Downtonian

Fluvio-marine

,v/ /U |

52%)

Delta (channel)

Delta (mud flats, lagoons)

50% |
50%)

11%

Dittonian

(, b ) Percentage of species present which are common to holomarine and
Ludlovian environments respectively.

Holomarine 85-92% 67%

Delta (channel) 77% 1

Delta (mud flats, lagoons) 77—82% / 0

Ludlovian

Dittonian

(c) Percentage of species present which are common to near-shore and
fluvio-marine environments and Downtonian environments respectively.

Holomarine
Near-shore marine
Fluviomarine

85%
74% I
70% /

22% Ludlovian

43% Downtonian

( d ) Percentage of species present which are common to Delta channel, mud
flats and lagoons and Dittonian environments respectively.

Long Quarry Beds. The assemblages are poorly preserved but in Capel Horeb Quarry
(Cwm Dwr region) a number of samples have yielded spores, acritarchs and chitino-
zoans; the spores are not abundant. Nevertheless no spore indicative of the Downtonian
has so far been found. Specifically identified spores R. cf. warringtonii, A. chulus vars.
chulus and inframurinatus , are long ranging, but indicate the possibility of a Ludlovian
age.

Red Marl Group. So far the only assemblage obtained from these beds is from expo-
sures at Freshwater East (north side of the bay). Samples from the ?Ludlovian contain
abundant chitinozoa and acritarchs and relatively few spores belonging to the following
species A. chulus var. chulus , R. cf. warringtonii and spores tentatively assigned to Ambiti-
sporites cf. dilutus. In contrast the overlying Red Marl Group has yielded an assemblage

212

PALAEONTOLOGY, VOLUME 12

including several typical Downtonian forms, e.g. Synorisporites verrucatus sp. nov.
and S. tripapillatus sp. nov., which are abundant in all Downtonian samples from the
Welsh Borderland. In addition Archaeozonotriletes cf. divellotnedium Chibrickova 1959,
Perotrilites sp. A, Apiculiretusispora synorea sp. nov. Emphanisporites micrornatus sp.
nov. and A. chulus var. chulus occur. This assemblage suggests a Downtonian age.

Senni Beds. No assemblages equivalent to the distinctive Middle Dittonian assemblage
have been seen in South Wales but a detailed study is in progress on the Breconian and
the results will be published elsewhere. The best Senni Beds assemblages have been
obtained from quarries at Storey Arms and Llanover (see also Mortimer 1967), and they
contain a number of spore species which also occur in the Middle Dittonian. Retuso-
triletes warringtonii, R. cf. minor Kedo 1963, R. cf. triangulatus Streel 1967, Stree/ispora
newportensis (Chaloner and Streel) comb, nov., Chelinospora cassicula sp. nov., Archaeo-
zonotriletes clndus var. chulus , and Emphanisporites micrornatus sp. nov. Most of these
are confined to the Llanover assemblages but both assemblages contain several forms
which have not been found at lower horizons: Apiculiretusispora cf. plicata (Allen) Streel
1967, Dibolisporites cf. Apiculiretusispora brandtii Streel 1964, Emphanisporites decor atus
Allen 1965, E. cf. rot atus, and E. cf. robust us McGregor 1961, Retusotriletes cf . frivolus
var. limbatus Chibrickova 1959, other Apiculiretusispora and Retusotriletes spp. and
Dictyotriletes sp. not seen in the lower assemblages.

These assemblages are strikingly similar in many respects to assemblages from the
Carmyllie Beds (‘Dittonian’, Midland Valley of Scotland) which also contain robust
ribbed Emphanisporites , the relatively large spores ( c . 80 //) Dibolisporites cf. brandtii ,
and the distinctive Retusotriletes cf. frivolus var. limbatus. In the Midland Valley this
assemblage is overlain by one which contains annulate species of Emphanisporites (spp.
annulatus-erraticus ) and relatively large zonate-pseudosaccate forms (Richardson 1967).
So far neither of the latter has been found in the Senni Beds but the species E. annulatus
McGregor 1961 and possible E. erraticus (Eisenack) McGregor 1961 occur in strata of
Senni-like lithology in the Witney borehole (Chaloner 1963, Richardson 1967).

PREVIOUS WORK AND COMPARISON WITH OTHER AREAS

Wenlock-Lud/ow. Hoffmeister (1959), Downie (1963) have recorded trilete spores from
the Silurian, and Cramer (1966) from near the Ludlovian-Gedinnian boundary. In
total these records are consistent with a poorly developed, but nevertheless distinctive,
spore flora in the Silurian. This lack of variety does not suggest a long pre-Silurian history
for trilete spores and although supposed trilete spores have been recorded from the
Ordovician (Taugourdeau 1965) and older strata (Naumova 1953), they are either too
poorly preserved to be certain of their nature or clearly lack haptotypic features and are
therefore more properly assignable to the acritarchs.

Hoffmeister (1959) described an assemblage from a borehole in Libya dated by grapto-
lites as belonging to ‘high Lower Silurian’. The assemblage, represented by two closely
similar spore species Ambitisporites avitus and A. cf. di/utus , probably constitutes the
oldest trilete spores in the geological record. Downie (1963) found similar spores (A.
cf. di/utus ) in the Wenlock Shale of the Welsh Borderland, and also a single specimen
with verrucate sculpture ( Lophotriletes ). These spores are all, with a single exception,
smooth-walled with a tendency to thicken in the equatorial region. Cramer’s (1966)

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

213

assemblage from Leon, Spain shows more variety than those described by Hoffmeister
and Downie, for, in addition to forms similar to A. avitus and A. cf. dilutus (pi. 2, fig. 1 5),
other smooth-walled spores with a distinctive proximal thinning ( Archaeozonotriletes
chulus), and spores with apiculate sculpture, occur. Other palynomorphs doubtfully
referred to as spores have verrucate to reticulate sculpture.

The Wenlock Shale contains smooth-walled trilete spores some of which are closely
similar to those previously recorded by Hoffmeister and Downie but here they are
referred to a single genus Ambitisporites e.g. A. dilutus, A. cf. dilutus , and A. cf. avitus.
In addition other smooth-walled spores, Retusotriletes cf. warringtonii and atypical
representatives of Archaeozonotriletes chulus var. nanus, were recorded. The Wenlock
Limestone assemblage is similar but contains rare verrucate spores and in the Ludlovian
there is an increasing diversity of sculptured spores which are, however, still rare.
Spores from the Upper Ludlow are comparable to Cramer’s assemblage from Spain
with Archaeozonotriletes chulus, and species of Apiculiretusispora although forms com-
parable to Cramer’s species have not been found.

Downtonian. Nothing comparable with the distinctive Lower Downtonian spore
assemblages has been described from elsewhere. However, Allen (1965, 1967) in his
description of Lower and Middle Devonian spore assemblages from Vestspitsbergen
records an assemblage from the Red Bay Group of Fraenkelryggen, ‘a probable equiva-
lent to the Upper Downtonian and Dittonian in the Anglo-Welsh area’. These spores
are poorly preserved and not figured, but the presence of E. minutus Allen 1965 (similar
to E. cf. neg/ectus) in both the Spitsbergen and the Welsh Borderland samples may be
significant. Only rare specimens of this species with poorly developed ribs have so far
been found in the Downtonian whereas it occurs in the ‘ Psanunosteus' Limestone Group
and the Middle Ditton Group, in the latter with other fine-ribbed Emphanisporites , many
of which have distal sculpture. This situation is broadly comparable with that described
for Spitsbergen where at higher horizons and in the Wood Bay Formation (Austfjorden
Sandstone Member) Allen records E. minutus and E. neg/ectus Vigran 1964, with E.
decoratus Allen 1965 which has distal sculpture. However, this assemblage contains
more complex forms, e.g. poorly preserved ?zonate Cirratriradites dissutus Allen 1965
and in the megaspore size range Trileites oxfordiensis Chaloner 1963; such types have
not so far been found in the Dittonian where all the spores, with one possible exception,
are of small size. The exception is a spinose body (? spore) which has so far only been
found in a fragmentary condition.

In general, although there have been relatively few areas studied in detail, these show
a similar pattern of Late Silurian and Early Devonian spore assemblages to that observed
in the Welsh Borderland. However, later Lower Devonian spore assemblages, e.g. those
described by Moreau-Benoit (1966, 1967) from the Siegenian to Emsian have much more
varied composition than those from strata of apparently equivalent age in Belgium
(Streel 1967).

Botanical significance. Chaloner (1967) commented on the spore evidence in relation to
land plant evolution when only a few Silurian samples had yielded clear trilete spores.
However, in spite of the number of Ludlovian samples investigated the overall trend
of spore diversification has not been substantially altered. Table 6 shows a gradual
increase in spore genera and species which appears to be evolutionary, and although

214

PALAEONTOLOGY, VOLUME 12

comparison with Muller's work suggests less spore variety in holomarine sediments,
the trend is consistent and repeated in Spain (Cramer 1966) and Gaspe (McGregor
1967). Within the Silurian and Lowermost Devonian spores are dominantly azonate
or with only small equatorial thickenings (Richardson 1967). Forms with proximal
radial ribs are at first apparently absent (Silurian) then poorly developed (Downtonian)
then diverse and later robust (Dittonian-Breconian). Surely these changes reflect con-
temporaneous land plant evolution in the Silurian and Lower Devonian.

More specifically the gradual morphological changes in spores of the Ambitisporites-
Archaeozonotri/etes complex through the Wenlock and Ludlow seem to suggest an
evolutionary cause, and the size of the spores in the present study confirms earlier work
(Chaloner 1967, Richardson 1967) in suggesting that the plants producing them were all
homosporous.

Although it is probable that most of the spores studied are of land vascular plants
there is unfortunately no direct evidence of this. The spores of Cooksonia (the only
vascular plant known in the Silurian and Downtonian) have not yet been described in
detail or clearly illustrated. However, many of the spores found in these rocks have very
thick walls which are more typical of land plants (bryophytes and pteridophytes) than
of algae, and one such thick-walled species, Archaeozonotri/etes chulus, occurs in con-
siderable numbers in fluviatile Dittonian sediments as well as marine strata and thus
most probably originated from a land plant.

SYSTEMATIC DESCRIPTIONS

All slides with the prefix WB are in the Department of Geology, King’s College,
London; instrument settings of Zeiss microscope 400349. Figured specimens bearing
the index letters MPK are stored in the Institute of Geological Sciences, Leeds.

Terminology used is that proposed by Potonie and Kremp (1954) with modifications
proposed by the International Commission for Palaeozoic Microfloras (Couper and
Grebe, Krefeld 1961, and Grebe, in preparation) and in addition the term ‘Biform
sculpture’ (Richardson 1965); and the term ‘perine’ to include perine-like layers which
may not be homologous with the perine of modern spores.

Genera and species described below are considered as form genera and species based
purely on arbitrary morphological criteria.

Anteturma sporites H. Potonie 1893
Turma triletes Reinsch 1891
Subturma azonotriletes Luber 1935
Infraturma laevigati (Bennie and Kidston) Potonie and Kremp 1954
Genus retusotriletes (Naumova) Richardson 1965 non Streel 1964

Type species. R. pychovii Naumova 1953 (lectotype species of Richardson 1965).

Discussion. Two emendations of the Genus Retusotriletes have been proposed. Richard-
son (1965) published an emendation proposing R. pychovii Naumova (1953, pi. 4, fig. 5)
as the type species. While this paper was in press Streel (1964) also published an emenda-
tion of the same genus but following Potonie in using R. simplex Naumova as the type
species. Potonie used an arbitrary procedure in selecting the first species of the genus

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

215

described by Naumova (see Lanjouw et ah, 1961, p. 65, para. 4). Examination of
Naumova's illustrations (pi. 2, fig. 9, and pi. 15, fig. 14) shows that R. simplex has
curvaturae imperfectae and no contact area differentiation and thus lacks the diagnostic
characters of the genus. On the other hand R. pyehovii has clearly defined contact areas,
emphasized in Naumova's description of this species (but not in the description for
R. simplex). Consequently R. pyehovii is preferred, although this must be regarded as
provisional until Naumova’s type and co-type material is re-examined.

Retusotriletes diltonensis sp. nov.

Plate 37, figs. 1, 2

Holotype. Size 41x54/x; slide WB 125, ref. 3141033. Ditton Group, Dairy Dingle, Gedinnian.
Occurrence. As above.

Diagnosis. Curvaturae perfectae well developed, contact areas slightly depressed; exine
of variable thickness, with the greatest thickness distally.

Description. Size range 35-57 p (30 specimens measured), mode 48 p. Amb circular, in
equatorial view hemispherical with flattened to slightly concave contact areas, exine
outside the contact area appears raised. Exine distally thicker than proximally, distally
4-6-5 p, equatorially 2-4 p (maximum observed variation on a single specimen, equa-
torial width 2-5, distal 6-5). Contact areas distinct, about §-§ spore radius, on some
specimens one contact area appears larger than the other two, occasionally apical region
darker, curvaturae perfectae form narrow ridges 0-5 p wide, contact faces shagrinate to
faintly striate, or slightly infragranular, exine outside contact areas homogeneous.
Triradiate mark distinct, sutures §-§ spore radius, occasionally accompanied by low lips.

Comparison and remarks. R. pyehovii Naumova 1953 has a similar size range, 40-50 p,
distinct curvaturae perfectae, and a relatively thick wall, but it is not possible to see
from Naumova’s drawings whether the exine is thickened distally. Almost identical
spores occur in the same assemblage which have a distinct, fine, radiating muri on the
contact areas (compare Emphanisporites sp. A). Similar specimens occur in the Down-
tonian but have a thinner distal exine and curvaturae which coincide with the equator
at their maximum extent; in polar compression the wall at the equator appears to be of
greater thickness in the interradial areas due to the coincidence of the curvaturae with the
equator.

Retusotriletes dubius (Eisenack) Richardson 1965
Plate 38, figs. 1-2

Occurrence. Lower Downtonian, Linton Quarry, and Downton Gorge. Relatively rare.

Remarks. The Downtonian specimens are 56-64 p (5 specimens measured). In common
with Eisenack’s specimens and the Scottish Middle Devonian material they are triangular
in outline, have curvaturae which coincide with the equator and give the appearance of
thickened interradial areas, and have a darkened apical area.

216

PALAEONTOLOGY, VOLUME 12

Retusotri/etes warringtonii sp. nov.

Plate 37, figs. 7-8

Holotype. Size 24x28 p; slide 135, ref. 386994, Ditton Group, Dairy Dingle; Gedinnian.

Occurrence. Lower Downtonian and Dittonian.

Diagnosis. Small triangular to subtriangular laevigate spores with curvaturae perfectae
that coincide with equator for most of their length.

Description. Size range 18-36 p (20 specimens measured). Amb sub-triangular to dis-
tinctly triangular. Exine smooth homogeneous relatively thick 1-5- 2 p. Contact areas
demarcated equatorially by curvaturae perfectae which usually coincide with the equator,
only seen clearly in tipped specimens. Triradiate mark nearly equals spore radius
accompanied by lips which taper from the pole towards the equator, maximum height
of the lips 1-2 p.

Comparison. Differs from R. cf. minor by its distinct sub-triangular to triangular equa-
torial outline.

Retusotri/etes cf. warringtonii sp. nov.

Plate 37, figs. 9-1 1

Occurrence. Wenlock, Ludlow, and Lower Downtonian.

Description. Size range 22-32 p (13 specimens measured). Exine homogeneous. Amb
subtriangular to triangular, relatively thin and frequently folded. Contact areas coincide
with the proximal face except in the interradial areas. Curvaturae perfectae coincide
with the equator, only seen clearly in slightly tipped specimens. Triradiate mark nearly
equals spore radius, accompanied by lips.

Comparison. In size similar to Retusotri/etes cf. minor and R. warringtonii but differs in
having a thinner crumpled exine.

EXPLANATION OF PLATE 37

All figures x 1,000 except where stated otherwise.

Figs. 1-12. Retusotriletes spp. 1-2. R. dittonensis sp. nov. 1, Holotype; unequal development of
contact areas. 2, Lateral compression showing thick exine over distal surface; WB 127/417959,
Ditton Group. 3-5. R. cf. trim gulatus (Streel) Streel 1967; Ditton Group. 3, Showing apical
triangular thickening with thinner apical area; WB 125/3601053. 4, With uniformly thickened
apical area; WB 128/451921. 5, Showing disintegrating outer sculptured layer; WB 135/410932.
6, R. sp. A, Lateral compression showing curvaturae perfectae; Downton Castle Sandstone Group,
WB 37/4041018. 7-8. R. warringtonii sp. nov. 7, Holotype. 8, Tipped specimen showing curva-
turae perfectae; Ditton Group. WB 135/282982. 9-11. R. cf. warringtonii sp. nov. 9, Thick-walled
specimen, Lower Elton Beds, MPK 15. 10, Thin-walled specimen. Lower Elton Beds, MPK 8.

1 1, Lower Whitclifife Beds, MPK 15. 12, R. cf. minor Kedo 1963; Ditton Group, WB 1 35/4261000.

Figs. 13-16. Apiculiretnsispora spp. 13-14. Apicidiretusispora cherata sp. nov.; holotype. 13, Distal
focus. 14, proximal focus showing smooth contact areas and Y-folds. 15-16. A. microconus sp.
nov.; holotype, x2,000. 1 5, Proximal focus showing lips. 16, Distal focus showing sparse minute

coni.

Palaeontology, Vol. 12

PLATE 37

RICHARDSON and LISTER, Silurian and Devonian miospores

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

217

Retusotriletes cf. minor Kedo 1963
Plate 37, fig. 12

Occurrence. Lower Downtonian and Dittonian.

Description. Size range 14-36 p (40 specimens measured) mode 28 p. Amb circular to
triangular with convex sides and rounded apices. Spores usually preserved in polar
compression. Exine 0-5-1 -5 p thick, smooth and homogeneous. Contact areas frequently
slightly depressed, occasional specimens show a thinner area at the proximal pole;
triradiate lips 0-5-2 p high, § to nearly equal spore radius, lips merge into curvaturae
perfectae which sometimes coincide with the equatorial outline; lips occasionally thick-
ened where they pass into the curvaturae.

Comparison and remarks. In size these spores compare with Retusotriletes minor Kedo
1963 (26-30 p), however the latter lacks lips. ‘ R.' simplex Naumova 1953 is also small
(30-5 p) but lacks lips and has curvaturae imperfectae.

Retusotriletes cf. (al. Phyllothecotriletes) triangu/atus (Streel) Streel 1967

Plate 37, figs. 3-5; text-fig. 3.
cf. 1 964 Phyllothecotriletes triangulatus Streel
Occurrence. Ditton Group, Dairy Dingle, Gedinnian; relatively common.

Description. Size range 41-68 p (100 specimens measured), mode 58 p. Amb circular to
subcircular. Spores usually preserved in polar compression or slightly oblique. Exine
typically 2 p thick, externally smooth. Contact areas delimited by distinct curvaturae
which usually follow the equatorial margin except in the radial areas in polar compres-
sion. Triradiate mark surrounded by a thickened triangular area in the apical region,
areas inside and outside the triangular area less dense, in some specimens triangular area
of uniform density; triangle with straight to slightly convex or concave sides, sutures
within the triangle distinct, about b radius, frequently splayed open, continued as dark
lines to the curvaturae, total length of triradiate mark §-§ radius.

Comparison. Several spore species have a thickened triangular apical area and some have,
in addition, curvaturae perfectae. Three species of the latter type resemble the spores
described above; these are ‘ Calamospora' witneyana Chaloner 1963, Phyllothecotriletes
rotundas and P. triangulatus (Streel 1964). C. witneyana is much larger (110-96 p) and
has a mean of 165 p. In size distribution the Dittonian specimens correspond closely
to P. rotundas but in the nature of the apical region they are more similar to P. triangu-
latus since the apical thickening is basically triangular in shape. The apical thickening
is sometimes less dense in the inner part and in some specimens this appears to be a
secondary development.

Botanical affinities. Recently a probable coenopterid fern (Dawson it es) has been described
from Gaspe (Banks, Hueber, and Leclerq 1964). The spores exines are two layered; the
outer layer (? perispore) is sculptured but frequently separates from an inner smooth
spore which has a darkened apical region and is closely similar to R. cf. triangulatus.
In the Ditton Group of the Welsh Borderland occasional specimens show this outer

218

PALAEONTOLOGY, VOLUME 12

layer still attached but the bulk of the specimens have lost it. Similar spores also occur
in the ‘Dittonian’ (Carmyllie and Strathmore beds) of the Midland Valley but here many
more of the specimens have retained the outer layer. McGregor and Owens (1966, pi. 2,
figs. 18, 19) also figure similar specimens from the Battery Point Formation, lower
part (Emsian), eastern Gaspe Peninsula, Quebec.

Phyllothecotriletes rotundus
Street (1964) (Givetian- Belgium)

Phyllothecotriletes triangulatus
Streel (1964) (Givetian-Belgium)

Retusotriletes cf triangulatus
(Gedimian- Welsh Borderland)

40 44

52 56 60 64 68

MAXIMUM DIAMETER

88^1

text-fig. 3. Size distribution of Retusotriletes cf. triangulatus (Streel) from the Dittonian of the Welsh
Borderland compared with Streel’s data from the Lower Givetian of Goe, Belgium (Streel 1964).

Retusotriletes sp. A

Plate 37, fig. 6

Occurrence. Upper Elton and Upper Whitcliffe Beds, Ludlovian; Lower Downtonian,
Linton quarry, Ludford and Downton Gorge.

Description. Size range 3CU68 p (24 specimens measured). Amb subcircular. Exine
homogeneous of variable thickness, equatorially 2-4 p thick, thickest in the interradial

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

219

areas, distally 3-3-5 p. Contact areas coincide with the proximal face except in the inter-
radial areas. Curvaturae only clearly seen in oblique compression as in polar view they
merge with the equator. Triradiate mark distinct f to nearly equal spore radius.

Comparison and remarks. Most of the specimens seen are distorted or poorly preserved
and hence no specific assignment is made. However, they are clearly distinct from R.
dittonensis in that the contact areas are not as distinct, curvaturae coincide with the
equator, and though the exine is variably thickened, it is not as thick distally as in
R. dittonensis sp. nov. Ludlovian specimens have a slightly thinner exine.

Infraturma apiculati (Bennie and Kidston) Potonie 1956
Genus apiculiretusispora Streel 1964

Type species. A. brandtii Streel 1964

Apiculiretusispora cherata sp. nov.

Plate 37, figs. 13-14

Holotype. Size 31 x 38 /x, including spines, spine length 2-3 /x; slide WB 128, ref. 437941 ; Ditton Group,
Dairy Dingle, Gedinnian.

Occurrence. As above.

Diagnosis. Exine relatively thick, sculpture spinose, elements have bulbous bases, slender
stems, and dominantly blunt, occasionally spatulate apices; triradiate mark nearly equal
to equal spore radius.

Description. Size 30-46 p (120 specimens measured), mode 38 p. Amb subcircular to
subtriangular, distal hemisphere convex in lateral view. Exine 2-3 p thick, typically
2-5 p. Contact areas, distinct, smooth and infragranular(?) towards the pole, granular
towards the equator; contact areas equal or nearly equal to spore radius. Exine outside
the contact areas bears dominantly spinose sculpture, occasional cones also present,
elements circular in plan, with broad bases, rapidly taper to slender parallel-sided or
slightly tapered stems, spine apices dominantly flattened but occasionally pointed, some-
times distinctly spatulate; width of bases typically 1-5 p, range 0-5-1 -5 /x, stem width
around 0-5 p, spine length variable, 1-6 p, range on a single specimen typically 3-3-5 p:
elements 1-2-5 p apart. Triradiate mark nearly equal, to equal, spore radius, sutures
sometimes accompanied by lips 1 -5-2-5 p high.

Comparison. ‘ Acanthotriletes' raptus Allen 1965 is similar but has shorter Y-rays and
more closely packed spines.

Apiculiretusispora microconus sp. nov.

Plate 37, figs. 15-16

Holotype. Size 16 x 19-5 p; slide WB 135, ref. 356982; Ditton Group, Dairy Dingle, Gedinnian.
Occurrence. As above.

Diagnosis. Small spores with minute distal sculpture of barely discernible coni or grana
to distinct coni.

220

PALAEONTOLOGY, VOLUME 12

Description. Size range 13-24 p (60 specimens measured), mode 18 p. Amb triangular
with convex sides and rounded apices. Exine homogeneous 0-5-1 p thick. Contact areas
smooth bordered by curvaturae which nearly equal spore radius or merge with the equa-
torial outline. Exine equatorially and distally sculptured by minute, barely discernible,
grana or coni, to distinct coni, up to 0-5 p wide and 0-5 p high, 1-2 p apart. Triradiate
mark distinct, sutures nearly equal to equal spore radius, sometimes accompanied by
triradiate folds.

Comparison. The small size and minute sculpture distinguish this species from other
species of Apiculiretusispora.

Apiculiretusispora spicula sp. nov.

Plate 38, figs. 3-4

Holotype. Size 35x40 p; slide WB62, ref. 3931022; Lower Downtonian, Linton Quarry.

Occurrence. Lower Downtonian, as above, Ludford and Downton Gorge.

Diagnosis. Contact areas distinct, sculpture consists of sparse, sharply pointed, slender
cones or small spines.

Description. Size range 30-46 p (34 specimens measured), mode 46 p. Amb circular to
subcircular. Exine 1-2 p thick, typically 1-5 p, at the equator slightly thicker distally.
Contact areas distinct usually unequal in size, delimited by fine curvaturae perfectae,
areas occasionally smooth, slightly granulose, or bear faint radial ‘muroid folds’ less
than 1 p wide, contact areas nearly equal to spore radius. Outside the contact areas exine
covered by slender sharply pointed spines or cones, elements 0-5-1 p wide, 1-2 p high,
height two to four times basal diameter; elements 1-3 p apart. Triradiate mark distinct,
sutures |-f spore radius.

Comparison and remarks. The sparse slender cones and spines distinguish this species
from other species described in the present paper. A. brandtii Streel 1964 is much larger.
Specimens from Ludford frequently show very fine, barely discernible, proximal ribs.

EXPLANATION OF PLATE 38

All figures x 1,000 except where stated otherwise.

Figs. 1-2. Retasotriletes dubius Richardson 1965; Downton Castle Sandstone Group. 1, Polar com-
pression showing thickened apical area; WB 38/433949. 2, oblique compression showing curva-
turae perfectae; WB 38/2831041.

Figs. 3-9. Apiculiretusispora spp. 3-4. A spicula sp. nov. 3, ITolotype. 4, Showing depressed smooth
contact areas; Downton Castle Sandstone Group, WB 32/4571042. 5-6. A. synorea sp. nov.

5, Holotype. 6, Showing wrinkling of contact areas; Downton Castle Sandstone Group, WB
32/341968. 7, A. sp. A; Downton Castle Sandstone Group, WB 64/371891. 8, A. sp. B; Ditton
Group, WB 125/400891. 9, A. sp. C; Lower Whitcliffe Beds, MPK 40.

Figs. 10-16. Emphanisporites spp. 10-11. E. micrornatus sp. nov.; X 2,000. 10, Holotype, tipped speci-
men showing proximal radial ribs and distal sculpture. 11, Proximal polar view, Ditton Group,
WB 127/347879. 12, E. cf. micrornatus sp. nov.; Downton Castle Sandstone Group, WB 54/426930.
1 3-1 5. E. epicautussp. nov. 13-14, Holotype. 13, Showing apical thickening. 14, Showing well-marked
contact areas. 15, Specimen showing thickenings at ends of Y-rays; Ditton Group, WB 139/363911.
16, E. cf. neglectus Vigran; specimen showing fine radial ribs and curvaturae that coincide with
equator, X 2,000; Ditton Group, WB 134/363910.

Palaeontology, Vol. 12

PLATE 38

RICHARDSON and LISTER, Silurian and Devonian miospores

*

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

221

Apiculiretusispora synorea sp. nov.

Plate 38, figs. 5-6

Holotype. Size 29 X 31-5 p; slide WB 32, ref. 4531084; Lower Downtonian, Linton Quarry, Gedinnian.

Occurrence. Upper Elton Beds, Ludlovian and Lower Downtonian.

Diagnosis. Contact areas distinctly wrinkled, bulge prominently in the interradial areas;
sculpture consists of stout, densely packed cones.

Description. Size range 26-43 p (80 specimens measured), mode 33 p. Amb circular to
subcircular. Exine 2 /x at the equator, 3 p at the distal pole. Contact areas distinct, more
or less \ the radius in the radial area, swell to nearly equal to the radius in the interradial
region, exine in the contact areas wrinkled into fine irregular folds. Exine outside the
contact areas sculptured, sculptural elements consist of stout cones, cones more or less
isodiametric, 0-5-1 -5 p, elements closely packed 0-5-1 p apart, rounded in plan, in
profile may be uniformly tapered, or have rapidly tapered bases surmounted by slender
pointed stems, occasional elements become distinctly biform but this does not form a
constant character. Triradiate mark J-f spore radius, accompanied by broad convolute
lips.

Comparison. The coarse, closely packed cones and bulging contact areas distinguish this
species from A. spicula sp. nov. A. brandtii Streel 1964 is much larger and has more
sparse sculpture.

Apiculiretusispora sp. A
Plate 38, fig. 7

Occurrence. Lower Downtonian, Linton Quarry, Ludford, and Downton Gorge.

Description. Size range 22-32 p (11 specimens measured). Amb triangular with convex
sides and rounded apices. Proximal face smooth or covered with fine radial muroid
folds, exine distally covered by short pointed spines, 0-5-1 p wide, 1-2 p high, elements
closely packed. Triradiate mark accompanied by large folds, 1-5-2 p high, equal spore
radius.

Comparison. The sculpture of these specimens is very similar to that of A. synorea sp.
nov.; however type A is distinctly triangular and has prominent lips which reach the
equator.

Apiculiretusispora sp. B
Plate 38, fig. 8

Occurrence. Downtonian, Gorsley Common, and Long Mountain, Ditton Group,
Dairy Dingle.

Description. Size range 21-8 p (10 specimens measured). Amb subtriangular, frequently
preserved in lateral compression. Contact areas bounded by distinct curvaturae, contact
face smooth. Exine homogeneous 1 p thick proximally, 1-2 p thick at the equator and
distally. Exine outside the contact areas covered by distinct coni, with broad bases, and
rounded to pointed apices, width 0-5-2 p, typically 1 p, height 0-5-1 p typically less

Q

C 6508

222 PALAEONTOLOGY, VOLUME 12

than 0-5 p, elements 0-5-1 -5 p apart. Triradiate mark § radius accompanied by lips 1 j u,
wide.

Comparison. Distinguished from Apiculiretusispora sp. A by broad, low coni, and
distinct curvaturae.

Apiculiretusispora sp. C
Plate 38, fig. 9

Occurrence. Upper Ludlovian and Lower Downtonian, Ludlow and Gorsley Common.
Rare.

Description. Size range 40-50 p (4 specimens measured). Amb subcircular to sub-
triangular, contact areas distinct delimited by thickened curvaturae perfectae, equal or
nearly equal spore radius. Except for contact areas which are smooth, exine covered by
minute closely packed sculptural elements, 0-5 p or less, more or less equidimensional.
Triradiate mark nearly equal to the spore radius accompanied by folds.

Remarks. These specimens are closely similar to those of Emphanisporites cf. micror-
natus sp. nov. except that they lack proximal radial ribs and tend to be larger.

Infraturma murornati Potonie and Kremp 1954
Genus emphanisporites McGregor 1961

Type species. Emphanisporites rotatus McGregor 1961.

Emphanisporites micrornatus sp. nov.

Plate 38, figs. 10-1 1

Holotype. Size 21 x24 p; slide WB 133, ref. 4161025; Ditton Group, Dairy Dingle, Gedinnian.
Occurrence. As above.

Diagnosis. Spores small with distinct curvaturae, relatively robust proximal radial muri,
and minute distal sculpture of coni to grana.

Description. Size range 19-38 p (100 specimens measured), mode 28 p. Amb circular to
subcircular, spores originally subspherical with flattened proximal pole, frequently
preserved in oblique compression. Exine 1—1 -5 p thick; proximal face with distinct
curvaturae perfectae, slightly thickened, contact areas slightly less than, or equal to,
spore radius, ornamented with 5-7 radially arranged muri, which are relatively robust,
only slightly tapering, and 1—2-5 p wide. Distal hemisphere sculptured by sparse minute
coni to grana less than 0-5 p high. Triradiate mark accompanied by folds f to nearly
equal spore radius.

Comparison. The minute distal sculpture of E. micrornatus sp. nov. distinguishes this
species from E. decor atus Allen 1965 which has clearly discernible and relatively large
cones or spines and from E. neglectus Vigran 1964 which is also distinctly subtriangular,
and smaller (Vigran’s size range is 9-5-17 p). Spores placed by Allen (1965) in the latter
species occasionally have fine granules and the figured specimen is closely similar to
E. micrornatus sp. nov. In E. spinaeformis Schultz (in Lanninger 1968), the proximal muri

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

223

are thicker and converge on the trilete sutures forming a ‘herring-bone’ pattern
(‘ fischgratenartige ’).

Remarks. The sparse minute sculpture can frequently only be seen under high magnifi-
cations and could easily be overlooked.

Emphanisporites cf. micrornatus sp. nov.

Plate 38, fig. 12

Occurrence. Downtonian, Linton Quarry and Wallop Hall Quarry, Long Mountain.

Description. Size 24-41 /x (11 specimens measured). Ambsubcircular to subtriangular,
contact areas distinct, delimited by thickened curvaturae perfectae; contact areas equal
to spore radius, bear radial muri, muri 1-1 -5 ft wide, rather indistinct, gradually tapering.
Distal surface bears sculpture of small rounded coni or grana, rounded in profile, more
or less equidimensional, 0-5 /x or less, number of muri 7-10 per area. Triradiate mark
nearly equal to equal radius accompanied by folds.

Comparison. These spores are similar to E. micrornatus sp. nov. in having fine sculpture,
but the sculptural elements are more densely packed and the spore exine is much thinner
and crumpled into taper pointed folds. Somewhat larger spores lacking the fine proximal
ribs but which are otherwise identical occur rarely in the Upper Ludlow and the Lower
Downtonian; they are referred to as Apiculiretusispora sp. C. Size range 40-50 /x (4
specimens).

Emphanisporites epicautus sp. nov.

Plate 38, figs. 13-15

Holotype. Size 30x30 ft; slide WB 135, ref. 3931030; Ditton Group, Dairy Dingle, Gedinnian.
Occurrence. As above.

Diagnosis. Spores small with distinct curvaturae perfectae and contact areas, fine proxi-
mal radial muri and thickened apical area; distally laevigate.

Description. Size range 25-40 ft (55 specimens measured), mode 32 ft. Amb subcircular
to subtriangular. Spores originally more or less hemispherical. Exine homogeneous
1-2 ft thick. Distal hemisphere smooth. Proximal face with well marked contact areas
bounded by distinct curvaturae perfectae, contact areas f to equal spore radius; each
contact area has 7-10 radiating muri which are 0-5 ft high and have a maximum width
of 0-5-1 -5 /x but taper sharply towards spore apex where some of them become fused
together, muri cover about f of the radius of the contact area. Spore apex has a distinct
triangular thickened area which extends along the Y-rays for their length. Tri-
radiate mark distinct, sutures § to nearly equal spore radius.

Remarks. Naumova (1953) figured but did not describe Stenozonotriletes ornatissimus ;
Chibrikova (1959) gave a description in which she recorded that S. ornatissimus had
proximal radial ‘striations’, a size range of 35-40 ft, and also a proximal apical triangular
thickening in some specimens. No other species of Emphanisporites has the latter feature
and E. epicautus sp. nov. differs from S. ornatissimus (Naum.) ex Chibrickova since

224

PALAEONTOLOGY, VOLUME 12

it has well developed contact areas, the three semicircular areas are clearly seen in polar
compression (PI. 38, figs. 14 and 15). Retusotriletes actinomorphus Chibrickova 1962 has
curvaturae perfectae and well-developed contact areas but lacks the apical thickening.

Emphanisporites cf. neglectus Vigran 1964

Plate 38, fig. 16

Occurrence. Lower Downtonian, Dittonian.

Description. Size range 18-24 p (16 specimens measured). Amb triangular to sub-
triangular; proximal face slightly concave, appears to be thinner than the rest of the
spore exine, sculptured by radial muri, 0-5-1 p wide, slightly tapered and sinuous,
usually 12 per interradial area; contact areas delimited by curvaturae perfectae which
frequently coincide with the equator; distally exine smooth, homogeneous, 1-1-5 p
thick. Triradiate mark distinct, lips nearly equal, or equal to the spore radius.

Comparison and remarks. The muri of the Dittonian specimens appear to be relatively
finer than those figured by Vigran 1964, however in the small size of the spores and the
presence of curvaturae they are similar. E. minutus Allen 1965 is also very similar but
E. neglectus Vigran has priority. Curvaturae are not recorded by Allen, however, the
figured specimen (Allen, pi. 97, fig. 20) may have curvaturae which approximate to the
equator in polar compression. Leiotriletes(l) actinomorphus Chibrickova 1962 is also
similar but apparently lacks curvaturae.

Downtonian specimens have broader rather indistinct ribs; they resemble Retuso-
triletes cf. minor (see above) except for the faint proximal radial rib development.

Emphanisporites sp. A
Plate 39, fig. 1

Occurrence. Dittonian, Dairy Dingle, rare; Gedinnian.

EXPLANATION OF PLATE 39

All figures X 1,000, and from Ditton Group, except where stated otherwise.

Figs. 1-2. Emphanisporites spp. 1, E. sp. A; tipped specimen showing thick exine over distal hemi-
sphere, x 2,000; WB 128/370893. 2, E. sp, B; tipped specimen showing proximal ribs and distal
cones; WB 128/418892.

Fig. 3. Dictyotriletes sp. A; specimen showing coarse reticulum and low muri; WB 126/374941. 4,
‘IDictyotriletes sp. B; specimen showing fine reticulum and ? Y-mark, x 2,000; Downton Castle
Sandstone Group, WB 48/367869.

Figs. 5-6. Acinosporites sa/opiensis sp. nov. ; holotype. 5, Proximal focus showing Y-folds. 6, Distal
surface focus showing reticulum, X 2,000.

Figs. 7-13. Perotr Hites microbaculatus sp. nov. 7-11. P. microbaculatus var. microbaculatus sp. et var.
nov. 7-8, Holotype. 7, Proximal focus showing separation of outer membrane, and smooth
proximal surface. 8, Distal focus showing fine sculpture. 9, Tipped specimen showing small folds
in ‘ perine’ over contact areas ; WB 128/417943. 10, Specimen with coarser sculpture; WB 140/442849.
11, Lateral compression showing thick exine (inner layer) over distal hemisphere; WB 135/453992.
12-13. P. microbaculatus var. attenuatus var. nov. 12, Holotype, proximal view. 13, Tipped speci-
men showing folding of ‘perine’ around margins of contact areas and thin exine (inner layer) over
distal hemisphere; WB 167/427841.

Palaeontology, Vol. 12

PLATE 39

RICHARDSON and LISTER, Devonian miospores

RICHARDSON AND LISTER: S PORE ASSEMBLAGES

225

Description. Size range 40-50 p (7 specimens measured). Amb circular to subcircular.
Exine variable in thickness, 4-4-5 p thick distally, 2-2-5 p at equator; contact areas
distinct, delimited by distinct curvaturae perfectae; which form small ridges 0-5 p wide;
contact areas with fine radiating ‘muri’ 1 p wide, around 13 on each contact face, some
of the ‘muri’ reach the spore apex. Triradiate mark distinct, sutures § spore radius.

Comparison and remarks. This form differs from described species of Emphanisporites by
the variable thickness of the exine. They are identical to Retusotriletes dittonensis sp. nov.
except for the possession of fine proximal radial muri.

Emphanisporites sp. B
Plate 39, fig. 2

Occurrence. Ditton Group, Dittonian. Gedinnian, rare.

Description. Size range 36-54 p (15 specimens measured). Amb subcircular, proximally
slightly concave; most frequently seen in oblique compression, with strongly convex
distal surface. Exine relatively thick 2-5-3 p , proximally sculptured with radial muri 1-2 p
wide, rounded in profile, in plan taper gradually to proximal pole; bounded by distinct
curvaturae perfectae. Distally sculptured with low, broad-based cones, verrucae to
rugulae, rounded or pointed in profile, rounded to polygonal to elongate and irregular
in plan, elements 0-5-1 -5 p high, 2-4 p wide. Triradiate mark equals radius, sutures
accompanied by low lips.

Comparison. Emphanisporites sp. B is distinguishable from E. decoratus Allen 1965 by
broader and lower sculptural elements, of coni, verrucae, and rugulae; and from E.
micrornatus sp. nov. by the greater size of the sculptural elements. E. verrucatus Lan-
ninger 1968 has two coarse radial muri in each interradial area and thick lips.

Genus acinosporites Richardson 1965
Acinosporites salopiensis sp. nov.

Plate 39, figs. 5-6

Holotype. Size 27x29 p; slide WB 127, ref. 384938; Ditton Group, Dairy Dingle; Gedinnian.
Occurrence. As above; rare.

Diagnosis. Spores small with well-marked contact areas and a distal reticulum; muri
intersections bear small cones or spines.

Description. Size range 21-39 p (30 specimens measured), mode 26 p. Amb subtriangu-
lar, hemispherical in lateral view. Proximal surface smooth, exine 1-1-5 p thick, homo-
geneous. Distal surface covered with a fine reticulum, discontinuous in some specimens
but usually completely developed, muri of equal width and height 0-5-1 p, lumina
1—2-5^ , at the intersections muri bear distinct cones or spines typically with stout bases
and fine pointed apices, elements 0-5-1 p wide, 1-6 p long (length typically 1-5-2 p).
Triradiate mark distinct accompanied by lips 1 p high, equal to spore radius, in obliquely
compressed specimens lips merge with curvaturae perfectae which coincide with the
equator.

226

PALAEONTOLOGY, VOLUME 12

Comparison. Dictyotriletes minor Naumova (1953) has a similar size range (20-30 p)
and appears spiny but lacks the prominent lips and has lumina 6 p wide. The fact that
the spores have spines superimposed on the reticulate muri excludes them from the
genus Dictyotriletes. A. macrospinosus Richardson 1965 is much larger, has a distinct
apical prominance, bears large spines, and has a more irregular reticulum.

Genus dictyotriletes (Naumova) Potonie and Kremp 1954
Dictyotriletes sp. A

Plate 39, fig. 3

Occurrence. Ditton Group, Dairy Dingle; Gedinnian, rare.

Description. Size 21-4 /x on two specimens. Amb subtriangular. Exine less than \p thick,
homogeneous, infragranular to granular. Proximal surface smooth to wrinkled. Distal
surface covered with a broad reticulum, muri 0-5 p high and of similar width, lumina
3-7 p (5-7 and 3-6 respectively). Triradiate mark distinct equals spore radius, accom-
panied by low lips.

Comparison. Acinosporites salopiensis has spines and a reticulum with small lumina.
D. minor Naumova (1953, pi. 2, fig. 7) has coarser muri and possibly has spines.

? Dictyotriletes sp. B
Plate 39, fig. 4

Occurrence. Ludlovian, Lower Downtonian, Linton Quarry, and Ditton Group, Dairy
Dingle, Dittonian (Gedinnian). Rare.

Description. Size 13-19 p (on six specimens). Dittonian specimen 25 p. Amb sub-
triangular. Exine covered by a fine reticulum. Muri 0-5 p , width more or less equal to
height, lumina 05-3 p. Most of the specimens show an apparent triradiate mark
accompanied by smooth low lips 1 p wide.

Remarks. These specimens are very small and it is difficult to determine if the ‘suture and
lips’ are primary tetrad scars or are fortuitous cracks and associated folds, the latter
are seen in four of the six specimens. Hence the spores are tentatively assigned to Dictyo-
triletes.

Subturma; perinotriletes Erdtman 1947
Genus perotrilites (Erdtman) Couper 1953
Perotrilites microbaculatus sp. nov.

Holotype. Size 52x 54 p\ slide WB 133, ref. 41 11031 ; Ditton Group, Dairy Dingle, Gedinnian.

Diagnosis. Outer layer, ‘perine’, thin, diaphanous, closely attached to the exine except
over the proximal face, sculptured except over the contact area, by closely packed small
rods, grana, or cones; inner layer, exine, relatively thick, distally thickened. Contact
areas distinct.

Comparison. The close attachment of the ‘perine’ except over the contact areas, dis-
tinguishes this species from most other spores assigned to this genus. Diaphanospora

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

227

apiculata Guennel 1963 has a tightly fitting perine but it lacks the well-defined contact
areas and has more sparsely distributed sculpture.

Perotrilites microbaculatus var. microbaculatus var. nov.

Plate 39, figs. 7-1 1

Holotype and occurrence. Same as species microbaculatus.

Diagnosis. ‘Perine’ forms prominent folds around the margins of the contact areas,
frequently wrinkled or folded over the contact areas, distally sculptured by micro-
baculae; exine relatively thick, thickness at the equator 2-3-5 p, distally 3-6 p.

Description. Size range 28-64 p (100 specimens measured), mode 51 p. Amb subcircular
to subtriangular, hemispherical in lateral view with flattened proximal surface. ‘Perine’
and exine closely attached except over the contact areas; ‘perine’ thin diaphanous
sculptured except over the contact areas. Sculpture of microbaculae, minute and fre-
quently difficult to resolve, elements dominantly parallel-sided and flat-topped but
some elements expand at their apices; microbaculae less than 0-5-1 p high, 0-5 p or less,
wide. Exine thick, thickest over the distal pole, homogeneous, smooth. Contact areas
distinct. Trilete sutures distinct on the exine, §, equal or nearly equal to the spore radius;
prominent trilete folds occur in the ‘perine’.

Comparison and remarks. The thick exine, size mode and sculpture distinguish this variety
from P. microbaculatus var. attenuatus var. nov.

The variable thickness of the exine can clearly be seen (Plate 39, figs. 9 and 11).
Retusotriletes dittonensis sp. nov. has a similarly thickened exine and size range and it
it possible that spores of the latter species are the inner bodies (exines) of P. microbacu-
latus var. nov. which have lost their ‘perine’.

Perotrilites microbaculatus var. attenuatus var. nov.

Plate 39, fig. 12-13

Holotype. Size 34x38 p ; slide WB 167, ref. 301864; Ditton Group, Dairy Dingle, Gedinnian.
Occurrence. As above.

Diagnosis. ‘ Perine’, closely adhering to the exine, forms small folds around the contact
areas; distally sculptured by microbaculae, coni or grana; exine 0-5-2 p thick at the
equator, distally 2-3 p.

Description. Size range 27-48 p (100 specimens measured), mode 33 p. ‘Perine’ and exine
closely attached except over contact areas. Sculpture distinct reduced on the proximal
surface and absent over the contact areas; elements vary from being minute and difficult
to resolve to relatively coarse; they consist of microbaculae with flat apices, or grana, and
coni; elements typically about 0-5-1 p high, 0-5 or less to 1 p wide. In all other respects
closely comparable to P. microbaculatus var. microbaculatus var. nov.

Comparison. The thinner exine, size mode, generally slightly coarser sculpture and more
closely attached ‘perine’ distinguishes this variety.

228

PALAEONTOLOGY, VOLUME 12

? Perotrilites sp. A
Plate 40, fig. 1

Occurrence. Lower Downtonian, Linton Quarry, Downton Gorge, Long Mountain.
Rare.

Description. Size range 37-50 p (6 specimens). Amb subtriangular. Spores two-layered,
outer layer (‘perine’) thin, diaphanous, exine 2-5-4 p thick, thinner in the interradial
areas. ‘Perine’ smooth, loosely attached and folded. Exine smooth to occasionally
slightly undulose. Triradiate folds on the ‘perine’ reach the equator.

Remarks. In the thick exine and the relatively thin outer layer (‘perine’) these spores
resemble other species placed in the genus Perotrilites. There are a number of spore
species in Downtonian and Dittonian strata in which occasional specimens show an
adhering diaphanous layer which is sometimes fragmentary. So in general appearance
and preservation they resemble perine of modern spores. Similar spores but with a more
closely attached ‘perine' occur in the Dittonian.

Subturma zonotriletes Waltz 1935
Infraturma crassiti Bharadwaj and Venkatachala 1961
Genus ambitisporites Hoffmeister 1959

Type species. A. avitus Hoffmeister 1959.

Remarks. The spores described below are tentatively left in the genus Ambitisporites
Hoffmeister 1959 and not placed in Stenozonotriletes (Naum.) Potonie 1958 or Astero-
calamotriletes (Luber) Potonie 1958 because of the uncertain status of these two genera.
All are defined on the basis of being smooth-walled and having a narrow zone of
equatorial thickening (crassitude).

In Stenozonotriletes however this is apparently not the case since the figured specimen
of the type species ( S . eonformis Naumova 1953, pi. 3, fig. 15) does not appear to have

EXPLANATION OF PLATE 40

All figures x 1,000 except where stated otherwise.

Fig. 1. ? Perotrilites sp. A; Downton Castle Sandstone Group, WB 29/458943.

Figs. 2-3. Ambitisporites spp. 2, A. cf. avitus (Hoffmeister) 1959; Wenlock Shale (Tickwood Beds),
MPK 7. 3, A. cf. dilutus (Hoffmeister) comb. nov. ; Lower Elton Beds, MPK 5.

Figs. 4-13. Synorisporites gen. nov. 4-5. S. downtonensis sp. nov. 4, Holotype, distal view showing
convolute muri. 5, Lateral compression showing thickened curvaturae perfectae and finer proximal
muri; Downton Castle Sandstone Group, WB 30/289908. 6, Cf. S. downtonensis sp. nov.; tetrad.
Lower Bringewood Beds, MPK 10. 7-9. S. tripapillatus sp. nov. 7-8, Holotype. 7, Proximal
focus showing papillae. 8, Distal focus showing convolute muri, X 2,000. 9, Tipped specimen
showing thickened curvaturae perfectae, X 2,000; Downton Castle Sandstone Group, WB 33/453875.
10-12. S. venucatus sp. nov., x 2,000. 10, Holotype, distal focus showing sculpture of verrucae

and muri. 11, Distal focus showing discrete verrucae; Downton Castle Sandstone Group, WB29 /
359941. 12, Tipped specimen showing thickened curvaturae perfectae; Downton Castle Sandstone
Group, WB 62/2641051. 13, Cf. S. venucatus sp. nov., lateral compression (proximal surface not

preserved); Lower Elton Beds, MPK 11.

Palaeontology , Vol. 12

PLATE 40

RICHARDSON and LISTER, Silurian and Devonian miospores

RICHARDSON AND LISTER: SPORE A SSEM BLAGES

229

any equatorial thickening. Similarly the nature of the genus Asterocalamotriletes is also
uncertain both from the original drawings (Luber 1955, pi. 1, 8-9) and description.

The exine of the spores described below is laevigate. The type species, however, is
described as ‘laevigate to faintly granular’, but no sculpture can be seen in Hoffmeister's
illustrations and it is possible that the observed faint granulation is either infrastructure
or due to preservation. In this paper smooth-walled spores with an equatorial crassitude
are tentatively assigned to Ambitisporites pending clarification of Stenozonotriletes,
forms with distinct granulate-apiculate sculpture in the genus Streelispora gen. nov., and
verrucate-murinate forms in the genus Svnorisporites gen. nov.

In all these spores the crassitude delimits the margin of the contact areas and diverges
from the trilete mark, i.e. it is curvaturate. In polar compression, however, the trilete
reaches or rarely nearly reaches the equator and it is only in the latter that the thicken-
ings do not coincide with the equator at the radial apices. Consequently although the
thickenings are curvaturate they form essentially an equatorial structure and therefore
these genera are placed in Infraturma Crassiti.

Ambitisporites cf. dilutus (Hoffmeister) comb. nov.

Plate 40, fig. 3

cf. 1959 Punctatisporites ? dilutus Hoffmeister, p. 334, pi. 1, figs. 9-13.

Occurrence. Wenlock shale, Wen lock Limestone, Elton beds, and ? present Upper
Whitcliffe beds.

Description. Size range 28-40 p (14 specimens measured). Essentially comparable with
Hoffmeister’s spores except that lips are developed in some of the specimens. In the
range charts spores lacking lips are referred to as Ambitisporites dilutus sensu stricto.

Comparison and remarks. The equatorial crassitude is also present in Ambitisporites
avitus (Hoffmeister 1959, pi. 1, fig. 4), and although in the latter the thickening is much
more pronounced it is possible that these two species intergrade. However, only rare
specimens resembling Ambitisporites avitus (PI. 40, fig. 2) have been found in the present
study.

There are also broad similarities between spores of the avitus-dilutus complex and the
species Archaeozonotriletes cbu/us (Cramer). However, the latter typically has a thicker
distal-equatorial wall and a thin proximal wall which is frequently folded into taper-
pointed folds or collapsed.

In the succession studied forms resembling the avitus-dilutus complex typify the lowest
part of the sequence (Wenlock Shale) whereas higher in the Silurian, and in the Lower
Devonian, spores of A. chains are typical and only a few spores doubtfully resembling
avitus-dilutus spp. occur. The specimen figured by Downie (1963, pi. 92, fig. 13) has lips
and is therefore closely similar.

Cramer (1966) figured three spores which he referred to the species Ambitisporites
avitus Hoffmeister 1959. One of Cramer’s spores (pi. 2, fig. 15) has a narrow darkened
border resembling that of A. dilutus (Hoffmeister). Another specimen (pi. 2, fig. 13)
has strong triradiate folds and is similar to the specimens herein referred to as A. cf.
avitus (PI. 40, fig. 2).

230

PALAEONTOLOGY, VOLUME 12

Genus streelispora gen. nov.

Type species. Streelispora newportensis (Chaloner and Streel) comb. nov.

Diagnosis. Radial, trilete, spores with a more or less equatorial crassitude which delimits
distinctive contact areas. Spores distally sculptured with grana, coni, spinae or biform
elements. Proximally smooth, or with interradial papillae, or variously sculptured.

Comparison and remarks. This genus is similar to Street's concept of Aneurospora Streel
1964. However Streel (1967, p. 47) now considers that the type species A. goensis Streel
1964 belongs to the genus Geminospora. Transfer of the type species necessitates the
creation of a new genus for the spores described below.

Cadiospora Kosanke 1950 has thickened lips and lacks prominent sculpture. In
Lycospora the thickenings are more distinct, clearly wedge-shaped, and project at the
equator. Further the type species shows a clear ‘flange’ development (Wilson and Coe
1940, pi. 1, fig. 6) in contrast to the narrow crassitude of Streelispora. Smith and Butter-
worth (1967) stress the wedge-shaped and projecting nature of the cingulum in dis-
tinguishing Lycospora from Stenozonotriletes. They state (p. 216) that Stenozonotriletes
differs from Lycospora and Denosporites in that in polar section the cingulum is of more
or less uniform thickness and does not show any flange development. This seems a
reasonable basis for subdivision but at present a wide range of forms are placed in the
genus Lycospora and there appears to be some overlap between it and the genus Steno-
zonotriletes. Smith and Butterworth tentatively place forms with sculpture in the genus
Stenozonotriletes (? Stenozonotriletes bracteolus , p. 217); however this genus should be
restricted to laevigate and punctate spores and forms like ? S. bracteolus should probably
be assigned to Streelispora gen. nov. The situation is further complicated by the uncertain
status of the genus Stenozonotriletes (see p. 228 above).

Streelispora newportensis (Chaloner and Streel) comb. nov.

Plate 41, figs. 3-6

1968 Granulatisporites newportensis Chaloner and Streel, p. 92, pi. 19, figs. 7-8.

Holotype. Chaloner and Streel 1968, slide no. PF 3239. Lower Ditton Group, Newport, south Wales.
Lower Gedinnian.

Occurrence. Ditton Group as above and Dairy Dingle; ? Senni Beds, Llanover.

Emended diagnosis. Equatorial crassitude 1-2 p wide. Proximal surface with three inter-
radial papillae surrounded by tangential and radial folds, exine over proximal surface
thin, distally sculptured by coni or biform coni.

Description. Size range 17-48 p; Dairy Dingle specimens 17-34 p (80 specimens
measured), mode 28 p. Amb triangular with convex sides and rounded apices, usually
compressed in polar view, spores originally hemispherical with flattened pyramidal
proximal surface. Exine homogeneous 0-5- 1-5 p thick distally. Contact areas highly
distinctive, bear three relatively large papillae, one in each interradial area, papillae
circular in plan, rounded in profile, 3-4 p wide, folds surround the papillae, most prominent
folds roughly parallel equator, but frequently other folds occur at right angles to these.
Distinct to barely distinguishable equatorial crassitude 1-2 p wide, Gf the spore

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

231

radius. Sculpture confined to the equatorial margin and distal surface, elements consist
of coni, with rounded to pointed apices, occasionally biform with sharply tapered basal
portion tipped by slender cones; width 0-5-2 p, height 0-5-1 p, elements typically spaced
0-5-2 p apart, rounded in plan. Triradiate mark distinct, sutures equal spore radius,
accompanied by lips 0-5-1 p wide.

Comparison and remarks. S. gramdata sp. nov. has a thicker exine and sculpture of
grana and small cones rather than cones and biform elements. The folds which surround
and radiate from the large proximal papillae may be due to shrinkage of a proximal
membrane which is relatively thin except in the region of the interradial papillae, how-
ever they form a constant feature. The proximal polar area typically appears thinner
than the rest of the exine (PI. 41, fig. 3).

Specimens described by Chaloner and Streel have been re-examined and are essentially
the same as the specimens from Dairy Dingle. However specimens from the latter
locality tend to have larger, more widely spaced sculptural elements, a thicker distal
wall and more distinct crassitude (PI. 41, figs. 5 and 6).

Streelispora gramdata sp. nov.

Plate 41, figs. 7-9

Holotype. Size 28 x 29 p, slide WB 135, ref. 409932, Ditton Group, Dairy Dingle, Gedinnian.

Occurrence. ? Present Ludlovian, Ludlow, and Lower Downtonian, Ludford, Downton
Gorge and Gorsley Common; Ditton Group as above.

Diagnosis. Exine relatively thick, equatorial crassitude thicker in the interradial areas,
2-4 p, than radially 1 -5-2-5 p\ distally sculptured by closely packed grana.

Description. Size 18-34 p (40 specimens measured), mode 28 p. Amb subtriangular with
convex sides and rounded apices. Original lenticular shape indicated since almost
invariably preserved in polar compression. Proximal face smooth or occasionally bears
three interradial papillae, around 4 p in diameter; exine at the equator and distally
covered with small coni or grana; elements circular to subcircular in plan, rounded to
pointed in profile; width 0-5-1 p , height of elements equal to or somewhat less than
width, typically around 0-5 p , elements spaced 0-5-1 p apart. Triradiate mark distinct,
rays equal or nearly equal to spore radius; occasionally accompanied by low lips.

Comparison. The thick exine and its variable thickness at the equator distinguishes this
species. Granulatisporites muninensis Allen 1965 has a thinner exine. Retusotriletes
multituberculatus Lanninger 1968 is much larger (75 p) and has sparser sculptural
elements. ‘ Levigatisporites ’ nmnstereifeliensis Franke 1965 appears similar but the figured
specimens (pi. 3, figs. 43 and 44) have an apical thickening and are too poorly preserved
to make precise comparisons.

Remarks. The Ludlovian and Downtonian specimens are poorly preserved, they have
a thick exine but it has not proved possible to determine whether this is thicker in the
interradial areas, consequently these spores are referred to as cf. Streelispora gramdata.

232

PALAEONTOLOGY, VOLUME 12

Genus synorisporites gen. nov.

Type species. Synorisporites downtonensis sp. nov.

Diagnosis. Radial, trilete spores with prominent curvaturae perfectae forming a more or
less equatorial crassitude. Contact areas distinct, smooth, or with interradial papillae,
or variously sculptured; distally sculptured with verrucae and/or, muri.

Comparison and remarks. Stree/ispora gen. nov. is structurally similar but has a distal
ornament of grana, coni, spinae, or biform elements.

Synorisporites downtonensis sp. nov.

Plate 40, figs. 4-5

Holotype. Size 52x58 p; slide WB 32, ref. 3991063; Lower Downtonian, Linton quarry.

Occurrence. Lower Downtonian, in all samples studied from Gorsley Common, Ludford,
Downton Gorge and Long Mountain.

Diagnosis. Distal sculpture of relatively large, convolute, and anastomosing muri, curved
in plan and rounded in profile; proximal sculpture consists of smaller muri more angular
in plan but rounded in profile.

Description. Size range 44-78 p (120 specimens measured), mode 58 p. Amb sub-
triangular with convex sides and rounded apices. Spores usually preserved in polar
compression suggesting an original of more or less lenticular shape. Exine homogeneous,
at equator and distally 2-3 p thick, excluding muri. Contact areas distinct, sometimes
depressed; crassitude 4-5 p wide, in lateral compression only extends slightly at the
equator; crassitude equatorially and distally smooth, proximally ridged, ridges tend to
be radially arranged and merge into proximal muri. Contact areas covered with irregular
convolute muri somewhat angular in plan, rounded to conical in profile; muri diminish
in size towards apex which is relatively smooth in some specimens; proximal muri
0-5-3 p wide (typically 1-2 p). Distal surface covered by convolute and anastomosing

EXPLANATION OF PLATE 41

All figures X 1,000 except where stated otherwise and all from the Ditton Group.

Figs. 1-2. Synorisporites sp. A. 1, Tipped specimen showing distal sculpture, proximal papillae and
curvaturae perfectae; WB 125/4281052. 2, Proximal surface; infra-structure WB125/308860.

Figs. 3-9. Streelispora gen. nov. 3-6. S. newportensis (Chaloner and Streel) comb, nov., x 2,000.
3-4, Polar view; WB 126/4111009. 3, Proximal focus, showing tangential folds around proximal
papillae. 4, Distal focus showing sculpture of cones. 5, Tipped specimen showing thickened
curvaturae perfectae and proximal papillae; WB 135/368909. 6, Lateral compression showing cur-
vaturae perfectae with projecting cones; WB 135/446962. 7-9. S. granidata sp. nov. 7-8, Holo-

type. 7, Proximal focus showing variable thickness of exine. 8, Distal focus showing sculpture.
9, Tipped specimen with proximal papillae; WB 135/331977.

Figs. 10-14. Cymbosporites spp. 10-13. C. dittonensis sp. nov. 10, Holotype, polar compression.
11-13, Lateral compression at different focus levels. 11, Showing thin proximal area, concentric
fold around contact areas, and thick distal patina. 12, Same, x 2,000. 13, Showing sculptural

elements. 14, C. cf. catillus Allen 1965, polar compression; WB 135/4301018.

Fig. 1 5. iChelinosporasp. A, showing contact areas, distal and equatorial muri, x 2,000; WB 135/432918.

Palaeontology, Vol. 12

PLATE 41

RICHARDSON and LISTER, Devonian miospores

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

233

muri, 2-4-5 p wide (typically 2-5— 3-5 /x), and 1-2 p high, usually closely packed but
occasionally well spaced. Triradiate mark distinct, sutures § to equal spore radius,
accompanied by elevated lips, 1-5-2 p wide, 2-5-4-5 p high, lips have crenulate outer
margins.

Comparison and remarks. S. tripapillatus sp. nov. is smaller and has prominent inter-
radial papillae. S. verrucatus is distally verrucate-murinate. Similar spores occur sparsely
in the Lower Ludlow (PI. 40, fig. 6); unfortunately the best specimens are in tetrads and
the details of the proximal face have not been seen. Consequently these spores are
tentatively referred to as cf. S. downtonensis in the text.

Synorisporites tripapillatus sp. nov.

Plate 40, figs. 7-9

Holotype. Size 20x20-5 p\ slide WB 28, ref. 462977; Lower Downtonian, Linton Quarry.

Occurrence. Lower Downtonian, occurs in all samples, relatively abundant.

Diagnosis. Spores small with distal sculpture of convolute muri and proximal surface
bearing three papillae, one in each interradial area.

Description. Size range 10-28 /x (150 specimens measured), mode 18 p. Amb triangular,
with convex sides and rounded apices; probably originally more or less hemispherical
in shape, only rarely seen in oblique compression. Exine 1-1-5 p thick. Sculpture distinct
convolute and anastomosing muri which are 1-2 p wide, 0-5-1 p high. Contact areas
distinct, appear thinner than the rest of the spore exine, equal to, or slightly less than,
the proximal surface; bounded by curvaturae perfectae forming an indistinct, more or
less equatorial, crassitude 2-3 p wide; proximal papillae circular in plan, rounded in
profile, 1-5-3 p in diameter, typically 2-5 /x, contact areas otherwise smooth. Triradiate
mark accompanied by folds which reach the equatorial margin.

Comparison and remarks. The small size and interradial papillae distinguish this species
from S. downtonensis sp. nov. Papillae are a constant feature but are sometimes indistinct.

Synorisporites verrucatus sp. nov.

Plate 40, figs. 10-12

Holotype. Size 24x24 p; slide WB 62, ref. 3821009; Lower Downtonian, Linton Quarry.

Occurrence. Lower Downtonian, occurs in all samples studied; ? present in ‘ Psammos-
teus ’ Limestone.

Diagnosis. Proximal face smooth, distally sculptured dominantly by small verrucae
occasionally fused into small groups.

Description. Size range 16-33 p (100 specimens measured), mode 23 p. Amb sub-
triangular; spores usually preserved in polar compression indicating originally lenti-
cular with flattened pyramidal proximal surface. Exine homogeneous 1-5-2 p thick
distally. Proximal face smooth. Contact areas distinct delimited by distinct curvaturae
perfectae only slightly thickened, forming an equatorial crassitude 2-3 p wide in polar
compression; crassitude proximally and distally smooth. Distal surface sculptured

234

PALAEONTOLOGY, VOLUME 12

dominantly by verrucae 1-4-5 , u wide (typically 2 \ a but size variable in a single spore),
0-5-1 -5 ju. high; verrucae rounded, subangular, polygonal, irregular, slightly indented
and elongate, occasionally fused into small groups to give a murinate appearance, muri
and verrucae can occur on the same specimen but verrucae are dominant; in profile
elements rounded to truncate with more or less parallel sides; elements spaced usually
0-5 p, apart. Triradiate mark distinct equal to spore radius, accompanied by lips up to
3 p high.

Comparison. Synorisporites tripapillatus is smaller and has a distal sculpture of convolute
and anastomosing muri, and three proximal interradial papillae. The sculpture of S.
verrucatus is dominantly verrucate although on some specimens the verrucae are joined
up to form short muri, discrete verrucae, however, occur along with the muri; further
the proximal face of S. verrucatus sp. nov. is smooth and has no interradial papillae.

Spores with similar verrucate-murinate sculpture occur sporadically through the Lud-
lovian and a single specimen in the Wenlock (different from the Ludlow specimens).
Unfortunately in the Silurian spores the proximal face is not well preserved and con-
sequently these spores are tentatively referred to as cf. S. verrucatus sp. nov. (PI. 40,
fig. 13). The holotype of Chelinospora vermiculata Chaloner and Streel (1968, pi. 20,
figs. 7-8) is similar in construction and may be a corroded specimen of A. chulus
(Cramer).

Synorisporites sp. A
Plate 41, figs. 1-2

Occurrence. Ditton Group, Dairy Dingle, Gedinnian.

Description. Size range 30-45 p (15 specimens measured). Amb subcircular, in lateral
view hemispherical. Exine 2-3-5 p thick. Contact areas distinct delimited by distinct
curvaturae perfectae only slightly thickened, which coincide with the equator for all their
length, except in the radial apices; curvaturae clearly seen in obliquely compressed
specimens. Proximal surface bears three interradial papillae, circular darkened areas
3-5 p wide, otherwise externally smooth but with distinct infrastructure of polygonal to
radial elements. Equatorially and distally covered with verrucae which are rounded,
subangular to elongate, 1-5 p wide, 0-4-1 p high, and typically 0-5-1 p apart. Some
specimens appear two-layered. Triradiate mark distinct nearly equal, or equal, to spore
radius, accompanied by lips 1 p wide, lips confluent with curvaturae.

Comparison and remarks. Differs from S. verrucatus sp. nov. in its larger size, and pre-
sence of three proximal papillae. Similar specimens in the Downtonian lack the papillae,
tend to be subtriangular, and have a smooth equatorial margin.

Tnfraturma patinati Butterworth and Williams 1958
Genus archaeozonotriletes (Naum.) Allen 1965

Type species. A. variabilis (Naum.) Allen 1965.

Archaeozonotriletes chulus (Cramer) comb. nov.

1966 Retusotriletes chulus Cramer, p. 74, pi. 2, fig. 14.

Holotype. Cramer 1966 (reference specimen) slide 224 (42), 118-1 X 35-7, pi. 2, fig. 14. Upper San
Pedro Formation, Leon, Spain ; Ludlovian-Lower Gedinnian.

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

235

Emended diagnosis. Trilete patinate spores, exine thin sometimes diaphanous in the
contact areas, equatorially and distally thickened, narrow equatorial crassitude delimits
contact area so that the exine thickness at the equator often exceeds that at the distal
pole. Exine laevigate but may show a distinctive infrastructure of radial or convolute
muri. Proximally thin contact areas frequently collapsed and the spores usually have
a narrow concentric fold, simulating curvaturae, just inside the equatorial border.

Comparison. Retusotriletes cliulus recently described by Cramer (1966) is clearly similar
to spores from the Welsh Borderland although the latter show greater variety than those
described by Cramer. However, Cramer’s description is inadequate, no reference is
made to spores of similar organisation, and no holotype is designated as such. In the
circumstances rather than erect a new species for closely similar spores it seems prefer-
able to extend Cramer’s description and to establish Cramer’s reference specimen as
the holotype. Ambitisporites avitus and Punctatisporitesl di/utus HofTmeister 1959 appear
to have a similar equatorial thickening, however, they can be distinguished from A.
chulus (Cramer) since they lack the thin proximal face and thick distal wall (compare
PI. 43, fig. 4 with pi. 1, fig. 4 in HofTmeister 1959). Retusotriletes semizonalis McGregor
1964 does not have the pronounced differential thickening between the proximal and
distal surfaces of the spores described above and has minute sculpture.

Remarks. In polar compression the spores resemble spores of the genus Ambitisporites
except that they have very thin contact areas. However, some tetrads and obliquely
compressed specimens show clearly (PI. 43, figs. 2-4) that the exine is much thicker at
the equator and over the distal surface. Consequently these spores approximate more
closely to the patinate genus Archaeozonotriletes (Naum.) Allen than to either Ambiti-
sporites or Stenozonotriletes. The patina in these Silurian and Lower Devonian spores is
uniformly thickened, or slightly thickened laterally. Allen distinguishes the two patinate
genera Archaeozonotriletes (Naum.) and Tholisporites (Butterworth and Williams) on
the basis of location of maximum thickness of the patina. Archaeozonotriletes (Naum.)
is defined as having a uniformly, or distally, thickened patina whereas in Tholisporites
the greatest thickness is equatorial. In practice without the aid of thin sections it may be
very difficult to separate these two genera.

Archaeozonotriletes chulus var. chulus var. nov.

Plate 43, figs. 1-6; text-fig. 4

Holotype. As for species.

Occurrence. Deposits of Upper Ludlovian to Lower Gedinnian age, Leon Spain; Lud-
lovian, Lower Downtonian, in all samples from Gorsley Common, Ludford, Downton
Gorge, and Long Mountain, Ditton Group, Dairy Dingle, and Senni beds, Breconshire,
Ludlovian to ?Emsian.

Diagnosis. Size mode 48 p, exine laevigate and lacks prominent infrastructure.

Description. Size range 36-60 p (130 specimens measured). Downtonian and Dittonian
specimens have identical modes and almost identical size ranges the latter are 36-58 p
and 38-60 p respectively. Amb triangular with convex sides and rounded apices; hemi-
spherical in lateral view. Exine over contact areas thin, approximately 1 p in thickness.

236

PALAEONTOLOGY, VOLUME 12

typically has a concentric fold just inside the spore margin, and occasionally there are
taper pointed folds across the proximal face. Exine thickness at the equator more or less
equal to exine over the distal pole but may be slightly greater or less. Downtonian
specimens exine 3-6 /x at the equator, slightly thicker in the interradial regions 4-6 /x,
distally 4-5 /x; Dittonian specimens exine 2-5-5 /x equatorially (typically 3-5-4-5 fx) some-
what less at the radial apices where there is frequently an invagination on the inner

20 23 26 29 32 35 38 41 44 47 50 53 56 59 62 65 68 JUi
Var. nanus J Var chulus

text-fig. 4. Size distribution of Archaeozonotriletes chulus (Cramer) from the Downtonian-Dittonian

of the Welsh Borderland.

margins of the exine; distally somewhat thinner, 2-2-5 /x. Exine smooth homogeneous
although occasionally shows a tendency to break down. Triradiate mark f to equal spore
radius, lips form distinctly elevated folds 2-3 /x high; occasionally in Downtonian
specimens the proximal pole exhibits a small triangular darkened area.

Remarks. The thickening of the exine at the equator which is seen in some Downtonian
and Dittonian specimens is curvatural, however, in polar compression curvatural

RICHARDSON AND LISTER: SPORE ASSEMBLAGES 237

invaginations are only rarely seen at the radial apices. Dittonian specimens have a
relatively thinner distal wall and are thicker at the equator.

Archaeozonotri/etes cluilus var. inframurinatus var. nov.

Plate 43, figs. 7-9

Holotype. Size 40x45 p; slide WB 41, ref. 342950; Upper Ludlovian, Linton Quarry.

Paratypes. Slide WB 44, ref. 396978, and WB 45, ref. 371920.

Occurrence. ? Present Wenlock; Ludlovian, relatively common; rare in Lower Down-
tonian, Linton Quarry, Ludford Lane, and Downton Gorge. Specimens from the Lower
Elton Beds and Wenlock are atypical in possessing a thinner equatorial and distal
exine.

Diagnosis. Size mode 48 p . Exine externally smooth but strongly inframurinate.

Description. Size range 30-60 p (79 specimens measured). Amb subtriangular with
convex sides and rounded apices; spores probably originally more or less hemispherical
with flattened proximal region. Contact areas covered by a thin smooth diaphanous
membrane, which is frequently collapsed and folded, or may be absent; surrounded in
most specimens by a fold, 1-1-5 p wide. Outside the contact surfaces the exine is thick,
3-5 p at the equator and over the distal pole; on some specimens the exine is thicker at
the equator and subequatorial areas than at the distal pole. Exine externally smooth
to slightly undulose, the undulations reflecting the strongly developed murinate infra-
structure. Inframuri more or less radial, converge in a smooth area at the distal pole;
inframuri may bifurcate 2-3 times, occasionally convolute, and discontinuous, but
essentially retaining a radial habit, inframuri have a maximum thickness of 1-3-5 p;
occasionally in distorted spores the infrastructure is pushed into the outer membrane
producing marked corrugations simulating sculpture; specimens in lateral view clearly
show that the exine is externally smooth but in corroded or abraded specimens the infra-
structure may appear as sculpture. Triradiate mark, simple, confined to the thin part
of the proximal membrane, sutures occasionally accompanied by small folds, equal
to | spore radius.

Comparison and remarks. Tholisporites ancylus Allen 1965 has a ‘corroded patina’
appearing ‘as partly anastomosing ridges, often radially directed’. It differs from A.
chains var. inframurinatus var. nov. in having a thick intexine clearly shown in Allen’s
sections (pi. 101, figs. 3-4); it is also much larger.

It is possible that the strong infrastructure development is a secondary feature and it
is interesting to note that this form features prominently in marine samples where salt
water may have aided in the breakdown of the spore wall. Apart from the infrastructure
these spores are identical to those of A. chulus var. cluilus var. nov. and therefore the
spores with a well-developed infrastructure are only tentatively placed in a distinct
variety. The justification for this is that the infrastructure of these spores is so striking.
If it is proved that the infrastructure is secondary then these spores will have to be trans-
ferred to variety chulus.

C 6508

R

238

PALAEONTOLOGY, VOLUME 12

Archaeozonotriletes chulus var. nanus var. nov.

Plate 43, figs. 10-1 1 ; text-fig. 4

Holotype. Size 22x29 /x; slide WB 48, ref. 439904; Linton Quarry.

Occurrence. Wenlock and Ludlow, rare; Lower Downtonian, all samples and Ditton
Group, Dittonian. Samples of Upper Ludlovian to Lower Gedinnian age, Leon, Spain.

Diagnosis. As A. chulus var. chulus var. nov. except that the size range is 23-35 p (30
specimens measured) and the mode is 26 p.

Description. Exine 2-5 p equatorially (typically 4-5 p) not seen in oblique compression.
Triradiate mark equals spore radius, accompanied by folds 1-3 p high (folds not always
preserved).

Comparison. Distinguished from A. chulus var. chulus var. nov. by the smaller size range
and mode. Downtonian specimens tend to have a relatively thicker border than Dittonian
forms.

?A rchaeozonotriletes cf. divellomedium Chibrickova 1959
Plate 43, fig. 12

Occurrence. Lower Downtonian, Linton Quarry, Ludford, Downton Gorge; Ditton
Group, Dairy Dingle, Dittonian (Gedinnian).

Description. Size range 30-56 k (62 specimens measured), mode 43 p. Amb subcircular.
Exine homogeneous, to finely infrapunctate or infragranular typically 1-5-2 p thick except
over the central area of ? proximal surface where it is usually absent. At the edge of
central area concentric fold or folds, central area subtriangular to subcircular, § to
nearly equal spore radius. In one specimen triradiate folds cross the central area, and
merge with the folds around the border of central area, trilete folds equal radius of
central area; in another larger specimen from the Downtonian a fine spongy-fibrous
membrane covers the central area.

Comparison. A. divellomedium Chibrickova 1959 appears to be closely similar but the
proximal aperture averages about half the spore radius. Chibrickova’s specimens are
from the Takata beds (Upper Eifelian), western Bashkiria, U.S.S.R.

Remarks. The large hole may be due to collapse of a thin proximal membrance since
this type of organization is common in these strata, however, no remnants of collapsed
membranes have been seen. The hole is on the proximal surface since it faces inwards
in the tetrad, and also one specimen shows trilete folds.

1 Archaeozonotriletes dubius sp. nov.

Plate 42, fig. 9

Holotype. Size 35 x 41 p; slide WB 29, ref. 454918; Lower Downtonian, Linton Quarry.
Occurrence. As above.

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

239

Diagnosis. Exine distally relatively robust, typically 2 p, with a distinct infrastructure of
convolute and anastomosing ridges, except over the contact areas where it is thin and
diaphanous.

Description. Size range 30 46 p (40 specimens measured), mode 38 p. Amb subcircular,
hemispherical in lateral view, frequently compressed laterally. Contact areas thin usually
collapsed or absent, bounded by curvaturae perfectae which form upstanding ridges
1-1-5 p high. Outside the contact areas exine is much thicker typically 2 p, externally
smooth to slightly undulose, internally distinctly inframurinate, inframuri convolute and
anastomosing, 1-2 p wide, separated by vermiculi (less than 0-5 p wide). Triradiate
mark rarely seen, more or less equals spore radius, accompanied by lips 1-1-5 p high.

Comparison. This species closely resembles ?A. cf. divellomedium Chibrickova except
for the inframurinate development. It is possible that the latter feature is due to second-
ary breakdown of the spore exine. A. chulus var. inframurinatus is subtriangular and
has a much thicker exine.

Remarks. It is not certain whether the thin membrane over the contact areas is a thin-
ning of the exine or whether the spores are two-layered with an exoexine which is absent
over the contact areas. Both types of organization are placed in this genus by Allen
(1965, pi. 100, fig. 9 and pi. 101, figs. 3 and 4 respectively). However, Smith and Butter-
worth (1967) define patina in the two-layered sense and emend Infraturma Patinati to
include ‘trilete cavate spores in which one whole hemisphere is enclosed in a prominent
thickening of the outer layer of the exine’. This seems to be a more important basis for
distinguishing Tholisporites from Archaeozonotri/etes than whether or not the patina
is equatorially thickened. Nevertheless it is in many cases just as difficult to determine
without the aid of thin sections and consequently it is doubtful whether the spores
described here are patinate in the sense of Smith and Butterworth. No evidence has
been seen of independent folding of an inner layer and so the spores are not ’cavate’
sensu Smith and Butterworth.

Genus cymbosporites Allen 1965

Type species. Cymbosporites cy at tins Allen 1965.

Cymbosporites echinatus sp. nov.

Plate 42, figs. D5

Holotype. Size 58-62 p; slide WB 38, ref. 4621048; Lower Downtonian, Linton Quarry.

Occurrence. Lower Downtonian, in all samples from Gorsley Common, Perton Lane,
Ludford, Downton Gorge, Long Mountain.

Diagnosis. Sculpture consists of individually biform spinose elements; elements basally
broad, conical, terminated by cones, or parallel-sided to spatulate spines, discrete or
fused into groups, groups commonly consist of 2-3 elements. Patina thickest in the
equatorial region.

240

PALAEONTOLOGY, VOLUME 12

Description. Size range 44-66 p. (100 specimens measured), mode 58 p. Amb subtri-
angular, with convex sides and rounded apices; spores probably originally more or less
hemispherical with slightly flattened proximal polar region. Proximal polar region
covered by a very thin diaphanous membrane, which is frequently collapsed and folded
into arcuate folds, or completely absent; outline of inner contact area coincides with
that of the spore. Outside the contact areas on the proximal and distal surfaces, the
exine is considerably thicker. In some specimens the exine appears thicker at the equator
than at the distal polar region; distally exine 2-3-5 p thick, equatorially 3-5-5 p thick.
Sculpture confined to the equatorial and distal areas; in profile dominantly biform;
bases broad sharply tapered, surmounted by cones, short parallel-sided spines, or spines
with constricted stems and spatulate tips; apices occasionally pointed, but usually flat,
or slightly curved; width of bases 1-5 p, stems 0-5-2 p, apices 0-5-2 p\ apices vary from
being equal to, or slightly less or greater than the stem; height 1-4-5 /x; sculpture in plan,
bases rounded, discrete, or coalescing into small groups of 2, 3, or more elements, but
commonly in pairs; apices rounded in plan. Triradiate mark accompanied by folds
2-5-3 /x high, confined to the thin proximal membrane, equal to § spore radius.

Variation. Within the limits defined above the sculpture is quite variable. Some forms
have closely packed, relatively low sculpture, 1-5-2 p high on a single spore, width
more or less equal to height. In these forms cones, and short parallel-sided spines with
only slightly constricted stems, are the dominant terminations of the biform elements.
At the other extreme there are spinose forms with longer stems (2-5-4-5 p high, total
height base plus stem) which have a preponderance of constricted stems with spatulate
tips. The ornament in the latter forms is usually more sparse. Intermediate forms, with
elements 2-3 p high, have dominantly parallel-sided to slightly invaginated stems.
Occasional specimens have been seen which have minute terminations (less than 0-5 p).

Comparison. C. echinatus sp. nov. is similar to specimens of C. cyathus Allen 1965
(especially pi. 101, figs. 8-9). However, the latter has a much thicker patina, ‘spinose’
terminations to the basal ‘cones’ which appear to be different from the sculptural
elements described above, and also C. cyathus is larger.

Remarks. C. echinatus sp. nov. frequently occurs in tetrads. Two of these tetrads, which
are overmacerated, show that the ‘patina’ is thickest in the equatorial region. Allen

EXPLANATION OF PLATE 42

All figures x 1,000, and from the Downton Castle Sandstone Group, except where stated otherwise.

Figs. 1-8. Cymbosporites spp. 1-5. C. echinatus sp. nov. 1, Holotype showing thin proximal surface
and biform sculptural elements. 2, Specimen showing Y-folds and biform sculptural elements with
more elongate terminations; WB 30/418923. 3, Tetrad showing equatorially and distally thick
exine; WB 37/3711033. 4, Sculpture of holotype plan view, X 2,000. 5, Specimen with sculpture

in profile; WB 31/2801055. 6-8. C. verrucosus sp. nov. 6, Showing thin radially wrinkled proximal
exine and Y-folds; WB 37/397983. 7, Holotype, proximal view. 8, Distal view of another specimen
showing rounded verrucae; WB 48/466923.

Fig. 9. lArchaeozonotriletes dubius sp. nov., holotype, lateral compression showing convolute infra-
muri, and curvatural thickening.

Figs. 10-12. Chelinospora cassicula sp. nov. 10, Lateral compression showing thin proximal surface;
Ditton Group, WB 164/397953. 11, Holotype. 12, Distal view showing coarse reticulum of mem-
branous muri; Ditton Group, WB 139/451925.

Palaeontology, Vol. 12

PLATE 42

RICHARDSON and LISTER, Devonian miospores

RICHARDSON AND LISTER: SPORE ASSEMBLAGES 241

(1965, p. 725) states in the diagnosis of Cymbosporites that the ‘patina of even thickness,
or with its greatest thickness in the distal polar area’. By this definition equatorially
thickened specimens should go into Tholisporites. However, the strongly developed
sculpture and general similarity to the type species necessitate, in the writers’ opinion,
the inclusion of the above specimens in the genus Cymbosporites.

Cymbosporites verrucosus sp. nov.

Plate 42, figs. 6-8

Holotype. Size 46x50 p\ slide WB 28, ref. 440919; Lower Downtonian, Linton Quarry.

Occurrence. Relatively rare but occurs in the Lower Downtonian from Gorsley
Common, Perton Lane, Ludford, and Long Mountain.

Diagnosis. Sculpture consists of relatively large, rounded verrucae on the distal hemi-
sphere; proximal membrane thin, diaphanous, folded into fine radial wrinkles.

Description. Size range 29-52 p (24 specimens measured), mode 48 p. Amb subcircular;
spores probably more or less hemispherical with slightly flattened proximal polar region.
Proximal pole covered by a relatively thin membrane frequently collapsed inwards and
covered by radial ‘thickenings’ either uniformly tapering from the equator to the centre
(0-5-1 -5 p wide) or irregular and anastomosing, although retaining an over-all radial
plan; surrounded by a thickened, raised, curvatural ridge, 2-3 p wide, which shows
a minutely convolute margin. Outside the contact areas the exine is thicker, 2-3 p, and
in lateral and polar compression is uniform in thickness, and occasionally shows faint
radial striations near the curvatural ridges. Sculpture confined to the equatorial and
distal areas, consists of verrucae, height 0-5-2-5 p, usually J of the width which is
2-5-6 p; in profile elements vary from low rounded verrucae, to forms which are more
or less parallel-sided with flattened to slightly curved apices; in plan, subcircular,
subangular, to polygonal; occasionally fused in pairs. Triradiate mark, indistinct,
rarely seen due to collapse of proximal membrane, equal to radius of thin proximal
membrane which varies from § to nearly equal spore radius.

Comparison. The large verrucae and proximal radial wrinkles distinguish this from other
species of Cymbosporites. The proximal ‘wrinkles’ are not as regular as the ridges of
Emphanisporites sp. B. Also the latter has a thicker proximal membrane.

Cymbosporites dittonensis sp. nov.

Plate 41, figs. 10-1 3

Holotype. Size 30x 33 p; slide WB 135, ref. 328984; Ditton Group, Dairy Dingle, Gedinnian.
Occurrence. As above.

Diagnosis. Patina relatively thin, sculpture consists of a mixture of verrucae and coni.

Description. Size range 17-36 p (20 specimens measured), mode 28 p. Amb triangular
with convex sides and rounded apices; usually preserved in polar compression. Proximal
surface laevigate, contact areas covered by a very thin diaphanous membrane, which is

242

PALAEONTOLOGY, VOLUME 12

frequently collapsed, torn, or folded; outline of inner area parallel to the equator; near
the periphery of the contact areas are distinct arcuate folds which form a constant
character. Outside the contact areas the exine is much thicker, 2-5-4 yu. equatorially and
distally. Sculpture confined to the equatorial margin and distal hemisphere; consists
typically of a mixture of relatively large verrucate or rugulate elements, and small pointed
cones; elements 1-7 p wide at the base, 0-5-1 p high; in plan rounded, subangular,
polygonal, elongate, and indented to irregular, in profile conical to rounded, or with
flattened apices. Triradiate mark § radius, sutures distinct and occasionally labrate, lips
small.

Comparison. C. cyathus Allen 1965 has a much thicker patina and a sculpture of large
cones. C. catillus Allen 1965 is similar and can have verrucae or grana, however, the
patina is 6-9 p thick, and the width of the verrucae appears less. C. echinatus sp. nov.
has a sculpture of dominantly biform spinose elements.

Cymbosporites cf. catillus Allen 1965
Plate 41, fig. 14

Occurrence. Ditton Group, Dairy Dingle, Gedinnian.

Comparison and remarks. Two specimens 24 and 38 p respectively. In general organiza-
tion identical to C. dittonensis sp. nov. but lack the wide verrucae. Sculpture consists
of grana and small cones. These spores are similar to the forms described by Allen
(1965, pi. 100, figs. 1 1—12) but have a thinner exine (2-5 yu,).

Genus chelinospora Allen 1965

Type species. C. concinna Allen 1965.

Chelinospora cassicula sp. nov.

Plate 42, figs. 10-12

Holotype. Size 40x40 p; slide WB 125, ref. 293981; Ditton Group, Gedinnian.

Occurrence. As above.

EXPLANATION OF PLATE 43

All figures X 1,000.

Figs. 1-12. Archaeozonotriletes spp. 1-6. A. chulus var. c/iulus sp. et var. nov. 1, Holotype, polar
view. 2-3, Tipped specimens showing thin exine over proximal surface; Ditton Group, WB
128/280989 and Downton Castle Sandstone Group, WB 48/436879 respectively. 4, Two specimens,
one lateral compression showing curvatural thickening, thin proximal and thick distal exine; Down-
ton Castle Sandstone Group, WB 33/2861063. 5, Specimen from Upper Whitcliffe Beds, MPK 12.
6, Specimen with wide border and collapsed proximal surface, patina corroded; Downton Castle
Sandstone Group, WB 48/4641005. 7-9. A. chulus var. inframurinatus var. nov. 7, Holotype show-
ing thin proximal face and distal radial inframuri . 8, Specimen showing more irregular ‘ breakdown ’ ;
Upper Whitcliffe Beds, WB 44/397978. 9, Specimen with coarse radial inframuri; Lower Bringe-
wood Beds, MPK 13. 10-11. A. chulus var. nanus var. nov. 10, Holotype. 11, Specimen from

Lower Elton Beds, MPK 14. 12, ?A. cf. divellomedium Chibrickova, showing thickening around

thin circular proximal area; Ditton Group, WB 125/480879.

Palaeontology, Vol. 12

PLATE 43

RICHARDSON and LISTER, Silurian and Devonian miospores

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

243

Diagnosis. Patina relatively thin, sculptured equatorially and distally with muri which
form an irregular reticulum; proximal face smooth.

Description. Size range 35-52 p (26 specimens measured), mode 38 p. Amb subcircular
to subtriangular. Exine variably thickened, appears thicker distally and equatorially
than on the proximal surface; exine excluding sculpture 3-5-4 p distally, 2-5 p at equator.
Proximal face appears much thinner than rest of the exine; equatorially and distally
spore covered with prominent muri which frequently form an irregular reticulum; muri
membranous, 4-6 p high, when compressed at the equator give a zonate appearance, muri
thickened at points of interconnection; lumina irregular, maximum diameter 6-14 p.
Contact areas distinct bounded by curvaturae perfectae. Triradiate mark distinct
accompanied by low lips, equal or nearly equal spore radius.

Comparison. C. ligurata Allen 1965 has a thicker patina and more closely spaced muri
which break down to give ‘the spore a very distinctive “sculptured” appearance of high,
close baculak C. concinna Allen 1965 has a thicker patina, proximal sculpture, and a
more even recticulum.

IChelinospora sp. A
Plate 41, fig. 15

Occurrence. Ditton Group, Dairy Dingle, Gedinnian; rare.

Description. Size range 24-30 p (10 specimens). Amb subtriangular, hemispherical in
lateral view. Proximal face thin, diaphanous, and has concentric folds at the margins.
Outside the contact areas exine relatively thick, bears low convolute and anastomosing
muri, 1-1-5 p wide, 0-5 p high, muri closely spaced 0-5-1 p apart. Triradiate mark dis-
tinct, sutures reach or nearly reach the equator, accompanied by membranous lips
1-1-5 p high.

Comparison. The low muri distinguish these spores from forms previously described.

REFERENCES

allen, j. r. l. 1963. Depositional features of Dittonian rocks: Pembrokeshire compared with the Welsh
Borderland. Geol. Mag. 100, 385-400.

and tarlo, l. b. 1963. The Downtonian and Dittonian facies of the Welsh Borderland. Ibid.

100, 129-55.

allen, k. c. 1965. Lower and Middle Devonian spores of north and central Vespitsbergen. Palaeon-
tology, 8, 687-748, pi. 94-108.

1967. Spore assemblages and their stratigraphic application in the Lower and Middle Devonian

of north and central Vespitsbergen. Ibid. 10, 280-97.
ball, h. w., and dineley, d. l. 1961. The Old Red Sandstone of Brown Clee Hill and the adjacent area.

Part I, Stratigraphy. Bull. Brit. Mas. (Nat. Hist.), 5, 178-240.
banks, h. p., hueber, f. ml, and leclerq, s. 1964. A probable fern in the Lower Devonian. Proc. Intern.

Botan. Congr., 10th, Edinburgh 1964, 041a, 515 (abstract).
butterworth, m. a., and williams, r. w. 1958. The small spore floras of coals in the Limestone Coal
Group and Upper Limestone Group of the Lower Carboniferous of Scotland. Trans. Roy. Soc.
Edin. 58, 353-92, 4 pi.

244 PALAEONTOLOGY, VOLUME 12

chaloner, w. g. 1963. Early Devonian spores from a borehole in southern England. Gratia Palynol.
4, 100-10, 1 pi.

1964. An outline of Pre-Cambrian and Pre-Devonian microfossil records, evidence of early land

plants from microfossils. Proc. Intern. Botan. Congr., 10th, Edinburgh 1964, 16-17 (abstract).

1967. Spores and land-plant evolution. Rev. Palaeobotan. Palynol. 1, 83-93.

and streel, m. 1968. Lower Devonian spores from South Wales. Argumenta Palaeobotanica, 1,

87-101, pi. 19-20.

chibrickova, e. v. 1959. Spores of the Devonian and older deposits of Bashkir. Akad. Nauk S.S.S.R.
(Bashkir), Materials on Palaeont. and Strut, of Devonian and older deposits of Bashkir, 3-116, 15 pi.
[In Russian.]

1962. Spores from Devonian terrigenous deposits of Bashkir and the southern slopes of the Urals.

In Brachiopods, Ostracods and Spores from the Middle and Upper Devonian of Bashkir. Izd. Akad.
Nauk S.S.S.R. Moscow, 351-476, 17 pi. [In Russian.]
cramer, F. h. 1966. Palynomorphs from the Siluro-Devonian boundary in north-west Spain. Notas
y Comuns, Inst. Geol. Minero de Espaha, 85, 71-82, 3 pi.
downie, c. 1963. ‘Hystrichospheres’ (acritarchs) and spores of the Wenlock Shales (Silurian) of Wen-
lock, England. Palaeontology, 6, 625-52, pi. 91-2.

franke, f. 1965. Mikrofossilien eines unterdevonischen Brandschieferprofils nahe Miinstereifel.
Inaug. Dissert. Univ. Berlin, 86 pp., 7 pi.

groot, j. j. 1966. Some observations on pollen grains in suspension in the estuary of the Delaware
River. Marine Geol. 4, 409-16.

and groot, c. r. 1966. Marine palynology: possibilities, limitations, problems. Ibid. 387-95.

guennel, g. k. 1963. Devonian spores in a middle Silurian reef. Grana Palynol. 4, 245-61, 1 pi.
hoffmeister, w. s. 1959. Lower Silurian plant spores from Libya. Micropaleontology, 5, 331-4,
1 pi.

Holland, c. h., and lawson, j. d. 1963. Facies patterns in the Ludlovian of Wales and the Welsh
Borderland. Lpool. Manchr. Geol. J. 3, 209-88.

and walmsley, v. g. 1963. The Silurian rocks of the Ludlow district, Shropshire. Bull.

Brit. Mus. Geol. 8, 95-171.

hopping, c. A. 1967. Palynology and the Oil Industry. Rev. Palaeobotan. Palynol. 2, 23^18, pi. 1-2.
kedo, G. i. 1963. Tournaisian spores from the Pripyat Depression and their stratigraphic significance.

Tr. Inst. Geol. Nauk. B.S.S.R., Ser. Stratigraf. Palaeontol. 4, 3-121, 11 pi. [In Russian.]
kosanke, r. m. 1950. Pennsylvanian spores of Illinois and their use in correlation. Bull. III. geol. Surv.
74, 1-128, 16 pi.

lanjouw, J. et al. 1961. International code of botanical nomenclature. Utrecht, 1-372.
lanninger, e. 1968. Sporen-Gesellschaften aus dem Ems der SW-Eifel. Palaeontographica B122,
95-170, pi. 20-6.

lawson, J. d. 1954. The Silurian succession at Gorsley (Herefordshire). Geol. Mag. 91, 227-37.
luber, a. a. 1955. Atlas of the spore and pollen of the Palaeozoic deposits of Kazakhstan. Izd. Akad.

Nauk Kazakh S.S.R., Alnui-Ata 1-125, 10 pi. [In Russian.]
mcgregor, d. c. 1961. Spores with proximal radial pattern from the Devonian of Canada. Bull. Geol.
Surv. Canada, 76, 1-11, 1 pi.

1964. Devonian miospores from the Ghost River formation Alberta. Ibid. 109, 1-31, 2 pi.

1967. Composition and range of some Devonian spore assemblages of Canada. Rev. Palaeobotan.

Palynol. 1, 173-83, 1 pi.

and owens, b. 1966. Illustrations of Canadian fossils. Devonian spores of eastern and northern

Canada. Geol. Surv. Canada papers 66-30, 1-66, 24 pi.
moreau-benoIt, a. 1966. Etude des spores du Devonien inferieur d'Avrille (Le Flechay), Anjou. Rev.
de Micropaleontologie, 8, 215-32, 3 pi.

1967. Premiers resultats d’une etude palynologique du Devonien de la Carriere des Fours a Chaux

d'Angers (Maine-et-Loire). Ibid. 9, 219^10, 4 pi.

mortimer, m. g. 1967. Some Lower Devonian microfloras from southern Britain. Rev. Palaeobotan.
Palynol. 1, 95-109, 2 pi.

muller, J. 1959. Palynology of Recent Orinoco delta and shelf sediments. Reports of the Orinoco Shelf
Expedition; vol. 5. Micropaleont. 5, 1-32, 1 pi.

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

245

naumova, s. n. 1953. Spore-pollen assemblages of the Upper Devonian of the Russian Platform and
their stratigraphic significance. Tr. Inst. geol. Nauk, Akad. Nauk S.S.S.R. 143 (60), 1-154, 6+22 pi.
[In Russian.]

obrhel, J. 1962. Die Flora der Pridoli-Schichten (Budnany-Stufe) des Mittelbohmischen Silurs.
Geologie, 11, 83-97, 2 pi.

potonie, r. 1956. Synopsis der Gattungen der Sporae dispersae. Teil 1, Sporites. Beih. geol. Jb. 23,
1-103, 11 pi.

1958. Idem; Teil 2, Sporites (Nachtrage), Saccites, Aletes, Praecolpates, Polyplicates, Mono-

colpates. Ibid. 31, 1-114, 11 pi.

1966. Idem; Teil 4, Nachtrage zu alien Gruppen (Turmae). Ibid. 72, 1-244, 15 pi.

and kremp, c. 1954. Die Gattungen der palaozoischen Sporae dispersae and ihre Stratigraphie.

Geol. Jb. 69, 111-94, pi. 4-20.

potter, j. f., and price, j. h. 1965. Comparative sections through rocks of Ludlovian-Downtonian
age in the Llandovery and Llandeilo districts. Proc. Geol. Assoc. 76, 379^102.
richardson, J. b. 1964. Stratigraphic distribution of some Devonian and Lower Carboniferous spores.
C. r. Stmt. Geol. carbonif. Paris (1963), 3, 1 111-14.

1965. Middle Old Red Sandstone spore assemblages from the Orcadian basin north-east Scotland.

Palaeontology, 7, 559-605, pi. 88-93.

1967. Some British Lower Devonian spore assemblages and their stratigraphic significance. Rev.

Palaeobotan. Palynol. 1,11 1-29, 4 pi.

shergold, j. h., and shirley, j. 1968. The faunal stratigraphy of the Ludlovian rocks between Craven
Arms and Bourton near Much Wenlock, Shropshire. Geol. Journ. 6, 119-38.
smith, a. h. v., and butterworth, m. a. 1967. Miospores in the coal seams of the Carboniferous of
Great Britain. Special Papers in Palaeontology, 1, 324 pp., 27 pi.
squirrel, h. c., and tucker, e. v. 1960. The geology of the Woolhope inlier, Herefordshire. Q. Jl.
geol. Soc. Lond. 116, 139-85.

streel, m. 1964. Une association de spores du Givetien inferieur de la Vesdre, a Goe (Belgique). Ann.
Soc. Geol. de Belgique, 87, 1-30, 2 pi.

1967. Associations de spores du Devonien inferieur Beige et leur signification stratigraphique.

Ibid. 90, 11-54, 5 pi.

taugourdeau, p. 1965. Chitinozoaires de l’Ordovicien des U.S.A.: comparaison avec les faunes de
l'ancien monde. Rev. Inst, franagis Petrole, 20, 463-84, 3 pi.
traverse, a., and ginsburg, r. n. 1966. Palynology of the surface sediments of Great Bahama Bank,
as related to water movement and sedimentation. Marine Geol. 4, 417-59.

1967. Pollen and associated microfossils in the marine surface sediments of the Great Bahama

Bank. Rev. Palaeobotan. Palynol. 3, 243-54.

tschudy, r. h. 1964. Palynology and time-stratigraphic determinations, in Palynology in Oil Explora-
tion ( a Symposium). Ed. A. T. Cross. Society of economic paleontologists and mineralogists, Special
publication, 11, 18-28.

vigran, j. 1964. Spores from Devonian deposits: Mimerdalen, Spitzbergen. Skr. Norsk Polarinst.
132, 1-30, 6 pi.

wilson, l. r., and coe, e. a. 1940. Descriptions of some unassigned plant microfossils from the Des
Moines series of Iowa. Amer. Midi Nat. 23, 182-6, 1 pi.
wood, e. m. r. 1900. The Lower Ludlow formation and its graptolite fauna. Q. Jl. geol. Soc. Lond. 56,
415-92.

JOHN B. RICHARDSON
Geology Department
University of London, King’s College
Strand, W.C. 2

T. RICHARD LISTER

Institute of Geological Sciences
Ring Road, Halton
Leeds 15

Typescript received 27 August 1968

246

PALAEONTOLOGY, VOLUME 12
APPENDIX (Locality and sample data)

Sheet numbers: scale 1 : 25,000.

Abbreviations for stratigraphic divisions: B.B. — Ludlow Bone Bed; B.C.B. — Black Cock Beds; C.M.S.
— Clifford’s Mesne Sandstone; C.P.F. — Carn Powell facies of Black Cock Beds; D. — Ditton Group;
D.C.S. — Downton Castle Sandstone; L.B.B. — Lower Bringewood Beds; L.C.C.B. — Lower Cwm Clyd
Beds; L.E.B. — Lower Elton Beds; L.L.B. — Lower Leintwardine Beds; L.Q.B. — Long Quarry Beds;
L.R.C.B. — Lower Roman Camp Beds; L.W.B. — Lower Whitcliffe Beds; M.E.B. — Middle Elton
Beds; R.B. — Rushall Beds; R.C.B. — Roman Camp Beds; R.D. — Red Downton Group; R.M.G. —
Red Marl Group; S.B. — Senni Beds; T.B. — Trichrug Beds; T.G.B. — Tresglen Beds; T.S. — Temeside
Shales; U.B.B. — Upper Bringewood Beds; U.C.C.B. — Upper Cwm Clyd Beds; U.E.B. — Upper Elton
Beds; U.L. — Upper Ludlovian; U.L.B. — Upper Leintwardine Beds; U.P.P. — Upper Phosphatized
Pebble-Bed; U.S. — Upper Siltstones; U.W.B. — Upper Whitcliffe Beds; W.L. — Wenlock Limestone;
W.S.— Wenlock Shale.

Microfossil data:

S, spores present; M, microplankton; C, Chitinozoa; — , no microfossils seen.

References: B.D. — Ball and Dineley 1961; H.L.W. — Holland, Lawson, and Walmsley 1963.

A. Sample data (Tables 1 and 2)

Stratigraphic Micro-

Sample

no.

Nat. Grid,
reference

Location

divisions

sampled

fossil

data

SHROPSHIRE

Ludlow (Sheet S047)
LD1 4726 7301

Impure nodular limestone; quarry in wood at
Pitch Coppice (Loc. 16, H.L.W. 1963)

W.L.

MC

LD2

”

Olive-grey siltstone 17 in. above base of L.E.B.
(Loc. 16, H.L.W. 1963)

L.E.B.

SMC

LD3

55

Limestone nodule 5 ft. 6 in. above LD2 (Loc.
16, H.L.W. 1963)

L.E.B.

SMC

LD5

4789 7357

Olive-grey calcareous siltstone; roadside ex-
posure 70 yd. SSW. of Gorsty Farm (Loc. 18,
H.L.W. 1963)

U.E.B.

SMC

LD6

4828 7377

Grey nodular siltstone approx. 90 ft. above
base of L.B.B. ; roadside exposure 170 yd.
NNE. Mary Knoll House (Loc. 19, H.L.W.
1963)

L.B.B.

M

LD7

4838 7378

Grey shelly calcareous siltstone; small road-
side quarry 120 yd. ESE. of LD6 (Loc. 201,
H.L.W. 1963)

L.B.B.

SM

LD8

4856 7381

Thin shelly limestone band; small quarry
100 yd. E. of LD7 (Loc. 205, H.L.W. 1963)

L.B.B.

SMC

LD9

4865 7385

Grey shelly limestone; roadside exposure 540
yd. ENE. Mary Knoll House (Loc. 208, H.L.W.
1963)

L.B.B.

SM

LD10

4874 7389

Hard nodular limestone near base of U.B.B.;
roadside exposure 660 yd. ENE. Mary Knoll
House (Loc. 23, H.L.W. 1963)

U.B.B.

SMC

LD1 1

4855 7369

Silty limestone; trackside quarry 400 yd. E.

U.B.B.

M

Mary Knoll House (Loc. 20, H.L.W. 1963)

Silty limestone 8 ft. above LD11 (Loc. 20, U.B.B. M

H.L.W. 1963)

LD12

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

247

Sample

no.

LD13

Nat. Grid
reference
4888 7392

Location

Olive-grey calcareous siltstone near base of
L.L.B.; roadside quarry 810 yd. ENE. Mary
Knoll House (Loc. 24, H.L.W. 1963)

Stratigraphic

divisions

sampled

L.L.B.

Micro-

fossil

data

MC

LD13B

5?

Olive-grey shelly siltstone 5 ft. above LD13
(Loc. 24, H.L.W. 1963)

L.L.B.

MC

LD14

?»

Olive-grey siltstone 6 ft. above LD13B (Loc.
24, H.L.W. 1963)

L.L.B.

M

LD15

4894 7392

Olive shelly siltstone approx. 20 ft. above
LD14; roadside exposure 880 yd. ENE. Mary
Knoll House (Loc. 212, H.L.W. 1963)

L.L.B.

SM

LD16

49(0 7399

Olive siltstone near top of L.L.B.; roadside
quarry 1,080 yd. ENE. Mary Knoll House
(Loc. 25, H.L.W. 1963)

L.L.B.

M

LD16B

Olive-green shelly calcareous siltstone 5 ft.
above LD16 (Loc. 25, H.L.W. 1963)

L.L.B.

MC

LD17

Soft olive-grey siltstone 5 ft. above LD16B
(Loc. 25, H.L.W. 1963)

L.L.B.

M

LD18

4922 7407

Buff-yellow shelly calcareous siltstone; road-
side exposure 1,230 yd. ENE. Mary Knoll
House (Loc. 26, H.L.W. 1963)

U.L.B.

SM

LD19

4930 7412

Flaggy siltstone at top of U.L.B.; roadside
exposure 840 yd. W. Whitcliffe North (Loc. 27,
H.L.W. 1963)

U.L.B.

SM

LD20

4937 7416

Olive-yellow shelly calcareous siltstone; road-

L.W.B.

SMC

side exposure 750 yd. W. Whitcliffe North
(Loc. 242, H.L.W. 1963)

Ludlow (Sheet S057)

LD22

5130 7419

Grey shelly siltstone 20 ft. 3 in. below Bone Bed ;
east end of Whitcliffe opposite Youth Hostel

U.W.B.

SMC

LD23

5120 7418

Buff-yellow flaggy siltstone 1 1 ft. 5 in. below
LD22; 80 yd. WSW. Ludford Bridge

U.W.B.

SMC

LD25

5120 7418

Flaggy siltstone 20 ft. below LD23; 110 yd.
WSW. Ludford Bridge

U.W.B.

SMC

LD26A

Olive-grey shelly calcareous laminated silt-
stone 10 ft. below LD25; 140 yd. WSW. Lud-
ford Bridge

U.W.B.

SMC

LD28

5103 7417

Shelly limestone 10 ft. 8 in. above LD29; 235
yd. WSW. Ludford Bridge

U.W.B.

SMC

LD29

5096 7417

Olive-grey siltstone 12 ft. 2 in. above LD30;
Whitcliffe quarry 345 yd. WSW. Ludford
Bridge (Loc. 29, H.L.W. 1963)

L.W.B.

SMC

LD30

5094 7415

Shelly buff siltstone 1 1 ft. above LD3 1 ; 375 yd.
WSW. Ludford Bridge

L.W.B.

SMC

LD31

5090 7417

Buff shelly siltstone 1 1 ft. above LD32; 395 yd.
WSW. Ludford Bridge (Loc. 5, H.L.W. 1963)

L.W.B.

MC

248

PALAEONTOLOGY, VOLUME 12

Sample

Nat. Grid

Stratigraphic

divisions

Micro-

fossil

no. reference Location

SHROPSHIRE

Ludlow (Sheet S057) cont.

sampled

data

LD32

55

Buff-yellow siltstone 9 ft. 6 in. above LD33
(Loc. 5, H.L.W. 1963)

L.W.B.

SMC

LD33

”

Buff shelly siltstone 36 ft. 6 in. above base of
L.W.B. (Loc. 5, H.L.W. 1963)

L.W.B.

MC

LD34

55

Grey silty limestone 10 ft. below base of
U.L.B.; lowest beds exposed in small stream
20 yd. SE. LD35

L.L.B.

SMC

LD35

5071 7428

Grey crinoidal limestone, base of U.L.B.; cliff
180 yd. SSE. Dinham Bridge (Loc. 3, ‘Bed C’,
H.L.W. 1963, fig. 5, p. 117)

U.L.B.

SMC

LD36

55

Hard grey shelly limestone 10 ft. above LD35;
13 yd. downstream of LD35

U.L.B.

MC

LD40 5123 7413

Ludlow (Sheet S047)

Flaggy siltstone 1 ft. 4 in. below Bone Bed;
exposure at junction of Ludford Lane and
Leominster road 80 yd. SSW. Ludford Bridge
(Loc. 7, H.L.W. 1963)

U.W.B.

MC

LD41

4306 7313

Coarse crinoidal limestone, top of U.B.B.;
riverside exposures just S. Bow Bridge (Loc.
45 H.L.W. 1963)

U.B.B.

MC

LD43

4631 7037

Buff-grey shelly calcareous siltstone; roadside
exposure, Elton Lane (Loc. E, Wood 1900)

M.E.B.

SMC

LD44

»

Hard flaggy siltstone; roadside exposure,
Elton Lane (Loc. F, Wood 1900)

M.E.B.

SMC

LD45

”

Buff-grey calcareous siltstone; roadside expo-
sure, Elton Lane (Loc. G, Wood 1900)

M.E.B.

MC

LD45B

55

Soft olive-grey graptolitic siltstone 2 ft. 6 in.
above LD45 (Loc. G, Wood 1900)

M.E.B.

SMC

LD46

”

Buff-grey graptolitic siltstone; roadside expo-
sure, Elton Lane (Loc. I, Wood 1900)

U.E.B.

SMC

LD47A

4669 7044

Olive- yellow flaggy siltstone; roadside expo-
sure, Elton Lane (midway between Loc. K and
L, Wood 1900)

U.E.B.

SMC

LD47B

,,

Grey flaggy siltstone 1 ft. above LD47A

U.E.B.

SMC

LD48

”

Soft buff siltstone, top of U.E.B.; roadside
exposure, Elton Lane (Loc. L, Wood 1900)

U.E.B.

SMC

LD49

4665 7041

Grey silty limestone; roadside exposure, Elton
Lane (Loc. K, Wood 1900)

U.E.B.

SMC

LD50

4628 7031

Soft grey shelly siltstone, base of M.E.B.;
roadside exposure, Elton Lane (Loc. C, Wood
1900)

M.E.B.

SMC

LD53

4619 7025

Shelly siltstone; junction of Elton Lane with
track to Evenhay Farm

L.E.B.

SMC

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

249

Stratigraphic

Micro-

Sample

Nat. Grid

divisions

fossil

no.

reference

Location

sampled

data

LD54

4612 7025

Olive-grey shelly siltstone, lowest Elton Bed
exposure in Elton Lane, approx. 25 ft. above
base; located in ditch (about 75 yd. W. of Loc.
B, Wood 1900).

L.E.B.

MC

LD54A

99

Olive-grey flaggy shelly siltstone; approx. 25
ft. above LD54; roadside exposure, Elton Lane
25 yd. E. of LD54

L.E.B.

SMC

LD54B

99

Olive-green mudstone, approx. 30 ft. above
LD54A; roadside exposure, Elton Lane 25 yd.
E. of LD54A

L.E.B.

SMC

LD55

4730 7379

Olive blocky calcareous siltstone; topmost bed
of landslip exposure, 700 yd. WNW. Gorsty
Farm

U.B.B.

SMC

LD56

4873 7292

Weathered olive-grey shelly siltstone, approx.
10 ft. above base of L. B.B.; track section 950
yd. NW. Sunnyhill Cottages (Loc. 196, H.L.W.
1963, p. 140, fig. 12)

L.B.B.

SMC

LD57

4603 7021

Crinoidal limestone, approx. 26 ft. below top
of Wenlock Limestone; roadside quarry, Elton
Lane (Loc. A, Wood 1900)

W.L.

MC

LD58

4873 7292

Decalcified buff-yellow shelly siltstone; same
locality as LD56, an estimated 25 ft. higher in
the succession

L.B.B.

MC

LD59

4603 7021

Crinoidal limestone, 18 ft. above LD57; road-
side quarry, Elton Lane (Loc. A, Wood 1900)

W.L.

SMC

DC2A

4567 7523

Fine-grained, finely laminated mudstone,
with small scale current-bedding, 28-30 in.
above B.B.; quarry behind old cottage, N.
bank river Teme, 300 yd. NE Forge Bridge
(Bed Ea, Elies and Slater 1906) DC samples
provided by K. Fryer (Univ. of Sheffield)

D.C.S.

SM

DC3A

99

Fine-grained, laminated micaceous siltstone,
44-46 in. above B.B.; locality as for DC2A
(Bed Ea, Elies and Slater 1906)

D.C.S.

SM

DC5A

Fine-grained, current-bedded micaceous silt-
stone, 6 ft. 3 in. above Downton Bone Bed;
locality as for DC2A (Bed Ec, Elies and Slater
1906)

D.C.S.

SM

Ludlow (Sheet S057)

LUI

5123 7413

Grey siltstone, 0-4" above B.B.; junction of
‘Ludford Lane’ and Leominster road 80 yd.
SSW Ludford Bridge (Loc. 7, fig. 7, p. 124,
H.L.W. 1963)

DCS.

SMC

LU2

”

Ostracod-bearing siltstone, 4' 10" above B.B.;
locality as for LUI

DCS.

SM

LU3

”

Khaki sitlstone with plant fragments, 5' 10"
above B.B.; locality as for LUI

D.C.S.

SM

250

PALAEONTOLOGY, VOLUME 12

Sample

no.

Nat. Grid
reference

Location

Stratigraphic

divisions

sampled

SHROPSHIRE

Millichope (Sheet S048)

MD3B

4430 8140

Siltstone in channel fill deposit at base of
L.L.B.; old quarry, Norton Camp Wood

L.L.B.

MD5B

4560 8352

M. tumescens flags, roadside exposure, NW. of
Upper Dinchope

U.E.B.

MD6

55

Same locality as MD5B, 22 ft. stratigraphically
above MD5B

U.E.B.

MD8

4480 8440

Shelly siltstone 1ft. 6in. above W.L. small
quarry, NW of Lower Dinchope

U.E.B.

MD9

4506 8464

Siltstone, 3ft. above base of L.E.B.; stream,
325 yd. N. of Dinchope.

L.E.B.

MD24

4992 8687

Silty limestone, 10ft. below top of U.L.B.;
roadside quarry near Birchley Coppice, NW.
of Diddlebury

L.L.B.

MD38

4825 8797

Siltstone in nodular limestone quarry in Harton
Hollow Wood, 700 yd. S. of Harton Village

W.L.

Millichope

area (Sheet S058)

MD12

5107 8953

Shelly siltstone lower-Middle Elton Junction
Beds; stream exposure approx. 300 yd. E. of
the Speller

L.E.B.

MD14

5210 8944

Shelly mudstone stream exposure NW. of
Upper Millichope

M.E.B.

MD16B

5271 8911

Thin limestone old quarry opposite side of
road to the North Lodge of Millichope Park;
15-20 ft. below base of U.B.B.

L.B.B.

MD17

5330 8925

Shelly siltstone, 5ft. below top of U.B.B. road-
side ditch section, 300 yd. W. of Holloway
Farm

U.B.B.

MD19

”

Shelly siltstone, approx. 18ft. below top of
U.B.B. same locality as MD17, 10ft. strati-
graphically above MD17

U.B.B.

MD26

5002 8685

Siltstone, 10ft. above base of L.W.B. roadside
exposure, 150 yd. ENE. of Fernhall Mill

L.W.B.

MD30

5017 8635

Siltstone; roadside exposure, 250 yd. N. of
Milford Cottages

L.W.B.

MD31

5029 8602

Siltstone; roadside exposure at entrance to
Milford Lodge

L.W.B.

MD33

5030 8592

Limestone, Acastella spinosa band; roadside
exposure, 200 yd. SW. Milford Lodge

U.W.B.

MD34

5035 8575

Siltstone, just below B.B. roadside exposure,
under house wall, at junction of Craven Arms
road and road to Milford Cottages

U.W.B.

Micro-

fossil

data

M

SM

SM

SMC

SMC

SM

SMC

SMC

SMC

SMC

SM

M

M

M

SM

SM

RICHARDSON AND LISTER: SPORE ASSEMBLAGES

251

Stratigraphic

Micro-

Sheet

Nat. Grid

divisions

fossil

no.

reference

Location

sampled

data

MD40

5042 9000

Siltstone, approx. 65 ft. below base of W.L.;
trackside exposure, 220 yd. downhill along
path leading from old quarry to Eaton
Village

W.S.

SM

MD41

,,

Siltstone, approx. 100 ft. below base of W.L.

w.s.

SM

same locality as MD40, 40 yd. further down
path

B. Other locality data

SHROPSHIRE

Downton Castle Bridge

S047 4449 7427 Trackside quarry near S. end of Castle D.C.S. SM

Bridge (Loc. 57, H.L.W. 1963)

„ 4480 7442 Stream section 300 yd. E. of Downton Castle R.D.

Bridge

Brown Clee Hill

SO68 6505 8555 Small exposure of grey-green siltstone in D. S

W. bank of Dairy Dingle. Approx. 800 yd.
downstream from the road (B 4364). Approx.

800 ft. above ‘ Psammosteus ’ Limestone
(B.D. 1961)

„ 6001 8301 Grey-green siltstone and sandstone with D. S

plants in E. bank of stream. Approx. 180 yd.

WSW. of Old Lodge Farm. Approx. 1 100 ft.
above ‘ Psammosteus ’ Limestone ( B.D. 1961 )

Long Mountain

SJ30

3149 0772

Grey-green siltstone with abundant plant
fragments. Old quarry 100 yd. N W of Wallop
Hall. (W. T. Gordon Coll., King’s College)

?T.S.

S

HEREFORDSHIRE

S062

6770 2570

Linton Quarry, Gorsley Common (Loc. F,

CMS (D.C.S.)

SM

Lawson 1954)

U.P.P. (L.B.B.)

—

U.S. (U.W.B.)

SM

S054

5971 4035

Old quarry, S. side of Perton village on E.
side of lane to Copgrove (Loc. F, Squirrel
and Tucker 1960)

R.B. (D.C.S.)

SM

Ledbury

S073

7152 3856

Roadside exposure; road junction NE.
corner of Dog Hill Wood

L.E.B.

SM

MONMOUTHSHIRE

SO20

2972 0798

Quarry in a copse on N. side of track, 1 83 m.
from Ffawydden 1|- miles SW. of Llanover
House

?S.B.

S

Usk

SO30

376 001

Roadside section opposite Llanbadoc
Church l mile S. of Usk

U.W.B.

SMC

252

PALAEONTOLOGY, VOLUME 12

Stratigraphic

Micro-

Sheet

Nat. Grid

divisions

fossil

no.

reference

Location

sampled

data

SOUTH

WALES

Breconshire

SN92

9712 2085

Quarry W. side of A 470 on sharp bend, |
mile NW. of Storey Arms Youth Hostel

S.B.

S

Cwm Dwr Section (Potter and Price 1965)

SN83

8443 3234

Quarry at Capel Horeb, N. side of A 40

L.Q.B. (7D.C.S.)

SM

R.C.B. (L.W.B.)

M

„

8385 3241

Small roadside quarry, N. side of A 40

L.C.C.B. (U.B.B.)

M

8361 3320

Trackside exposures on W. side of Nant y
Tresglen

T.G.B.

M

CARMARTHENSHIRE

Sawdde Valley Section (Potter and Price 1965)

SN72

7268 2478

E. bank of Sawdde Gorge from Cwar Glas

U.C.C.B.

SM

quarries to Pont-Ar-Llechau bridge

T.B.

C.P.F.

SM

B.C.B.

—

Cennen

Valley Section (Potter and Price 1965)

SN61

6145 1915

Small quarry E. side of A 483, opp. junc. with
minor road

L.Q.B.

?M

,,

6101 1895

Roadside exposures W. side of A. 476

R.M.G.

—

”

6103 1905

(Llandeilo to Llanelly road)

U.C.C.B.

L.R.C.B.

M

99

6100 1910

T.B.

—

?>

6099 1913

B.C.B.

?M

PEMBROKESHIRE

Freshwater East

SS09

0236 9812

N. side of bay exposures on foreshore and

R.M.G.

S

in cliffs; beds containing ?U.L. and R.M.G.

?U.L.

SM

separated by fault

ADDENDUM

Jardine and Yapaudjian (1968) described Silurian and Devonian deposits from the Polignac Basin
(Sahara) including a general account of spore distribution. The lower part of their sequence shows
a succession of spore assemblages comparable to that described in the present paper, particularly
with respect to the increase of sculptural diversity, the incoming of spores with proximal papillae,
and the appearance and succession of various Emphanisporites spp. Papers by Lanninger (1968) and
Schultz (1968) confirm the importance and diversity of the latter genus in the Emsian.

jardine, s. et yapaudjian, l. 1968. Lithostratigraphie et Palynologie du Devonien-Gothlandien
Greseux du Bassin de Polignac (Sahara). Revue Inst. fr. Petrole , 23, 439-68, 6 pi.
schultz, g. 1968. Eine Unterdevonische mikroflora aus den Klerfer Schichten der Eifel (Rheinisches
Schiefergebirge). Palaeontographica, B123, 5-42, 4 pi.

A NEW BRITISH CARBONIFEROUS CALAMITE
CONE, PARACALAMOSTACHYS SPADICIFO RM IS

by B. A. THOMAS

Abstract. Paracalamostachys spadiciformis is described as a new species of calamitean cone from the lower
Westphalian of Northumberland, England, from which isolated cones, attached cones, and associated shoots were
collected. The cones, which are up to 9 cm. long and about 1 cm. broad with whorls of about 16 bracts and
6 sporangiophores, are bisexual with spores referable to Calamospora cf. laevigata (Ibrahim) Schopf, Wilson,
and Bentall sensu Smith and Butterworth, C . perrugosa (Loose) S. W. & B., C. microrugosa (Ibrahim) S. W. & B.
and C. pallida (Loose) S. W. & B. The cones were borne in close whorls on broad stems which were themselves
probably produced terminally on narrow shoots; this attachment of the cones is unusual and unlike previous
descriptions.

Many species of calamite cones have been described either as compressions or petri-
factions and have often been found attached to parent shoots. The spore contents have
frequently been described showing that there are both unisexual and bisexual cone
species.

This account deals with a collection of compressions of isolated and attached cones,
leafy and non-leafy shoots which were all found in close association. They all came from
one shattered and weathered block of light grey shale about 70 cm. square and 30 cm.
thick. The shale came from an old colliery tip which was being re-excavated near
Bedlington, Northumberland (Grid reference A A 246815). The original stratigraphical
horizon of the shale can only be given as Productive Coal Measures below the Ashington
Marine Band (Westphalian A or B).

The specimens were examined dry and under xylol and several isolated cones were
transfered on to glass slides by the Walton method, but with ‘Lakeside’ as the mounting
medium. Spore samples were prepared by macerating small fragments of compression
in Schulze solution and any small spore aggregates that remained were dispersed with
ultrasonic vibrations.

The specimens and preparations have been deposited in the collections of the
Geological Survey, London; nos. 77226-38 and PF4450, 1.

DESCRIPTION

The cones. The isolated and attached cones are described together as one species. The
only dissimilarity is one of length and this is not considered of specific importance in this
instance.

Most of the detached cones are incomplete but all are longer than the 3 cm. length of
the largest attached cone. The longest, no. 77229 (Pi. 44, fig. 2), is 9 cm., but even this
one is incomplete at the apex. All are roughly 1 cm. broad except no. 77229 with sporo-
phylls more widely spreading than in other cones. The cone axes are about 1-3 mm.
diameter and have a basal swelling 3-4 mm. broad. There are whorls of bracts at 3-4
mm. distance on the axes with the lowest whorl 5 mm. from the basal swelling. There
are about 16 bracts in each whorl although the exact number could not be seen in any

(Palaeontology, Vol. 12, Part 2, 1969, pp. 253-261, pis. 44-45.]

C 0508 S

254

PALAEONTOLOGY, VOLUME 12

whorl. Each bract is about 1 cm. long and 0-6 mm. broad near its base gradually tapering
towards its apex. The bracts leave the cone axis at right angles but then turn upwards in
varying amounts, becoming roughly parallel to the axis in some specimens. The basal
three or four whorls are sterile, but the rest possess whorls of about six sporangiophores.
The greatest number of fertile whorls observed was 21 on no. 77228. The alignment of
the sporangia, especially in the longitudinally split cones, suggests that the sporangio-
phores were borne in the axils of the bracts. However, there is no visible attachment
point to prove this. The sporangia are about 3 mm. long and 2 mm. broad but no details
were seen of their attachment to a sporangiophore.

The attached cones are borne in close whorls on broad stems. Two portions of broad
stem were found but unfortunately both were broken by shale fragmentation prior to
collection. No. 77226a ( PI. 44, fig. 3) is the lower part of such a stem attached to a narrow
articulated stem bearing whorls of small leaves at its nodes. The broad part of no.
77226a has round-polygonal areas with what appear to be bracts. The internodes of the
narrow stem decrease in length acropetally from 12 mm. to 1-5 mm., with a rapid
decrease in the size for the last two internodes below the abrupt increase in stem diameter.
No. 77227 (PI. 45, fig. 6) also appears to be the lower part of a swollen stem but is not
attached to a narrow shoot. No. 77227, however, has rectangular areas and, unlike
no. 77226a, has lost most of its compression. Both stems bore lateral leafy shoots but
only no. 77227 is seen to have cones.

Maceration of part of the compression from the broad stem (no. 77227) gave only
a very few spores and no cuticle. The spores were similar to the microspores described
below and are, no doubt, merely liberated spores that have become trapped on the stem
surface.

The spores. Spores were obtained by macerating small fragments of compression from
various positions on the cones. Microspores and megaspores were recovered showing
the cones to be hermaphrodite.

All the spores were probably roughly spherical before compression as their walls
show numerous folds, but in the compressed condition they appear oval or round.
Distinct trilete rays are shown, often with raised lips, and the contact areas are visible
in most spores. The spore exines are translucent and laevigate or minutely granular.
All the spores would be included in the genus Calamospora Schopf, Wilson, and
Bentall (1944) if found in the dispersed state. The range of spore size is shown in text-fig. 1
and the spores are interpreted as microspores (55-130^) and megaspores (c. 100-350 p).
The macerations usually gave only microspores but occasionally microspores and
megaspores were obtained. Megaspores were never prepared alone suggesting that the
megasporangia were few and dispersed. The larger number of spores in the size range
100-30 /x in the mixed spore populations suggests that some of these are small mega-
spores and not microspores. The recovery of both microspores and megaspores from
single macerations could be taken as evidence of bisexual sporangia but it is more likely
that the spores were from adjacent but adhering sporangia. No definite arrangement of
the two kinds of sporangia was discovered except that megaspores were only recovered
from the basal areas of the cones.

Microspores. The microspores are normally 65-130 p in diameter with the occasional
spore as small as 55 p. The mean diameter is 93 p and the standard deviation 7-6 p.

B. A. THOMAS: NEW BRITISH CARBONIFEROUS CALAMITE 255

The trilete rays are straight or slightly flexuose and have small lips about 1 /x high. They
are about one quarter to one third of the spore radius. The spore exine is structureless
and slightly less than 1 /x thick.

Most of these spores are very similar to the dispersed spores known as Calamospora
microrugosa (Ibrahim) Schopf, Wilson, and Bentall 1944. Imgrund (1960) and Playford
(1962) stated the trilete rays to be up to two thirds the spore radius but no such lengths

text-fig. 1. Histograms of spore size distribution in Paracalamostachys spadiciformis sp. nov. ; slides

PF 4450, 1.

have been found in the spores studied here. Smith and Butterworth (1967) have described
some spores as C. cf. microrugosa distinguishing them by their oval shape and greater
size range (57-97 p against 62-104 p. for their C. microrugosa sensu stricto) and because
their trilete marks are mostly hidden by folds. However as such variations are shown
within the present spore population this distinction would no longer appear necessary.
The smallest forms (below 80 /x) are indistinguishable from C. pallida (Loose) Schopf,
Wilson, and Bentall which is itself similar to C. microrugosa in all but size. Smith and
Butterworth separated these two species by size alone using 15 p diameter as the dividing
measurement.

Megaspores. Text-fig. 1 shows that the megaspores have a very wide size range and that
they can be arbitrarily divided into two groups at 210 /x, with roughly one quarter of
the spores belonging to the larger-sized group. Both groups are closely comparable to
different species of dispersed spore.

The larger spores have a mean diameter of 246 p and a standard deviation of 15-4 /x.
The trilete rays vary in length from about 25-40 p and have lips which are about 3 p
thick near the centre but which gradually thin further out and often disappear before the

256

PALAEONTOLOGY, VOLUME 12

end of the ray. The spore exine is about 2 /x thick and scabrate. The contact area is
normally clearly visible due to denser granulation of the exine in this region.

These spores are almost identical with those described by Smith and Butterworth
(1967) as Calamospora cf. laevigata (Ibrahim) Schopf, Wilson, and Bentall 1944. The
only difference being their quoted size range of 150-260 p. No spores were recovered
from the cones which fully agreed with C. laevigata sensu stricto. Although some came
within the size range of 250-500 p all possess visible contact areas, which C. laevigata
does not, and all have exines thinner than the 4—7 p quoted for the species.

The smaller megaspores are intermediate in character between the microspores and
the larger megaspores. The trilete rays are straight, about one-third of the spore radius,
and have lips about 1 p high. The mean diameter is about 135 p but neither this nor the
standard deviation can be given accurately as the smallest megaspores are indistinguish-
able from the largest microspores.

The closest dispersed spore species is Calamospora perrugosa (Loose) Schopf, Wilson,
and Bentall, which differs from the spores described here only in its narrower size range
(130-60 jtx). Horst (1955) and Potonie and Kremp (1955) have compared C. perrugosa
to a large form of C. microrugosa while Smith and Butterworth have distinguished these
two species merely on size. It is therefore interesting to find spores resembling these two
dispersed spore species within a single cone.

Associated shoots and stems. Leafy shoots, that would be included in Aster ophyllites
Brongniart, and leafless stems, that would be included in Calamites Suckow, were found
in close association with the cones. The leafy shoots are either terminal as in Plate 44,
fig. 4 or larger but non-terminal as in Plate 44, fig. 5. There are 12-16 leaves in each
whorl; individual leaves being linear and broadest at their base. In the terminal shoots
they are attached at near right-angles but in the larger shoots they depart at more acute
angles. The largest specimen had leaves 2 cm. long and internodes 9 mm. long. The
leafless stems possess ridge and furrow markings, alternating at the nodes, and fine
longitudinal striations. All these stems are about 1-1-5 cm. broad with internodes 3-5-
5 cm. long.

Generic attribution. The cones have the typical calamite arrangement of alternating
whorls of sporangiophores and bracts and the spores clearly belong to the genus Calamo-
spora which has often been described from such cones.

The lack of knowledge about the attachment positions of the sporangiophores prevents
the specimens being included within the better-defined genera Calamostachys Schimper,
in which the sporangiophores are attached to the cone axis half-way between the bract
whorls, and Palaeostachya Weiss where they are attached in, or a little above, the axils
of the bract whorls. Although the orientation of the sporangia suggests Palaeostachya
to be the more likely genus, the present cones are included in Paracalamostachys which
was instituted for such generically indeterminable specimens.

EXPLANATION OF PLATE 44

Figs. 1, 2, 6. Paracalamostachys spadiciforttiis sp. nov. 1, no. 77228, X 1. 2, no. 77229, X 1. 6, portion
of split cone, no. 77230, X 4.

Fig. 3. Swollen shoot bearing leafy shoots, no. 77226a, x2.

Figs. 4, 5. Associated leafy shoots, no. 77231, X 1.

Palaeontology, Vol. 12

PLATE 44

THOMAS, Carboniferous calamite cone

B. A. THOMAS: NEW BRITISH CARBONIFEROUS CALAMITE

257

Genus paracalamostachys Weiss
Paracalamostachys spadiciformis sp. nov.

Plate 44, figs. 1-3, 6; Plate 45, figs. 1-6

Diagnosis. Cone up to 9 cm. long and 1-3 cm. diameter; borne in close whorls on
stems about 2-5 cm. broad. Cone axes 1-3 mm. diameter, with basal swellings 3-4 mm.
broad. Whorls of about 16 bracts, 3-4 mm. apart, on cone axis; bracts about 1 cm.
long, 0-6 mm. broad. Sporangiophore whorls between all bract whorls except the

text-fig. 2. Suggested reconstruction of fertile shoot of Paracalamostachys spadiciformis sp. nov.

basal three or four which are barren; about six sporangiophores in a whorl. Sporangia
3 mm. long, 2 mm. broad. Cones hermaphrodite; microspores, 55-130 p. diameter,
similar to Calamospora microrugosa (Ibrahim) Schopf, Wilson, and Bentall and C. pal-
lida (Loose) S. W. & B; megaspores, 100-350 p. diameter, similar to C. cf. laevigata
(Ibrahim) S. W. & B. sensu Smith and Butterworth and C. perntgosa (Loose) S. W. & B

Holotype. No. 77227, Geological Survey Museum, London.

Name derivation. From spadix, being a spike with a fleshy axis.

Stratigraphical occurrence. Productive coal measures, below the Ashington Marine Band.
Northumberland (Westphalian A or B).

258

PALAEONTOLOGY, VOLUME 12

DISCUSSION

Cone production. Calamite cones have previously been described as occurring individually
at the nodes, in terminal groups or infructescences, or on specialized branches (Andrews
1961). The cones described here are unusual in being borne in close whorls on broad
stems. How many cones were produced is not known, but possibly all the round poly-
gonal areas on the broad stems represent positions of former cone attachment.

The fact that the detached cones are larger than those still attached need not be
regarded as evidence for species distinction; it could also suggest that those cones still
attached had not grown to their full length and being smaller were less likely to be
detached during fossilization. The lowest whorls of bracts and sporophylls on the
attached cones are like those of the detached cones while their upper whorls are more
compact. This is comparable with the cones of the extant Equisetum which expand to
full size from the base upwards. The calamites and Equisetales possibly had different
rates of cone expansion, which could be taken as a reflection of growth habit of the plant
as a whole. Equisetum, although having annual aerial shoots, still expands its cones
quickly at the beginning of the growing season. This it is able to do by developing its
cones to maturity, in everything but size, during the preceeding season and allowing
them to overwinter on the perennial rhizome (Manton 1950). Calamites , in contrast, had
perennial aerial shoots and would not have had the same need to produce cones quickly
and simultaneously as there would not have been such distinct growing seasons. The
swollen bases of the cone axes of P. spadiciformis probably represent abscission zones
where the cones were themselves shed after spore liberation had ceased. After cone
production and spore liberation had ended the swollen stems may have been shed or
withered.

This method of cone production has not been described before and the only known
specimens similar to these broad shoots were figured by Weiss (1844, pi. 10, figs. 2, 3)
as Asterophyllites longifolius Sternberg. They are both articulated leafy shoots being in
part narrow and in part swollen. Suggestions of leafy lateral shoots are shown but
neither bears cones. They differ further in having a gradual stem expansion, quite unlike
the abrupt increase shown by no. 77226a, and in having equally spaced nodes along their
lengths. This, together with the fact that Weiss’ figures show a narrow stem width above
the broad part, suggests that his specimens were not homologous with those described
here.

Spore variation. The spore contents of many calamite cones have been described on
several occasions and the fact that spores from one cone may be recorded as more than
one species of dispersed spore has been often noted. Schopf, Wilson, and Bentall men-
tioned this possibility when they instituted the genus Calamospora. The present work

EXPLANATION OF PLATE 45

Figs. 1-5. Isolated spores from Paracakmwstachys spadiciformis sp. nov.; slide PF 4450, x 250.

1, Megaspore comparable to Calamospora cf. laevigata (Ibrahim) Schopf, Wilson, and Bentall.

2, Small megaspore comparable to C. perrugosa (Loose) S. W. & B. 3, Microspore comparable to
C. microrugosa (Ibrahim) S. W. & B. 4, Microspore comparable to C. cf. microritgosa (Ibrahim)
Smith and Butterworth. 5, Microspore comparable to C. pallida (Loose) S. W. & B.

Fig. 6. Swollen stem bearing leafy shoots and cones, no. 77227, x 2.

Palaeontology, Vol. 12

PLATE 45

THOMAS, Carboniferous calamite cone

B. A. THOMAS: NEW BRITISH CARBONIFEROUS CALAMITE 259

shows that spores resembling four species and one extra form of dispersed spores can
be found within a single cone. This would suggest that many more spore species have
been recorded than cone species. However, Crookall (1968) lists 19 British species of
calamite cones while Smith and Butterworth (1967) give only 12 species and forms of
Calamospora , although this latter number is lower than it might have been because they
were recognizing a limited selection for practical purposes. Calamospora has also been
recovered from fructifications of Eleutherophyllaceae, Sphenophyllaceae, Equisetaceae,
Noeggerathiineae (Potonie 1962, 1965), and Protopityales (Walton 1957). There must
be therefore a great number of botanical spore species which differ in only the minutest
details making their recognition extremely difficult when separated from their parent
fructifications. A comparison can be made with some groups of extant plants in which
several species produce similar pollen grains. For example, the 13 North American
pines have pollen grains which intergrade morphologically and can be distinguished
only by detailed statistical analysis relying on measurement ratios (Ting 1966). Previous
less detailed studies failed to separate the pollen species.

The ratio of one large to three small megaspores suggests that one member of each
megaspore tetrad may have developed at the partial expense of the others. It is not
suggested that the smaller megaspores are abortive as they are still relatively large and
greater in size than the microspores. No complete tetrads could be found but small
groups of spores showed this one to three size ratio.

COMPARISON

The main difficulty in palaeontologic taxonomy is deciding how much variation can
be reasonably allowed within one species. If the cones of the extant Equisetum are
examined large variation of both cone size and number of sporangiophores per whorl
can be found and it is difficult to distinguish the species by isolated cones. A correspond-
ing variation can be expected within the calamite cone species and slight differences in
cone size and number of parts must be regarded cautiously. Spores recovered from the
cones can be of value in species comparison but, as shown above, difficulties exist
because of variation within a population and overlap of characters of species. A com-
parison of the parental shoots can be useful but this is often impossible as many speci-
mens are found isolated.

Hermaphrodite species of Paracalamostachys and Calamostachys are known and the
incomplete specimens of Palaeostachya andrewsii Baxter have spores, 270-320 p, in
diameter, which are probably megaspores. Including this last species the known
hermaphrodite cones are Calamostachys casheana Williamson (1887 and 1894), C. solmsi
Weiss (1876), C. americana Arnold (1958), Palaeostachya andrewsii Baxter ( 1958), Para-
calamostachys heterospora Remy and Remy (1958), and P. striata Weiss (1884). The
hermaphrodite genus Calamocarpon Baxter (1963) differs in having only one megaspore
in each sporangium and also in bract details and need not be considered further.

Paracalamostachys striata Weiss is the most similar species, being closely comparable
with the Bedlington cones in diameter, number of bracts and sporangiophores per whorl,
and in having similar-sized spores. The type specimens of this species were only 4-5 cm.
long which is half the length of the Bedlington cones, but as shown above size alone
should not be used for species differentiation. Other differences do however support their

260

PALAEONTOLOGY, VOLUME 12

distinction. The spores have a close resemblance although the megaspores described by
Hartung (1933) have relatively longer trilete rays and the contact areas were not
visible. These spores are thus closer to Calamospora laevigata (Ibrahim) Schopf, Wilson,
and Bentall than those described from P. spadiciformis. The spore size ranges are also
slightly different as in P. striata there is no overlap of size between the microspores and
the smaller megaspores. The two species also differ in the way they were borne on the
parent shoots. P. striata was borne terminally or in a panicle where P. spadiciformis was
borne on specialized broad shoots.

Ca/amostachys solmsi is distinguished by its megasporangia being above its micro-
sporangia. C. americana can be distinguished by its larger size (up to 4 cm. diameter),
its correspondingly larger number of bracts and sporangiophores and because the relative
number of bracts to sporangiophores is less than 2:1. C. casheana is only 5 mm. in
diameter, being slightly less than half the size of the Bedlington cones, and has smaller
microspores. Palaeostachya andrewsii and Paracalamostachys heterospora have slightly
larger diameters ( c . T5 cm.), relatively more bracts and sporangiophores per whorl
and spores with larger size ranges than have the Bedlington cones. P. andrewsii also
has a thicker axis compared with its ‘complete’ diameter. None of these four species has
been found attached to a parent shoot, so no comparison can be made about the way
they were borne.

Acknowledgements. 1 thank Dr. A. H. V. Smith for confirming my spore determinations and Mr. C. N.
Page for helpful discussions on Equisetum. The work was carried out during the tenure of the Lord
Adams Fellowship from the University of Newcastle upon Tyne.

REFERENCES

Andrews, h. n. 1961. Studies in Paleobotany , 487 pp. New York and London.

Arnold, c. A. 1958. Petrified Cones of the Genus Calamostachys from the Carboniferous of Illinois.
Contr. Mus. Paleont. Univ. Mich. 14, 149-65.

Baxter, r. w. 1958. Palaeostachya andrewsii, a new species of calamitean cone from the American
Carboniferous. Amer. Journ. Bot. 42, 342-51.

1963. Calamocarpon insignis, a new genus of heterosporous, petrified calamitean cones from the

American Carboniferous. Ibid. 50, 469-76.

crookall, r. 1969. Fossil plants of the Carboniferous Rocks of Great Britain. Mem. Geol. Surv.,
Palaeontology, IV, part 5 (in press).

hartung, w. 1933. Die Sporenverhaltnisse der Calamariaceen. Inst. Paldobot. u. Petrog. d. Brennsteine
Arb. 3, 95-149.

horst, u. 1955. Die Sporae dispersae des Namurs von Westoberschlesien und Mahrisch-Ostrau.
Palaeontographica, B 98, 1 37-236.

imgrund, r. 1960. Sporae dispersae des Kaipingbeckens, ihre palaontologische und stratigraphische
Bearbeitung im Hindblick auf eine Parallelisierung mit dem Ruhrkarbon und dem Pennsylvanian
von Illinois. Geol. Jb. 77, 143-204.

manton, i. 1950. Problems of Cytology and Evolution in the Pteridophyta. 316 pp. Cambridge.
playford, g. 1962. The Lower Carboniferous microfloras of Spitsbergen. Palaeontology, 5, 550-678.
potonie, r. 1962. Synopsis der Sporae in situ. Beih. Geol. Jb. 52, 204 pp.

1965. Fossil Sporae in situ. ForschBer. Landes N Rhein-Westf . 1483, 74 pp.

and kremp, g. 1955. Die sporae dispersae der Ruhrkarbons, ihre Morphologie und Stratigraphie

mit Ausblicken auf Arten anderer Gebiete und Zeitabschnitte: Teil I. Palaeontographica, B98, 1-136.
remy, r., and remy, w. 1958. Beitrage zur Kenntnis d. Rothliegendflora Thiiringens: Teil III. Sitzber.
Dtsch. Akad. 1 Viss. 3, 1-16.

schopf, j. m., wilson, l. r., and bentall, r. 1944. An annotated synopsis of Paleozoic fossil spores
and the definition of generic groups. Rep. Invest. III. geol. Surv. 91, 1-66.

B. A. THOMAS: NEW BRITISH CARBONIFEROUS CALAMITE 261

smith, a. h. v., and butterworth, m. a. 1967. Miospores in the Coal Seams of the Carboniferous of
Great Britain. Special Papers in Palaeontology, 1, 1-324.
ting, w. s. 1966. Determination of Pinus species by pollen statistics. Univ. Calif. Pabl. Geol. Sci. 58,
1-168, 7 pi.

walton, j. 1957. On Protopity s (Goppert): with description of a fertile specimen ‘ Protopity s scotica ’
sp. nov. from the Calciferous Sandstone series of Dunbartonshire. Trans. R. Soc. Edinb. 63, 333-9.
weiss, c. E. 1876. Steinkohlen — Calamarien. Abhand. Geol. Spezialkarte. v. Preufien it. d. Thiiringischen
Staaten, 2, Heft 1 ; Text 149 pp., Atlas 19 pi.

1884. Steinkohlen-Calamarien II. Ibid. 5, Heft 2; Text 204 pp., Atlas 28 pi.

williamson, w. c. 1887. On recent Researches amongst the Carboniferous Plants of Halifax. Rep.
Br. /Iss. Advmt. Sci. (for 1886), 654-5.

and scott, d. h. 1894. Further Observations on the Organisation of the Fossil Plants of the Coal-

Measures. Part 1, Calamites, Calamostachys, and Sphenophyllum. Pltil. Trans. R. Soc. 185 B, 863-959

15 pi.

B. A. THOMAS
Biology Department

University of London Goldsmiths’ College

Typescript received 6 May 1968 London, S.E. 14

A LOWER CARBONIFEROUS CONODONT FAUNA
FROM EAST CORNWALL

by S. C. MATTHEWS

Abstract. Abundant moulds of conodonts have been collected from a Lower Carboniferous siliceous shale in
east Cornwall. Careful inspection of the distribution of moulds produces no evidence of assemblages. The
conodonts, studied as latex casts, show the association of Dinantian forms typical of Voges's aiichoralis- Zone,
but include, in addition, certain forms currently regarded as limited to ranges in the Upper Devonian. The
stratigraphic circumstances of this example of recurrence of form are examined.

The Lower Carboniferous around St. Mellion in east Cornwall contains conodont
material sufficiently well preserved to serve as a means of dating particular parts of the
succession. There is a reference to the siliceous Lower Carboniferous rocks there in
Hinde and Fox (1896), and Flinde was the leading student of conodonts in his time.
Flowever, in 1896 he and Fox were concerned to record the radiolarian content of these
rocks in the ground west of Dartmoor, and they left no note of having observed the
conodonts which occasionally appear on parting-surfaces. The first report of conodonts
from this same siliceous sequence appeared much more recently (Matthews 1961).

The single occurrence of conodonts briefly noticed in 1961 is discussed more fully
here, and with three purposes in mind. One is to offer an example of the usefulness of
latex impressions in dealing with occurrences of moulds of these small fossils. A second
is to check this Cornish association of forms against associations reported from the
Lower Carboniferous of Germany. The third involves explanation of the meaning of the
presence of a few ‘ Upper Devonian’ forms in this Lower Carboniferous fauna in Corn-
wall.

The Lower Carboniferous of the St. Mellion area in east Cornwall exists in two differ-
ent structural situations: as part of the generally inverted pile of Upper Devonian,
Lower Carboniferous, and Upper Carboniferous rocks which is found to be faulted into
the belt of Upper Devonian slate outcrop south of Callington, or in isolated k/ippen
which apparently have no relation to elements in the lower structure of the district.
One such klippe can be mapped on Viverdon Down south of Callington. It proves to
include a lower rock succession in which siltstones predominate, but which has also
beds of material of sand grade. From this lower succession a Tournaisian cephalopod
fauna has been recorded (Matthews, 1965). The higher succession in the klippe has
consistently siliceous rocks, generally of fine grain-size, and best described by the
German term Kieselschiefer. Within this consistently siliceous succession and roughly
100 ft. above the cephalopod horizon (as judged by field mapping) there is the occurrence
of conodonts discussed here.

The conodont locality is in an old quarry on the northern side of Viverdon Down
(National Grid Reference SX 375676). At the rear of a ledge some 6 ft. above the
western end of the present quarry floor there is a 2-in. thickness of siliceous shale which
reveals on its parting-surfaces crowds of what prove to be moulds of conodonts This
particularly prolific occurrence includes any form to be found elsewhere in the quarry.

[Palaeontology, Vol. 12, Part 2, 1969, pp. 262-275, pis. 46-50. j

S. C. MATTHEWS: LOWER CARBONIFEROUS CONODONT FAUNA

263

In many cases the moulds hold fragile ferruginous casts of the conodonts, ‘limonite’
replacing the original phosphatic substance of the fossils.

Conodonts are usually collected from residues of disaggregated rocks which greatly
reduces the possibility of recognizing any systematic spatial association of forms. In the
present case the rock is fine grained, the environment of sedimentation was apparently
one of relatively low energy, and conodonts can be seen as they lie within their rock-
matrix. It seemed worthwhile to search the parting-surfaces for any suggestion of sur-
vival of organized distribution; but none of the observable arrangements of forms could
be argued to be other than fortuitous (PI. 50). Possibly, after arrival in the sediment,
the conodonts may have been disarranged by the activity of an endofauna.

The preservation appears to be exactly that encountered by Branson and Mehl (1941 b)
in the material from the Harz (see also Meyer 1965) which they used in their comparison
of American and European conodont genera. In collecting material of this kind it is
important to retain the two opposing surfaces which a parting provides, for they record
details of two different aspects of single specimens. A latex solution, such as Revultex,
can be used to prepare positives. In the present case, black Revultex casts were dusted
with white ammonium chloride sublimate and photographed. A few drops of detergent
were added to the Revultex in order to reduce the surface tension. The casting-process,
repeated several times, is useful also as a means of clearing the moulds of their limonitic
contents.

Forms identified are:

Doliognathus lata Branson and Mehl
Gnathodus delicatus Branson and Mehl
Gnathodus punctatas (Cooper)

Gnathodus texanus Roundy
Hindeodella segaformis Bischoff
Palmatolepis gracilis gracilis Branson and Mehl
Palmatolepis gonioclymeniae Muller
Palmatolepis perlobata schindewolfi Muller
Palmatolepis rugosa trachytera Ziegler

Palmatolepis sp. indet.

Palmatolepis sp.

Polygnathus communis Branson and Mehl
Pseudopoly gnathus triangula pinnata Voges
Pseudopoly gnathus triangula triangula Voges
Pseudopoly gnathus aff. triangula Voges
Pseudopoly gnathus sp.

Scaliognathus anchoralis Branson and Mehl
Siphonodella obsoleta Hass

In addition there are abundant representatives of the bar genera Bryantodus , Hindeodella (other than
H. segaformis), Ligonodina, Lonchodina and Neoprioniodus. The detail of these long-ranging forms
need not be recorded here.

No count of individuals is given. Broken or incompletely exposed specimens would
tend to blur the meaning of any such count. Also, the surfaces on which conodonts are
exposed do not necessarily coincide with bedding, and this, too, would diminish the
significance of any tally of exposed individuals. All of the forms identified above are so
oriented with respect to the local parting surface as to allow a satisfactory check of
species-characteristics. Gnathodids, for example, can be referred to specific categories
where an oral-surface is seen, but specific determination is rarely possible if the lateral
aspect only is available.

Voges’s (1959) findings serve as a standard for dating. It can be seen that the Viver-
don Down fauna and Voges’s anchoralis- Zone faunas have a number of features in
common (cf. text-fig. 1):

1. Voges nominated Scaliognathus anchoralis , Hindeodella segaformis and Dolio-
gnathus lata as anchoralis- Zone indices. All three are represented in the Viverdon Down
fauna.

264

PALAEONTOLOGY, VOLUME 12

text-fig. 1. Ranges of conodonts identified in the Viverdon Down fauna, from Ziegler (1962) for the Upper Devonian and Voges
(1959) for the early Carboniferous. For further information on Pseudopoly gnathus triangula triangula and on Gnathodus delicatus,
see remarks in the text. Association of orthochronology and conodont-chronology after Ziegler (1962, 1965) for the Devonian,
and according to the author's own observations for the early Carboniferous.

S. C. MATTHEWS: LOWER CARBONIFEROUS CONODONT FAUNA 265

2. Pseudopoly gnathus triangula pinnata , also well represented, is found to be confined
to the anchoralis- Zone (although it should be noted that Collinson, Scott, and Rexroad
(1962) reported an abundance of Ps. triangula pinnata in their Bactrognathus-Poly gnathus
communis Zone, which has none of the definitive characteristics of the German anchoralis-
Zone association).

3. In the Sauerland, the anchoralis- Zone has some few, late siphonodellids. Sipho-
nodella obsoleta can be recognized in the Viverdon Down material.

4. The pattern of gnathodid occurrence is repeated. The presence of Gnathodus
delicatus would, according to Voges, indicate the later part of the anchoralis- Zone and
equivalence with the Erdbacherkalk; but subsequent information (Ziegler 1960)
suggests that this refinement of the date would not be permissible.

5. Voges found palmatolepids in the anchoralis- Zone, and an assortment of such
forms can be identified here. It is insufficient to see in this merely a further instance of
common character. Voges recorded his palmatolepids as having been reworked. The
possible significance of the Cornubian example of recurrence is treated below.

The Viverdon Down fauna plainly bears the stamp of the German anchoralis- Zone
association, whose character and derivation has recently been restated in closer detail
by Meischner (in press). It is satisfactory to discover a full range of comparability, for
this suggests free intermigration of conodontifers. The age-correlation is then more
firmly founded than one based on isolated individuals.

Translation of the conclusion on age into cephalopod terms is not a straightforward
matter. Voges (1960) tentatively equated his anchoralis- Zone with cu II/I/y in the
approved (cephalopod-based) orthochronology, although recognizing that the anchor-
a/is-Zone did not continue to the upper limit of the Erdbacherkalk, the typical expression
of cully. More recently, Belgian evidence (Conil, Lys, and Mauvier 1964) has suggested
that Sca/iognathus anchoralis occurs in that part of the Belgian stratigraphic sequence
which produced the Ammonellipsites princeps-Muensteroceras complanatum cephalopod
fauna taken by Schmidt (1925) to define culla. It would be right to conclude from these
observations that the Viverdon Down conodont fauna is of cull age (without closer
specification) in cephalopod terms, and to conclude in addition that any future attempt
to subdivide on a time basis the conodont faunas of the anchoralis- Zone need accept
no obligation to account for culla, /3, nor y.

PALMATOLEPIDS IN THE LOWER CARBONIFEROUS

Voges saw the palmatolepids in the anchoralis- Zone as having been reworked. Krebs
(1963, 1964) later added further records of Lower Carboniferous occurrences of Upper
Devonian forms and discussed the implications of reworking of conodont material.
It is now clear that such anomalies, rather than bringing only confusion to the business
of dating sedimentary rocks, may instead be made to yield useful information on sources
of sediment and so may be of some assistance in indicating relative highs in the
palaeogeography.

There appear to be three possible approaches to an interpretation of this recurrence
of palmatolepid form observed in the Lower Carboniferous of east Cornwall. One might
first consider the question of extending the ranges of these forms. But the full German
evidence from the earliest Carboniferous sequences would discredit any such suggestion.

266

PALAEONTOLOGY, VOLUME 12

The limits of occurrence seen in the Upper Devonian by Ziegler (1962) can be accepted
as real. A hint of an alternative exists in the growing record of cases of ‘homoeomorphy’
in conodonts (Muller 1962). In order that such a proposal might command acceptance,
it would be necessary to demonstrate emergence of palmatolepid form out of some incon-
trovertibly Dinantian archetype. This cannot be done at the present time (although
it might be observed that we are almost equally ill-informed as to the antecedence of
such forms as Scaliognathus ) and proof appears unlikely to come later, for it is not easy
to conceive of such a faithful Carboniferous counterfeiting of several different examples
of Devonian form. The suggestion of regeneration perhaps best deserves mention for
the reason that the third possible means of explaining recurrence is also incapable of
producing a firm conclusion. The third course would look to the evidence of stratigraphy
in order to make a case for mechanical reintroduction (reworking) and the evidence of
this kind, at the site of recurrence, does little to justify reworking as an explanation.
The sequence there is to all appearances conformable, and to support this suggestion
there is the presence, at a slightly lower horizon, of a Tournaisian cephalopod fauna.
No conglomeratic development nor any other indication of delivery of coarse clastic
sediment is to be found. Instead, the rock-matrix is so fine as to imply that the conodonts
in their original physical condition would have been larger and heavier than any other
particle in the accumulate. There is nothing to be seen in the palmatolepid specimens
(so far as can be judged from moulds or latex pulls) which would indicate a degree of
mechanical wear beyond any experienced by (for example) the anchora/is-Zone indices
present. Altogether, the local evidence produces little hint of the nature of any physical
process by which reintroduction of the palmatolepids might have been effected. Krebs
(1963, 1964) has, however, recognized comparable cases in Germany and has proposed
that the ‘admixed’ conodonts were swept from highs in the submarine topography of
the time. He has succeeded in identifying such sources in the Upper Devonian fillings
of pockets in, or on, reef limestone masses of Middle or early Upper Devonian age.
The significance of these as sources is in the fact that they must represent almost a
minimum case of Upper Devonian stratigraphic thickness, with little other than cono-
donts to yield to the basin sequence of the surrounding area during Dinantian time. It is
his success in identifying potential source-situations at, or near, the upper surface of the
massive limestone developments that particularly commends Krebs’s case for reworking.
Rather than proceed to assume parallel stratigraphic accidents in south-west England,
however, it would be right to see that the proof of reworking of palmatolepids remains
to be sought by closer study of the Devonian as well as the Carboniferous stratigraphy
there. One thing is clear: it is not necessary to see in any hint of Upper Devonian cono-
donts reworked in the Lower Carboniferous a suggestion of uplift, nor of emergence,
nor of the workings of an early Variscan fold-phase.

SYSTEMATIC DESCRIPTIONS

The material described here is deposited in the Museum of the Geology Department of the Univer-
sity of Bristol. Five-figure numbers prefixed BU identify rock-specimens, and also a conodont mould
if only one is available on the surface of that rock-specimen. Suffixes to the five-figure numbers locate
particular conodont moulds where several are present on the surface of one rock-specimen. It will be
understood that two different numbers may then refer to two different aspects of one conodont.

The synonymies of the forms treated have been discussed in a number of recent works, and these
sources can be cited here, where relevant, without repetition of detail.

S. C. MATTHEWS: LOWER CARBONIFEROUS CONODONT FAUNA

267

Genus doliognathus Branson and Mehl 1941
Doliognathus lata Branson and Mehl 1941

Plate 46, figs. 5-1 1

1941a Doliognathus lata Branson and Mehl, pp. 100-1, pi. 19, figs. 22-6.

1967 Doliognathus lata Branson and Mehl; Thompson, p. 34, pi. 2, figs. 11, 14, 17, 19, 20, 22
(with synonymy).

Material. BU 19203/2, 3; BU 19205/8, 10; BU 19209/1; BU 19210/1; BU 19212/1; BU 19217/2;
BU 19218/11, 14, 20; BU 19219/1, 12.

Remarks. The doliognathids seen here have, in every case, relatively restricted basal
cavities. The lateral process is well developed. Some specimens show on the lateral
process a secondary carina whose constituent nodes tend to be discrete, and which does
not continue proximally to meet the main carina. One such (PI. 46, fig. 6) shows these
characteristics and also a tendency for the peripheral ornamentation to be node-like
rather than ridge-like and radial. Also, there is a more elongate form (PI. 46, fig. 8)
whose peripheral ornament is much reduced, especially on the main lobe. However, the
presence of a well-formed secondary carina and the relative smallness of the basal
cavity serve to separate this form from D. dubia.

Genus gnathodus Pander 1856
Gnathodus delicatus Branson and Mehl 1938

Plate 46, fig. 4

1938 Gnathodus delicatus Branson and Mehl, p. 144, pi. 34, figs. 25-7.

1967 Gnathodus delicatus Branson and Mehl; Thompson, pp. 39-40, pi. 3, figs. I, 6.

71967 Gnathodus delicatus Branson and Mehl, s. 1; Boogaert, p. 179, pi. 2, figs. 13-15 (with
synonymy).

71967 Gnathodus sp. cf. G. bilineatus (Roundy); Thompson, p. 37, pi. 3, figs. 8, 10, 12, 17.
Material. BU 19215.

Remarks. The specimen identified here corresponds in character with the earlier form
of G. delicatus distinguished by Boogaert (1967). The proper affiliation of that author’s
later, broader variant of G. delicatus may emerge from a more detailed analysis of the
Goniatites-Stufe gnathodids.

Gnathodus punctatus (Cooper, 1939)

Plate 46, fig. 2

1939 Dryphenotus punctatus (Cooper); p. 386, pi. 41, figs. 42, 43; pi. 42, figs. 10, II.

1965 Gnathodus punctatus (Cooper); Budinger, p. 58-9 (with synonymy).

1967 Gnathodus punctatus (Cooper); Boogaert, p. 179, pi. 2, fig. 19.

1967 Gnathodus punctatus (Cooper); Thompson, pp. 40-1, pi. 5, figs. 12-15 (with synonymy).
Material. BU 19203/8; BU 19220.

Remarks. The material available here includes one large specimen which shows the
concave-outward course of the curved line of nodes on the outer side of the carina. This

268

PALAEONTOLOGY, VOLUME 12

mould of an oral surface is available on a splinter of rock too small to allow preparation
of a latex pull. The other specimen, which is figured, is smaller, lacks the curved arrange-
ment of nodes, and is interpreted (following Voges) as a G. punctatus variant.

Gnathodus texanus Roundy 1926

Plate 46, fig. 3

1926 Gnathodus texanus Roundy in Roundy, Girty, and Goldman, p. 12, pi. 2, figs. 7, 8.

Gnathodus texanus group

Material. BU 19203/1; BU 19205/6; BU 19218/27; 32, BU 19219/17.

Remarks. Voges (1959) treating the early Carboniferous gnathodids, made distinctions
between species mainly by reference to the pattern of ornament developed on the oral
surface of the cup. He. included under the name Gnathodus texanus Roundy a range of
forms which departed, in several respects of ornamentation, from the relatively simple
type of Roundy (1926), but proposed to be guided by the characteristic outline of the
cup in referring these to G. texanus. An exception was made in the case of the form given
the name G. girtyi by Hass (1953). Ziegler (1963), aware of new opinion then forming
in North America, used the term Gnathodus texanus s.l. in referring to a further German
occurrence of such forms. In 1964, Rexroad and Scott proposed a more narrowly drawn
set of specific categories to accommodate texanoid and girtyoid forms. Budinger (1965),
writing before Rexroad and Scott’s proposals were available to him, distinguished several
G. texanus variants. For these, Boogaert (1967) has offered a reconciliation with Rexroad
and Scott’s specific categories. Thompson (1967), like van Adrichem Boogaert, uses
Rexroad and Scott’s set of names.

It is necessary to ask whether Rexroad and Scott’s analysis fully accounts for the
texanoid gnathodids. The query is justified by the evidence of an interruption of the
Mississippian sequence as can be suspected from what is seen in Collinson, Scott, and
Rexroad’s charts of 1962 and which is plainly admitted in fig. 1 of Rexroad and Scott
(1964). The incomplete state of their stratigraphic record may be transmitted to their
taxonomic analysis and detracts too, from the credibility of their suggestions on phylo-
geny. The gnathodids of the anchoralis- Zone association deserve restudy, especially the
broader texanoids and their variants which approach G. delicatus. Until such a study
has been carried out, on a stratigraphically acceptable body of material, it seems good
to continue to adopt a conservative attitude to the Gnathodus species.

EXPLANATION OF PLATE 46

Revultex pulls dusted with ammonium chloride. All magnifications x 30.

Fig. 1. Siphonodella obsoleta Hass. BU 19205/7.

Fig. 2. Gnathodus punctatus (Cooper). BU 19219/20.

Fig. 3. Gnathodus texanus (Roundy). BU 19210/27.

Fig. 4. Gnathodus delicatus Branson and Mehl. BU 19215.

Figs. 5-11. Doliognathuslata Branson and Mehl. 5, Oral view, BU 19218/20. 6, Oral view, BU 19218/11.
7, Aboral view, BU 19219, of the individual seen in 5. 8, Oral view, BU 19219/1, of an elongate
form. 9, Aboral view, BU 19205/8. 10, Oral view, BU 19205/10. 11, Oral view, BU 19210.

Palaeontology, Vol. 12

PLATE 46

MATTHEWS, Conodonts from Cornwall

S. C. MATTHEWS: LOWER CARBONIFEROUS CONODONT FAUNA

269

Genus palmatolepis Ulrich and Bassler 1926
Palmcitolepis gonioclymeniae Muller 1956

Plate 47, figs. 5, 6

1956 Palmatolepis [Palmatolepis) gonioclymeniae Muller, pp. 26-7, pi. 7, figs. 12, 16, 17, 19.

1 962 Palmatolepis gonioclymeniae Muller; Ziegler, pp. 59-60, pi. 3, figs. 29-31 (with synonymy).

Material. BU 19218/28; BU 19219/19.

Remarks. The blade is seen to bend at a point anterior to the central node. The area
of the outer side of the platform exceeds that of the inner.

Palmatolepis gracilis gracilis Branson and Mehl 1934

Plate 47, fig. 9

1934 Palmatolepis gracilis Branson and Mehl, p. 238, pi. 18, figs. 2, 8.

1966 Palmatolepis gracilis gracilis Branson and Mehl; Klapper, p. 31, pi. 6, fig. 3.

1966 Palmatolepis gracilis gracilis Branson and Mehl; Glenister and Klapper, 1966, pp. 514-15,

pi. 90, fig. 6 (with synonymy).

1967 Palmatolepis gracilis gracilis Branson and Mehl; Boogaert, pp. 182-3, pi. 2, figs. 28-9.
Material. BU 19218/25.

Remarks. The form present here is the one formerly referred to Palmatolepis ( Deflecto -
lepis) deflectens Muller 1956. Glenister and Klapper (1966) have explained how the neo-
type of P. gracilis falls within the range of variation of P. deflectens, which therefore
lapses into junior synonymy.

Palmatolepis perlobata schindewolfi Muller 1956
Plate 47, figs. 1-3

1956 Palmatolepis (Palmatolepis) schindewolfi Muller, pp. 27-8, pi. 8, figs. 22-3, 25-31, pi. 9,
fig. 33.

71968 Palmatolepis perlobata schindewolfi Muller; Schulze, p. 207, pi. 19, fig. 9 (with
synonymy).

Material. BU 19218/1, 26, BU 19219/22.

Remarks. Glenister and Klapper (1966) declined to separate this from the subspecies
P. perlobata perlobata on the grounds that the proposed characteristics of the two are
inconsistent within single samples. They reported variation in terms of presence or
absence of secondary carinae and of weak posterior or anterior direction of the inner
lobe. Schulze (1968) retains P. perlobata schindewolfi but does not refer to Glenister and
Klapper’s view. Huddle (1968), in redescribing Palmatolepis perlobata Ulrich and Bass-
ler, suggests, tentatively, that the more delicate and more finely ornamented P. perlobata
schindewolfi may be distinct, but is unable to state the means of distinction concisely.
In view of this present variety of opinion the name P. perlobata schindewolfi is employed
again here. It appears to apply especially well to the specimen illustrated on Plate 47,
figs. 1 and 2. The specimen illustrated in fig. 3 is more robust, more heavily ornamented,

C 6508

T

270

PALAEONTOLOGY, VOLUME 12

and may more closely resemble P. perlobata perlobata without finally matching any of
the forms described by Huddle.

Pabnatolepis rugosa trachytera Ziegler 1960

Plate 47, fig. 7

I960 Pcilmatolepis rugosa trachytera, Ziegler in Kronberg, Pilger, Scherp, and Ziegler, p. 38,
pi. 1, fig. 6, pi. 2, figs. 1-9.

1968 Pabnatolepis rugosa trachytera Ziegler; Schulze, p. 208 (with synonymy).

Material. BU 19218/31.

Pcilmatolepis sp. indet.

Plate 47, fig. 8

Material. BU 19218/2; BU 19219/23.

Remarks. This single large specimen is incompletely moulded. Those of its characters
available for study (crestal profile, sharply projecting inner lobe, local fine ornament of
nodes tending to be developed as short, near-radial ridges on the inner lobe) suggest
similarity to P. maxima Muller 1956. It is, however, impossible to check the full form
of the posterior part of the platform and the detail of the outer part.

Pcilmatolepis sp.

Plate 47, fig. 4

Material. BU 19218/24.

Remarks. A small palmatolepid, whose outer character cannot be determined.

EXPLANATION OF PLATE 47

Revultex pulls dusted with ammonium chloride. All magnifications X 30.

Figs. 1-3. Pabnatolepis perlobata schindewolfi Muller. 1, Oral view, BU 19218/1. 2, Aboral view,
BU 19219/22, of the individual seen in 1. 3, Oral view, BU 19218/26.

Fig. 4. Pabnatolepis sp. BU 19218/24.

Figs. 5, 6. Pabnatolepis gonioclymeniae Muller. 5, Oral view, BU 19219/19. 6, Aboral view, BU
19218/28, of the individual seen in 5.

Fig. 7. Pabnatolepis rugosa trachytera Ziegler, BU 19218/31.

Fig. 8. Pabnatolepis sp. indet. BU 19218/2.

Fig. 9. Pabnatolepis gracilis gracilis Branson and Mehl BU 19218/25.

Figs. 10, 11. HindeodeUa segaformis Bischoff. 10, Oral view, BU 19218/37. 11, Lateral view, BU
19219/21.

EXPLANATION OF PLATE 48

Revultex pulls dusted with ammonium chloride. All magnifications X 30.

Fig. 1. Polygnathus communis Branson and Mehl. BU 19219/9.

Figs. 2, 7. Pseudopoly gnathus triangula triangula Voges. 2, BU 19205/5. 7, BU 19218/10.

Figs. 3, 4, 8, 10, 11. Pseudopolvgnathus triangula pinnata Voges. 3, BU 19205/1. 4, BU 19204.

8, BU 19219/8. 10, BU 19217/1. 11, BU 19205/4.

Figs. 5, 9. Pseudopolvgnathus aff. triangula Voges. 5, Oral view, BU 19219/7. 9, Aboral view,

BU 19218/7 of the individual seen in 5.

Fig. 6. Pseudopolvgnathus sp. BU 19218/22.

Palaeontology, Vol. 12

PLATE 47

MATTHEWS, Conodonts from Cornwall

Palaeontology , Vol. 12

PLATE 48

MATTHEWS, Conodonts from Cornwall

S. C. MATTHEWS: LOWER CARBONIFEROUS CONODONT FAUNA

271

Genus pseudopolygnathus Branson and Mehl 1934
Pseudopoly gnathus triangula Voges 1959

1959 Pseudopolygnathus triangula Voges, p. 301, pi. 34, figs. 51-6, pi. 35, figs. 1-13.

1967 Pseudopolygnathus triangula Voges; Thompson, pp. 49-50, pi. 4, figs. 17-18 (with
synonymy).

Pseudopolygnathus triangula pinnata Voges 1959
Plate 48, figs. 3, 4, 8, 10 1 1

1959 Pseudopolygnathus triangula pinnata Voges, pp. 302-4, pi. 34, figs. 59-66, pi. 35, figs. 1-6.
1967 Pseudopolygnathus triangula pinnata Voges; van Adrichem Boogaert, p. 185, pi. 3, figs. 9,
10 (with synonymy).

Material. BU 19203/4, 5,7;BU 19204/1 ; BU 19205/1, 2,4; BU 19217/1 ; BU 19218/3, 32; BU 19219/5,8.

Remarks. Forms allocated to this subspecies vary in external form (particularly in the
degree to which the pinnate character of the antero-lateral corner of the platform is
developed on the inner side), in the presence or absence of isolated nodes or transverse
ridges beside the blade at the anterior margin of the platform on the inner or outer side
or both, in the degree to which platform ridges extend from the margin to approach the
carina and in whether these ridges are transverse rather than radial. All of these variants
are present and illustrated here. The ‘most pinnate’ form (PI. 48, fig. 4) shows failure of
lateral ridges and near-failure of the platform itself at the posterior end. The broadest
(questionably, since it is incompletely exposed — PI. 48, fig. 10) shows a near-radial array
of short platform ridges. It may be observed that forms currently referred to the sub-
species Pseudopolygnathus triangula pinnata vary widely, not merely in degree of develop-
ment of particular characters, but even in presence or absence of distinct tricks of form.

Pseudopolygnathus triangula triangula Voges 1959
Plate 48, figs. 2, 7

1959 Pseudopolygnathus triangula triangula Voges, pp. 304-5, pi. 35, figs. 7-13.

Material. BU 19205/5; BU 19218/10.

Remarks. Voges reported that this subspecies and Pseudopolygnathus triangula pinnata
are linked by variants in common. The convex outward outer margin of the platform,
relatively high carinal nodes, and the tendency to isolation seen among the most posterior
of these justify reference to this subspecies.

Voges’s range-chart of 1959 shows an upper limit of occurrence of this subspecies
within the Siphonode/la crenulata-Zone. Meischner (in press) represents a continuous
development of form leading into Ps. triangula pinnata.

Pseudopolygnathus aflf. triangula
Plate 48, figs. 5, 9

Material. BU 19218/7; BU 19219/7.

Remarks. This specimen is in general form and character of ornament comparable with
Pseudopolygnathus triangula. It is, however, more elongate and more symmetrical in the

272

PALAEONTOLOGY, VOLUME 12

relative areal extent of its platform halves and also their relative height at the anterior
margin of the platform. The posterior part of the platform is distinctly slim, and the
carinal nodes here tend to be isolated. Platform ornament, which includes only short
elongate ridges at the margin, is more reduced than in any form referred with confidence
to Ps. triangula pinnata. The basal cavity is relatively small, elongate, and suggests
a polygnathid affinity. Because of the ornament and the course of the platform margins,
the specimen is here referred to Pseudopolygnathus.

Pseudopoly gnathus sp.

Plate 48, fig. 6

Material. BU 19218/22.

Remarks. A small, slightly asymmetrical pseudopolygnathid, slim posteriorly where the
carinal nodes tend to be isolated, and robust at the anterior part of the platform where
the transverse ornament becomes bulbous. In the degree of development of the platform
the specimen bears some resemblance to Ps. multistriata Mehl and Thomas 1947, but its
platform is distinctly broader anteriorly.

Genus scaliognathus Branson and Mehl 1941
Scaliognathus anchor alls Branson and Mehl 1941

Plate 49, figs. 1-10

1941a Scaliognathus anchoralis Branson and Mehl, p. 102, pi. 19, figs. 29-32.

1967 Scaliognathus anchoralis Branson and Mehl; Boogaert, p. 185, pi. 3, fig. 1 1.

1967 Scaliognathus anchoralis Branson and Mehl; Thompson, pp. 50-1, pi. 5, figs. 2-4, 8, 9.

1968 Scaliognathus anchoralis Branson and Mehl; Schulze, pp. 220-1, pi. 20, fig. 32 (with

synonymy).

Material. BU 19203/6, 9; BU 19211/1, 2; BU 19217/3; BU 19218/4, 6, 8, 9, 15, 16, 17, 21, 29, 34, 35;
BU 19219/2, 3, 4, 6, 8, 18.

EXPLANATION OF PLATE 49

Revultex pulls dusted with ammonium chloride. Fig. 4 X 20. All other magnifications X 30.

Figs. 1-10. Scaliognathus anchoralis Branson and Mehl. 1, Oral view of an individual with slim,
curved, unequal, heavily denticulate lateral processes, BU 19218/35. 2, Oral view of relatively small,
near-quadrate individual with short nodes arranged along axes of flat lateral processes, BU 19203/9.
3, Aboral view, BU 19219/18. 4, Aboral view, BU 19218/8. 5, Oral view, BU 19219/13 of a small,
slim individual with straight slender lateral processes. 6, Oral view, BU 19219/6 of a small individual.
7, Oral view, BU 19218/9, of an individual with slim, but straight lateral processes which bear elongate,
posteriorly directed denticles. 8, Oral view, BU 19218/17. 9, Oral view, BU 19219/2. 10, Aboral
view, 192 18/4 of the individual seen in 9.

EXPLANATION OF PLATE 50

Revultex pulls dusted with ammonium chloride. Magnification approximately X 10.

Figs. 1, 2. Two areas of BU 19219. These serve to demonstrate the variety and abundance of conodonts,
including bar-like forms, in the Viverdon Down occurrence. No assemblages have been identified:
it is evident that there has been some disarrangement, post mortem, of the members of any primary
association of form.

Palaeontology, Vol. 12

PLATE 49

MATTHEWS, Conodonts from Cornwall

Palaeontology, Vol. 12

PLATE 50

MATTHEWS, Conodonts from Cornwall

S. C. MATTHEWS: LOWER CARBONIFEROUS CONODONT FAUNA 273

Remarks. The species is interpreted in a broad sense here. Branson and Mehl’s (1941#)
original is anchor-shaped, with unequal, relatively broad lateral processes which bear
nodes along their axes, and with a slight development of peripheral ornament. All speci-
mens here have unequal lateral processes and have a conspicuously well-developed
posterior process which bears a low continuation of the main carinal nodes, but there is
considerable variation in general form, in the siting of denticles or nodes on the lateral
processes, and in the degree of development of peripheral ornament. The following
variants may be recognized.

1. Forms whose main and lateral processes are broad. These have a peripheral orna-
ment of nodes or short ridges arranged at right-angles to the margin. Their lateral pro-
cesses bear robust nodes, rather than denticles, and these are sited along the axes of the
processes, rather than at their posterior margins. One small form (PI. 49, fig. 2) has
peripheral ornament so well developed as to give to the main process a near-quadrate
outline. It is members of this group that bear most resemblance to Branson and Mehl’s
type.

2. Forms whose main process is slimmer than in members of the first group, and whose
lateral processes bear denticles originating from the posterior margin. These scaliog-
nathids are of variable size, and appear to include the forms most frequently encountered
in Europe. One variant mentioned by Budinger (1965), whose lateral processes in their
distal part run almost parallel to the main process is available (BU 19219/3) but is not
illustrated here.

3. Forms with slim processes, the lateral processes curved, and with peripheral
ornament poorly developed and available only, if at all, on the posterior part of the main
process (PI. 49, figs. 1, 6).

4. Forms with well-developed, posteriorly directed denticles emerging from the pos-
terior margin of slim, straight, lateral processes. These denticles are arranged in the
plane of the main and lateral processes and may compete in length with the major,
axial posterior process which bears a carinal crest. Along the slim anterior part of the
conodont the distinctly high carina has a curved profile (PI. 49, figs. 5, 7).

Members of groups 3 and 4 depart far from what is typical of the genus. It is clear that
the variety of such forms deserves closer analysis than it has so far received (the variety
of Pseudopoly gnathus triangula pinnata , as reported above, is equally ripe for closer
inspection). No formal proposals are made here, for it is not always possible to examine
these specimens in every aspect. The process of closer analysis is better reserved for
an occasion when these forms are again available and in a stratigraphically tightly
observed sequence of faunas.

Genus siphonodella Branson and Mehl 1944
Siphonodella obsoleta Hass 1959

Plate 46, fig. 1

1959 Siphonodella obsoleta Hass, pp. 392-3, pi. 47, figs. 1, 2.

1965 Siphonodella obsoleta Hass; Budinger, p. 78.

71967 Siphonodella obsoleta Hass; Boogaert, p. 186, pi. 3, fig. 15 (with synonymy).
1967 Siphonodella obsoleta Hass; Thompson, pp. 52-3 (with synonymy).

Material. BU 19205/7.

274

PALAEONTOLOGY, VOLUME 12

Remarks. This single siphonodellid is a late representative of the genus like those recorded
in anchoralis- Zone faunas by Voges. The slight, remaining outer platform ornament of
ridges and, especially, the course of the long outer rostral ridge serve clearly to identify
the species.

Acknowledgements. This paper embodies a revision of work done while the author held a Shell Inter-
national Petroleum Company research studentship. That financial support is here gratefully acknow-
ledged. Likewise, it would be right to acknowledge the generosity of the Deutscher Akademischer
Austauschdienst, by which the author was able to spend part of the year 1966 in Germany and profit
by meeting Professor Dr. K. Krommelbein and Dr. H. Boger (Kiel) and Dr. D. Meischner (Gottingen).
On an earlier visit to Germany, Dr. W. Ziegler (Krefeld) kindly introduced the author to critical
sections in the Devonian and Carboniferous of the Sauerland.

The photographic illustrations are by Mr. E. W. Seavill of the University of Bristol.

REFERENCES

boogaert, H. A. van A. 1967. Devonian and Lower Carboniferous conodonts of the Cantabrian Moun-
tains (Spain) and their stratigraphic application. Proefschrift, University of Leiden, 129-192, pi. 1-3.
branson, e. b., and mehl, M. G. 1934. Conodonts from the Grassy Creek Shale of Missouri. Univ.
Missouri Studies, 8 (1933), 171-259, pi. 13-21.

1938. Conodonts from the Lower Mississippian of Missouri. Ibid. 13, 128—48, pi. 33, 34.

1941a. New and little known Carboniferous conodont genera. J. Paleont. 15, 97-106, pi. 19.

19416. A record of typical American conodont genera in various parts of Europe. J. Scient.

Labs. Denison Univ. 35 (7), 189-94, pi. 7.

1944. Conodonts in shimer, h. w., and shrock, r. r., Index fossils of North America, New

York, Wiley and Sons, pp. 235-46, pi. 93^4.

budinger, p. 1965. Conodonten aus dem Oberdevon und Karbon des Kantabrischen Gebirges ( Norc! -
spanien). Inauguraldissertation, University of Tubingen. 1-103, pi. 1-5.
collinson, c., scott, A. J., and rexroad, c. b. 1962. Six charts showing biostratigraphic zones, and
correlations based on conodonts from Devonian and Mississippian rocks of the upper Mississippi
Valley. Circ. Illinois geol. Survey, 328, 1-32.

conil, r., lys, m., and mauvier, a. 1964. Criteres micropaleontologiques essentiels des formations-
types du Carbonifere (Dinantien) du bassin franco-beige. C.R. Cong. Avanc. Etud. Stratigr. carb. Paris
1963, 1, 325-32.

cooper, c. l. 1939. Conodonts from a Bushberg-Hannibal horizon in Oklahoma. J. Paleont. 13, 379-
422, pi. 39^17.

glenister, b., and klapper, g. 1966. Upper Devonian conodonts from the Canning Basin, Western
Australia. Ibid. 40, 777-842, pi. 85-96.

hass, w. h. 1953. Conodonts of the Barnett Formation of Texas. Prof. Pap. U.S. geol. Surv. 243-F,
69-94, pi. 14-16.

1959. Conodonts from the Chappel limestone of Texas. Ibid. 294-J, 365-99, pi. 46-50.

hinde, G. J., and fox, h. 1896. Supplementary notes on the radiolarian rocks in the Lower Culm-
Measures to the west of Dartmoor. Rep. Trans. Devon. Ass. Advmt. Sci. 28, 774-89.
huddle, j. w. 1968. Redescription of Upper Devonian conodont genera and species proposed by Ulrich
and Bassler in 1926. Prof. Pap. U.S. geol. Surv. 578, 1-55, pi. 1-17.
klapper, g. 1966. Upper Devonian and Lower Mississippian conodont zones in Montana, Wyoming,
and South Dakota. Paleont. Contr. Univ. Kans. Pap. 3, 1 — 43, pi. 1-6.
krebs, w. 1963. Oberdevonische Conodonten im Unterkarbon des rheinischen Schiefergebirges und
des Harzes. Z. dtsch. geol. Ges. 114, 57-84, pi. 9, 10.

1964. Zur faziellen Deutung von Conodonten-Mischfaunen. Senckenberg. leth. 45, 245-84.

Matthews, s. c. 1961. A Carboniferous conodont fauna from Callington, east Cornwall. Abstr. Proc.

Conf. Geol. Geomorph. S. W. England, R. Geol. Soc. Cornwall, Penzance 1963, 13-14.

1965. Carboniferous outcrops around St. Mellion, east Cornwall. Thesis, University of Bristol

S. C. MATTHEWS: LOWER CARBONIFEROUS CONODONT FAUNA 275

mehl, m. g., and thomas, l. a. 1947. Conodonts from the Fern Glen of Missouri. J. Scient. Labs.
Denison Univ. 40, 3-20, pi. 1.

meischner, d. (in press). Conodont zonation of the German Carboniferous. C'.R. Cong. Avanc. Etud.
Stratigr. carb. Sheffield, 1967.

meyer, k.-d. 1965. Stratigraphie und Tektonik des Allerzuges am Nordwestrand des Acker-Bruch-
berges im Harz. Geol. Jb. 82, 385-436, pi. 17-21.

muller, k.-j. 1956. Zur Kenntnis der Conodonten-Fauna des europaischen Devons. 1. Die Gattung
Palmatolepis. Abh. Senckenb. naturforsch. Ges. 494, 1-70, pi. 1-11.

1962. Taxonomy, evolution, and ecology of conodonts. In Treatise on invertebrate paleontology,

ed. R. C. Moore, (W) Miscellanea, Univ. Kansas Press, W 83-91.
rexroad, c. b., and scott, a. j. 1964. Conodont zones in the Rockford Limestone and the lower part
of the New Providence Shale. Bull. Indiana Geol. Surv. 30, 7-54, pi. 2, 3.
roundy, p. v. 1926. Part 2. The microfauna, in, roundy, p. v., girty, g. h., and Goldman, m. i., Mis-
sissippian formations of San Saba County, Texas. Prof. Pap. U.S. Geol. Surv. 146, 5-23, pi. 1-4.
schmidt, h. 1925. Die carbonischen Goniatiten Deutschlands. Jb. preufi. Geol. Landesanst. BergAkad.
45 (1924), 489-609, pi. 19-26.

schulze, r. 1968. Die Conodonten aus dem Palaozoikum der mittleren Karawanken (Seeberggebiet).

Neues Jb. Geol. Palaont., Abh. 130, 133-245, pi. 16-20.

Thompson, t. l. 1967. Conodont zonation of Lower Osagean rocks (Lower Mississippian) of south-
western Missouri. Missouri Geol. Surv. Wat. Resour. Rept. Invest. 39, 88 pp., pi. 1-6.
voges, a. 1959. Conodonten aus dem Unterkarbon I und II (Gattendorfia- und Pericyclus-Stufe) des
Sauerlandes. Palaont. Z. 33, 266-314, pi. 33-5.

— 1960. Die Bedeutung der Conodonten fur die Stratigraphie des Unterkarbons I und II (Gatten-
dorfia- und Pericyclus-Stufe) im Sauerland. Fortschr. Geol. Rheinld. West fi. 3 (1), 197-288.
ziegler, w. 1960. In kronberg, p., pilger, a., scherp, a., and ziegler, w., Spuren altvariscischer
Bewegungen im nordostlichen Teil des Rheinischen Schiefergebirges. Fortschr. Geol. Rheinl.
West f. 3 (1), 1-46, pi. 1-7.

1962. Taxionomie und Phylogenie Oberdevonischer Conodonten und ihre Stratigraphische

Bedeutung. Abh. hess. Landesamt. Bodenforsch. 38, 11-166, pi. 1-14.

1963. Conodonten aus dem Unterkarbon der Bohrung Munsterland I. Fortschr. Geol. Rheinl.

West, f. 11, 319-28, pi. 1, 2

S. C. MATTHEWS

Geology Department
Queen’s Building
University Walk
Bristol, 8

Typescript received 10 May 1968

TWO CONODONT FAUNAS FROM THE LOWER
CARBONIFEROUS OF CHUDLEIGH,
SOUTH DEVON

by S. C. MATTHEWS

Abstract. Two conodont faunas are reported from the Lower Carboniferous of Chudleigh, south Devon. The
lower includes Siphonodella cooperi, S. isosticha and Gnathodus aff. semiglaber. The higher has these siphono-
dellids in association with Scaliognathus anchoralis. Comparisons are made with other European and with
North American records.

Two conodont faunas collected at Chudleigh by Professor M. R. House and Mr. N. E.
Butcher provide proof of the Dinantian age of part of the stratigraphic succession there.
Only some details of the fauna are given here. The occurrences of conodonts will be
discussed in their wider geological context in House and Butcher’s forthcoming paper
on the Chudleigh district.

The lower of the two faunas comes from the southern side of a track 110 ft. WSW.
of Winstow Cottages and immediately below a quarry in the Winstow Cherts. The
horizon is almost at the base of the Winstow Cherts of House and Butcher. The cono-
dont material exists in this case as empty moulds of specimens in the siliceous shale.
The higher fauna was found in siliceous shales exposed in a temporary trench cut beside
a hedge at a point 180 ft. to the south-west of Winstow Cottages. House and Butcher
place this horizon in the lithological transition from Winstow Cherts to Posidonia
Shales (see their paper). This second collection of material showed light-coloured cono-
dont specimens (presumably degraded remnants of the originally phosphatic micro-
fossils) set in now slightly coarser siliceous rocks. It proved useful to remove the
substance of these specimens with concentrated hydrochloric acid in order to produce
again a set of moulds. Rubber casts could then be prepared and studied.

The following have been identified:
Lower fauna

Fa I codas ? sp.

Gnathodus aff. semiglaber (Bischoff)
Gnathodus sp.

Hindeodella sp. indet.

Polygnathus communis Branson & Mehl
Siphonodella cooperi Hass
Siphonodella isosticha (Cooper)
Chondrites sp. and other ichnofossils

Higher fauna

Gnathodus delicatus Branson and Mehl
Gnathodus semiglaber ( Bischoff)

Gnathodus texanus (sensu german ico)
Gnathodus cf. punctatus (Cooper)
Hindeodella cf. segaformis Bischoff
Polygnathus sp.

Pseudopoly gnathus triangula pinnata Voges
Scaliognathus anchoralis Branson and Mehl
Siphonodella cooperi Hass
Siphonodella sexp/icata (Branson and Mehl)
Siphonodella isosticha (Cooper)

Ostracods

Chitinophosphatic brachiopod

(Palaeontology, Vol. 12, Part 2, 1969, pp. 276-280, pi. 51.]

S. C. MATTHEWS: TWO CONODONT FAUNAS

277

The conodonts, ostracods, and the chitinophosphatic brachiopod may be taken to
be representatives of the pelagic fauna of the times. The ichnofossils, on the other hand,
record the activity of members of an endofauna. It may be observed that there is no
systematic relationship between the distribution of the conodonts and the courses taken
by the endobionts.

The matter of the ages of the two faunas demands careful discussion. The lower
fauna may be treated as resembling some mentioned by Voges (1960) and regarded by
him as having their place in the upper part of his SiphonodeUa crenulata- Zone. He identi-
fied, in these cases, relatively early occurrence of Gnathodus semiglaber in association
with siphonodellids. Ziegler (1960) reported a gnathodid-siphonodellid association from
a pvt-anehoralis-Zone situation and Boger (1962) recorded a similar coincidence of form.
All of these authors, at their times of writing, would have suggested that a SiphonodeUa
crenulata-Zone conodont fauna implies culla age by the cephalopod-based Dinantian
standard. Likewise, a first statement on the Chudleigh Dinantian conodont faunas
(reported in House and Butcher 1962) gave the age of the lower fauna as culla. But this
equation can now be seen to be invalid (Matthews, in press). The only permissible
translation into cephalopod terms would suggest that the SiphonodeUa crenuIata-Zone
post-dates the Hangenbergkalk (cul) and pre-dates any western European cull cepha-
lopod fauna recorded in the literature.

The higher fauna may be referred with confidence to Voges’s anchoralis- Zone. Sca/iog-
nathus anchoralis and Hindeodella cf. segafonnis have been identified, and nothing in the
remaining elements of the fauna would contradict their indication of age. Conodont
faunas of this character have been obtained from cull horizons.

Comparisons with American findings are instructive. The lower fauna, with Sipho-
nodeUa cooperi, S. isosticlm , Polygnathus communis , and the gnathodids, matches in
many respects the association of form reported by Collinson, Scott, and Rexroad (1962)
from the late Kinderhookian of the Mississippi Valley and treated by them as deter-
mining a SiphonodeUa n. sp. A-Siphonodella cooperi Zone. Later, Rexroad and Scott
(1964) advised that SiphonodeUa n. sp. A should have the name SiphonodeUa iso-
sticha. These American investigations produced no account of the anchoralis-Zone
fauna which European experience (now repeated again at Chudleigh) had shown to
succeed the faunas dominated by siphonodellids. Instead, Collinson, Scott, and Rexroad
(1962) referred to a major unconformity as fixing the local upper limit of occurrence of
SiphonodeUa and other forms in the Mississippi Valley. The fact of interruption was not,
however, made plain in their offer of a sequence of zones, nor in their set of proposals
on European correlatives. Rexroad and Scott’s (1964) paper made more explicit refer-
ence (fig. 1 of their paper) to a gap in the Mississippi Valley standard. Burton (1964) has
recorded the presence in the Mississippian of New Mexico of Scaliognathus , Doliog-
nathus and other forms familiar in Europe. He emphasizes (personal communication)
the fact that faunal breaks are sharp and coincide with member or formation boundaries
throughout the Mississippian of the Sacramento Mountains. From these observations
he reasonably draws the conclusion that the ranges of particular forms might appear to
be quite different in fuller rock-successions elsewhere. Thompson (1967) encountered
Scaliognathus and Doliognathus in his study of certain conodont faunas from south-
western Missouri. It was in fact in the Mississippian of that region that these two genera
were first found (Branson and Mehl 1941).

278

PALAEONTOLOGY, VOLUME 12

The two faunas from Chudleigh are from a single section in basinal stratigraphy, and
the higher fauna shows coincidence of Scaliognathus and siphonodellids. No such coin-
cidence is encountered in North America. One possible interpretation of the Chudleigh
evidence is that there is recorded, here, a set of associations of conodonts the pattern of
whose occurrence in the Mississippian is distorted by interruptions of the stratigraphic
succession. If the Mississippian evidence is not in this way distorted, it may be necessary
to recognize a differentiation of faunas by which the anchoralis- Zone associations
recorded in Europe were made distinct from their Mississippian contemporaries. But in
that case, there would remain the fact that no such differentiation is evident in the faunas
of time immediately preceding.

Acknowledgements. 1 am grateful to Professor House and Mr. Butcher for allowing me the opportunity
to study and make comment on their collection of Lower Carboniferous conodonts from Chudleigh.
The photographs are the work of Mr. E. W. Seavill to whom also I offer my thanks.

SYSTEMATIC NOTES

Numbers given, with prefix LZ, refer to the collections of the Institute of Geological Sciences
(Geological Survey and Museum). Each four-figure number identifies a rock specimen. A fifth figure,
added as a suffix, identifies one particular conodont mould among the number available on the surface
of that rock specimen. Thus in Plate 51, figs. 1 and 2 (oral and aboral views of Scaliognathus anchoralis)
are both taken from LZ 5660 and cannot refer to one and the same conodont. Conversely, figs. 3 and 4
on that plate (aboral and oral views of Polygnathus sp.) although they refer to rock-specimens LZ 5664
and LZ 5665, do represent two different aspects of a single individual, revealed as moulds on a rock
surface (on 5664) and its counterpart (on 5665).

Falcodus ? sp.

Plate 51, fig. 10

Material. LZ 5649.

Remarks. Hass (1959) illustrated a Falcodus from the Chappell limestone of Texas and
Klapper (1966), too, has recorded a Mississippian falcodid. Krebs (1960) reported
Falcodus ? sp. in a triangula inaequalis- Zone fauna and Dvorak and Freyer (1961) listed
Falcodus sp. A and Falcodus sp. B in a fauna which they suggested to be of an age near

EXPLANATION OF PLATE 51

All figures X 30.

Figs. 1-10 refer to conodonts in the higher fauna, and 11-18 to conodonts in the lower fauna.
Figs. 1, 2. Scaliognathus anchoralis. 1, Aboral view of LZ 5660/2. 2, Oral view of LZ 5660/3.

Figs. 3, 4. Polygnathus sp. Oral (LZ 5664, fig. 3) and aboral (LZ 5665, fig. 4) views of one conodont.
Figs. 5, 16. Siphonodella isosticha. LZ 5662/1, LZ 5652/1 Oral.

Fig. 6. Siphonodella sexplicata LZ 5660/1, Oral.

Fig. 7. Gnathodus delicatus. LZ 5661/2. Oral.

Fig. 8. Pseudopoly gnathus triangula pinnata. LZ 5663. Oral.

Figs. 9, 14, 15. Siphonodella cooperi. LZ 5661/1, LZ 5653, LZ 5650. Oral.

Fig. 10. Falcodus ? sp. LZ 5649. Lateral.

Fig. 1 1. Polygnathus communis LZ 5651/1. Oral.

Fig. 12. Gnathodus cf. punctatus. LZ 5666. Oral.

Fig. 13. Siphonodella sp. LZ 5651/2. Aboral.

Figs. 17, 18. Gnathodus aff. semiglaber. Oral views of LZ 5659 and LZ 5658.

Palaeontology, Vol. 12

PLATE 51

MATTHEWS, Carboniferous conodonts

S. C. MATTHEWS: TWO CONODONT FAUNAS

279

to the cul-cull limit. Krebs interpreted his specimen as having been reworked. Neither
in his nor in Dvorak and Freyer’s case was there illustration or description of specimens.
There is therefore no possibility of attempting comparisons with the form encountered
at Chudleigh.

There must be considerable uncertainty as to the proper generic placing of this
specimen. In some respects there is similarity to Angulodus. Or, again, there is the form
to which Rexroad and Furnish (1964) gave the name Hindeodus and which is, by their
interpretation a Hindeodella deviant. A similar interpretation may apply here.

Gnathodus aff. semiglaber Bischoff 1957
Plate 51, figs. 17, 18

Material. LZ 5659, LZ 5658.

Remarks. The holotype has a cup which is developed to the posterior end on either
side of the carina, and the Chudleigh form differs from that condition in having no cup-
development on the outer side of the posterior part of the carina. Gnathodus sp. C of
Thompson (1967) is closely similar.

Siphonodella cooperi Hass 1959

Plate 51, figs. 9, 14, 15
Material. LZ 5661/1, LZ 5653, LZ 5650.

Remarks. Hass introduced this species of the genus Siphonodella and also S. obsoleta ,
which is distinguished by the ornament (lacking transverse ridges) on the outer side of
the platform and by the notably long rostral ridge which merges posteriorly with the
outer margin of the platform. Voges (1959), referring to German occurrences of S.
obsoleta , offered the observation that some specimens from the anchora/is- Zone resemble
S. cooperi in the details of their platform ornament and suggested that such characteris-
tics do not provide a means of separating the two species (see Voges, 1959, pi. 35, figs.
48-50 for illustration of forms of S. obsoleta with ‘atypical upper surfaces of platforms’).
It is possible that certain existing records of S. obsoleta may deserve revision. The
Chudleigh specimens are consistent with S. cooperi as given by Hass. It can be seen that
the carina is slim in its anterior part, then more powerfully developed along that part
of the platform which is posterior to the termination of the inner rostral ridge.

Siphonodella isosticha Cooper 1939
Plate 51, figs. 5, 16

Material. LZ 5651/1, LZ 5652/1, LZ 5654/1, LZ 5655/1, LZ 5662/1.

Remarks. Rexroad and Scott (1964) advised that certain siphonodellids earlier treated
by Collinson, Scott, and Rexroad (1962) as Siphonodella n. sp. A should be referred to
Cooper’s species S. isosticha. In the diagnosis offered by Rexroad and Scott a smooth
platform (except for the carina and rostral ridges) is specified. A slight development of
nodes is nevertheless evident on the specimen which they illustrate on pi. 3, fig. 23 of
their paper. Some nodes remain on certain of the Chudleigh specimens also, but they

280

PALAEONTOLOGY, VOLUME 12

are not of an abundance to suggest reference to another species. In all cases, the develop-
ment of rostral ridges is quite other than that which distinguishes S. obsolete!. A speci-
men illustrated by van Adrichem Boogaert (1967, pi. 3, fig. 15) is in some ways
comparable with S. isosticha.

REFERENCES

bischoff, g. 1957. Die Conodonten-Stratigraphie des rheno-herzynischen Unterkarbons mit Beriick-
sichtigung der Wocklumeria-Stufe und der Devon/Karbon-Grenze. Abhandl. hess. Landesamt.
Bodenforsch. 19, 64 pp.

boger, h. 1962. Zur Stratigraphie des Unterkarbons im Velberter Sattel. Declieniana, 114, 113-70, pi. 1.

boogaert, h. A. van a. 1967. Devonian and Lower Carboniferous conodonts of the Cantabrian Moun-
tains (Spain) and their stratigraphic application. Proefschrift, University of Leiden.

branson, E. B., and mehl, m. g. 1941. New and little known Carboniferous conodont genera. J.
Paleont. 15, 97-106, pi. 19.

burton, r. c. 1964. A preliminary range chart of Lake Valley formation (Osage) conodonts in the
southern Sacramento Mountains, New Mexico. New Mexico Geological Society, 15th Field Con-
ference, 73-5.

collinson, c., scott, a. ,i., and rexroad, c. b. 1962. Six charts showing biostratigraphic zones and
correlations based on conodonts from the Devonian and Mississippian rocks of the upper Missis-
sippi Valley. Circ. Illinois geol. Surv. 328, 1-32.

cooper, c. l. 1939. Conodonts from a Bushberg-Hannibal horizon in Oklahoma. J. Paleont. 13, 379-
422, pi. 39-47.

Dvorak, j., and freyer, g. 1961. Die Devon/Karbon-Grenze im Mahrischen Karst (Siidteil des
mahrischen Sedimentationsbeckens) auf der Grundlage von Conodontenfaunen. Geologie, 10,
881-95.

hass, w. h. 1959. Conodonts from the Chappel limestone of Texas. Prof. Pap. U.S. geol. Surv. 294-J,
365-99, pi. 46-50.

house, m. r., and butcher, n. e. 1962. Excavations in the Devonian and Carboniferous rocks of the
Chudleigh area, south Devon. Proc. Ussh. Soc. 1, 28-9.

klapper, g. 1966. Upper Devonian and Lower Mississippian conodont zones in Montana, Wyoming,
and South Dakota. Univ. Kansas Paleont. Contr. Pap. 3, 1-43, pi. 1-6.

krebs, w. 1960. Neue Ergebnisse zur Stratigraphie des Oberdevons und Unterkarbons in der sud-
westlichen Dill-Mulde (Rheinisches Schiefergebirge). Notizbl. hess. Landesamt. Bodenforsch.
Wiesbaden , 88, 216-42.

Matthews, s. c. (in press). Comments on palaeontological standards for the Dinantian C.R. Congr.
Avanc. Etud. Stratigr. carb. Sheffield, 1967.

rexroad, c. b., and furnish, w. m. 1964. Conodonts from the Pella Formation (Mississippian) of
south-central Iowa. J. Paleont. 38, 557-76, pi. 111.

and scott, a. j. 1964. Conodont zones in the Rockford limestone and the lower part of the New
Providence Shale (Mississippian) in Indiana. Bull. Indiana Geol. Surv. 30, 7-54, pi. 2, 3.

Thompson, t. l. 1967. Conodont zonation of Lower Osagean rocks (Lower Mississippian) of south-
western Missouri. Missouri geol. Surv. wat. Resour., Rept. Invest. 39, 88 pp., pi. 1-6.

voces, a. 1959. Conodonten aus dem Unterkarbon I und II (Gattendorfia- und Pericyclus-Stufe) des
Sauerlandes. Palaont. Z. 33, 266-314, pi. 33-5.

1960. Die Bedeutung der Conodonten fur die Stratigraphie des Unterkarbons I und II (Gatten-
dorfia- und Pericyclus-Stufe) im Sauerland. Fortschr. Geol. Rheinld. Westf. 3 (1), 197-228.

ziegler, w. 1960. In kronberg, p., pilger, a., scherp, a., and ziegler, w., Spuren altvariscischer
Bewegungen im nordostlichen Teil des Rheinischen Schiefergebirges. Fortschr. Geol. Rheinld. Westf.
3 (1), 1-46, pi. 1-7.

S. C. MATTHEWS
Geology Department
Queen's Building
University Walk
Bristol, 8

Typescript received 10 May 1968

SKELETAL STRUCTURE AND GROWTH IN
THE FENESTELLIDAE (BRYOZOA)

by R. TAVENER-SMITH

Abstract. Branch walls in fenestellid bryozoans are of threefold construction: a granular layer is flanked by
inner and outer laminated tissue. The granular component resulted from continuous deposition, while the lami-
nated tissue was formed by regular, discrete additions. Skeletal rods originate from the granular layer and traverse
the laminated skeleton.

The granular layer pre-dates the laminated tissue, and use of the terms primary and secondary is therefore
justifiable. The primary and outer secondary zones were secreted by an external (or colonial) mantle, while the
inner secondary tissue was laid down by the zooidal ectoderm. The external mantle probably originated as an
ectodermal evagination from the vestibular region of the ancestrula, and was subsequently associated with the
growth of all colonial structures.

The wall arrangement in carinal nodes, dissepiments, and spinose outgrowths is similar to that of branches,
but the inner secondary layer is absent. These structures had no internal communication with zooecial chambers.
Massive colonial supports such as those of Lyropora and Archimedes consist entirely of secondary tissue formed
by localized secretion from the external mantle. Calcite deposits of this kind also played an effective part in the
repair of structural damage to the meshwork.

For a long time species of Fenestella, the commonest and best known of fenestrate
cryptostomes, were recognized by external features alone. The genus is characterized by
a net-like expanse of regularly spaced branches, connected by short, transverse bars
known as dissepiments. The dissepiments in Fenestella are ‘sterile’, that is they bear
no zooecia, while the branches contain two rows of zooecial chambers. Each zooecium
has an aperture, and all apertures open on one side of a frond, the obverse, ‘celluli-
ferous’ or frontal side. On this surface there is a longitudinal median carina or keel,
which in most species is ornamented by uniserial nodes. Branches may show longitudinal
ridges and grooves (‘striae’ of earlier authors), particularly on the reverse, and may also
give rise to a variety of spinous outgrowths. Colonies are attached to the substratum by
a massively calcified basal holdfast.

Nicholson was among the earliest to section fossil bryozoa, and he published the first
illustration of the microstructure of the fenestellid wall (Nicholson and Lydekker 1889,
p. 608). Fie observed that, ‘. . . in the family of the Fenestellidae a portion of the poly-
zoary consists of dense calcareous tissue which exhibits under the microscope a finely
punctate appearance. When a sufficiently thin section of this punctate layer is prepared
and examined the tissue is seen to be penetrated by innumerable exceedingly minute
tubuli . . . which run at right angles to the surface of the polyzoary.’

Ulrich sectioned many species of Fenestella and related genera and recognized two
principal constituents in the skeletal tissue. These were, ‘. . . the original basal or ger-
minal plate’, and ‘. . . the subsequently added layers of calcareous tissue’ (1890, p. 352).
He pointed out that the two are generally quite distinct from one another, especially
when viewed in transverse thin sections of branches. Ulrich did not describe the struc-
ture which he called the germinal plate in detail, but observed that, ‘almost invariably
the lower side of the plate presents a number of tooth-like projections that represent
transverse sections of former longitudinal striations’. Although Ulrich said nothing

(Palaeontology, Vol. 12, Part 2, 1969, pp. 281-309, pis. 52-56.]

282

PALAEONTOLOGY, VOLUME 12

about the upper side of the germinal plate his illustrations (1890, pi. 54-5) clearly imply
that it continued upward between zooecial chambers as a median wall which projected
above the obverse surface of a branch to form the carina. The skeletal tissue that
enveloped the germinal plate was variously referred to by Ulrich as ‘schlerenchyma’,
‘layers of calcareous tissue’, ‘dense portions of the zoarium’, ‘stony deposit’, and
‘secondary deposit’. He described it briefly thus (1890, p. 353): ‘A finely laminated
condition prevails throughout, and very delicate vertical tubuli penetrating the laminae
can, as a rule, be demonstrated. The tubuli again are generally arranged in series and,
though varying in number, are always abundant.’

Simpson (1895, p. 434) described ‘tubuli’ visible in sections of the thick secondary
deposit on the reverse of Fenestella but considered them to be merely part of the orna-
mentation. He did, however, make an important observation, namely that, ‘the deposit
of calcareous matter continues after the animals in the immediate vicinity are dead, and
all ornamentations of the surface are obliterated’. So great, he said, may be the difference
in appearance between the younger sculptured portions and the older, smoother parts
of a fenestellid frond, ‘that, seen in different fragments they would be considered as
belonging to two species’.

Cumings (1904), in his classic paper on the development of some palaeozoic bryozoa,
was concerned with the pattern of budding in the early stages of colony formation rather
than with wall structure. Nevertheless, he distinguished the main skeletal components
and made important observations on the origin of the carina in Fenestella. He said
(p. 64) that, ‘the primary carinae first make their appearance in the metanepiastic stage
(when the initial circle of zooecia is completed), and are intimately related to the basal
plate. In fact the carina seems to originate as an upgrowth or fold of the basal plate’.
He pointed out that the carina is a ‘triple structure’, the axis of which is an upward
extension of the basal plate. This is flanked on either side by layers of, ‘dense, punctate
schlerenchyma’ which are a continuation of the outer, secondary skeleton of the branch.
These may cause the carina to attain, ‘great size and prominence’ (1904, p. 61).

Studies of the microstructure of the wall in Fenestella and related genera by Russian
workers have added greatly to our knowledge of these features. Likharev (1926)
examined in detail the wall structure of certain Fenestella. He found that the skeleton
consisted of outer and inner parts, the inner being lighter coloured. He noticed that the
light substance, in addition to forming the germinal plate on which zooecia rested,
enveloped them from the sides and formed their roof. It also formed the axial part of
dissepiments. The tubercles and outgrowths upon a carina also had a core of ‘light
substance comparable to that which surrounds the zooecia; and they are covered by
a darker peripheral layer’ (free translation from the Russian — p. 1025). Likharev's inner
layer of light substance corresponds with Ulrich's basal or germinal plate, and his outer,
darker or ‘porous’ layer to the secondary schlerenchyma.

Shulga-Nesterenko (1931, 1941) made a careful investigation of the microstructure of
encrusting tissue in Fenestella and related genera, and her findings represent an impor-
tant advance towards an understanding of the fenestrate skeleton. She concluded that
'pores’ in the outer substance of a branch were the means by which amorphous calcium
carbonate was conveyed from zooids to build the walls. In support of this argument she
mentioned the existence of such pores not only between adjacent zooecia, but also
directed outward in the wall facing fenestrules. She suggested the presence of a capillary

R. TAVENER-SMITH: FENESTELLIDAE (BRYOZOA)

283

system permeating branches and composed of elements of two kinds. These were the
‘capillary canals’ lying parallel to the length of a branch and situated within the striae,
ribs, or corrugations on the underside of the germinal plate, and the ‘capillary tubules’
which originated near the ‘crests’ of germinal plate ribs and passed through the
secondary skeleton to the periphery of a branch. The last-named structures, clearly
evident in suitably thin sections (PI. 54, figs. 1, 2), are the ‘tubuli’ of earlier authors.
Shulga-Nesterenko considered them to be hollow pores or canals that conveyed ‘skeletal
substance’ from zooids to the branch periphery where it was ‘deposited in the form of
foliaceous, undulating layers constituting the tissue of branches and dissepiments’ (1931,
p. 77). This author, therefore, introduced the idea that in the Fenestellidae successive
skeletal increments were added from the outside and over the general surface of a growing
branch. Her ideas subsequently underwent some modification, for she later stated (1949,
p. 38) that she had abandoned her earlier interpretation of the capillary tubules as carriers
of lime to the outer surface of branches, and instead supposed that they conveyed nutrition
to a peripheral ectodermal epithelium, the latter precipitating the outer skeleton of the
colony. She seems, however, to have envisaged a single external epithelium immediately
overlying the skeletal substance, which was not the case.

Condra and Elias (1944) in their revision of Archimedes (Hall) rejected Shulga-
Nesterenko’s ideas on the formation of the secondary skeleton. Instead they suggested
that (pp. 23 et seq.) Archimedes was a consortium of Fenestella (forming the spiral
meshwork) and an alga-like organism that contributed the axis or screw. On p. 25 they
‘suggest that Archimedes is made of Fenestella, and that the encrusting tissue about it
belongs to a different organism in a symbiotic relationship’. The same explanation was
proposed for the presence of thick secondary skeletal deposits in other cryptostome
genera.

The same authors presented somewhat modified ideas in their (1957) account of
‘ Fenestella from the Permian of West Texas’. They recognised three basic skeletal
components (pp. 25-45) which were: (1) the colonial or germinal plexus, essentially the
germinal plate of Ulrich; (2) laminated schlerenchyma, ‘a secondary calcareous deposit
whose laminae correspond to the rhythmic growth lines of brachiopods, molluscs and
other invertebrates’. This is the substance described in the earlier paper as ‘phytomor-
phic tissue’, and supposed to be of algal origin; (3) transverse ‘spicules or filaments’.
These are the tubuli of early workers and ‘capillary tubules’ of Shulga-Nesterenko.
Elias and Condra (1957, pp. 20-1 ) maintained, however, that these structures were solid
and not axially perforate. The colonial plexus was described as follows (op. cit. , p. 29):
‘the principal (or basal) cylindrically rolled germinal plate extends upward over all
external surfaces of zooecial chambers and also sends out a thin central wall into the
narrow space between them. Radial ribs rise from it along the reverse of a branch and
along its sides, although the lateral ribs are not as tall as the dorsal ribs. The central
platy wall that meanders between the two rows of zooecia usually expands above the
latter and furnishes the core of the structure known as carina’. The authors (op. cit.,
p. 38) drew attention to the fact that, owing to the continuous, foil-like nature of the
colonial plexus, the calcareous wall between adjacent zooecia is common to both and not
separated into discrete parts. This offers an exact parallel with the general condition in
Cyclostomata (Borg 1926b, p. 192) but is apparently contrary to that in Cheilostomata
(Levinsen 1909, p. 11).

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PALAEONTOLOGY, VOLUME 12

With regard to the laminated outer, or secondary skeleton, it was proposed (Elias
and Condra 1957, p. 37) that this, ‘was secreted by the ectoderm that stretched externally
over the whole zoarium, not by a special “capillary system” The writers thus expressed
their continued disagreement with Shulga-Nesterenko as to the structure and develop-
ment of the zoarial wall, but had moved closer to the ideas of Borg (19266) and Harmer
(1934) on that subject. Although they no longer considered the laminated secondary
skeleton itself to be of algal origin, they continued to regard the ‘tubuli’ traversing the
skeleton in that light. It was suggested (op. cit., p. 44) that these structures were originally
algal hyphae or filaments embedded in the outer skeleton of the bryozoan by an algal
symbiont. In support of this idea it was contended that the ‘spicules’, as Elias and
Condra preferred to call them, originated on the outer surface of a fenestrate branch
and penetrated inward; that they traversed the laminated skeleton only and did not
enter the colonial plexus; and that they had no direct connection with the ‘striae’ or
ribs on the reverse of the latter (pp. 41-3). These things being so, said Elias and Condra,
it was impossible for the ‘spicules’ to have fulfilled the functions attributed to them by
Shulga-Nesterenko.

Borg’s exhaustive study of cyclostome morphology added much to the knowledge of
that subject, not least in respect of skeletal structure. He had the advantage of dealing
with modern forms, and was able to examine the soft parts in relation to their calcareous
investment. Many of his findings may have general application within the bryozoa, and
by careful extrapolation much can be learned about the origin and development of the
skeleton in extinct groups such as the Fenestellidae.

Borg (19266, p. 191) found that in most cyclostome stocks the zooecial wall is com-
posed of an external cuticle, a calcareous layer, ectoderm and mesoderm (in that order),
the first two being secreted by the ectodermal epithelium of a zooid. In the families
Horneridae and Lichenoporidae, however, the structure is more complex and, according
to Borg (1926# p. 595, text-fig. 6; 19266; p. 196) there are, in fact, two separate walls,
an outer one of cuticle lined by epithelium and mesoderm, and an inner, calcareous wall
with ectoderm and mesoderm on either side. They are separated by a slit-like space and,
since this has mesodermal layers on both sides and is in communication with the zooidal
coelom, it must be regarded as a coelomic cavity. Borg termed this the ‘hypostegal
coelom’ because it is extra-zooecial and, though very thin, bounds the colonial skeleton
on all sides. The outer membrane of cuticle lined by ectoderm and mesoderm is also
common to the whole colony.

Borg (19266, pp. 196-7) pointed out that in the Horneridae and Lichenoporidae,
particularly the former, the calcareous wall may attain a remarkable thickness. He went
on to say that the zooarial exterior in these families presents, ‘an uneven surface with
ridges and furrows, contrary to the condition found in other Cyclostomata; in numerous
species of Lichenopora bristles or spines of calcareous matter are found on the outside
of the zoarium. The origin of all these formations is easily understood when one realises
that the calcareous layer is covered with an ectodermal epithelium capable of secreting
calcareous matter’. In a paper published posthumously Borg (1965) extended his con-
cept of the ‘double wall’ to certain extinct cyclostome groups, notably the Fistuliporidae
and Ceramoporidae, and to some of the Trepostomata.

R. TAVENER-SMITH: FENESTELLID AE (BR YOZO A)

285

WALL STRUCTURE

The branch wall of Fenestella, seen in thin section, consists of three basic parts. These
are (text-fig. 1), from the interior outwards: a narrow, laminated zone which lines zoo-
ecial chambers; an apparently clear and structureless layer enclosing the chambers and
their lining; and a wide, outer, closely laminated zone traversed by numerous, slender,
radially disposed, skeletal rods.

A. B.

text-fig. 1 Generalized structure of a branch in Fenestellcr, a, transverse section; b, longitudinal

section.

The middle layer is the germinal plate, or colonial plexus of earlier workers, and has
generally been considered the fundamental component of the branch wall. It is less
strongly developed than the outer laminated zone, but is invariably present as a continu-
ous structure, completely enveloping zooecial chambers and extending above them as
the core of the carina. A distinctive feature is the total absence of laminar structure.
Under the electron microscope this wall component has a granular or rubbly appearance
(PI. 55, figs. 3, 5), and differently orientated sections show that the calcite particles,
though varying somewhat in shape, are roughly equidimensional. Particle shapes and
relationships suggest the former presence of intergranular material, probably proteinous,
and this may originally have formed a sheath around each calcite crystal. Diagenetic
effects in some cases obscure the granular texture, which is the main characteristic of
this layer, so that it appears to be of unitary construction, even under high magnification
(PI. 56, figs. 1-4).

Borg’s (19266) work suggests that there are important parallels between skeletal
characteristics in certain cyclostome genera, notably Hornera, and those of fenestrate
cryptostomes. For this reason an examination was made of wall structure in that genus.
In H.frondiculata, a living species, the basic arrangement of wall components was found

C 6508

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to be essentially as in Fenestella , and a granular layer showing all the features mentioned
above occurs in a corresponding structural position (PI. 55, fig. 2).

The outer, laminated zone of a fenestellid branch is in most cases strongly developed,
particularly on the reverse side (PI. 52, fig. 1 ; PI. 53, fig. 1). Each lamina consists of a
thin, sheet-like mosaic of calcite particles which show similar narrowly elongate shapes
in transverse or longitudinal sections, and must therefore be of a platy nature. Adjacent
laminae (and plates within a lamina) are clearly defined, and were probably separated
in the living condition by protein films (cf. Wilbur, 1960, p. 16, fig. 2). The relationship
of individual calcite plates to cells of the secretory epithelium is, of course, unknown
but, to judge from the diameter of the former (commonly 10 fim to 15 /xm), it is unlikely
that this was on a one-to-one basis. In H. frondiculata, which shows a virtually identical
arrangement of plates in the outer laminated skeleton to that of Fenestella , there is
evidence that two or more calcite crystals seeded and grew within the limits of a single
plate. It appears that fusion of material from several growth centres was necessary for
the formation of a plate, which must therefore have transgressed cell boundaries.
Observed differences in the area of plates may reflect the number of growth centres
involved in their formation. Similarly, the apparent absence of a consistent geometrical
pattern between plates, such as that found by Williams (1968) in brachiopods, is perhaps
attributable to the lack of a simple relationship between plates and epithelial cells.

Skeletal laminae in the outer zone have been recognized by earlier authors (e.g. Elias
and Condra 1957, p. 26) as growth phenomena, and Williams (1968, pp. 19, 43) suggested
that in brachiopod shells a diurnal periodicity is represented by similar features. Crude
estimates based on the number of laminae commonly present on the reverse of a Fene-
stella branch (in the order of several hundreds) and the approximate longevity of the most
closely comparable living bryozoa, such as Hornera, suggest the possibility of a similar
relationship in fenestrate cryptostomes.

EXPLANATION OF PLATE 52

Fig. 1. Polypora sp., Pennsylvanian (Upper Coal Measures), St. Joseph, Missouri. U.S.N.M. 93706,
x 100. Transverse section of branch showing inter-zooecial walls with core of primary material (light)
flanked by inner laminated skeleton (dark). Main wall consists of primary tissue (light) with 'toothed'
under side grading into thick outer laminated zone (dark).

Fig. 2. Archimedes sp., Mississippian (Chester group). West Lighton, Alabama. U.S.N.M. 2379, x 170.
Longitudinal section of branch showing tripartite construction of inter-zooecial walls and well-
developed primary layer (light) beneath chambers. Skeletal rods originating from primary layer
penetrate the outer laminated zone (dark).

Figs. 3,4. Archimedes wortheni Hall, Mississippian (Warsaw Beds), Warsaw, Illinois. A. M.N.H., 7525/1 A,
X 160. 3, Tangential section showing chambers with laminated lining. Primary tissue of inter-zooecial
walls is continuous with that of main wall, which grades externally into outer laminated skeleton.
4, Shallow tangential section in colonial meshwork close to axial screw. Fenestrule is much reduced
in size due to progressive deposition of secondary laminae on adjacent branches and dissepiments.

Fig. 5. Lyropora quincuncialis Hall, Mississippian (Chester group), Chester, Illinois. U.S.N.M. 55742,
x 50. Longitudinal section of branch within colonial support. Apertural peristomes have extended
distally into funnel-like features. White ellipses beneath branch are relics of fenestrules occluded by
secondary growth.

Fig. 6. Archimedes wortheni Hall, Mississippian (Warsaw beds), Warsaw, Illinois. U.S.N.M. 44140,
x 55. Longitudinal section of branch within colonial support. Peristomial funnels show narrow distal
terminations. Pale, slender shaft rising from branch between two 'funnels’ is an elongated carinal
node.

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R. TAVENER-SMITH: FENESTELLIDAE (BRYOZOA) 287

If laminae were formed as successive skeletal increments laid down during equivalent
periods of time, then the rate of growth was not constant. Minor fluctuations in this
respect are implicit in width differences between laminae which, though not commonly
evident, may be strongly marked. The rate of secretion was also, on occasion, differential
from place to place within the same time interval, for though laminae commonly main-
tain a near-constant width, a rapid increase led, in some instances to the formation of
a localized lens or wedge-shaped expansion (PI. 55, fig. 4). Examination of such struc-
tures shows that their formation was attended by certain changes in the shape of com-
ponent calcite particles. As the width of the lamina increased the platy character of
these became less marked, and more stoutly tabular and even equidimensional grain
shapes became common. At the same time the originally single-layered structure of the
lamina was replaced by an increasingly disoriented arrangement due to the presence of
less regularly shaped crystals within the lens. The resultant structure may bear close
comparison with that of the granular skeletal layer, but a transitional relationship with
adjacent laminae is nevertheless clear.

Earlier workers always considered the ‘colonial plexus’ and outer ‘secondary schler-
enchyma’ to be quite separate entities, but electron micrographs show that the junction
between them is gradational in the most complete sense (PI. 55, fig. 3). Laminae immedi-
ately adjacent to the granular zone are poorly defined, discontinuous, and relatively
widely spaced, while further from it they become progressively more strongly and regu-
larly developed. A concomitant change in particle shape from granular to platy
accompanies the transition, and follows a similar pattern to that noted in connection
with ‘lens formation’ in the laminated skeleton.

Nevertheless, and in spite of the demonstrably transitional relationship between
them, the essential contrast between laminar and non-laminar skeletal layers, with their
respective platy and granular textures, is striking, and it is natural to speculate on their
significance. It is reasonable to suppose, for instance, that if laminae represent the dis-
crete addition of skeletal fractions (that is, intermittent deposition), then the absence of
laminae implies that deposition was continuous. Similarly, since there is a change from
platy to granular particle shapes in situations where the growth rate was clearly acceler-
ated (for example, in lenses within the laminated skeleton) it is logical to associate
granular shapes with a higher growth rate. Granted these premises, a conclusion seems
justifiable, namely, that the granular skeleton was formed as the result of a single, con-
tinuous, relatively rapid episode of skeletal growth, while the laminated zone was the
outcome of regular and discrete additions over a prolonged period. It would be in har-
mony with this conclusion to suppose that the epithelium secreting successive laminae
was fairly static, since this might be expected to facilitate the formation of platy particles,
with large area relative to thickness. In contrast, during the formation of the granular
skeleton it might be supposed that the associated epithelium was steadily withdrawing,
laying down as it did so particles with a thickness more nearly matched to their other
dimensions. Why, under these circumstances, approximately equidimensional forms
rather than prisms resulted is not evident, though it is possible that physiological
controls of growth dictated regular pauses in calcareous secretion to permit the plasma
membranes of epithelial cells to exude protein substance. Such an arrangement would
have effectively prevented the formation of columnar crystals.

The inner wall element, that lining zooecial chambers, is of similar appearance and

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PALAEONTOLOGY, VOLUME 12

construction to the outer laminated zone. The banding is, however, more regular (PI. 55,
fig. 1) and in this respect a comparison might be made with the microstructure of pro-
duced spines (Williams 1968, p. 42, pi. 22, figs. 3, 4). The inner layer is feebly developed
in comparison with the outer zone of corresponding structure. This is readily explicable
for, if the chamber lining was secreted from within as would seem most natural,
its continued formation would have posed an increasingly urgent and potentially
insoluble space problem. It seems likely, therefore, that when the chamber lining had
achieved a certain thickness a physiological check operated, and deposition virtually
ceased.

Thin partitions between adjacent zooecial chambers are essentially inward projections
of the main wall. Each consists of a sheet of granular tissue, continuous with that of the
‘colonial plexus’, flanked by laminated skeletal material constituting part of the lining
of adjacent chambers (PI. 52, figs. 1, 3). Inter-zooecial walls are therefore bilaterally
symmetrical, the laminated component on either side being generally narrower than the
granular central layer. The junction between granular and laminated material is moder-
ately well defined and not gradational. Electron micrographs (PI. 55, fig. 5) show that
in detail it is not clear-cut, however, for there is a tendency for adjacent particles of the
two kinds to be welded together so that the actual junction is obscured. The character
of laminae closest to the contact contributes to the non-gradational appearance, for
these are wide and clearly delineated. Further from the junction they assume a progres-
sively narrower and less strongly marked appearance. This arrangement implies that
within the inner laminated zone skeletal growth proceeded most rapidly in the initial
stages, later declining in inverse ratio to the rate at which the wall thickened. After no
great period (to judge from the number of laminae generally present) the addition of
further material appears to have ceased.

The above pattern, seen in fenestellid bryozoans, is also present in Hornera frondicu-
lata (PI. 55, figs. 2, 6) where inner laminated tissue was found in chambers close to the
tips of growing branches. It is apparent from this that the layer is a fundamental wall
component, and not merely a late stage deposit characterizing senility.

A notable feature of the fenestellid skeleton is the presence in the outer (but never the
inner) laminated zone of numbers of slender, rod-like elements. These structures are

EXPLANATION OF PLATE 53

Fig. 1. Polypora sp., Pennsylvanian, Missouri. U.S.N.M. 93706, x47. Transverse section of branches
and dissepiment. Primary core of latter is co-extensive with that of branches. Zooecial chambers at
either end of dissepiment show attenuation in shape towards it.

Fig. 2. Archimedes sp., Mississippian, Alabama. U.S.N.M. 2379, X 80. Transverse section of branch
within axial screw. Skeletal rods traversing secondary laminae arise from primary layer of branch.
Latter is separated from zooecial chamber lining by a poorly defined zone of dark granules.

Fig. 3. Archimedes sp., Mississippian, Alabama. U.S.N.M. 2379, X 100. Longitudinal section of branch
at margin of axial screw. Only the narrow, pale band immediately adjacent to zooecial chambers at
top-left is primary tissue. Curvature of secondary laminae against skeletal rods is evident.

Fig. 4. Archimedes sp., Mississippian, Alabama. U.S.N.M. 2379, X 180. Transverse section showing
emergence of skeletal rods at branch surface to form papillae.

Fig. 5. Polypora cestriensis Ulrich. Mississippian (Chester group), Sloans Valley, Kentucky. U.S.N.M.
163, X 37. Obverse of branch showing streaming of papillae around zooecial apertures.

Fig. 6. Polypora cestriensis Ulrich. Mississippian, Alabama. U.S.N.M. 163, X 37. Reverse view showing
arrangement of papillae in bands. These curve onto a dissepiment in the top-centre part of the field.

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evident in most transverse sections of branches, particularly on the reverse side, where
they diverge from the ribbed lower surface of the granular skeleton (‘colonial plexus’)
and traverse the outer, laminated zone to the periphery ( PI. 54, figs. 1, 2). On the under-
side of well-preserved branches parallel longitudinal rows of minute pustules, marking
the points of emergence of rods, commonly follow the crests of ridges which correspond
at the surface to ribs of the granular skeleton (PI. 53, fig. 6). The rods are also present,
though less noticeably, in laminated tissue elsewhere in the skeleton. On the obverse
of branches their presence is indicated by sinuous rows of pustules which may be visible
between zooecial apertures (PI. 53, fig. 5). In certain fenestellid species (e.g. Fenestella
cingulata Ulrich; F.fenestratum (Young and Young); Polypora dendroides M‘Coy) every
aperture is surrounded by a circlet of pustules, each representing the termination of
a skeletal rod. The rods are also present in carinal nodes, dissepiments, and spiny
outgrowths, where they radiate from granular tissue in the core of the structure and
penetrate the external secondary skeleton, giving a radiate or stellate appearance in
transverse sections (text-fig. 3a).

Most earlier workers believed the skeletal rods to be hollow, hence the term ‘tubules’
by which they were known, though Elias and Condra (1957, pp. 20-1) maintained that
they were solid ‘spicules’ of algal origin. There is no evidence to support the last idea,
but of the solid construction there can be no doubt. Detailed examination under light
and electron microscopes showed no signs of communication, past or present, between
the inner ends of rods and zooecial chambers. This would have been a prime requisite,
had the structures been tubules performing functions of the kind attributed to them by
Shulga-Nesterenko (1941, 1949). Furthermore, if the structures had been hollow, an
indication of this might have been provided by the presence of sparry calcite within them.
But there is no trace of this. On the contrary, they are composed throughout of calcite
particles similar to those of the primary skeleton. Nor is there anything resembling an
outer wall and central cavity, which would have been expected if the structures had been
tubular. On the other hand it is evident that, where they are in contact with rods,
laminae of the outer skeleton are deflected distally to form a succession of close-fitting
cones (PI. 53, fig. 3; PI. 56, figs. 1-4). This persistent deflection of laminae must have been
induced by contact with an already existing structure, and this can only have been the
solid rod itself. Finally, in the outer laminated skeleton of H.frondiculata there are rods
that appear to correspond in all respects with those in Fenestella (PI. 56, fig. 5), and it is
certain that these are solid.

Detailed examination shows that the skeletal rods originate from the granular wall
component, with which they are in direct continuity (PI. 53, fig. 2; PI. 54, fig. 3). In
addition, it is possible that a few may have derived from lenses of granular-type tissue
within the outer laminated skeleton, but this is uncertain. The cone-in-cone structure
around rods, caused by the deflection of closely spaced secondary laminae, is continued
to the branch surface where it is reflected in the formation of minute pustules (PI. 53,
fig. 4). The core and highest point of each of these is formed by the rod axis and, to
judge from the curvature of adjacent laminae, it appears that growth of the rod was
always slightly in advance of that of surrounding tissue. Because of the lack of lamination
in the rods it is also likely that their growth was continuous, not intermittent. These
rods may therefore be considered as solid structures which formed as a result of con-
tinuous growth from an infinity of points on the surface of the granular skeleton. They

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PALAEONTOLOGY, VOLUME 12

are therefore integral parts of the colonial wall, and not external in origin as Elias and
Condra (1957, p. 44) supposed.

The function of the skeletal rods is a matter for speculation, as they do not appear
to have served any obvious purpose. Further study of living hornerids may in due course
furnish an explanation. Meanwhile, it is relevant to draw attention to the remarkable
similarity between these rod-like structures in fenestellid and hornerid bryozoans and
the taleolae of strophomenide brachiopods (Williams, 1956, pp. 251-2; 1968, pp. 39-41).
Williams considered it possible that taleolae played some part in strengthening the skele-
ton by rivetting together the secondary laminae they penetrated. He suggested, however,
that their primary purpose may have been to provide anchorage points for tendons
lying within the connective tissue. Subsequent discussion will show that such a function
could have had great relevance in fenestellid colonies.

Morphological similarities between the skeletal rods of fenestellid bryozoans and
so-called acanthopores in other cryptostome groups and the Trepostomata, are also
worthy of comment. In both cases a ‘tubule’ with associated cone-in-cone structure
penetrates laminated tissue in the peripheral part of the colonial wall. Future work may
well show that these features are homologous.

RECONSTRUCTION OF GROWTH PROCESSES

In addition to comprehending the structure of the branch wall it is desirable to inquire
into the nature and sequence of the processes responsible for its formation, for these may
contribute to an understanding of colonial growth. It is generally recognized that cal-
careous skeletal structures in invertebrate animals are secreted by closely associated
epithelia, and a reasonable prima facie inference would therefore be that the fenestellid
branch wall was formed by the concerted activity of the ectodermal epithelia of zooids
within it. Reflection shows that this is impossible, for the wall, particularly on the reverse
side, is commonly many times thicker than the diameter of a zooid. For such a hypothesis

EXPLANATION OF PLATE 54

Fig. 1 . Archimedes sp., Mississippian, Alabama. U.S.N.M. 2379, X 45. Transverse section of branches
at margin of axial support. Laminar structure of secondary tissue forming screw is prominently
shown. Skeletal rods radiate from primary layer of branches. Strong carinal nodes are also present.

Fig. 2. Archimedes sp., Mississippian, Alabama. U.S.N.M. 2379, x45. Oblique-longitudinal section of
branch at margin of axial screw. Skeletal rods show variously oriented sections in passing towards
periphery.

Fig. 3. Archimedes sp., Mississippian, Alabama. U.S.N.M. 2379, x 140. Longitudinal section of branch
showing derivation of skeletal rods from primary tissue. An irregular band of dark granules separates
primary layer from inner laminated zone lining zooecial chambers.

Figs. 4, 5. Lyropora quincuncialis Hall, Mississippian, Illinois. A.M.N.H. 7873/1 . 4, Transverse section
of part of colonial support and enclosed meshwork. Skeletal rods radiate from branches through
secondary tissue of which support is composed. Strong growth laminae visible on the right, x42.
5, Enlargement from previous figure, showing last branch connected by dissepiment to sterile spinose
structure. Latter is probably a distal extension of a normal branch and consists of a primary core
within secondary laminae, x 160.

Fig. 6. Lyropora quincuncialis Hall. Mississippian, Illinois. U.S.N.M. 55742, X 60. Transverse section
of branches within colonial support. Peristomial funnels are strongly developed and tall, slender
carinal nodes are also present.

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TAVENER-SMITH, Fine structure of fenestellids

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291

to be workable it would be necessary to suppose that the young zooid was excessively
large, and that it progressively decreased in size during life: a clear absurdity. Also, the
increase in thickness of the outer laminated skeleton with increasing age suggests that
additions were made on the outer, and not the inner side of the branch wall. Further,
the gradational nature of the contact between the two outer wall zones, their relative
positions, and the fact that skeletal rods originating from the granular layer undoubtedly
grew outward through the laminated tissue, indicate with certainty the earlier age of the
former. It is also certain, however, from the structure of inter-zooecial walls, that the
granular layer pre-dated the inner laminated tissue which lines zooecial chambers. It
must therefore be concluded that granular tissue was the earliest formed wall component,
and is primary in that respect. It will henceforward be referred to as the primary skeleton.
The outer and inner laminated skeletal components were added later, and are therefore
of secondary origin. The formation of secondary layers on either side of the primary
skeleton indicates the former presence of two wall secreting epithelia, and from this it
is logical to conclude that in the Fenestellidae the architecture of the wall and associated
soft tissues followed a pattern similar to that observed by Borg (19266) in certain
Cyclostomata, notably Hornera.

According to that author three epithelial layers contribute to the formation of the
calcareous wall in Hornera. Of these, the inner (or zooidal) epithelium encloses the
polypide, lines the zooecial chamber and secretes the inner part of the calcareous wall.
The outer (or colonial) epithelia are separated from the inner one by the thickness
of the wall, and form a complete exterior investment of the colony. This external
envelope will be referred to as the external mantle, for in skeletal secretion it fulfils similar
functions to the mantle of brachiopods, from which it differs mainly in its external posi-
tion. This structure, as described by Borg, is bounded by two epithelia, outer and inner,
of which the last is immediately adjacent to the calcareous wall, and partly responsible
for its formation. The outer mantle epithelium in most species of Hornera (Borg 19266,
p. 197) secretes only a cuticular sheath, but no calcareous substance. This outer layer
may, by greatly increasing the area over which gaseous exchange is possible, have per-
formed an important respiratory function (see Ryland 1968, p. 1041). Between the two-
mantle epithelia Borg recognized a slit-like cavity which he designated the hypostegal
coelom. This common external coelomic space is apparently in communication with the
body cavities of individual zooids through a continuity beneath their apertures (Borg
19266, p. 204) and by means of pores traversing the calcareous wall. It is, therefore,
possible for an exchange of coelomic fluid to take place between hypostegal and zooidal
cavities, and a circulation of this nature is the most probable means by which cells of
the external mantle are nourished. In Hornera , as in most cyclostomes, mural pores in
inter-zooecial walls further promote the interchange of coelomic fluid between zooids
(Borg 19266, p. 201).

Organization of the wall in fenestellid bryozoans strongly suggests the former presence
of an external, membraneous colonial investment, and the suggestion is reinforced by
a close similarity to the wall structure of Hornera , in which such a feature is known to
exist. Other skeletal characteristics of the fenestellid group point to the same conclusion.
It is a matter of common observation, for instance, that in the older, proximal parts of
colonies secondary laminae encroached upon, sealed, and accumulated to considerable
thickness over zooecial apertures. Such tissues must have been deposited from the

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PALAEONTOLOGY, VOLUME 12

exterior, and cannot have been contributed by any single zooid. Again, holdfasts and
colonial supports are massive deposits of outer laminated tissue which cannot have
been secreted from within. Also, skeletal evidence relating to the growth and develop-
ment of carinal nodes, dissepiments, and spinose outgrowths can only reasonably be
interpreted in terms of calcite secretion from an external mantle.

These considerations appear to establish conclusively the former existence of an outer
membraneous investment of fenestellid colonies. The presence of such a structure has
already been hinted at by Shulga-Nesterenko (1949, p. 38) and Elias and Condra
(1957, p. 37), but the latter authors did no more than mention the possibility, while
Shulga-Nesterenko was mistaken in supposing that only a single outer epithelium was
present. Her concept of a system of ‘capillary canals’ and ‘tubules’ which nourished the
external epithelium was also in error, for the ‘canals’ are, in fact, integral parts of the
primary skeleton and were not hollow, while her ‘tubules’ are the solid rods that pierce
the outer secondary skeleton. This author (1941, p. 121) also reported the presence in
FenesteUa of mural pores allowing communication between zooids. Such structures
must be a rarity, for there is no other record of them nor, in spite of careful search, has
the present writer been able to detect any, though they are common in Hornera. It is
likely that in most fenestellids the only means of inter-zooidal communication was by
the circulation of coelomic fluid through the hypostegal space, and that the mantle
epithelia were nourished by this means also. Rod-like structures in the outer secondary
skeleton, which Shulga-Nesterenko mistakenly believed to be tubules connecting zoo-
ecial chambers with the branch periphery, may nevertheless have fulfilled an important
function in connection with the external mantle. This consisted of two epithelia separated
by a coelomic space, the inner epithelial layer being attached to the calcareous wall on
the external side of the latter (text-fig. 2b). Provision would have been necessary to
maintain the outer mantle epithelium in a static position relative to the corresponding
epithelial layer beneath it, and Williams’s (1956, p. 252) suggestion regarding the func-
tion of taleolae in strophomenide brachiopods may have a direct relevance here. It is
possible that, like the taleolae, the tips of skeletal rods in fenestellid bryozoans may have
afforded attachment points for tendons holding the outer epithelium in place. The

EXPLANATION OF PLATE 55

Electron micrographs of single stage negative replicas — cellulose acetate/carbon: shadowed with gold-

palladium at 1 in 1 . All figs, x 3,000; scale at bottom left of Fig. 1 is equivalent to 1 pm.

Fig. 1 . Hemitrypa hibernica M‘Coy. Transverse section of inner laminated tissue lining zooecial chamber
(top right-hand corner). Laminated tissue is in contact with granular (primary) skeleton which
occupies the lower-left part of the field.

Fig. 2. Hornera frondiculata Busk. Transverse section of skeletal layers corresponding to those of Fig. 1,
and in a comparable situation (part of zooecial chamber seen at top left). Here the primary layer
grades into tissue of the outer laminated zone present in the bottom right-hand corner.

Fig. 3. Hemitrypa hibernica M'Coy. Longitudinal section of a branch showing a gradational relation-
ship between granular (primary) and outer laminated skeletal zones.

Fig. 4. Hornera frondiculata Busk. Transverse section of a branch showing development of a granular
lens within the outer laminated zone.

Fig. 5. Hemitrypa hibernica M‘Coy. Longitudinal section of an inter-zooecial wall showing the core of
primary tissue flanked by the inner laminated material lining zooecial chambers.

Fig. 6. Hornera frondiculata Busk. A typical inter-zooecial wall with tripartite structure similar to that
shown in the preceding figure.

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presence in some species of a circlet of these structures around zooecial apertures
appears to emphasize the importance of a stable orientation of the outer mantle wall in
that situation.

The association of proteinous cellular exudation with the formation of calcareous
skeletal substance is now clearly established, and it is also known that secretory epithelia
always produce a cuticular layer before calcite deposition commences. If two such epi-
thelia should be in juxtaposition facing one another, it is therefore logical to suppose

A. B.

outer mantle

text-fig. 2. A reconstruction illustrating the probable relationship between wall epithelia and skeleton
in Fenestella. a, transverse section of branch with external mantle in position; b, exserted polypide
showing the mantle components and communication between hypostegal and zoidal coelomic cavities.

that a layer of cuticle, possibly doubled, would separate them. In the formation of the
fenestellid (and hornerid) wall such a situation must have arisen with respect to the
inner epithelia, and it is implicit in the foregoing account that, after the commencement
of calcareous deposition, the position of the cuticular layer was between the inner
secondary (laminated) and primary wall zones. This inference, initially based on the
absence of a clear gradational contact between those layers, receives support from other
considerations. First, the presence in the outer secondary zone of skeletal rods which
derive from the primary layer, but the complete absence of such structures from the
inner secondary zone. This suggests that the two outer layers had a common origin not
shared with the zooecial lining, and the most likely position for a cuticular partition
within the wall would therefore be on the inner side of the primary layer. Secondly,
carinal nodes, dissepiments and spiny outgrowths consist of a granular core (in con-
tinuity with the primary skeleton of the branch wall) enclosed by outer secondary tissue.
The inner laminated zone is not present, nor is there any axial space which might have
accommodated an epithelium: the core of these structures is quite imperforate (text-fig
3). It is notable, however, that in the axial position there is commonly a trail of dark

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granules extending along the length of the structure concerned. Traced to its origin
this is seen to derive from the junction between the primary layer and the laminated
lining of the nearest zooecial chamber in the adjacent branch. It is therefore possible that
the dark particles mark the former position of a cuticular spindle drawn out from the
partition within the branch wall to provide a base for calcite nucleation. If so, the posi-
tion and derivation of the streams of dark particles confirm the former presence of a
cuticle between the primary and inner secondary wall layers. In addition, the occurrence
of dark trails in axial positions within carinal nodes, dissepiments, and spines adds
weight to the suggestion that the inner laminated skeleton was never present there.

These considerations provide the best available guide to the former position of the
intra-mural cuticle but, assuming that the indications are correct, it is perhaps surprising
that such a partition did not cause the junction between the two wall zones to be more
sharply defined. As an internal cuticle, however, the structure may have been no more
than a film, thick enough only to provide a base for the nucleation of calcite crystallites.
Proof that intra-mural junctions may be poorly defined in detail, in spite of the original
presence of a cuticular layer between the units concerned is afforded by electron micro-
graphs of wall structure in Hornera frondiculata , a living species. These show an obvious
contact between a laminated skeletal overgrowth and an eroded earlier surface of the
same colony (PI. 56, fig. 6). The overgrowth was laid down by the inner epithelium of
the external mantle, and the cuticle associated with that layer must initially have coated
the worn surface on which the overgrowth rests. Yet, although the trend of the contact
is clear in a general way, it is difficult to trace in detail the junction between particles of
earlier and later age, and an interlocking texture between them is locally evident.

For reasons stated above it is probable that the initial non-calcareous branch wall in
fenestellid bryozoans consisted of a threefold repetition of ectodermal epithelium and
associated cuticle. The inner epithelium provided the immediate investment of the poly-
pide, while the outer ones formed the external mantle, a double-walled envelope over
the entire outer surface of the colony (text-fig. 2a). Calcareous wall formation com-
menced with the secretion of granular tissue from the inner mantle epithelium. Deposi-
tion was continuous and relatively rapid as the epithelium migrated progressively
outward during growth, taking the outer mantle epithelium with it. In this way the
primary wall was laid down.

A decrease in the rate of secretion, accompanied by a change from continuous to
intermittent deposition, succeeded the initial phase and is reflected in a transitiona

EXPLANATION OF PLATE 56

Electron micrographs of single stage negative replicas — cellulose acetate/carbon: shadowed with gold-

palladium at I in 1. All figs, x 3,000; scale at bottom left of Fig 1 is equivalent to 1 pm.

Figs. 1, 2. Hemitrypci hibernica M'Coy. Longitudinal sections showing the relationship in peripheral
parts of branches between laminae of the outer skeletal zone and rod-like structures which penetrate
them. Distal to the right in each case.

Figs. 3, 4. Transverse sections in the outer parts of branches in the above species, showing skeletal
rods surrounded by roughly concentric secondary laminae.

Fig. 5. Hornera frondiculata Busk. Transverse section of a skeletal rod penetrating outer laminated
tissue.

Fig. 6. Longitudinal section in the same specimen showing an ‘ unconformable’ junction in the outer
skeletal zone between a slightly eroded old branch surface and a later overgrowth.

Palaeontology, Vol. 12

PLATE 56

TAVENER-SMITH, Fine structure of fenesteliids

R. TAVENER-SMITH: FENESTELLIDAE (BRYOZOA)

295

relationship between the primary and outer secondary skeleton (PI. 55, fig. 3). The outer
laminated investment continued to increase in thickness by the regular addition of
layers at the periphery as long as the colony lived. At the same time, continuous growth
outward from the primary layer persisted at a number of separated points, resulting in
the formation of rods and shafts piercing the laminated tissue. Granular calcite for the
skeletal rods must have been secreted by special groups of cells of the inner mantle
epithelium, in a manner similar to that described by Williams (1968, pp. 39-41 and text-
figs. 23-4) for taleolae in brachiopods.

A.

B.

outer

text-fig. 3. Dissepimental structure in Fenestella. a, transverse section; b, tangential view showing
distorted chambers at root of dissepiment and axial trail of dark granules.

Initial calcareous deposition from the zooidal epithelium (on the inner side of the
primary layer, and separated from it by a cuticular sheet or film) probably followed close
on the formation of the earliest granular tissue. Rhythmic deposition resulted in a
laminate wall structure, but the rate of secretion decreased with time. At the outset it
was relatively fast, causing the formation of wide laminae immediately adjacent to the
primary wall. A progressive decline in the rate is reflected by narrower additions and,
to judge from the number of laminae commonly present, calcareous deposition was not
long maintained.

In addition to comprehending the general sequence of events during wall formation,
it is necessary to inquire into the origin of the secretory tissues, and the way in which
they extended in the course of colonial growth. The nature of the zooidal epithelium is
not in doubt for, following the basic principles of budding in bryozoa, this must have
been an extension of the ancestrular ectoderm. The origin of the external mantle presents
greater difficulty particularly as, in an extinct group, its very existence is hypothetical.
On general grounds, however, it seems probable that it originated as a peripheral
evagination of ectodermal epithelium from the vestibular region of the ancestrula
(text-fig. 4a). The thin but extensive membrane so formed was closely adherent to the

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PALAEONTOLOGY, VOLUME 12

cuticular cover of the ancestrular surface, and commonly extended considerably beyond
this (text-fig. 4b). When calcification commenced the inner mantle epithelium (the mid
one of the three concerned in wall formation) laid down the relatively extensive, but
initially thin, surface encrustation which firmly secured the colony to its substrate, and
from which later growth proceeded. This was referred to by Cumings (1904, p. 58, figs.
44-6) as the basal plate. Later additions of thick, laminated secondary skeletal substance
from the same epithelium commonly converted this structure and the proximal part of
a colony into a massive holdfast. From the earliest stages the inner mantle epithelium
was the main secretory layer, and in comparison only a thin wall was formed from within
the ancestrula. Cumings (1905, p. 171) found that in basal holdfasts of Fenestella the
position of the ancestrula was commonly marked by a minute concavity near the centre
of the lower surface. In some sections, however, a thin wall could be seen flooring the
depression. This must have been formed by the epithelium lining the ancestrula (text-fig.
4d), and contrasts with the massive structure of the surrounding holdfast laid down by
external deposition from the mantle epithelium.

The extension of the external mantle to form a continuous investment over the surface
of a growing colony took place as a logical consequence of budding from the first
individual. This necessarily involved the expanded original membraneous evagination,
and probably followed a pattern like that illustrated in text-fig. 4b-d. As successive
zooids were grouped to form incipient branches, the extremities of these were at every
stage enclosed within the mantle which, by terminal proliferation, continually extended
to form an outer covering pierced only by zooecial apertures. There are strong indica-
tions that zooecial buds at the tips of growing branches were, like the ancestrula,
initially enclosed in cuticular envelopes, and that calcification commenced only after the
attainment of adult size and shape. The tips of perfectly preserved branches from young
fenestellid colonies do not, in the writer’s experience, show calcified chambers that are
partly formed. The last chamber is invariably complete and of adult proportions, though
its wall is extremely thin (so as to be translucent in some cases) and consists of primary
skeleton with little or no laminated secondary investment. Certain subsequently men-
tioned features of dissepimental growth also indicate that the inception of calcareous
secretion post-dated the achievement of adult form.

In fenestellid colonies, as in modern ramose bryozoans, the tips of branches were the
main points of growth, and it is in that situation that the proliferation of epithelial cells
and formation of external cuticle must have taken place. Schneider (1963) has shown
that this is so, for example, in the modern cheilostome Bugula. Skeletal evidence suggests
that just behind the advancing tip of a fenestellid branch, where buds had attained adult
dimensions, the inner mantle epithelium commenced to secrete granular calcite, and
the primary zooecial skeleton was laid down. The secretory phase appears to have oper-
ated as long as growth was maintained, and the deposition of granular tissue was,
therefore, a continuous process as deduced earlier on other grounds. As forward growth
proceeded, earlier formed cells of the inner mantle epithelium were left progressively
further behind, and a second change of secretory regime appears to have taken place.
The deposition of calcite particles, previously continuous, became intermittent, particle
shape changed from granular to platy, and the outer laminated skeleton was formed.
Thus it appears that, by physiological adaptation, a single epithelial layer secreted dif-
ferent products during successive phases of growth (text-fig. 5). This offers a striking

R. TAVENER-SMITH: FENESTELLIDAE (BRYOZOA)

297

A.

external cuticle

E.

text-fig. 4. a-d, earliest stages of a generalized fenestellid colony, showing the suggested origin of the
external mantle from the ancestrula and development of a first generation daughter zooid; e-h, recon-
struction of stages in the formation of the calcareous inter-zooecial wall of Fenestella; e, early non-
calcihed stage corresponding to the dividing wall between zooids in d; f, differential secretion of early
primary skeleton and initiation of inner laminated wall; g, formation of the primary wall: lines repre-
sent the progressive withdrawal of the inner mantle epithelium; h, completely calcified inter-zooecial
wall with beginnings of secondary deposition on the branch exterior.

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PALAEONTOLOGY, VOLUME 12

parallel to the ‘conveyor belt’ principle involved in the construction of the brachiopod
shell (Williams 1956, 1968). It is, in fact, apparent that in matters of wall construction
there are important parallels between at least some brachiopod groups and fenestellid
bryozoans. This is not unexpected, for brachiopods and bryozoans are phyla which,
on more general grounds, have long been considered to show certain affinities.

inner secondary

zone of secondary wall zone of primary wall zone of

formation formation cuticular wall

text-fig. 5. Longitudinal section of a fenestellid branch tip, showing the operation of the ‘conveyor

belt’ principle in skeletal formation.

The sequence of events attending the formation of the calcareous branch wall has
already been outlined, but that concerned with inter-zooecial partitions merits further
discussion. Initially, the deposition of calcite to form these structures probably took
place from the outer surfaces of two layers of inner mantle epithelium occupying back
to back positions within the original soft inter-chamber partition. These originated as
an invagination of the inner mantle epithelium of the branch wall during the budding
process (text-fig. 4 c, d). The formation of inter-chamber partitions by invagination in
a similar way is suggested by Lutaud's (1961) illustration of inter-zooidal differentiation
in the giant buds of Membranipora membranacea. Once primary deposition had com-
menced, the epithelia appear to have retreated inward, towards one another, laying
down granular wall substance as they did so (text-fig. 4f). When the two epithelial sheets
were in contact, the coelomic cavity between them having been occluded, fusion probably
took place beginning at the central point of the wall. The fused epithelium then
developed a central perforation which increased in size in the manner of an opening
iris diaphragm, as the doubled epithelium withdrew radially towards the outer wall of
the branch (text-fig. 4g). During this process calcite crystals secreted from the tips of the
shrinking epithelial lobes filled the central space being vacated and completed the for-
mation of the primary wall (text-fig. 4h). The absence of laminations or growth struc-
tures of any kind within the primary core of inter-chamber partitions must be attributed
to the continuous nature of the depositional process.

Secretion of the inner laminated wall by the zooidal epithelium probably commenced

R. TAVENER-SMITH: FENESTELLID AE (BRYOZOA)

299

at about the same time as, or soon after, the initiation of the primary layer. It then pro-
ceeded in the manner already described, and the completed wall, consisting of a granular
core buttressed on either side by laminated components, no doubt had relatively strong
mechanical characteristics.

In his pioneer work on the early growth of some palaeozoic bryozoa, (Turnings (1904,
p. 64, figs. 47-62) suggested that the median keel, or carina, on the obverse of Fenestella

text-fig. 6. An early stage in the formation of a cup-shaped colony, showing the flange connecting
branch keel and basal plate, a, longitudinal section of colony; b-c, transverse sections of branches at

approximate positions shown in a.

branches originated as an upfold of the basal plate. This was in harmony with his
observation that in many fenestellids (e.g. Fenestella , Unit ry pa, Loculipora , but not
Polypora) zooecial apertures are on the outer face of a cone- or cup-shaped colony.
Consequently, the obverse of a branch, close to the growth origin, is directly adjacent
to the basal plate (text-fig. 6a). A union between the two in this region would have pro-
vided support for the developing branch, and the carina of later growth stages could
be considered as a vestige of the earlier connecting flange. The lower part of such a
structure would have been secreted from an upfold of the epithelium that laid down the
basal plate (i.e. the inner mantle epithelium; that responsible for the formation of the
greater part of the skeleton). It would therefore have consisted initially of granular
primary tissue, and union with the corresponding epithelial layer of the branch would
have led to the formation of a continuous skeletal connecting structure (text-fig. 6b).
Subsequent addition of secondary laminated tissue would have completed the process

300 PALAEONTOLOGY, VOLUME 12

and, beyond the connection with the basal plate, given rise to the orthodox branch
keel (text-fig. 6c).

THE FORMATION OF OTHER SKELETAL ELEMENTS

A logical explanation of the affinities, origin, and growth of other colonial structures
such as carinal nodes, dissepiments, and spinose outgrowths follows from what has gone
before. Transverse sections of these show that they consist of a primary or granular core
enclosed by outer laminated skeleton. A stellate or ‘spider’s web’ pattern is commonly
evident, due to the presence of skeletal rods radiating from the core through secondary
tissue to the branch periphery (text-fig. 3a). There is no inner laminated wall component
nor any hint of the former presence of an axial perforation that might have accommo-
dated a protoplasmic extension from neighbouring zooids. There is commonly observ-
able, however, a trail of dark particles in the axial region (text-fig. 3), and this may be
of organic origin, representing a former continuation into the structure concerned of the
cuticular layer separating primary and inner laminated tissue in the adjacent branch.
A proteinous axial filament of this kind would have afforded a base for the nucleation
of calcite particles.

In the absence of evidence of an internal secretory epithelium it is necessary to con-
clude that carinal nodes, dissepiments, and spinose structures were laid down from the
outside , that they had no direct communication with zooids, and that consequently they
are colonial and not zooeeial features. This conclusion may have important taxonomic
implications, for it is probable that the colonial skeleton (which may be considered as
simply a supporting framework for the constituent zooids) was more liable to external
influences and less rigidly controlled genetically than the individuals within it. This
being so, it is possible that zooeeial characteristics in fenestellid bryozoans will ulti-
mately prove of greater diagnostic value than colonial ones, and that the present tax-
onomic use of such structures as dissepiments and carinal nodes will discontinue. This
has lately been happening in other groups of more modern bryozoa (Lagaaij and
Gautier 1965, p. 39), and many years ago Waters (1896, p. 255) pointed out the futility
of attempting to classify species of Mediterranean reteporids on the basis of slight
differences of colonial meshwork.

Dissepiments in FenesteUa resulted from the union of opposing outgrowths from
adjacent branches (Elias and Condra 1957, p. 29). The sequence of events leading to their
formation probably commenced with the appearance of buds on the flanks of branches,
close to the growing tips. The buds were probably conical evaginations of the outer
mantle: the inner (zooidal) epithelium does not appear to have been involved. There is,
however, a strong indication that growth of the bud was proceeding vigorously while
adjacent zooeeial walls were still flexible, for it is commonly observed that the end of
a zooeeial chamber opposite a dissepiment is drawn out into a shallow cone directed
towards the base of the latter (PI. 53, fig. 1 ; text-fig. 3b). It is difficult to interpret this
as anything but the effect of outward tissue drag due to the growth of the bud. The dis-
tortion must have taken place during the earliest stages of wall development, for it
could scarcely have occurred after calcification had commenced. From the apex of such
a cone a trail of dark granules may continue into and along the dissepimental axis,
suggesting that although the inner epithelium did not extend into the dissepimental
bud, the cuticular sheet between it and the internal mantle epithelium did so.

R. TAVENER-SMITH: FENESTELLID AE (BRYOZOA) 301

The growth of opposing buds towards one another duly led to their contact, and to the
fusion of corresponding epithelia. This may have involved a delicate matching up of
tissues, for it is not uncommon to find on well-preserved dissepiments signs of rotation,
in the curvature of slender parallel ridges, the striae of earlier authors. These follow
the trend of a dissepiment at its ends, but may show a concerted and localized twist
about midway along its length (text-fig. 7 a-b). Condra and Elias (1944, p. 36) suggested
that similar torsional features in the ‘screw’ of Archimedes were caused by current
action, but in this instance it is more likely that they reflect a physiologically induced

A B- C.

bud with

text-fig. 7. The advance of secondary calcification in growth zones of a fenestellid colony, showing
the relationship between distal lobes, longitudinal ridges (or striae) and pustules, a, branch tip, obverse
view; b, the same, reverse side; c, the tip of a silicified spinose structure from which the calcareous

primary core had been removed by etching.

realignment of epithelial tissue strips at the junction between opposing dissepimental
buds. Whatever the precise cause of the rotation, it seems certain that it occurred while
the structure was still flexible, and that the pattern was preserved in the subsequently
formed skeleton.

Union of the buds was followed by calcification, commencing with the formation of
a granular, primary core on a protein base, probably provided by an axial thread. With
advancing time the nature of the secretion changed and laminated tissue was laid down,
also by the internal mantle epithelium. Skeletal rods originating from the primary core
traversed the outer secondary layers and formed minute pustules at the surface. These
are commonly in linear series and tend to occur along the crests of longitudinal surface
ridges. It seems likely that each of the latter corresponded to, and was secreted by, a
definite strip of the underlying epithelium. A similar relationship is evident near the
tips of young branches: secondary (laminated) tissue is not present at the branch tips,
but makes its appearance as a translucent film perhaps 0-5-1 -0 mm. from the ends. Its
advancing front is defined by a number of distally directed lobes and behind the apex
of each extends a longitudinal ridge bearing on its crest a uniserial row of pustules
(text-fig. 7a, b). Borg (19266, p. 309) noted a comparable arrangement in Hornera circtica.

C 6508

X

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PALAEONTOLOGY, VOLUME 12

It seems possible that the secondary skeleton was laid down as a number of independent,
parallel strips which subsequently became welded together, and that the underlying
epithelium was physiologically differentiated to that end.

Carinal nodes, which in many fenestellid species are more suitably described as spines,
have essentially the same structure and origin as dissepiments. They rise from the keel
at more or less constant intervals and an extension of primary skeleton from the branch
wall forms the core of each node. This is enclosed within laminated secondary tissue
which is penetrated by radiating skeletal rods. There is no indication of the former
presence of soft parts within a node, nor of any internal connection with zooecial
chambers. As in dissepiments, however, and probably for the same reason, a trail of
dark granules is commonly aligned along the axis.

In thin section the tips of nodes are bluntly rounded and imperforate, though hand
specimens commonly show broken carinal nodes which, because of non-replacement or
differential weathering, are hollow. This was not the original condition but it has caused
some writers (Condra and Elias 1944, p. 26; Bassler 1953, p. G120; Miller 1961, p. 223)
to speculate on the possibility that the nodes originally housed acanthopores. This
suggestion is quite unsupported by evidence, and seems to have been prompted by the
apparent need to protect the obverse of a colony from predators and from larval
encrustation. It is probably true that the carinal nodes themselves at least partly ful-
filled this purpose by presenting a spiky, unwelcoming aspect. This was particularly so
in the genus Cervella , in which numerous, closely spaced carinal nodes branched distally,
giving a distinctly repellant appearance.

In some genera (e.g. Hemitrypa) the distal ends of nodes divided into several geo-
metrically oriented bars in the same plane as the meshwork. These united with cor-
responding extensions from adjacent nodes to form a regular superstructure. Sections
through superstructure elements show them to have basically the same construction as
other skeletal outgrowths. Calcareous secretion must have taken place from an external
epithelium, there being no trace of an axial perforation to permit the presence of soft
tissues internally. These superstructures also, no doubt, served a protective purpose, and
their formation by the union of symmetrically disposed projections from the ends of
carinal nodes, provides an outstanding example of the closely integrated control that
operated during colonial growth. How such control was effected is unknown, but it
seems reasonable to connect it with the presence of an external colonial mantle and
coelomic cavity for, in the absence of mural pores, the latter presumably afforded the
only means of communications between zooids.

Spinose structures, greatly exceeding the length of carinal nodes, are commonly
present in considerable number and variety. Fenestellid colonies, like certain modern
cheilostomes (e.g. Adeonellopsis) had the ability to develop such outgrowths in many
situations and for many purposes. Slender spines, up to 1 cm. long, may occur in about
equal numbers on the obverse and reverse of a frond, particularly in the proximal
region. In many cases they were evidently supporting struts which acted in association
with a massively calcified basal holdfast. The skeletal organization of spines is identical
to that of carinal nodes, and it appears that a few of the latter developed into spinose
processes by continued growth.

Transverse sections of spines show an identical stellate or ‘spider’s web’ pattern to
that of dissepiments and carinal nodes: there is a primary core of granular tissue, giving

R. TAVENER-SMITH: FENESTELLIDAE (BRYOZOA)

303

rise to radially arranged skeletal rods which traverse outer laminated substance to the
periphery. Rods emerge at the surface as pustules which commonly form uniserial
lines, each following the crest of a longitudinal ridge (text-fig. 7c). These parallel ridges,
which characterize the external surface of spines, are continuous with corresponding
features on the parent branch.

In certain cases spines project laterally from the margin of a fenestrate frond as direct
continuations of branches. These are found in areas where branch growth had ceased,
and are the ‘infertile branches’ of earlier authors. The absence of zooecia from these
continuations is evident not only in the lack of apertures, but also in a marked reduction
of diameter where the ‘infertile’ part of a branch commences. In the absence of median
keel and apertures, longitudinal ridges and grooves are present over the whole surface,
as with other spinose structures. These lateral spines must have resulted from the con-
tinued forward extension of the external mantle after the budding of zooecia within a
branch had ceased. In such circumstances it would not be anticipated that the inner
laminated tissue normally lining zooecial chambers would be present within the exten-
sion, and this is so (PI. 54, fig. 5). However, a trail of dark granules may persist beyond
the last chamber, suggesting that the associated intra-mural protein layer continued
into the axial region of the spine, as in carinal nodes and dissepiments. Increase in length
must have taken place, as in productid spines (Williams 1968, p. 42) by the proliferation
of new epithelial cells at the tip of the structure. Unlike the brachiopod equivalent, how-
ever, the secretory epithelium lay outside the calcareous skeleton, and not within it.

Certain spines, having diverged from a colony, later re-united with it elsewhere. At
the point of re-union the spine may be locally thickened, but immediately thereafter it
divides to form a number of cord-like (ridged and grooved) extensions that ramify along
branches and dissepiments in different directions before becoming attenuated and merg-
ing with the meshwork. It is notable that the pattern of longitudinal ridges on an exten-
sion from the spine tip commonly fails to coincide with that of the branch surface on
which it rests. It would, therefore, appear that a random union between the growing
tip of a spine and another part of the same colony did not involve a matching up of
epithelial tissue strips (and hence, of surface ridge patterns) like that which accompanied
the formation of dissepiments and superstructures. In fact, in these circumstances the
tip of the spine seems to have behaved in a manner similar to that of any supporting
strut from the colony at its junction with a foreign substrate. It must be recalled that
unions associated with the formation of dissepiments and superstructures were between
geometrically opposed skeletal outgrowths of identical type, and therefore of quite a
different nature.

The most reasonable interpretation, based on skeletal evidence, of the sequence of
events when a spine rejoined the colonial meshwork seems to be as follows (text-fig. 8).
At the point of contact the external mantle of the spine divided into a number of slender,
finger-like lobes which diverged to traverse the surface of the meshwork (text-fig. 8a, b).
The outer mantle epithelium of branch and lobe, being in direct contact, subsequently
fused, so that coelomic continuity was established between them. It is probable, however
that skeletal deposition still proceeded independently leading, in the case of each lobe
to the formation of a slender, stolon-like, primary extension of the spine tip (text-fig.
8c). As growth proceeded the addition of concentric secondary laminae enlarged the
diameter of this calcareous ‘stolon’. The inner mantle epithelium secreting the ‘stolon’

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PALAEONTOLOGY, VOLUME 12

was initially separated from its counterpart laying down the branch skeleton by a narrow
coelomic cavity but, as development proceeded, this was progressively reduced. Eventu-
ally the two epithelia must have occupied back-to-back positions, the coelomic space
between them having been completely occluded (text-fig. 8d). At this stage the epithelia
probably fused along a median line beneath each ‘stolon’ and subsequently withdrew
to either side, leaving the structure welded to the outer calcareous branch wall. Later
deposition must progressively have increased the area of contact between them (text-fig.
8e). In essence ‘stolon’ and branch wall developed independently, and it is, therefore,

A.

B. C.

text-fig. 8. A reconstruction of the morphological pattern at a junction between the distal extremity of
a spinose outgrowth and another part of the same colony, a, longitudinal section showing an early-
stage relationship between an extension from the spine tip and the branch surface on which it rests;
b, transverse section at position b in previous diagram; c-e, later stages, suggesting the progressive

coalescence of epithelial layers.

not surprising that, in general, their surface ridge patterns fail to coincide. In a few cases,
however, deposition continued for some time after fusion occurred, so that later skeletal
layers (and their ridge pattern) may be continuous from ‘stolon’ to branch. Excessive
secondary deposition caused the separate entity of the ‘stolon’ to be progressively
obscured by sheets of laminated tissue which, in advanced stages, show a smooth exterior
devoid of pattern.

The proximal extremities of fenestellid colonies, particularly those of mature develop-
ment, commonly show thick, calcareous deposits which weld the skeleton to its substrate
and constitute the holdfast. This structure consisted initially of a thin ‘basal plate’,
secreted from the lower surface of the external mantle where this extended over the
substratum to which the ancestrula was attached. To the primary granular skeleton
there were added, throughout the life of the colony, incremental secondary layers.

R. TAVENER-SMITH: FENESTELLIDAE (BRYOZOA)

305

resulting in a laminated texture and the attainment of massive proportions. Thick,
secondary laminae were also added to adjacent proximal parts of a colony, and branches
in this region became generally enlarged. Associated zooecial apertures were commonly
sealed by a translucent, plate-like deposit, but close examination shows that this is
not an opercular structure, as at first seems possible, but a continuation of the outer,
laminated tissue over the aperture. The translucent appearance is due to the fact that
there is a hollow chamber beneath the thin skeletal seal. In some cases the seal is pierced
by a small central orifice, and the general aspect is then reminiscent of ‘blind cells’ in
certain Cheilostomata (Bassler 1953, p. G156). It is probable that this represents a stage
in the encroachment of secondary material at which the moribund zooid was still able
to function weakly (PI. 52, fig. 6). The occlusion of zooecial apertures in this way pro-
vides a convincing argument for the deposition of skeletal substance from the exterior
and for the former presence of an external secretory mantle.

The presence of an external membrane permitted the effective repair of damage to the
colonial meshwork by the rapid, localized deposition of skeletal tissue wherever and
whenever necessary. Many fenestellid fragments show evidence of this in the smoothly
rounded stumps of what were originally broken branch ends. It seems that after the
damage had occurred (leaving a jagged branch end and torn external membrane) the
lacerated edges of the mantle grew forward over the fractured surface and coalesced
to form an enclosing sheath. The inner epithelial layer then secreted a succession of thin
skeletal laminae, resulting in the formation of a smooth stump which sealed the breakage.
There is, in this process, a strong hint of the considerable powers of regeneration and
mobility possessed by the external mantle. I n other cases dislocated sections of meshwork
were stabilized by the development of supporting struts, or dissepiments of abnormal
length and shape, and by the secretion of masses of secondary calcite which ‘welded’
broken sections together. In such instances the damage clearly acted as a stimulant to
metabolic activity, and the value of copious secretion of secondary material in effecting
repairs is evident.

Nowhere is the remarkable ability of bryozoans to secrete masses of calcite for skeletal
support better illustrated than in the Fenestellidae. The capacity to do so must be
attributed to the presence of an external mantle, which provided a means for the intensive
localized deposition of skeletal material at any point on the colonial surface. In Lyro-
pora , Lyroporel/a, and Anastomopora the framework of branches and dissepiments is
supported by a V-shaped marginal rib originating at the basal holdfast. Its formation
commenced at an early developmental stage, with the selective deposition of outer
laminated tissue on branches at the lateral extremities of a fan-shaped frond. These
rapidly increased in diameter, and secondary accretion in due course attained a consider-
able thickness about zooecial apertures. This led to a progressive increase in the length
of vestibular tubes, which eventually assumed the proportions of shafts several times
the height of zooecial chambers (PI. 54, fig. 6). Such a development clearly had an
adverse effect upon zooids, for signs of declining vigour are evident in a sharp decrease
in the diameter of many shafts at their distal ends. This, in turn, caused a drastic reduc-
tion in the amount of water entering the shaft, a circumstance which shortly led to the
death of the zooid, for the narrowed entrance did not persist for long before being sealed
altogether (PI. 52, fig. 6). All zooecial apertures on lateral branches were eventually
sealed in this way as branch diameters continued to increase by sustained secondary

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PALAEONTOLOGY, VOLUME 12

deposition. With the passage of time other branches close to the frond margins, and
associated dissepiments, were also affected. The selective deposition of calcite in these
areas continued (PI. 52, fig. 4) until the greatly enlarged structures came into contact
and the fenestrules between them were eliminated. As this occurred the external mantles
of branches and dissepiments fused to form a single membrane enclosing the whole
developing support. Successive secondary laminae were secreted from the inner epithe-
lium of this soft envelope, until the support was 8-12 times the thickness of the original
branches (PI. 54, fig. 4; text-fig. 9). Half a dozen or more branches were incorporated in

text-fig. 9. Transverse section of a colonial support in Lyropora. Drawn from a peel (U.S.N.M.

43771-1) of L. subquadrans (Hall) at approximate magnification x 24.

each supporting rib, and between the two extended the normal, fan-shaped fenestellid
meshwork. This growth sequence is abundantly documented in thin sections by the
laminated structure within supports.

Probably the most impressive example of differential skeletal secretion in bryozoa is
provided by the axial ‘screw’ of Archimedes. In this genus a spirally coiled meshwork,
in all other respects identical to that of Fenestella , is supported by a massive central
column with a screw-like flange. Sections show that the frond is continuous through the
axis, and on entering and leaving it the outer laminated tissue of branches shows a pro-
gressive and rapid increase in thickness. The development of the primary skeleton, on
the other hand, remains constant. Careful examination shows that the dense, laminated
tissue composing the support is identical in all respects to that of the secondary skeleton
of branches, with which it is in direct continuity. The colonial axis is penetrated by
innumerable slender skeletal rods, and the origin of these can be traced back to the
primary layer of branches (PI. 53, fig. 2; PI. 54, figs. 1, 2). As with skeletal supports in
Lyropora , zooecial chambers of branches within the screw show the development of
vestibular ‘chimney structures’, and their external orifices were eventually sealed by
secondary tissue. High carinal nodes, present in some species, were also completely

R. TAVENER-SMITH: FENESTELLIDAE (BRYOZOA)

307

immersed in the axial region. There is no doubt that, like other supporting structures,
the screw of Archimedes consists of orthodox secondary skeletal tissue, and only the
shape is unique. The structure represents a massive localized secretion at the axis of
coiling, and the innumerable laminae composing it can only have been added from the
exterior. Sustained selective deposition of calcite in the axial region long after individual
zooids within the screw were dead bears powerful witness to the integrated nature of
growth in a bryozoan colony. It is also incontrovertible evidence of the former presence
of an outer mantle, which provided the means of centralizing calcium carbonate in the
axial region and causing it to be deposited there.

CONCLUSIONS

1 . There is incontrovertible evidence that the major part of the fenestellid skeleton
was secreted from the exterior: the available facts will bear no other interpretation. It is
therefore necessary to infer the former existence of a soft external mantle from which
deposition took place. It is thought that this structure originated as an ectodermal
evagination from the vestibular region of the ancestrula.

2. The inner mantle epithelium was the chief calcite-secreting surface and contributed
the granular ‘colonial plexus’ and the thick laminated tissue on its outer side. The
ectodermal epithelium of individual zooids, on the other hand, laid down only the thin,
laminated lining of zooecial chambers.

3. Study of the wall structure of branches shows that the granular tissue was first
formed, and is therefore primary in origin, while the inner and outer laminated skeleton,
being laid down subsequently, is secondary.

4. Secretion of the colonial skeleton in fenestellid bryozoans probably followed the
‘conveyor belt’ pattern described by Williams (1956, pp. 244-6; 1968, p. 2) for brachio-
pods, a feature of which is the ability of an epithelium to vary its secretory product with
time. The internal mantle epithelium, responsible for the major part of the fenestellid
skeleton, appears to have been proliferated at the tips of growing branches, and to have
secreted in that region a thin cuticular covering. As the branch tip advanced through
growth, and the ‘conveyor belt moved to the rear’, the same epithelium seems to have
laid down in successive phases the primary and then the outer secondary layers of the
calcareous skeleton.

5. Skeletal rods which penetrate the outer laminated zone originate from the primary
layer and are solid. There is no reason to believe that they were ever tubular. They are
an integral part of the wall structure and appear to correspond in all respects with the
taleolae of strophomenide brachiopods. Their function may have been to furnish an
attachment for tendons which held the outer mantle epithelium in position.

6. Carinal nodes and dissepiments have no internal connection with zooecial
chambers, and appear to have been formed quite independently of them. Secretion of
these structures took place entirely from the external mantle and they are therefore of
‘colonial’ not ‘zooecial’ origin. Spinose outgrowths and superstructure bars have the
same basic construction as carinal nodes and dissepiments. Inner laminated tissue, the
characteristic secretion of the zooidal epithelium, is absent from them all.

7. Colonial holdfasts and supporting structures, such as those of Lyropora and Archi-
medes, were formed by massive, localized deposition of secondary tissue from the inner

308

PALAEONTOLOGY, VOLUME 12

mantle epithelium. The repair of damage to a colony was effected by similar means.
The ability of fenestellid bryozoans to form thick skeletal deposits where and when
necessary suggests a high degree of centralized control of physiological effort. It seems
reasonable to associate such control with the external mantle, that being the only
unifying factor between the zooids of a colony.

Acknowledgements. I am indebted to Professor Alwyn Williams, and to the technical staff of the Elec-
tron Microscopy Unit, Queen's University, Belfast, for instruction in the preparation and examination
of some of the material discussed in this paper; also to Professor Gareth Owen of the Zoology Depart-
ment, for advice on histological matters. I wish to thank Dr. Richard S. Boardman and his colleagues
at the U.S. National Museum for their hospitality, the provision of working facilities, and for interesting
discussions in their company. Mr. D. Dean, also of the U.S. National Museum, made many thin
sections and peels, which were of great value. Miss P. L. Cook, of the British Museum (Natural
History), kindly provided specimens of Hornera, and Dr. Boardman readily made available on loan
material in his charge. I am indebted to the Director of the American Museum of Natural History
for permission to use photographs of specimens in that collection. Finally, I wish to acknowledge with
thanks a grant in aid of publication, by the Queen's University.

REFERENCES

bassler, r. s. 1953. Bryozoa. Part G of Treatise on invertebrate paleontology, ed. R. C. Moore, Kansas.
xiii+253 pp.

borg, f. 1926 a. On the body-wall in bryozoa. Quart. Jl. Microsc. Sci. n.s. 70 (4), 595-615.

19266. Studies on Recent cyclostomatous bryozoa. Zool. Bidr. Upps. 10, 181-507.

1965. A comparative and phyletic study on fossil and Recent bryozoa of the suborders Cyclo-
stomata and Trepostomata. Ark. Zool. [2] 17 (1), 91 pp.
condra, g. e., and elias, m. k. 1944. Study and revision of Archimedes (Hall). Spec. Pap. geol. Soc.
Amer. 53, viii + 243 pp.

cumings, e. r. 1904. Development of some Paleozoic bryozoa. Amer. J. Sci. [4] 17, 49-78.

1905. Development of Fenestella. Ibid. [4] 20, 169-77.

elias, m. k. and condra, g. e. 1957. Fenestella from the Permian of West Texas. Mem. geol. Soc.
Amer. 70, ix+158 pp.

harmer, Sir s. F. 1934. The Folyzoa of the Siboga Expedition, Part 3, Cheilostomata, Ascophora, family
Reteporidae. 503-637. Leiden.

lagaaij, r., and gautier, y. v. 1965. Bryozoan assemblages from marine sediments of the Rhone
delta, France. Micropaleontology, 11, 39-58.

levinsen, G. M. r. 1909. Morphological and systematic studies on the cheilostomatous Bryozoa. 431 pp.
Copenhagen.

likharev, b. 1926. Quelques bryozoaires du Permien superieur du gouvernement de Vologda. Bull.

Comm, geol Leningrad, 43, 1011-36 (in Russian with French summary).
lutaud, g. 1961. Contribution a l'etude du bourgeonnement et de la croissance des colonies chez
Membranipora membranacea (Linne), bryozoaire chilostome. An ids Soc. r. zool. Belg. 91, 157-299.
miller, t. g. 1961 . Type species of the genus Fenestella from the Lower Carboniferous of Great Britain.
Palaeontology, 4, 221^42.

nicholson, H. a. and lydekker, r. 1889. Manual of palaeontologie. Blackwood, Edinburgh and Lon-
don. xviii + 885 pp.

ryland, J. s. 1967. Polyzoa. Oceanogr. Mar. Biol. Ann. Rev. 5, 343-69.

1968. Respiration in polyzoa (ectoprocta). Nature, Lond. 216, 1040-1041.

Schneider, d. 1963. Normal and phototropic growth reactions in the marine bryozoan Bugula avicu-
laria. In symposium vol.: The Lower Metazoa. Berkeley, California, 357-71.
shulga-nesterenko, m. i. 1931. A Lower Permian bryozoan, Lyrocladia nov. gen., from Pechoraland.
Ann. Soc. Paleont. de Russie, 9, 47-86 (in Russian with English summary).

1941. Lower Permian bryozoa of the Urals. Akad. Nauk. S.S.S.R., Palaeont. Inst., Palaeont.

(J.S.S.R. 5 (5), 226 pp. (in Russian with English summary).

R. TAVENER-SMITH: FENESTELLIDAE (BRYOZOA) 309

shulga-nesterenko, 1949. Functsionalnoe filogeneticheskoe i stratigraficheskoe znachenie mikro-
struktury skeletnykh tkanei mshanok. Akad. Nauk. S.S.S.R., Palaeonl. Inst. Trans. 23, 67 pp.
simpson, g. b. 1895. A handbook of the genera of the North American paleozoic bryozoa. N. Y. State
Geol. Ann. Rept. for 1894, 407-608.
ulrich, e. o. 1890. Paleozoic bryozoa. III. geol. Surv. 8, 283-688.

waters, a. w. 1896. On Mediterranean and New Zealand reteporae and fenestrate bryozoa. J. Linn.
Soc. (Zook) 25, 255-71.

wilbur, K. M. 1960. Shell structure and mineralisation in molluscs. In Calcification in biological
systems , ed. R. F. Sognnaes. Amer. Assoc. Adv. Sci. 64, 15-36.
williams, A. 1956. The calcareous shell of the brachiopoda and its importance to their classification.
Biol. Rev. 31, 243-87.

1968. Evolution in the shell structure of articulate brachiopods. Spec. Pap. Palaeonl. 2, v+55 pp.

r. tavener-smith
Department of Geology
The Queen's University

Typescript received 21 June 1968 Belfast

THE CROSSED-BLADED FABRICS OF THE
SHELLS OF TERRAKEA SOLIDA (ETHERIDGE
AND DUN) AND STREPTO RH YNC HU S
PELICANENSIS FLETCHER

by JOHN ARMSTRONG

Abstract. The shells of Terrakea solida (Etheridge and Dun) and Streptorhynchus pelicanensis Fletcher lack
physically distinguishable primary layers and consist of superimposed and overlapping sheets parallel to the
surfaces of the shell. Each sheet is composed of parallel tabular blades whose greatest dimensions are parallel
to the sheet. In cross-section a blade has a rectangular outline unlike the secondary layer fibres of rhynchonellids,
terebratulids, spiriferids, pentamerids, and orthids. The blades of a sheet are not usually parallel to the blades
in adjacent co-planar sheets or to the blades of the contiguous underlying and overlying sheets. For this micro-
structural arrangement the term crossed-bladed is proposed to distinguish the structure from the parallel-fibrous
fabrics of the secondary layers of rhynchonellids, terebratulids, spiriferids, pentamerids, and orthids. It is sug-
gested that the blades of a crossed-bladed shell were each deposited by a single outer epithelial cell like the fibres
comprising the secondary layers of rhynchonellid and terebratulid shells.

Williams (1968) has published a very comprehensive and authoritative account of
the mode of deposition of the shells of living representatives of the Terebratulida and
the Rhynchonellida. He has used the data thereby obtained to formulate pictures of the
manner of shell deposition in extinct orders of the Articulata. In the Strophomenida, as
currently constituted, Williams found a number of distinctive micro-structural patterns
and on this basis he has argued for a reappraisal of some existing ordinal and super-
familial groupings. In this paper the micro-structural fabrics of the shells of Terrakea
solida (Productacea) and Streptorhynchus pelicanensis (Davidsoniacea) are described
and the manner of growth of the shells is considered in the light of Williams's interpreta-
tions.

The micro-structural components of the shells of Terrakea solida (Etheridge and Dun)
and Streptorhynchus pelicanensis Fletcher seem to be arranged identically to the com-
ponents of pholidostrophid shells (Towe and Harper 1966). However, in other repects the
shells of each of the first two species are quite dissimilar. Terrakea solida has a pseudo-
punctate shell, whereas the shell of S. pelicanensis is pierced by pores indistinguishable
from true punctae. The presence of the latter structures in shells of Streptorhynchus was
first recognized by Thomas (1958) who pointed out the resemblance of the structures to
punctae rather than to pseudopunctae. However, the shell of 5”. pelicanensis is built of
components quite different from those of other punctate articulate brachiopod shells.
Apart from perhaps necessitating re-examination of the systematic position of Strepto-
rhynchus pelicanensis and its associates, the existence of punctae in shells possessing
entirely different micro-structural patterns would lend support to contentions that
punctae evolved independently in different stocks of articulate brachiopods.

Material and techniques. The specimen of Terrakea solida which was used for the present study is from
the Permian Peawaddy Formation in the Bowen Basin, Queensland. It is from University of Queens-
land, Department of Geology locality L3094, which is a small quarry 27-5 miles from Springsure on the

[Palaeontology, Vol. 12, Part 2, 1969, pp. 310-320, pis. 57-60.1

J. ARMSTRONG: CROSSED-BLADED FABRICS OF SHELLS

311

road from Springsure to Tanderra via Wealwandangie. The co-ordinates of UQL3094 on the Spring-
sure 1 : 250,000 map are 147° 59' E., 24° 21' S. The specimens of Streptorhynchus pelicanensis are from
the ‘ Streptorhynchus pelicanensis bed’ in the Permian Blenheim Formation, also in the Bowen Basin.
They are from UQL3131 which is in the north bank of Pelican Creek just downstream from the small
gully which is 0-2 miles downstream from the junction of Corduroy and Pelican Creeks. Remaining
fragments of all of the specimens are retained in the type collection of the Department of Geology,
University of Queensland and the original specimens are designated by a number prefixed by F. Where
sections of the shells were to be examined, the surface of the section was first polished to the fineness
obtainable with a 1 p powder, and then it was etched for a few seconds with a mixture of 1 per cent of
nitric acid in ethyl alcohol. In the two-stage replication technique employed, the intermediate stage
was nitrocellulose, and subsequent shadowing with a one to one mixture of gold and palladium was at
angles of approximately 30°. In many instances the shell material was neither polished nor etched,
replicas simply being taken directly from exfoliated surfaces of the shell. The figures in Plates 57 and
58 were obtained from exfoliated surfaces of shell whereas all those in Plates 59 and 60, except figs. 1
and 2 in Plate 59, were obtained from polished and etched sections.

The taxonomy of Terrakea solicla and Streptorhynchus pelicanensis is currently being reviewed by
Dr. J. F. Dear of the Geological Survey of Queensland as part of a study of the Permian Stropho-
menida of Queensland.

SHELL STRUCTURE

Pseudopunctae. The concept of a pseudopuncta is based on Kozlowski’s (1929) figures
and descriptions of structures in shells of Strophonella podolica (Siemiradzki), although
Kozlowski did not actually call them pseudopunctae. The structures figured by Kozlow-
ski consist of rods of calcite about which there are internally directed flexures of the
sheets comprising the shell. Kozlowski noted that the structures of Strophonella podolica
were quite distinct from the ‘punctuations’ (punctae, endopunctae) described by Car-
penter (1853) in terebratulids. Kozlowski observed that the traces of the rods (taleolae
of Williams 1956) in the shell will be exposed at the external surface of the shell simulat-
ing a porosity (i.e. simulating punctae) if the outer parts of the shell are lost. Opik (1932,
1934) seems to have been the earliest worker to apply the term pseudopunctae to the
structures described by Kozlowski.

Streptorhynchus pelicanensis Fletcher 1952. No physically distinctive primary layer has
been identified on the studied shells of Streptorhynchus pelicanensis. The entire shell
seems to possess a uniform structural pattern consisting of well-defined sheets disposed
parallel to the surfaces of the shell (PI. 57, fig. 1 ; PI. 58, fig. 3). The sheets are best
observed by replicating exfoliated surfaces of shell without etching the surface. In Plate
57, fig. 1 and Plate 58, fig. 3, the section normal to the shell surface is visible. The sheets
are clearly delineated. The surfaces of the sheets bear sets of parallel ridges and grooves
(PI. 57, figs. 3, 6), each of the grooves being confluent with one of the regular breaks
across a sheet (PI. 57, fig. 1 ; PI. 58, fig. 3). Thus the sheets are composed of parallel
tabular units which are oriented with their greatest dimensions parallel to the sheet
(PI. 57, figs. 1,2; PI. 58, fig. 3). Each of these units will be referred to as a blade and it is
believed that blades may have been deposited in the same way as the secondary layer
fibres of articulate brachiopods with a two-layered shell (see below). Grooves on the
surface of a sheet mark inter-blade boundaries whereas the ridges on the surface of a
heet are the parts of the blades comprising the sheet which interlocked with or infilled
the inter-blade grooves in the base of the contiguous sheet above. In the upper left-
hand corner of Plate 57, fig. 6 the ridges on the surface in the figure are confluent with

312

PALAEONTOLOGY, VOLUME 12

the inter-blade boundaries of the overlying sheet. Similar crossing sets of grooves and
ridges are known in the shells of pholidostrophids (Towe and Harper 1966) and
Marginifera ornata Waagen (Grant 1968) suggesting that these shells are built of micro-
structural units similar to those of S. pelicanensis. Zigzag sutures (PI. 57, fig. 6) often
terminate a set of parallel blades of a sheet and they may or may not mark a change in
orientation of the blades. The sheets of the shell of S. pelicanensis form a continuously
overlapping succession (PI. 57, fig. 2; text-fig. 1b) which results from the mode of growth
of the shell (see below).

On the basis of thin sections Thomas (1958) described the structures of the shells of
a number of species of Streptorhynchus. He pointed out that there is a concentration of
small pores in the shell material comprising the costellae on the shell and that around
each pore the components of the shell are deflected towards the shell’s external surface.
Thomas observed that most of the pores in the shells of his species of Streptorhynchus
are filled with the matrix in which the shell is preserved. He did not detect structures
analogous to the taleolae of pseudopunctae and he noted the resemblance between the
pores in shells of Streptorhynchus and true punctae.

Around each pore of Streptorhynchus pelicanensis the sheets of the shell are deflected
towards the external surface of the shell particularly where the pore is normal to the
shell surface (PI. 60, figs. 1 , 2). The pores are sinuous and in some cases are parallel to the
sheets (PI. 57, fig. 4). Invariably the pores are either void or occupied by a mass of irregular
grains (PI. 57, fig. 4; PI. 58, fig. 4; PI. 60, fig. 2) quite unlike the taleolae of pseudopunctae
(cf. PI. 59, figs. 3, 4). Only in one of the pores examined was the pore partially filled with
grains of calcite but these lack the homogeneity of a taleola (PI. 60, fig. 1). The absence
of taleolae from the pores of Streptorhynchus pelicanensis and the deflection of sheets
adjacent to the pore in an external rather than an internal direction clearly dissociate
the pores from pseudopunctae. On the other hand, as Thomas (1958) suggested, the
pores are very similar to true punctae and seemingly they would have originated from
invaginations of the outer epithelium in a manner similar to that envisaged for the
punctae of terrebratulids (Williams 1956, p. 247). Thomas (1958) identified the same
puncta-like structures in the species Kiangsiella condoni Thomas as he observed in
Streptorhynchus.

Terrakea solida ( Etheridge and Dun) 1909. A primary layer structurally distinct from a
secondary layer has not been observed at the external surface of the shell of Terrakea
solida although a number of replicas were prepared specifically to detect it. In all cases
the external surface of the shell was made up of the same structural components as

EXPLANATION OF PLATE 57

Figs. 1-6. Streptorhynchus pelicanensis Fletcher. 1, UQF56050, three-dimensional aspects of the shell
depicting sheets and blades, x 2,000. 2, UQF56050, transverse section of a number of sheets. The
lateral boundaries of three sheets are visible (see text-fig. 1b), x 2,000. 3, UQF56050, view of the
surfaces of two sheets of the shell showing the characteristic crossing sets of parallel ridges and
grooves (see text, p. 311), x 1,000. 4, UQF56050, section of a puncta parallel to its length showing
the sedimentary infilling of the puncta, x 1,000. 5, UQF56051, longitudinal fracture pattern of a
blade, x 4,000. 6, UQF56050, three-dimensional picture of components of shell and view of a
zigzag suture which transects several blades without displacement of the blades, x 1,000.

Palaeontology, Vol. 12

PLATE 57

ARMSTRONG, Brachiopod shell structure

J. ARMSTRONG: CROSSED-BLADED FABRICS OF SHELLS

313

comprise the remainder of the shell. Shells of Marinurnula mantuanensis Campbell
(1965) from the same locality as the specimen of T. solida have a well-preserved and
readily distinguishable primary layer. Like that of Streptorhynchus pelicanensis the
shell of T. solida is composed of sheets parallel to the surfaces of the shell ( PI. 59, fig. 6).
Surfaces of the sheets display non-parallel sets of grooves and ridges (PI. 58, figs. 1, 2)
and it is inferred that the sheets of T. solida are also composed of tabular blades. As in
Streptorhynchus pelicanensis zigzag sutures often terminate a set of parallel blades (PI. 58,
fig. 6). The sutures may or may not mark a change in orientation of the blades and the
inter-blade boundaries on each side of the suture may or may not be slightly displaced
(PI. 57, fig. 6; PI. 58, fig. 6). The blades of a sheet are disposed with their greatest dimen-
sions parallel to the sheet.

In Plate 58, fig. 2 (text-fig. 1a) there are a number of sheets and several sets of blades.
Surface S is the surface of a sheet (A) whose blades are separated by boundaries repre-
sented by the grooves (a). The ridges on surface S indicate the disposition of the blades
comprising the sheets overlying sheet A. Ridges ( b ) and blade (/) indicate the existence
of a set of blades in one sheet ( B ) overlying A, and ridges (c) indicate the blades of
another sheet (C) which partially overlay A and partially overlay B. Ridges e and /
on blade 1 seem to be extensions of ridges e' and /' (components of set c) on surface S
thus suggesting that sheet C was deposited over sheet B. Sheet C overlapped sheet B
along line x-x. This point of overlap would correspond to x in the transverse section in
text-fig. 1b. Although the transverse section in text-fig. 1b is from a shell of Strepto-
rhynchus pelicanensis the relationship between sheets A , 5, and C in the section corre-
sponds to the relationship inferred to have existed between sheets A , B , and C in Plate
58, fig. 2. The upper surface of sheet A in text-fig. 1b corresponds to surface 5 in Plate
58, fig. 2.

The surfaces of the blades of Terrakea solida and Streptorhynchus pelicanensis display
transverse arcuate corrugations (PI. 58, figs. 1, 5). In some instances there appear to be
similarly developed corrugations in a line across several blades suggesting that the cor-
rugations may represent increments of growth. On T. solida the increments vary from
0-0005 to 0-005 mm. (0-5-5 p) across, and correspondingly their concentration ranges
from about 2,000 to 200 per mm. Small and large increments are intermixed and an
average concentration is of the order of 500 per mm. Where a blade is interrupted by a
zigzag suture parallelism of the arcuate corrugations on a blade and the angular termina-
tion of the blade suggests that the zigzag sutures are produced by halts in the growth of
the blades. Longitudinal fracturing of a blade yields surfaces with a strong fabric-
oriented normal to the sheets (PI. 57, fig. 5; PI. 58, fig. 1). Possibly this texture of the
fractured surface is related to the increments of growth inferred to have been added to
each blade.

The sheets of the shell of Terrakea solida form conical deflections around taleolae
in the shell. The taleolae are oblique and are inclined slightly forwards towards the inter-
nal surface of the shell (PI. 59, figs. 1, 2). In a tangential section of the shell each taleola
appears as a circular core of calcite, of the order of 5 ft in diameter, concentrically
surrounded by sections of the conically arranged sheets around it (PI. 59, figs. 3, 4).
Apices of the cones of sheets are directed towards the internal surface of the shell where
a pseudopuncta (taleola plus conical deflections) usually projects as a small spine
(PI. 59, figs. 1, 2, 3).

314

PALAEONTOLOGY, VOLUME 12

Discussion. Apart from their punctate and pseudopunctate aspects the shells of Strepto-
rhynchus pelicanensis and Terrakea solida are built of identical micro-structural units.
Their shells consist of a continuum of overlapping and superimposed sheets disposed
parallel to the surfaces of the shell. Each sheet is composed of blades with rectangular
cross-sectional outlines. The greatest dimensions of a blade are parallel to the sheet of
which it is a part. Sheets consist of sets of parallel blades and the terminal junctions of
a set are marked by zigzag sutures. The blades of adjacent coplanar or contiguous over-
lying sheets are usually not parallel. Text-fig. lc depicts the arrangement of the blades
in two superimposed sheets. The cross-sectional appearance of the sheets corresponds
to text-fig. 1b and the appearance of the surfaces of the sheets corresponds to Plate 57,
fig. 3 or to Plate 58, figs. 1 and 2. The grooves and ridges on the surfaces of the sheets
are purposely accentuated in the diagram. Grooves a and b are the expressions on the
surface of sheet 1 of the boundaries between the blades comprising the sheet, and grooves
e,f, and g are the boundaries between the blades of sheet 2. Ridges/' and g' on the surface
of sheet 1 are the parts of the blades of sheet 1 which infilled the inter-blade grooves on
the base of sheet 2 corresponding to grooves / and g. Similarly, ridges h /', and / indicate
the presence of a third sheet above sheet 2 in which the blades are ‘crossed’ with respect
to the blades in sheet 2.

Towe and Harper (1966) referred to the above structural arrangement as crossed-
lamellar, a term used to describe a type of shell structure characteristic of certain
Mollusca. In a crossed-lamellar molluscan shell there are three orders of lamellae.
A first-order lamella comprises second-order lamellae oriented transversely with respect
to its length, and each second-order lamella consists of smaller third-order lamellae
oriented parallel to the first-order lamella (MacClintock 1967, text-fig. 19). The sheets of
shells of Streptorhynchus pelicanensis and Terrakea solida are parallel whereas it is the
blades comprising adjacent sheets which have non-parallel orientations (text-fig. lc).
Clearly the term crossed-lamellar should be reserved for shells composed strictly of a
hierarchy of sets of parallel lamellae, and a new term seems to be needed to denote the
arrangement of the components of shells like Streptorhynchus pelicanensis. It is proposed
to name this arrangement crossed-bladded in order to reflect the non-parallel orienta-
tions of the blades in successive sheets. Other shells probably possessing a crossed-bladed
structure are Marginifera ornata Waagen (Grant 1968) pholidostrophids (Towe and
Harper 1966), and some strophomenids (Williams 1968).

EXPLANATION OF PLATE 58

Figs. 1, 2. Terrakea solida (Etheridge and Dun). UQF56053, views of the surfaces of a number of the
sheets which comprise the shell; illustrating the crossing sets of grooves and ridges characteristic of
the surfaces of the sheets of a crossed-bladed shell. Fig. 2 forms the basis for text-fig. 1a; x 1,000
and x 1,500 respectively.

Figs. 3-5. Streptorhynchus pelicanensis Fletcher. 3, UQF56050, three dimensional picture of the sheets
and blades which comprise the shell, x 1,000. 4, UQF56050, section normal to the length of a
puncta showing aspects of the sheets and blades of the shell and the sedimentary infilling of the
puncta, x 1 ,000. 5, UQF5605 1 , view of the surfaces of several blades showing the transverse arcuate
corrugations on the surface of each blade, x 1 ,000.

Fig. 6. Terrakea solida (Etheridge and Dun). UQF56053, view of the surfaces of two sheets showing the
boundaries between blades and the zigzag sutures which terminate a set of parallel blades. Note the
small displacement of the boundaries of the blades across one of the zigzag sutures, x 2,500.

Palaeontology, Vol. 12

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ARMSTRONG, Brachiopod shell structure

J. ARMSTRONG: CROSSED-BL ADED FABRICS OF SHELLS

315

text-fig. 1a. Sketch based on Plate 58, fig. 2. Grooves on the surfaces of the sheets in the figure are
represented by discontinuous lines, and ridges are represented by continuous lines. For a description
see text, p. 313. 1b. Sketch based on Plate 57, fig. 2. For a description of the figure see text, p. 313.
lc. Stylized diagram depicting the nature and arrangement of tabular blades which comprise two sheets
(1 and 2) of a crossed-bladed shell. The symbols on the diagram are discussed in the text (p. 314).

Unfortunately it has not been possible to obtain mosaics from the shells of Strepto-
rhynchus pelicanensis or Terrakea solida. However, the pattern of the mosaic of Juresania
sp. (Williams 1968, pi. 21, fig. 3) suggests that it possesses a crossed-bladed shell and the
mode of growth of crossed-bladed shells can be discussed by compounding data from
this species with information about the species described herein.

SHELL GROWTH

Williams (1968) believed that ‘the key to productine shell deposition is provided by
the micro-structure of the external hollow spines that communicated with canals that
penetrated to the shell interior’. His studies suggested that a spine consists of bands

316

PALAEONTOLOGY, VOLUME 12

(sheets herein) undivided by any consistent pattern of grooves. Williams measured the
periodicity of the bands of strophomenid shells and speculated that banding registered
daily deposition. Internal mosaics of Juresania sp. (Williams 1968, pi. 21, figs. 2, 3)
show the ends of the sets of parallel blades here inferred to have comprised the shell.
Directions of growth of the blades can be determined from the dispositions of the ends
of the blades on the mosaic (Williams 1968, text-fig. 25). Because of the irregularity of
the subdivisions of his bands, Williams did not consider the linear grooves crossing the
mosaic to be coincident with intercellular boundaries. He suggested that such grooves
represented proteinous extensions from the secretory surface of a cell (Williams 1968,
text-fig. 25).

The shells of Streptorhynchus pelicanensis and Terrakea solida are composed of sheets
like the banded strophomenid shells described by Williams but in this case the sheets
are quite regularly subdivided. In a transverse section the apparent widths of the blades
comprising a sheet are a function of the dispositions of the blades of the sheet relative
to the section. Thus in the one section some sheets can appear less closely subdivided
than others. This relationship may explain the appearance of the transverse section of a
valve of Pholidostrophia cf. geniculata Imbrie illustrated by Williams (1968, pi. 21, fig. 1).
A sheet will appear undivided in a section if the blades of the sheet are essentially parallel
to the section. Often a group of several sheets which are closely subdivided will be
followed by sheets apparently undivided. Because of the irregular subdivisions of the
sheets he examined, Williams inferred that each unit of a sheet was not deposited by a
single outer epithelial cell. However, in Streptorhynchus pelicanensis and Terrakea solida
the boundaries between blades are quite regular and the non-appearance of subdivisions
of a sheet in a section is explicable in terms of the variable orientations of blades com-
prising different sheets. The regularity and completeness of the blades of S. pelicanensis
and T. solida suggests that protein was formerly located along inter-blade boundaries
and that each blade may have been deposited by a single outer epithelial cell. The same
relationships may apply to the crossed-bladed strophomenids described by Williams.

The direction of growth of the outer epithelial cells can be inferred from the orienta-
tions of the blades on the internal mosaic of the shell (Williams 1968, text-fig. 25). It
would seem that cells were organized into differently oriented rows, each of which
deposited a set of parallel blades. The ends of sets of blades are visible in Williams
(1968) plate 21, fig. 3. Growth enabled a row of cells to deposit a sheet and as each sheet
grew it concealed and overlapped the sheets of blades deposited by younger rows of
cells. Periodically, portions of the outer epithelium became reorganized into different
groups of cells and then new sets of perhaps differently oriented blades were laid down.

EXPLANATION OF PLATE 59

Figs. 1-6. Terrakea solida (Etheridge and Dun). UQF56053. 1, Thin section of the shell showing

pseudopunctae in the shell projecting as small spines on the internal surface of the shell, X 20.
2, An enlargement by 4 of one of the pseudopunctae in fig. 1 . 3, Section normal to the length of a
pseudopuncta showing taleola and sections of the adjacent deflected sheets of the shell, x 4,000.
4, An enlargement approximately by 2-25 of the taleola in fig. 3. 5, Section of the spinose projec-
tion of a pseudopuncta at the internal surface of the shell. The boundary between the spine and the
enclosing matrix runs down the left-hand side of the figure, x 1,000. 6, Exfoliated surface of the
shell showing the sheet-like character of the components of the shell, X 1,000.

Palaeontology, Vol. 12

PLATE 59

ARMSTRONG, Brachiopod shell structure

J. ARMSTRONG: CROSSED-BLADED FABRICS OF SHELLS

317

One factor which may have precipitated a cellular reorganization could have been the
stress created in the epithelium by divergent and convergent growth directions of differ-
ent rows of cells. The positions of reorganization of the cells at the end of one set of
parallel blades and at the beginning of the next are probably marked by the zigzag sutures
which periodically cross the blades (PI. 57, fig. 6; PI. 58, fig. 6). Continuity of the inter-
blade boundaries across a zigzag discontinuity suggests that the epithelial cells retained
their relative positions and that the zigzag suture is simply a halt in growth. Non-
correspondence of the inter-blade boundaries across a zigzag discontinuity may indicate
that a cellular reorganization took place, displacing the row of cells to a new position,
thereby enabling deposition of a new set of blades. The new blades may or may not be
parallel to the former set deposited by the same row of epithelial cells. Such cellular
reorganizations probably involved small-scale separations of the epithelium from the
blades as envisaged by Williams (1968, p. 46).

If the above inferences regarding the deposition of the blades of Streptorhynchus
peliconensis and Terrakea solida are correct then the blades of a crossed-bladed shell
were deposited in much the same way as the secondary layer fibres of the shells of tere-
bratulids, rhynchonellids, spiriferids, pentamerids, and orthids. In the latter type of
secondary layer the fibres are essentially parallel and are inclined forward towards the
internal surface of the shell. This type of arrangement may be referred to as parallel-
fibrous in order to distinguish it from the crossed-bladed type of fabric discussed above.
If Streptorhynchus peliconensis is a prototype for the crossed-bladed fabric, then the
concept of a parallel-fibrous fabric can satisfactorily be founded on Williams’s description
of the secondary layer of Macandrevia cranium (Muller) (Williams 1968, pi. 6,
figs. 1-4).

In a parallel-fibrous fabric each fibre is a unit to which calcite was continuously
added throughout the life of the shell (Williams 1968, text-fig. 5). On the other hand a
particular blade of the crossed-bladed structure is usually not continuous for any great
distance suggesting that each outer epithelial cell did not deposit a single continuous
blade throughout shell growth. Growth of the crossed-bladed shell would seem to have
been somewhat more irregular than the growth of a parallel-fibrous fabric.

Representatives of the Strophomenacea, Davidsoniacea, Productidina, and Choneti-
dina seem to possess crossed-bladed shells (Towe and Harper 1966; Grant 1968;
Williams 1968) that contain pseudopunctae. Triplesiidine shells may also be crossed-
bladed (Williams 1968, pi. 23, figs. 4-6), but in this case the shell, like some davidsoni-
acean shells, is impunctate. Streptorhynchus (currently considered a davidsoniacean)
possesses a punctate crossed-bladed shell and this condition may also be found to
characterize Kiangsiella (Thomas 1958). Thus in shells with a crossed-bladed fabric
there are forms which are impunctate, pseudopunctate, and punctate. Similarly, in shells
with a parallel-fibrous secondary layer there are impunctate forms (e.g. rhynchonellids,
pentamerids), punctate forms (e.g. terebratulids), and pseudopunctate forms (plect-
ambonitaceans, Williams 1968). The plectambonitacean primary layer (Williams 1968,
p. 37) comprises units (laminae of Williams, 1968) similar to those of a crossed-bladed
shell and Williams (1968, p. 53) homologised this layer with the entire crossed-bladed
shell. Secretion of the parallel-fibrous secondary layer is apparently suppressed in some
plectambonitaceans and Williams suggests that these forms were ancestral to stropho-
menid shells consisting entirely of a crossed-bladed fabric.

C 0508

Y

318

PALAEONTOLOGY, VOLUME 12

Summary. Recognition that regularly shaped and systematically disposed blades com-
prise the shells of Streptorhynchus pelicanensis and Terrakea solida suggests that the
(non-plectambonitacean) strophomenid shell was deposited in a manner comparable
with that which led to the deposition of the parallel fibrous secondary layer of a tere-
bratulid shell. To confirm Williams’s (1968) proposition that the entire (non-plectam-
bonitacean) strophomenid shell is homologous with the plectambonitacean primary
layer, it will be necessary to try to establish the phylogenies of the different types of
articulate brachiopod primary layers and to trace the evolutionary development of the
(non-plectambonitacean) strophomenid shell from the similar but structurally distinct
plectambonitacean primary layer. Currently, data relevant to the solution of these pro-
blems are unavailable. Nevertheless, in the light of the above inferences about the secre-
tion of a crossed-bladed shell, it is clear that the homology suggested by Williams implies
quite different modes of deposition for the primary layers of plectambonitaceans and
terebratulids. Whereas in extant terebratulids intercellular boundaries are not recog-
nizable in the primary layer, it seems probable that the components of the plectamboni-
tacean primary layer were each deposited by a single outer epithelial cell.

The presence of punctae in the shell of Streptorhynchus pelicanensis raises the question
of the systematic position of the genus and its allies. Streptorhynchus is the only stropho-
menid certainly possessing a punctate shell, although work by Thomas (1958) suggests
that Kiangsiel/a , another Carboniferous and Permian genus, may also be punctate. The
fabric of the shell of Streptorhynchus appears to be identical with that of (non-plectam-
bonitacean) strophomenid shells so that Streptorhynchus clearly has affinities with this
group. To firmly establish and to clarify this position, however, it is essential to also
study the fabrics of the shells of other davidsoniaceans now grouped with Strepto-
rhynchus. Moreover, the relationships between the genera will be fully understood only
when the impunctate or pseudopunctate natures of other davidsoniacean shells are con-
firmed. If indeed both Streptorhynchus and Kiangsiel/a are characterized by a punctate
shell then they comprise a distinct stock of punctate davidsoniaceans. Progenitors of
a punctate shell are most probably impunctate ones and currently, as propounded by
Thomas ( 1 958, text-fig. 7), the likely ancestor for Streptorhynchus seems to be the crossed-
bladed apparently impunctate Devonian, Carboniferous, and Permian genus Schucher-
te/la.

NOMENCLATURE

The following terms may prove useful in descriptions of the fabrics of articulate
brachiopod shells. Some of the terms apply to structures already well documented and
others refer to structures discussed herein. For the two most commonly occurring
calcareous layers of articulate brachiopod shells Williams (1968, p. 2 n.) advocates
adoption of the names primary and secondary. This usage will avoid ambiguities which
might arise from the application of such variably utilized terms as prismatic and lamellar.

EXPLANATION OF PLATE 60

Figs. 1,2. Streptorhynchus pelicanensis Fletcher. UQF56053, sections of punctae parallel to their length.
In both figures the external surface is in the direction of the upper left-hand corner of the figure.
Adjacent to each puncta the sheets comprising the shell are deflected towards the shell’s external
surface, both x750.

Palaeontology, Vol. 12

PLATE 60

ARMSTRONG, Brachiopod shell structure

J. ARMSTRONG: CROSSED-BLADED FABRICS OF SHELLS 319

The terms discussed here can be employed to describe either one of the layers of the shell
or the entire shell.

Fibre. A Fibre is a component of the secondary layer of an articulate brachiopod shell
having the characteristic cross-sectional shape of the secondary layer components of
Macandrevia cranium Muller ( Williams 1968, pi. 6, fig. 2). Williams (1968) has concluded
that each fibre was deposited by a single outer epithelial cell and was ensheathed by
protein laid down by this and adjoining cells. Fibres have a characteristic internal mosaic
and their deposition took place relatively continuously throughout growth of the shell
(Williams 1968, text-figs. 4-6). Fibres are characteristic of the secondary layers of
rhynchonellids, terebratulids, spiriferids, pentamerids, and orthids. Williams (1968)
employed the term fibre in this sense.

Parallel-fibrous fabric. This is the name proposed for articulate brachiopod secondary
shell layers that consist of fibres. The fibres are parallel and are inclined forwards at a
low angle from their loci of origin on the inner surface of the primary layer towards the
internal surface of the shell. The fibres of successive rows are alternately placed.

Blade. It is suggested (p. 3 1 1 ) that the tabular components of articulate brachiopod shells
be termed blades. A blade has a rectangular cross-section (PI. 57, figs. 1, 2), is of the order
of two, three, or four times wider than high, and is many times longer than wide (PI. 58,
fig. 2). It seems important to recognize the distinction between components with these
characteristics and components with the features of a fibre as defined above.

Crossed-bladed fabric. The strophomenid (non-plectambonitacean) shell consists of
blades arranged into parallel superimposed overlapping sheets in which the greatest
dimensions of a blade are parallel to the sheet (PI. 57, figs. 1, 2; PI. 58, fig. 3). In a sheet
the blades form sets in each of which all of the blades are essentially parallel. Blades in
successive sheets are neither parallel nor alternate like the fibres of a parallel-fibrous
fabric. Rather, a set of parallel blades in a sheet bears a crossed (non-parallel) relationship
to the blades in adjacent co-planar sheets and to the blades in contiguous underlying
or overlying sheets (text-fig. lc).

Sheet. Crossed-bladed fabrics comprise plate-like or lamellar units parallel to the
surfaces of the shell. However, these terms are already much used in the description of
brachiopod morphology and to preclude multiple applications of names the work sheet
has been employed for these micro-structural lamellar units.

Lamina. According to Williams (1968, p. 38) the plectambonitacean primary layer
consists of tabular units ‘arranged neatly one above the other (pi. 19, fig. 4)’. Williams
proposed to call such units ‘laminae’ and he pointed out that laminae do not lie in alter-
nate rows like fibres. Williams also noted that the tabular blade-like components of the
shells of other (non-plectambonitacean) strophomenids are like the laminae of the
plectambonitacean primary layer, and subsequently he employed laminae to describe
the former. If the crossed-bladed fabric described above is characteristic of non-plect-
ambonitacean strophomenids then there may be a number of differences between the
fabric of the plectambonitacean primary layer and the structure of other strophomenid
shells. Blades of a crossed-bladed shell are not stacked one above the other but are

320

PALAEONTOLOGY, VOLUME 12

arranged into clearly delineated sheets. The blades of a sheet do not bear any systematic
relationship to the blades of underlying and overlying sheets, but are only linked in a
regular manner with other blades of the sheet to which they belong. Thus, apparently,
the fabric of the plectambonitacean primary layer is not closely similar to that of other
strophomenid shells although the basic components involved in each case seem to be
similar. Perhaps lamina should be restricted to the description of components of the
plectambonitacean primary layer and a separate term (i.e. blade) introduced for com-
ponents of other strophomenid shells. Indeed, if a lamina is morphologically inseparable
from a blade, as defined herein, it may be preferable to employ blade in both instances.
Thus parallel-bladed could be invoked to denote the fabric of the plectambonitacean
primary layer, and usage of parallel-bladed and crossed-bladed rather than parallel-
laminar and crossed-laminar may help to avoid confusion with the molluscan shell
structural term crossed-lamellar.

Acknowledgements. I am grateful to the University of Queensland for making available the facilities at
its Electron Microscope Unit. The staff of the unit were most helpful during all phases of the study,
and I am particularly appreciative of the work of Mr. Bob Grimmer who carried out all of the technical
preparations. The work was performed while the author held a Commonwealth Post Graduate Award
at the Department of Geology, University of Queensland. Professor D. Hill, F.R.S. kindly read the
manuscript.

REFERENCES

Campbell, k. s. w. 1965. Australian Permian terebratuloids. Bull. Bur. Miner. Resour. Geol. Geophys.
Aust. 68, 1 14 pp.

carpenter, w. b. 1853. On the intimate structure of the shells of Brachiopods. In Davidson, T., British
fossil Brachiopoda, Palaeontogr. Soc. ( Monogr .), 1, 23-40.
etheridge, r. and dun, w. s. 1909. Notes on the Permo-Carboniferous producti of eastern Australia;

with synonymy. Rec. geol. Surv. N.S.W. 8 (4), 293-304.
fletcher, h. o. 1952. Permian fossils from Southland. Part 1. Permian fossils from the Wairak
district, Southland, New Zealand. Bull. geol. Surv. N.Z. Palaeont. 19, 5-17.
grant, r. e. 1968. Structural adaptation in two Permian brachiopod genera, Salt Range, West Pakistan.
J. Paleont. 42, 1-32.

kozlowski, r. 1929. Les brachiopodes gothlandiens de la Podolie polonaise. Palaeont. pol. 1, 1-254.
macclintock, c. 1967. Shell structure of patelloid and bellerophontoid gastropods (Mollusca). Bull.
Peabody Mas. not. Hist. 22, 1-140.

opik, a. 1932. Uber die Plectellinen. Acta Comment. Univ. Tartu., ser. A, 23 (3), 1-85.

1934. Uber Klitamboniten. Ibid., ser. A, 26 (3), 1-239.

thomas, G. a. 1958. The Permian Orthotetacea of Western Australia. Bull. Bur. Miner. Resour. Geol.
Geophys. Aust. 39, 1 15 pp.

towe, k. m. and harper, c. w. 1966. Pholidostrophid brachiopods: origin of the nacreous lustre.
Science, 154 (3745), 153-5.

williams, a. 1956. The calcareous shell of the Brachiopoda and its importance to their classification.
Biol. Rev. 31, 243-87.

- 1968. Evolution of the shell structure of articulate brachiopods. Palaeontology, Special Paper 2,
55 pp.

JOHN ARMSTRONG

Department of Geology and Mineralogy
University of Queensland
St. Lucia, Brisbane
Queensland

Typescript received 12 July 1968 Australia

THE INTERPRETATION OF GROWTH AND
FORM IN SERIAL SECTIONS THROUGH
BRACHIOPODS, EXEMPLIFIED BY THE
TRIGON IRHYNCH1I D SEPTALIUM

by PETER WESTBROEK

Abstract. Some possible misinterpretations of serial sections through brachiopod shells are discussed; the
trigonirhynchiid septalium is taken as an example. Growth-lines in transverse sections suggest that a septalium
may have arisen either by fusion of the inner hinge plates or by division of the septum. However, it can be
shown that, when the whole structural complex is considered and not only sections through it, the question
whether the septalium has grown in either of the two manners becomes meaningless. The suggestion given by the
growth-lines in the sections depends on a number of factors, such as the direction and the location of the section,
the ontogenetical age of the specimen, and the three-dimensional shape of the septum and septalium. The shape
of the septalium in the transverse sections is determined by the same factors as the manner of growth, and the
same applies to the size. It is therefore dangerous to distinguish between septalia which are wide and narrow in
transverse sections and to use this distinction as a character in systematics. A good description can be given
when a three-dimensional reconstruction is taken as a starting-point. Measurements of the septalium and the
septum which may be used for statistical treatment, can be performed on a projection of the septalium and the
septum on the plane of symmetry and on specially selected sections.

The serial sectioning technique is commonly applied to the study and interpretation of
the internal structure of fossil brachiopod shells. Generally, transverse sections are taken
through the shell, and acetate peels taken of the sectioned surfaces. These peels may
show the form and structure of the internal elements very clearly, but interpretation of
the sections is liable to error, and it is, therefore, opportune to point out and to correct
possible misinterpretations more methodically.

The problem can best be elucidated by considering transverse serial sections through
the septalium of, for instance, trigonirhynchiid rhynchonellides. Williams and Rowell
(1965) define this term as: ‘troughlike structure of brachial valve between hingeplates
(or homologues) consisting of septalial plates (or homologues) and buttressed by median
septum; does not carry adductor muscles’ (text-fig. 1).

It is of interest to examine how earlier authors have considered the septalium. The
following selection of quotations may demonstrate that there is disagreement as to
how a septalium grows. Leidhold (1920, p. 354) introduced the term in the following
manner:

Als Septalium bezeichne ich die loffelformige bis dreieckige Aushohlung zwischen den geteilten
Schlossplattchen der Dorsalen, entstanden durch eine Gabelung des Dorsalseptums an seinem hin-
teren Ende und Verschmelzung der Gabelstiicke mit den Schlossplattchen. Das Septalium ist nicht zu.
verwechseln mit dem Cruralium der Pentameraceen, das durch Verwachsung der Cruralplatten
entsteht.

In 1928 (p. 11) he gave the following definition:

Eine durch Spaltung der Dorsalseptums an seinem hinteren Ende hervorgegangene dreieckige bis
loffel-formige Aushohlung zwischen den beiden Schlossplattchen.

(Palaeontology, Vol. 12, Part 2, 1969, pp. 321-32, pi. 61. 1

322

PALAEONTOLOGY, VOLUME 12

This definition is charged with a statement about the genesis of the structure: it is formed
by division of the median septum. This led to a small yet significant confusion in brachio-
pod literature.

1. Wisniewska (1932, p. 6) stated:

Par le nom de septalium Leidhold a designe une fossette formee par des lamelles allant de la plaque
cardinale au septum, avec lequel elles s’unissent en forme d’un Y. En apparence le septalium est forme
par la bifurcation du septum, mais en realite, comme on le constate dans les sections transparentes, le
septum ne se divise pas, ce sont les rebords internes inflechis de la plaque cardinale qui viennent se
souder a son extremite posterieure.

text-fig. 1. Trigonirhynchia pcireti. (De Verneuil, 1850), Emsian,
NW. Spain. Three-dimensional reconstruction of brachial interior
from serial sections. (After Westbroek, 1967.)

It is surprising, however, to observe that in at least one of the three drawings of these
transparent sections through the brachial valve (Wisniewska’s fig. 1 b) the course of the
growth-lines clearly displays an incipient bifurcation of the septum, the two ends uniting
halfway along the septalial plates with the dorsally growing ends of the hinge plates.
This use of the term septalium by Wisniewska is in contradiction with the original
definition of Leidhold.

2. Cloud (1942, pp. 10-11) proposed a new term, crural trough, which more or less
corresponds with the term cruralium as designated by Leidhold. Cloud’s definition is:

A ventrally concave structure at the posterior of the dorsal valve of some terebratuloids, formed by the
basal convergence of crural plates to form a duplex median septum, while their ventral ends remain in
context with the edges of the outer hinge plates. The crural trough so formed is then the median portion
of one kind of a cardinal plate ... A crural trough is not the same as a septalium (Leidhold, 1920,
p. 354), which is a structure of similar appearance in the Rhynchonellacea formed by the forking of the
dorsal median septum at its posterior end.

P. WESTBROEK: SERIAL SECTION INTERPRETATION

323

It appears as though Cloud concluded that the crural trough is formed by basal
convergence of crural plates because he found it associated with a duplex median septum.
A duplex median septum consists of a median ‘intraseptal lamella’ and of laterally
flanking shell deposits with a different structure and earlier thought to have arisen by
an incomplete fusion of these flanks, which in this case would be dorsal prolongations
of the crural plates. The underlying assumption that the flanks of the septum were first
separately formed and then fused together is in plain contrast with the fact that septa
are secreted in a single epithelial fold. Williams and Rowell (1965, pp. H113-H114) and
Williams (1968, p. 35) have correctly observed that the difference in structure betweeen
the intraseptal lamella and the flanks of the septum is due to a local difference in secre-
tory activity of the surrounding epithelium. (See also Krans (1965, p. 104) and West-
broek (1967, pp. 30-4)).

3. Cooper (1959, pp. 9-10) makes, inter alia, the following statement concerning the
septalium:

In a few genera of Recent and Tertiary, Frieleia for example, the median septum joins folds from the
inside of the crural bases to form a small chamber at the posterior. . . . These [i.e. the hinge plates]
do not seem to constitute a septalium in the true sense of the word as defined by Leidhold (1928, p. 1 1)
who says that the median septum divides to produce the chamber. Wisniewska (1932, p. 6), on the other
hand, states that the septalium of the Mesozoic rhynchonelloids is formed by internal inflection of the
hinge plate to meet the median septum. This seems to be the method of formation of this structure in
Frieleia rather than division of the median septum.

4. Sartenaer (1961, p. 6), finally, wants the term to denote exclusively a certain form:

Ce terme n’est, a nos yeux, que descriptif, et nous estimons qu’il est premature d’en reduire la portee,
vu que la signification morphologique et fonctionnelle est loin d’etre comprise dans le groupe qui nous
occupe.

Another interesting point is, that Sartenaer distinguishes in many of his descriptions
between amphora-shaped and cupula-shaped septalia, the former enclosing a narrow
and the latter a wide cavity in transverse sections. Actually, many authors make this
distinction, but generally another terminology is used to designate both types of sep-
talia.

Two conclusions can be drawn from this cursory survey of the relevant literature.
Firstly, that uncertainty exists as to whether the septalium has originated by division of
the septum or by fusion of the hinge plates, and secondly, that distinction is often made
between septalia which are narrow and amphora-shaped or wide and cupula-shaped in
transverse sections. In the following account these two matters are dealt with successively.

Terminology. The term septalial plates is taken to mean the lateral walls of the septalium, irrespective
of the way they have grown. The inner hinge plates are those parts of the septalial plates which have
originated by dorso-medially directed growth starting from the sub-horizontal outer hinge plates or
from the crural bases. This term approximately corresponds with the crural plates as conceived by
Cloud (1942, p. 10). In the following account it is demonstrated that both terms — inner hinge plates
and crural plates — when used in this sense are not helpful, and are best avoided altogether.

The problem of how the septalium grows can be investigated by the study of growth-
lines in serial sections through the structures concerned. In living brachiopods the inner
shell surface is lined with an outer epithelium which is responsible for the shell secretion.
In both valves this epithelium extends towards the commissure and the growth of the

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PALAEONTOLOGY, VOLUME 12

outer shell surface is the result of a corresponding increase in size of the outer epithelium.
Along the inner surface of the shell, and thus also along the surface of the internal shell
structures such as the septum and the septalium, shell material is deposited at a rate
which varies from one position to another. Old inner shell surfaces are thus buried in the
subsequently deposited shell material. They intersect the outer shell surface as growth-
lines and run more or less parallel to the actual inner shell surface which, of course, can
be considered as the final one (text-fig. 2). Thus, they can only be studied in sections

text-fig. 2. The position of growth-lines and growth surfaces in
the shell. (After Westbroek, 1967.)

through the shell and on the outer shell surface. Old inner shell surfaces which are recog-
nizable as such are termed growth surfaces and in the sections they appear as growth-
lines. These growth-lines enable the reconstruction of the growth process of the shell.
It is, however, often far from easy to detect growth-lines in sections. Rhynchonellid
shells mainly consist of calcite fibres which normally make very acute angles with the
inner shell surface and intersect the growth surfaces. When the fibres are cut according
to their long axes they are liable to be mistaken for growth-lines; when they are trans-
versely cut, however, their arrangement may be such that the growth-lines can be more
easily followed (PI. 61, fig. 3). In the literature one often finds drawings of serial sections
in which the fine structure has been indicated in some detail. Such drawings are certainly
much more useful than the black spots which are normally given, but often the growth-
lines and the fibres are not properly distinguished. In spite of the fact that they are

EXPLANATION OF PLATE 61

Figs. 1, 2. Pivchomaletoechia cf. gonthieri (Gosselet, 1887), Cremenes Limestone (Frasnian-Famennian
boundary), NW. Spain. 1, Transverse section through septum and septalium of gerontic specimen.
Septalium consists entirely of hinge plates and is amphora-shaped, x 40. 2, Transverse section
through septum and septalium of adult specimen. Bi-furcating septum; septalium is cupula-shaped
and consists partly of outgrowths of septum and partly of inner hinge plates, X 40.

Fig. 3. Trigonirhynchia paretHDe Verneuil, 1850), Emsian, La Vid Formation, Cantabrian Mountains,
Spain. Transverse section showing transition between septum and septalium. Fibres of secondary
shell are transversely cut, and growth-lines can be traced. The course of these growth-line suggests
a bifurcation of the septum. X 150.

Palaeontology, Vol. 12

PLATE 61

WESTBROEK, Transverse sections of septa and septalia

P. WESTBROEK: SERIAL SECTION INTERPRETATION

325

generally not very clearly defined, the growth-lines in the sections can often be traced,
though with some difficulty so that at least an impression can be obtained of how the
different shell structures have grown.

Text-fig. 3 a shows a section through the brachial valve of a specimen of Ptychomale-
toechia cf. gonthieri (Cremenes Limestone, Frasnian-Famennian, N. Spain; see West-
broek, 1964). Growth-lines have been drawn wherever they could be identified. It appears
that the septum grew from the bottom of the valve in ventral direction until point A
was reached. There it divided into two elements which grew symmetrically in both

text-fig. 3. Plychomaletoechia cf .gonthieri (Gosselet, 1887), Cremenes Limestone (Frasnian-Famen-
nian boundary), NW. Spain. Transverse sections in umbonal part of brachial valves. Growth-lines have
been indicated, a, Section through adult specimen, showing bifurcation of the septum, the cupula-
shaped septalium consisting of the resulting outgrowths of the septum and of the inner hinge-plates.
b. Section through gerontic specimen. Amphora-shaped septalium, consisting of inner hinge plates,
which have united at their dorsal end and then have fused with the monocarinate septum.

ventro-lateral directions. Each outgrowth of the septum then met a corresponding inner
hinge plate growing dorso-medially, so that a full-grown septalium arose (PI. 61, fig. 2).
This type of growth is intermediate between the manner of growth of Leidhold’s
septalium and Cloud’s crural trough and might warrant a new term. However, inspec-
tion of text-fig. 3 b, which represents a section through the brachial valve of another,
more gerontic, specimen from the same locality and most probably also belonging to
P. cf. gonthieri (PI. 61, fig. 1) shows both septalial plates to consist entirely of the inner
hinge plates which have grown in dorsal direction, then have united and finally con-
nected with the median septum which has remained mono-carinate during its entire
growth. This structure complies with the crural trough of Cloud and cannot be con-
sidered as a septalium as conceived by Leidhold.

The questions now arise as to how these differences may be interpreted and how
important they are systematically. The relation between the structural types of the
septalium becomes clear when the three-dimensional shape of this element and not only
plane sections through it are taken into consideration. Text-fig. 4 gives a schematic
three-dimensional representation of the septum and septalium. For convenience sur-
rounding structures are omitted. The structural complex displayed radiates as a whole
from the umbo, from which it has actually grown approximately anteriorly, whilst also
thickening. Text-fig. 5 a represents a projection of the septum and septalium on the
median plane. Line AB represents the connection between the two elements. In this

a

b

326

PALAEONTOLOGY, VOLUME 12

projection the structure has grown by a gradual anterior shifting and a concomitant en-
largement of the anterior boundary. A series of growth stages is also represented in text-
fig. 5 a. They actually constitute the projections of the anterior boundaries of a series
of successive growth surfaces which, as we have seen, envelop each other. By means of
this figure two arbitrary points, P and Q , can be located so that P is the older and was
first reached by the anteriorly growing structure. Assuming that the number of growth

text-fig. 4. Schematic three-dimensional representation of septum and septalium.

surfaces at a particular point in the projection corresponds with the number of drawn
anterior boundaries which are successively intersected by a line connecting that point
with the final anterior boundary, then that number is 3 for P and 2 for Q. Consequently
it is possible to reconstruct the course of the growth-lines in any section perpendicular
to the plane of symmetry.

An attempt is made to reconstruct a section RS (text-fig. 5a). Point T obviously is the
oldest point cut by the section; the number of growth-lines will be maximal here. From
T in the direction of S progressively younger parts of the structure are cut, and the
number of growth-lines decreases until V is reached, where the plane of the section is
tangential to the anterior boundary of a growth surface. Consequently, V is the youngest
point cut by the section and the number of growth-lines reaches its minimum here.
From V to W the age of the structure and the number of growth-lines increases again.
Point U represents the boundary between the septum and the septalium in the section.
Since V is situated ventrally in relation to U the course of the growth-lines in the section
must suggest a division of the septum (text-fig. 5b).

P. WESTBROEK: SERIAL SECTION INTERPRETATION

327

TU and UW are the projections of the section through the septum and the two septalial plates,
respectively. Consequently the number of growth-lines is duplicated from U ventrally. This, of course,
has not been taken into consideration in the above argument.

The course of the growth-lines can be reconstructed likewise in section R'S' (text-fig.
5a), and since in this section V' is situated dorsally in relation to U' the septalium will
consist here entirely of the hinge plates; these plates even fuse to form the most ventral
part of the septum (text-fig. 5c).

text-fig. 5. a. Projection of a septum and septalium on the plane of symmetry; a series of early growth
stages is represented, b. Section RS through this septum and septalium. c, Section R S' through same

structure.

Thus, it is demonstrated that there is no fundamental difference between a septalium
which is formed partly or entirely by bifurcation of the septum and one which has been
brought about by fusion of the inner hinge plates. It all depends on the relative positions
of U and V in the section: when U is situated dorsally in respect of V the septum bifur-
cates; when it is situated ventrally of V the hinge plates fuse together.

The relative position of U and V depends on a number of factors. As we have seen,
the direction of the section is important (text-fig. 5). Since generally the sections are
taken perpendicularly to the plane of the commissure and since the angle between the
most posterior part of the outer surface of the brachial valve and the plane of the com-
missure increases according to the ontogenetical age of the specimen, V tends to be
situated more dorsally relative to U, and thus the septalium tends to be more completely
constituted by the hinge plates in older specimens (text-fig. 6 top). The effect of the
location of the section is determined by the general curvature of the structure (text-fig.
6 bottom). Posterior sections generally show a septalium which consists more fully of
the hinge plates than more anterior ones. Another important factor is, of course, the
shape of the structural complex. Differences, for example in the course of the anterior
boundaries of the growth surfaces, may have an effect on the sections, as represented in
text-fig. 7 (top), and differences in the line of connection between the septum and the

S'

R’

a

b

c

328

PALAEONTOLOGY, VOLUME 12

septalial plates naturally also affect the relative position of U and V. In many species the
anterior boundaries of the septum and the septalium are not continuous: the septum
protrudes a little beyond the septalial plates, anteriorly as well as ventrally, in lateral

text-fig. 6 (Top) The influence of the ontogenetical age of the specimen on the shape and structure
of the septum and septalium in the section. (Bottom) The influence of the location of the section on the
displayed shape and structure of the septum and septalium.

view, and it seems to have more individuality, to be a more ‘primary’ structure. Recon-
structions of sections through a structural complex of this type are given in text-fig. 7
(bottom). It appears that a division of the septum may be suggested in certain sections,
the septum then tending to divide ventrally into three parts. A growth pattern in which
the septalial plates first unite and then fuse with the septum can hardly occur, the direct
fusion of the septalial plates being prevented by the intermediate septum in the sections.

When in a piece of wood the annual rings run as indicated in text-fig. 8 there is no
particular reason to conclude that the whole tree has originated by fusion of two

P. WESTBROEK: SERIAL SECTION INTERPRETATION

329

originally independent structures, one growing upward from the root and the other
downward from the top, although for the represented section itself this assumption
certainly holds good. For the same reason the question whether the septalium has grown
by bifurcation of the septum or by fusion of the hinge plates makes sense only as long
as sections through the structure are considered and it becomes irrelevant as soon as the
entire structure is taken into consideration. Campbell (1965, p. 13) appears to have

text-fig. 7 (Top) The influence of the shape of the anterior boundary of the septum and the septalium
on the structure of these elements in tranverse sections. (Bottom) Two sections showing the effect of the
protrusion of the septum beyond the septalial plates, anteriorly as well as ventrally.

understood this when he characterizes Cloud’s distinction between a septalium and a
crural trough as ‘singularly unhelpful since it is concerned only with appearances and
not with origins’. The cardinalia must be considered as a single though complicated
structural complex which grows as a whole from the umbo anteriorly. During this pro-
cess it increases in size but does not change essentially in shape. Division of a septum
would mean that originally only one septum would occur in the shell, and that at a
certain moment in the ontogenetical development two distinct septa would arise out
of this single septum by accretional growth in front of it. This would mean that the
cardinalia would change essentially in shape during growth. A similar reasoning can be
applied to the process of fusion. In other words: terms like division and fusion are

330

PALAEONTOLOGY, VOLUME 12

top

meaningless unless they refer to a process which takes place within a time-interval
which is small relative to the entire period of growth : before this time-interval the struc-
ture concerned is not divided or fused, and afterwards it is.

A few conclusions may be drawn concerning the terminology of the elements. Since
the criteria by which the terms ‘septalium’ and "crural trough’ are distinguished are
invalid, there is good reason to reject the term ‘crural trough’. To denote the lateral

walls of the septalium the terms ‘inner hinge plates’ and
‘crural plates’ are quite inappropriate for the reasons given
■r — — ! — Y"f / j above. Instead, the use of the term ‘septalial plates’ is
\ it ill/ recommended.

\ 1 1 1111/ The shape of the septalium as it appears in the section is

\ \ I /// determined, as is the course of the growth-lines, by the
^ \ ^ / 1 1 1 1 direction and the location of the sections on the one hand

and by the three-dimensional shape of the whole structure
on the other, and the same applies to the size. The influence
of the direction of the section on the shape can be
I / * \ \ visualized by reference to sections RS and R'S' in text-fig. 5,

jj \ \ \ \ which show a wide, cupula-shaped, and a narrow, amphora-

f J! i 11 \ \ shaped, septalium, respectively. Text-fig. 6 (top) illustrates

J f i 1 \ \ \ the influence of the age of the specimen : in young specimens

/If 1 \ \ 1 the sections tend to show a wider septalium than in old

ones. An extreme instance of this effect was demonstrated
by Rouselle (1965), who showed the shape of the septalium
to be affected beyond recognition in transverse sections
through old specimens of mesozoic Rhynchonellida and
Zeilleriacea. In view of the structure anteriorly from the
umbo, sections through the posterior part of the septalium
will be generally relatively narrower than more anteriorly
located ones (text-fig. 6 bottom). Sartenaer’s distinction between amphora-shaped and
cupula-shaped septalia is therefore deceptive.

The shape of a septalium can only be illustrated accurately after a three-dimensional
reconstruction. A method for the preparation of three-dimensional reconstructions after
serial sections is described by Westbroek (1967, p. 12). Enlargements of the sections are
drawn on thin glass plates which are then mounted in a way as to be appropriately
situated relatively to each other. Stereophotographs are then prepared of this arrange-
ment and the reconstruction is drawn by means of a stereoscope. The drawing of the
reconstruction is, even under these circumstances, a difficult procedure, and probably
the mere representation of the stereo-photographs will do as well, or sometimes even
better. A shortcoming of the three-dimensional reconstructions is that they only provide
a realistic impression of the shape of the structure, without giving measurable data which
can be expressed numerically and are suited for computation. For such an elaboration,
the projection of the septum and septalium on the plane of symmetry and the sections
themselves together give a lot of reliable information. Such a projection can easily be
constructed by drawing a lateral view of the specimen before sectioning, then by marking
the location of the sections in this drawing as exactly as possible, and finally by indicat-
ing in the drawing the relevant data of each section, such as the point of fusion of the

root

text-fig. 8. Annual rings in a
piece of wood. The manner in
which the tree has grown in this
section differs from the manner
of growth of the whole tree.

P. WESTBROEK: SERIAL SECTION INTERPRETATION

331

septum and the septalium, the youngest point cut by the section and the ventral boundary
of the septalium. Connection of the corresponding points provides the projection
requested. For statistical computation the following may serve as measureable variables :
the depth of the septalium at its anterior boundary, the distance between the anterior
boundary and the beak, the height of the septum at the anterior boundary of the sep-
talium and the unrolled length of the base of the septum. The width of the septalium

text-fig. 9. Some variables, a , b , c , and d , which can be measured in the projection
of the septalium and the septum on the plane of symmetry and on a specially selected
section, and which can be used for statistical treatment.

at its anterior boundary is another important variable; it can be found in a selected
section (text-fig. 9). A statistical treatment of these measurements would of course be
a most laborious procedure, since serial sections must be made through a considerable
number of specimens in order to obtain a significant sample. Consequently, this method
can only be applied in very special cases, e.g. when the discrimination between two
species is very difficult and when the collections are very large.

The considerations given above can be applied to many structures which increase in
size by accretionary growth, especially to other brachiopod shell elements such as the
pentamerid spondylium. Even in the interpretation of sedimentary structures — which
often display a striking analogy to brachiopod shells — similar problems may arise.

Acknowledgements. I wish to express my sincere gratitude to Professor A. Brouwer of the State Univer-
sity of Leiden (Netherlands) and to Professor A. Williams of the Queen’s University in Belfast (Nor-
thern Ireland) for reading the manuscript of this paper and for giving valuable advice. 1 am also indebted
to Mr. W. C. Laurijssen who provided the photographic work; Mr. F. J. Fritz who prepared most of
the text-figures; and Miss M. L. van Leeuwen who typed the manuscript.

Campbell, k. s. w. 1965. Australian Permian terebratuloids. Bur. Min. Resour. Aust. Bud. 68, 146 pp.,
17 pi.

cloud, p. e. 1942. Terebratuloid Brachiopoda of the Silurian and Devonian. Spec. Pap. geol. Soc.
Amer. 38, 182 pp., 26 pi.

REFERENCES

332 PALAEONTOLOGY, VOLUME 12

cooper, G. a. 1959. Genera of Tertiary and Recent rhynchonelloid brachiopods. Smithsonian Misc.
Coll. 139 (5), 90 pp., 22 pi.

krans, th. f. 1965. Etudes morphologiques de quelques spiriferes devoniens de la Chaine cantabrique
(Espagne). Leiclse geol. Meded. 33, 74-148, 16 pi.

leidhold, c. 1920. Beitrag zur genaueren Kenntniss und Systematik einiger Rhynchonelliden des
reichslandischen Jura. Nenes Jb. Miner., Geol. Paldont. Beil Bd. 44, 343-68, pi. 4-6.

1928. Beitrag zur Kenntniss der Fauna des rheinischen Stringocephalenkalkes, insbesondere

seiner Brachiopodenfauna. Abh. preuss. geol. Landesanst. n.f. 109, 99 pp., 7 pi.

rouselle, l. 1965. Sur la mise en evidence, par sections transversales, du septalium des Rhynchonelli-
dae (Brachiopodes). C.R. somm. Soc. geol. France 6, 207-8.

sartenaer, p. 1961. Etude nouvelle, en deux parties, du genre Camarotoechia Hall & Clarke, 1893.
lre partie: Atrypa congregata conrad, espece-type. Ball. Inst, royal Sci. nat. Belg. 37 (22), 11 pp.,
1 pi.

westbroek, p. 1964. Systematique et importance stratigraphique des rhynchonelles du Calcaire de
Cremenes (Devonien superieur. Province de Leon, Espagne). Leidse geol. Meded. 30, 243-52, 2 pi.

1967. Morphological observations with systematic implications on some Palaeozoic Rhynchonel-

lida from Europe, with special emphasis on the Uncinulidae. Ibid. 41, 1-82, 16 pi.

williams, a. 1968. Evolution of the shell structure of articulate brachiopods. Spec. Pap. Palaeont.
2, 55 pp., 24 pi.

and rowell, a. j. 1965. Morphology. In Treatise on invertebrate paleontology (ed. Moore, R. C.)

Part H, Brachiopoda , 1, H57-H155. Lawrence (Univ. of Kansas).

wisniewska, m. 1932. Les rhynchonellides du Jurassique Sup. de Pologne. Palaeont. Polonica , 2 (1),
1-72, 6 pi.

peter westbroek

Geologisch-en Mineralogisch Instituut
der Rijksuniversiteit
Garenmarkt, Leiden
Netherlands

(address until August 1970)
Department of Biochemistry
Queen’s University
Belfast

Typescript received 15 July 1968 Northern Ireland

SOME BRITISH WEALDEN MEGASPORES AND
THEIR FACIES DISTRIBUTION

by D. J. BATTEN

Abstract. Three new species of megaspores, viz. Thomsonia alata sp. nov., T. fairliglitensis sp. nov., and
Minerisporites alius sp. nov.; and four records, viz. cfA. Arcellites medusus (Dijkstra 1951) Potter 1963,cfB.
A. medusus, cfB. Thomsonia pseudotenella (Dijkstra 1951) Madler 1954 and cfB. Minerisporites marginatus
(Dijkstra 1951) Potoni6 1956, are described from the British Wealden. Scanning electron microscopy resolved
sculptural and structural details not revealed optically. Aspects of the distribution of megaspores in Wealden
sediments are discussed. Assemblages with the greatest abundance of megaspores have been recovered from
unsorted grey and brownish grey non-calcareous silts which contain sand and clay and a few small plant frag-
ments; they are believed to have been derived from the local vegetation.

As part of an investigation of Wealden palynological facies, selected rock samples have
been examined for megaspores and associated microfossils. Numerous well-preserved
megaspores have been recovered and some are recorded here for their stratigraphical
importance (see Hughes 1958).

Megaspores are frequently difficult to study by light microscopy because of their size
and the often dense opaque nature of their exine. Problems which cannot be resolved
frequently arise concerning the interpretation of certain structural or sculptural features.
To assist in solving these problems, electron microscope techniques have been employed
by some workers (e.g. Pettit 1966, Stainier 1965, and others). Scanning electron micro-
scopy used here has yielded information not revealed optically and has resolved features
which might have been open to misinterpretation from optical examination alone.

Sample preparation. 50 grams of rock were soaked in 20 vol. H202 solution, and then in
cold 50% HC1 if calcareous; the residue was then sieved, treated with HF, sieved again
(using a 100-mesh sieve on both occasions) and picked by brush from water. Several
selected specimens of the same species were mounted on "Durofix’ spots on 12-mm.
specimen holders and coated with gold-palladium or aluminium for examination with
the ‘ Stereoscan ’. Other specimens were mounted dry or treated for 20 min. with con-
centrated HN03, cleared in dilute NH4OH, mounted in a Clearcol film and sealed by
DePeX.

Storage. Coated specimens have not been designated as types or included in the recorded
data, as it is not known how long they will keep; they were of course taken from topo-
type material. The holders have been stored in individual dust-proof tubes.

Remarks. The diagnoses and descriptions of the new species have been based on obser-
vations of not less than 100 specimens. Adequate comparisons with similar species in the
literature are not always possible because of the insufficiently detailed descriptions of
some previously published species. When the diagnoses and descriptions of the records
described here can be fitted into or are more or less similar to the diagnoses and descrip-
tions of previously described species, they are called by that species name, but prefixed

[Palaeontology, Vol. 12, Part 2, 1969, pp. 333-350, pis. 62-67.]

C 6508 Z

334

PALAEONTOLOGY, VOLUME 12

by cfA, cfB or cfC, following the procedure recommended by Hughes and Moody-Stuart
(1967). At a later date after further detailed examination of similar spores from other
horizons it may be necessary to give some of these records formal species names. The
holotypes designated are translucent mounts.

The sectioning technique employed was that described by Hughes, Dettmann, and
Playford (1962); the sections were mounted in glycerine jelly. The colour classification
of the rock samples is from the Rock Colour Chart (1963) published by the Geological
Society of America. Stage co-ordinates refer to Leitz Laborlux (LI) microscope, number
557187, Department of Geology, Cambridge University. The slides have been deposited
in the Sedgwick Museum palynology collection.

RECORD

Anteturma sporites H. Potonie 1893
Turma triletes (Reinsch 1881) Dettmann 1963
Subturma pyrobolotriletes Potonie 1956
Genus arcellites (Miner 1935) Ellis and Tschudy 1964

Type species. A. disciformis Miner 1935, p. 600, pi. 20, fig. 64.

cfA. Arcellites medusas (Dijkstra 1951) Potter 1963

Plate 62, figs. 1-1 1 ; Plate 63, fig. 1 ; Plate 67, figs. 1, 2, 4, 10

Sample. CUC 442, Cuckfield No. 1 Borehole, Sidnye Farm, Sussex, England (TQ 2962 2729), depth
442 ft.; Upper Tunbridge Wells Sand, Hauterivian. Brownish grey (5 YR 4/1) consolidated poorly
sorted silt; small cuticle and wood fragments present. Prep. MT 395: megaspores recovered; 88%
cfB Minerisporites marginatus (Dijkstra 1951) Potonie 1956, 8% Thomsonia cilata sp. nov., 3% cfA.
Arcellites medusas (Dijkstra) Potter 1963, and 1% cfB. Arcellites medusas (Dijkstra) Potter 1963.

Description. The mean and observed limits of the maximum diameter of the spore body
(i.e. excluding the appendages and the neck) of this trilete megaspore are 146 (236) 319 p
(standard deviation 42-8 p, coefficient of variation 18-1%; 100 specimens). The amb is
circular or subcircular in outline. The neck is conspicuous, tapered, has an ill-defined
base and is lacking in precise form. The maximum diameter of the neck (75 (142) 240 p,
75 specimens) is generally at its base; the maximum length (75 (145) 224 p, 67 specimens)
is generally shorter than the diameter of the spore body (64 specimens) although occa-
sionally (3 specimens) it may be slightly longer. It is a dimension which is difficult to
measure with accuracy since the line of contact between the neck walls and the spore

EXPLANATION OF PLATE 62

All scanning electron micrographs.

Figs. 1-11. cfA. Arcellites medusas (Dijkstra 1951) Potter 1963. 1, 10, 11, Specimen on holder (SH)DB
7. 1, Laterally compressed, leaves of neck partly opened out, X 100. 10, Same, neck detail; X 500.
1 1 , Same, base of appendage showing grooves and irregular ring-shaped thickenings ; X 1 ,0000
2,5, Specimen on (SH) DB 11. 2, Obliquely compressed; X 100. 5, Same, neck detail; X250.
3, 4, 6, Specimen on (SH) DB 11. 3, Compressed asymmetrically laterally with appendages incom-
pletely formed and/or broken ; X 250. 4, Spore body exine, x 500. 6, Same ; X 250. 7, Specimen
on (SH)DB 1 1 , spore body exine structure ; x 1 ,000. 8, 9, Specimen on (SH)DB 11. 8, Appendages
connected at bases by ridges; x500. 9, Same; x250.

Palaeontology, Vol. 12

PLATE 62

BATTEN, Early Cretaceous megaspores

D. J. BATTEN: BRITISH WEALDEN MEGASPORES

335

body is variable and indistinct. It appears as if the neck is formed by 6 segments or leaves
but, in view of the fact that the leaves are generally fused together along their length,
microscopic examination has not fully substantiated this. The leaves are extensions of
the outer layer, or ektexine, of the spore body exine. They are thickest at their bases,
becoming gradually thinner towards their extremities. They are fused at their margins
forming upward-directed ridges and are usually folded inwards between these ridges
(PI. 62, fig. 3). Their basal configuration is similar to that of Arcel/ites vectis (Hughes)
Potter 1963 (see Hughes 1955, text-fig. 1). Splitting has occurred along the length of the
ridges on some (9) specimens with the result that one or more of the leaves have (partly)
opened out. The unopened necks of some specimens appear to be somewhat shrivelled.

Within the neck is an irregular conical chamber 45-60 p high and 30-45 p wide at
the base (seen on 3 specimens only). Weakly developed leasurae with slight adjacent
thickening are at the base of the neck and completely enclosed by it (PI. 67, fig. 4), the
neck being an elevated specialized extension of the ektexine rather than upturned exten-
sions of the triradiate lips. The observed length of the rays is 47-73 p (3 specimens). The
triradiate mark is only visible if some of the neck leaves have been partially removed
(PI. 67, fig. 4).

The total thickness of the two layered exine is 9-20 p (PI. 67, fig. 10). The inner layer,
or endexine, is homogenous, forming a smooth wall to the central lumen, and is 1 (2-5)
4 / x thick (31 specimens). The nature of the exine stratification is based on optical obser-
vations of whole and sectioned specimens. The outer layer has a spongy constituency
and is very thick (7-18 p). The thickness in an individual may be more or less constant
or rather variable. Ridges up to 30 p high and round swellings up to 30 p high and 30 p
in maximum diameter may be present. At the outer edge of the outer layer, the sporo-
pollenin units become discontinuous and the wall texture is more open and porous in
appearance. This part of the wall is composed of anastomosing bars up to 5 /x wide,
separated by interstitial ‘spaces’ 1 p or less wide and up to 2 p deep (PI. 62, figs. 7-11;
PI. 63, fig. 1). The bars on the appendages are usually aligned more or less parallel to
their length (PI. 62, fig. 1 1) but on the central body they are generally more irregular.
The interstitial spaces between the bars on the appendages tend to be deeper when the
walls are thinner than usual; this may be the result of wall shrinkage. Scattered irregular
rings of thickening 0-2 p wide and 1-3 p in diameter (PI. 62, figs. 7, 1 1 ; PI. 63, fig. 1 )
may also be present on the outer surface. They are not resolved optically. The number
of appendages is variable (6 (13) 22; 94 specimens). They are tubular, commonly slightly
constricted 5-40 p above their bases but gradually increase in diameter towards their
apices. They are commonly twisted and curved towards the spore body; their bases may
be connected by body ridges (PI. 62, figs. 8, 9); and their walls are thick except towards
their apices where they become much thinner. Their dimensions vary: minimum width,
1 1 (24) 36 /x ; maximum width, 21 (48) 85 /x; length 95 (246) 435 /x (based on measurements
of 100 appendages from specimens picked at random). A few are apparently malformed,
being twisted and ‘lumpy’ (PI. 67, fig. 9) and some of these lack expanded tips and are
much shorter (maximum length, 73 p) than normal. Four clusters (groups of two or
more spores held together by interlocking appendages) of spores were recovered.

Preservation and compression. The specimens are generally well preserved but the neck
and one or more of the appendages per specimen are frequently broken. There is a

z 2

336

PALAEONTOLOGY, VOLUME 12

tendency for corroded specimens to have thinner and more crinkled neck-leaves and
appendages than usual. The spores are spherical or sub-spherical if uncompressed, but
most are compressed, usually in lateral or asymmetrically lateral aspect. Hughes (1955)
has pointed out that such compression indicates that the top of the spore below and at
the base of the neck is the most rigid part. The exine of the spores cfA. A. medusus
is thickest at the base of the neck and this part of the spore is strengthened further by the
neck ridges which extend on to and over part of the spore body.

Remarks. The wall structure of cfA. A. medusus is similar to that of some modern spores
of SelagineUa. The acetolyzed megaspore wall of Selaginella mainly consists of a very
thick spongy outer layer and a much thinner inner layer which is not more than ^ of the
total thickness of the exine (Pettit 1966). In addition, electron micrographs of Sela-
gineUa selaginoides (in Afzelius, Erdtman, and Sjostrand 1954), S. myosurus (in Martens
1960, and Stainier 1965), S. kraussiana (in Stainier 1965) and S. pulcherrima (in Pettit
1966) have shown that the outer layer of the exine is composed of anastomosing bars of
sporopollenin and that interstitial ‘spaces’ occur between them. Electron micrographs
of S. pulcherrima show that, at the outer edge of the outer layer, the sporopollenin units
become discontinuous and the wall texture is more open and porous in appearance.
Towards the inner limit of the layer, the sporopollenin elements gradually become
reduced in thickness and less widely spaced (Pettit 1966). The thin-walled expanded
apices of the appendages may be deflated bladders.

Distinction

Local. CfB. A. medusus (Dijkstra 1951) Potter 1963 is smaller, has fewer appendages,
and the proportions of the length of the neck relative to the diameter of the spore body
are different.

Literature. A. disciformis (Miner 1935) Ellis and Tschudy 1964 differs chiefly in that it
has a longer and different neck structure and shorter, wider body appendages. The body
of A. hexapartitus (Dijkstra 1951) Potter 1963 is covered with short blunt appendages,
the neck is longer and the leaves are usually slightly twisted in an anti-clockwise

EXPLANATION OF PLATE 63

All scanning electron micrographs.

Fig. 1. cfA. Arcellites medusus (Dijkstra 1951) Potter 1963 to show structure of spore body exine,
x 2,000; (SH)DB 7.

Figs. 2, 3, 5, 7, 8. cfB. A. medusus (Dijkstra 1951) Potter 1963. 2, 5, 8, Specimen on (SH)DB 7.
2, Lateral aspect, x200. 5, Spore body (shrunken?) with rings of thickening. 8, Same, rings of
thickening; x 4,000. 3, 7, Another specimen on (SH)DB 7. 3, x 500. 7, Sculpture similar to that
on A. minis , rings of thickening only weakly developed, x 500.

Figs. 4, 6, 9-15. Thomsonia alata sp. nov. 4, Proximal polar view; X 50, (SH)DB 11. 6, 15, Specimen
on (SH)DB 10. 6, Distal surface collapsed, concave, pressed against inner surface of convex

proximal face; x 100. 15, Distal sculpture; x 250. 9, Part of triradiate appendage, loosely con-

nected to adjacent appendage; x 2,000, (SH)DB 11. 10, 1 1, Another specimen on (SH)DB 10. 10,
Sculpture, proximal face; x 500. 1 1, Compressed laterally; X 100. 12, Reticulum and pitting;

x 1,000, (SH)DB 7. 13, Part of proximal lumen and murus showing pitting; x 3,000, (SH)DB 7.

14, Distal sculpture; x 500, (SH)DB II.

Palaeontology, Vol. 12

PLATE 63

a&B&m

S^lk . • ' JT T» .

BATTEN, Early Cretaceous megaspores

D. J. BATTEN: BRITISH WEALDEN MEGASPORES 337

direction. Pyrobolospora vectis Hughes 1955 has a greater number of appendages which
are different in shape, extend from low ridges and are thin walled.

Comparison

Local. Similar specimens have been recovered from only one other horizon in the Upper
Tunbridge Wells Sand, and from two core samples of 1 Wealden’ (see Lees and Taitt
1945) from the Kingsclere No. 1 Borehole, one (K475) from near the upper limit of the
‘Wealden’ (probably Upper Barremian (see Kemp 1968) or Aptian (Hughes 1958)) and
the other (K777) from 302 feet below this (Valanginian (Hughes 1958)).

Literature. Although it is very likely that the species A. medusas described by Dijkstra
(1951) is the same as the cfA. A. medusus described here, satisfactory comparison is not
possible since Dijkstra ’s description is insufficiently detailed and is based on only four
specimens. Hughes (1955) recovered a specimen from K777 which he assigned to A.
medusus , and which I regard as indistinguishable from my specimens.

A sub-sample of some of the type material was processed, but no specimen of A.
medusus was recovered although many other megaspores were seen.

cfB. ArceUites medusus (Dijkstra 1951) Potter 1963

Plate 63, figs. 2, 3, 5, 7, 8; Plate 67, figs. 5-7

Sample and preparation. As for cfA. A. medusus (Dijkstra 1951) Potter 1963; 27 specimens recovered.

Description. The mean and observed limits of the maximum diameter of the spore body
(i.e. excluding the appendages and the neck) of this small trilete megaspore are 44 (71)
98 p (standard deviation 14 p, coefficient of variation 19%; 27 specimens). The average
size of the spore including the appendages and neck is rather less than 200 p. The amb is
circular or subcircular in outline. The neck is similar in form to that of cfA. A. medusus,
but is usually less tapered and has fewer and more weakly developed upward extending
ridges and thus possibly fewer leaves, although the exact number has not been deter-
mined. The leaves are commonly thin and may be (partly) membraneous (10 specimens).
They may be folded inwards between the ridges. Splitting has occurred along the length
of the ridges of some (10) specimens and consequently one or more of the leaves have
(partly) opened out. The width of the neck is 39 (60) 90 p (23 specimens), slightly less than
or equal to the diameter of the spore body. The widest part is usually at the base. The
length is greater than (1 1 specimens) or more or less equal to the length of the spore
body diameter (48 (78) 155 p; 23 specimens). The neck chamber was not seen. The
laesurae are at the base of the neck and are completely enclosed by it. They are relatively
short (12-14 p; 2 specimens only) and weakly developed.

The total thickness of the two layered exine is 5-9 p; the inner layer is 1-2-5 p thick
(6 specimens); the thickness of the outer layer is irregular (4-8 p) and is usually greatest
at the bases of the neck and the appendages. The outer layer of the spore body has a
spongy consistency. At the outer edge of the outer layer the wall texture is more open in
appearance and in addition irregular, occasionally anastomosing bars of sporopollenin
up to 5 p wide, separated by interstitial spaces 0-5-1 p wide and up to 3 p deep are usually
present (PI. 63, figs. 5 and 7). In addition, scattered irregular rings of thickening 0-5 p

338

PALAEONTOLOGY, VOLUME 12

wide and 2-4 p in maximum diameter (PI. 63, fig. 8) are present on the outer surface.
Swellings up to 13 p high are present on the body of one specimen. One other specimen
has scattered verrucae with rounded bases on the corpus, 6-9 p in diameter and 1-2 ix
high. There are few body appendages (2-7) and these are tubular, similar in structure
to those of cfA. A. medusus although their basal diameter may be greater than the
diameter of their tips (9 specimens), and their walls may be thin (membraneous) and
crumpled for their entire length (PI. 67, fig. 7). Their dimensions (based on measurements
of 53 appendages) vary: minimum width, 11 (19) 47 /x ; maximum width, 17 (33) 55 p;
length, 55 (84) 125 p. Clusters of specimens were not recovered.

Preservation and compression. The preservation state of the specimens observed is good,
but some are pitted and three are slightly corroded. All are compressed laterally or
asymmetrically laterally. Some have a shrunken appearance (e.g. PI. 63, fig. 5).

Distinction. This record is probably an abortive form of cfA. A. medusus. It has been
found only in one sample (CUC 442) associated with that species. Until more evidence
of an association has been found it has, however, been excluded from it, on the basis of
size, number of appendages and the proportions of the neck relative to the diameter
of the body of the spore. In addition, the rings of thickening tend to be more strongly
developed (PI. 63, figs. 5, 8).

Turma barbates Madler 1954
Genus thomsonia Madler 1954

Type species. T. reticulata Madler 1954, p. 150 pi. 5, fig. 15.

\\vV * \\eTe.-s

Thomsonia alata sp. nov.

Plate 63, figs. 6, 9-15; Plate 64, figs. 1-5, 7, 9, 12; Plate 67, figs. 3, 8
Type sample amt preparation. See under cfA. ArceUites medusus (Dijkstra 1951) Potter 1963.

Diagnosis. Megaspore, trilete. Mean maximum diameter of spore body (i.e. excluding
equatorial outgrowths and sculpture) 451 p ; standard deviation 53-5 p (100 specimens).
Spore body spherical or subspherical if uncompressed, circular to convexly triangular

EXPLANATION OF PLATE 64

All scanning electron micrographs.

Figs. 1-5, 7, 9, 12. Thomsonia alata sp. nov. 1, Part of equatorial interradial zona; x 1,000; (SH)DB
11. 2,1, Another specimen; (SH)DB 11. 2, Triradiate lips, detail at equatorial radial outgrowth;
x 100. 7, Distal sculpture; X 500. 3, Proximal view; x 50, (SH)DB 3. 4, Distal view; X 50,
(SH)DB 7. 5, Distal surface, part removed, x 100; second specimen, (SH)DB 7. 9, Lateral view;
x50, third specimen, (SH)DB 7. 12, Proximal face; x 100, fourth specimen, (SH)DB 7.

Fig. 6. cfA. Thomsonia fairlightensis sp. nov. from sample DB 170, Fairlight Clay; part of triradiate
lips and proximal sculpture; X 250, (SH)DB 1.

Figs. 8, 10, 11, 13-16. Thomsonia fairlightensis sp. nov. 8, 10, (SH)DB 15. 8, Narrow equatorial
interradial ridge and sculpture on either side (proximal and distal); x 500. 10, Sculpture, detail

showing pitting; x 2,500. 11, Detail of triradiate lips and adjacent appendages; x 250, second

specimen. (SH) DB 15. 13, 16, Third specimen, (SH)DB 15. 13, Oblique view; x 100. 16, Detail
of triradiate lips; X 500. 14, Lateral view; x 100, fourth specimen, (SH)DB 15. 15, Obliquely

compressed; x 100, fifth specimen, (SH)DB 15.

PLATE 64

Palaeontology, Vol. 12

BATTEN, Early Cretaceous megaspores

D. J. BATTEN: BRITISH WEALDEN MEGASPORES

339

in polar view. Total thickness of two layered exine, 4-9 p: inner layer 1-3 p thick; outer
layer 2-5-6 p (excluding sculpture). Sculpture reticulate. Tapered hair-like or spine-like
appendages (capilli) frequently extend from points where the muri connect with each
other (PI. 63, fig. 10). On the distal face, the capilli are generally 35-100 p long (longest
observed near or at the distal pole) and 3— 1 5 /x in basal diameter. There are usually fewer
capilli on the proximal surface than on the distal and these tend to be shorter; occasion-
ally they are virtually absent. Near the laesurae, however, considerably longer capilli
with basal diameters up to 15 p are usually present (longest observed, 2\5 p). The muri
are tapered, < 1-4 /x wide (at base) and 5-12 p in height. The exine is also pitted in a
regular manner (PI. 63, figs. 12, 13); the pits are 0-5-1 -5 /x in diameter and up to 1-5 /x
apart.

The trilete mark extends to the outer margin of the radial equatorial outgrowths and
is bordered by ‘fibrous’ labra from which extend flattened (broadest parallel to the lae-
surae) blunt-ended appendages (7-13 per ray) of similar structure; the ‘fibres’ are 0-5-4
H x in diameter (PI. 63, fig. 9). Although most are separated except near their base, some
may be partially or entirely connected along their length (PI. 67, fig. 8). The observed
limits of the maximum width of the appendages are 8-45 /x; their lengths, including the
basal (undissected) part of the labra range from 84 to 440 p; they are usually longest
at the proximal pole and shortest on the radial outgrowths. The equatorial outgrowths
are ribbed, variable in shape and size (120-440 p long, 143-407 /x wide) and structurally
similar to the triradiate appendages; the outer margin is usually serrated (PI. 64, fig. 4).
More or less equatorial, arcuate ridges connect the radial outgrowths and may project
as lamellae (PI. 64, fig. 9) up to 88 p wide. The lamellae are structurally similar to the
radial outgrowths but lack ribbing; the outer margin is irregular.

Holotype. Slide preparation MT 395/14, LI 41-7 1 16-2; pi. 67, fig. 3.

Description. The observed limits of the maximum diameter of the spore body are 352—
605 j a. The coefficient of variation is 1 1 -8%. The mean and observed limits of the lateral
diameter of the spore body are 313 (393) 495 p (16 specimens). Sometimes the triradiate
appendages are connected only at their extremities.

Preservation and compression. The state of preservation of the material is good, with a
tendency for the capilli to be shorter on corroded specimens. Specimens are commonly
compressed in polar or asymmetrical polar aspect but 20 are compressed laterally; these
tend to have rather longer appendages than average bordering the laesurae which
would, at the time of their deposition, have counteracted the effect the equatorial
outgrowths usually had in bringing about a polar orientation. Dehydration of many
specimens has led to the collapse of parts of the spore wall; the collapsed wall may be
concave and (closely) pressed against the inner surface of the opposite, convex face.

Distinction

Local. CfB. Thomsonia pseudotene/la (Dijkstra 1951) Madler 1954 and Thomsonia
fairlightensis sp. nov. are smaller, have smaller equatorial radial outgrowths and their
triradiate lips and sculpture are different.

Literature. Thomsonia pseudotenella (Dijkstra 1951) Madler 1954 lacks a reticulum and
the equatorial radial outgrowths are smaller; T. phyllicus (Murray 1939) Potonie 1956

340

PALAEONTOLOGY, VOLUME 12

is smaller and lacks pronounced equatorial radial outgrowths; T. reticulata Madler 1954,
T. thorensis Madler 1954 and T. granulata Madler 1954 have smaller radial outgrowths,
T. granulata also has granulate and warty sculpture; T. dakotaensis Hall 1963 has smaller,
differently shaped radial outgrowths and the margins of the laesurae are different;
T. midas (Dijkstra 1951) Madler 1954 and T. divisa (Dijkstra 1951) Madler 1954 are
verrucate; T. mensura (Harris 1935) Potonie 1956, has different sculpture and lamel-
lae, a shorter triradiate mark and is without radial outgrowths; Minerisporites ales
(Harris 1935) Potonie 1956 has a different sculpture and the triradiate flange is more or
less complete; Triletes datura Harris 1961 is smaller, the appendages extending from
triradiate lamellae are shorter and arcuate lamellae different in nature; species of Tenel-
lisporites Potonie 1956 lack radial outgrowths and possess a zona with finger-like
projections.

Comparison. Local. Specimens of cfA. Thomsonia alata have been recovered from other
horizons in the Upper Tunbridge Wells Sand.

Thomsonia fairlightensis sp. nov.

Plate 64, figs. 10, 11, 13-16; Plate 67, fig. 14

Type sample. DB 51, Fairlight Glen, near Hastings (TQ 8523 1063) approximately 50 ft. above shore;
Fairlight Clay d (White 1928, p. 22) Berriasian. Medium dark grey (N4) medium silt, frequent plant
remains. Preparation MT025; megaspores uncommon but several species present; Thomsonia fair-
lightensis is the most abundant.

Diagnosis. Megaspore, trilete. Mean maximum diameter of spore body (i.e. excluding
equatorial outgrowths and sculpture) 224 /u. ; standard deviation 26-5 p. Spore body
more or less spherical if uncompressed. Total thickness of the two layered exine, 4-8 p;
inner layer 1-2 p thick; outer layer 3-6 p. Sculpture, a reticulum. The muri are widest
(up to 7 p) at their bases and where they intersect (PI. 64, fig. 8); between intersections
they are up to 5 p wide basally. They are tapered, rapidly becoming membraneous,
1 1 p in maximum height between connections, highest (up to 23 p) where they intersect,
the nodes of the reticulum net being prolonged to form short simple appendages. On
the proximal face, the appendages (capilli) rapidly increase in length near to and are
considerably longer (up to 140 p) adjacent to the triradiate lips (PI. 64, figs. 1 1, 13-15);
they are simple or (occasionally) forked, straight or curved, rounded or flattened in
cross-section and up to 25 p broad. The lumina are rounded or (occasionally) rather
irregular in shape, 3-34 p in diameter. Regular pitting of the exine is also present; the
pits are small (0-25-0-75 p in diameter) and up to 2 p apart (PI. 64, fig. 10).

The laesurae extend to the equator of the spoie body and are bordered by irregular,
considerably elevated, delicate, irregularly ribbed, fringe-like lips (PI. 64, figs. 1 1, 13-16)
70-175 p high and 3-6 p in basal width. Capilli may be (partly) joined to them. They
are pitted but the pits become holes towards their outer margin producing a network
separating rounded or elongated vesicles up to 3 p in diameter.

The equatorial outgrowths are small, structurally similar to the triradiate lips and
often crumpled from folding. They are 84-143 p in maximum length and 70-123 p in
maximum width. Narrow equatorial interradial (arcuate) ridges connect the radial out-
growths. These are occasionally extended to form a membraneous zona (maximum

D. J. BATTEN: BRITISH WEALDEN MEGASPORES

341

width interradially, 30 p ) , structurally similar to the equatorial radial outgrowths and
the triradiate lips. The outer margin is irregular, having a ‘frayed’ appearance.

Holotype. Slide preparation MT025/3, LI 51-4 118-4; plate 67, fig. 14.

Description. The observed limits of the maximum diameter of the spore body are 165—
290 p (coefficient of variation 11-8%). The pitting of the ektexine is a structural feature
and not one of corrosion. The ektexine forms the triradiate lips, reticulum, capilli and
equatorial outgrowths.

Preservation and compression. The specimens are well preserved. Only about 15% of the
specimens are compressed proximo-distally, the remainder are compressed laterally or
obliquely. Dehydration of a few specimens has led to the collapse of parts of the spore
wall.

Distinction. Literature. Although descriptive details are lacking, it is apparent that 0

Thomsonia reticulata Madler 1 954 and T. thoerenensis Madler 1954 are larger and that the \
laesurae are bordered by appendages and not by extended lips. Other previously pub-
lished species (except Triletes phyllicus Harris 1961 and T. gryensis Dijkstra 1959, see Y
below) possess different sculpture and/or have triradiate lips of different form or differ: /
in these anc^therwaysT^)^ -)

Comparison

Local. Specimens assigned to cfA. Thomsonia f air light ensis have been recovered from
other Fairlight Clay samples and from the Ashdown and Lower Tunbridge Wells sands.
Some recovered from the Upper Tunbridge Wells Sands appear to be slightly different
and have been recorded (MS) as cfB. Thomsonia fairlight ensis for the present.

Literature. Type, figured, and other material of Triletes phyllicus described by Murray
(1939) from the Upper Deltaic of Rutland has been examined and it is apparent that the
species is distinct from Thomsonia fairlight ensis. T. phyllicus has elevated lips which
obscure the laesurae but they are rarely wavy from side to side; they are more like those
bordering the laesurae of cfB. Minerisporites marginatus except that they are higher and
the outer margin may be more deeply incised. The luminae are more irregular in shape
and are larger; the equatorial outgrowths may be considerably larger; the exine is
thicker (10-15 p) and one layered; and specimens much larger than any specimens of
T. fairlight ensis have been recovered (see Murray 1939). Triletes gryensis Dijkstra is
similar but lacks long capilli near the triradiate lips.

cfB. Thomsonia pseudotenella (Dijkstra 1951) Madler 1954
Plate 65, figs. 1-8; Plate 67, fig. 16

Sample. CUC 971, Cuckfield No. 1 Borehole (TQ 2961 2731), depth 971 ft.; Ashdown Sand, Valan-
ginian. Light brownish grey (5 YR 6/1) massive, indurated, medium silt; general size of coarse frac-
tion, 30 p. Cuticle common but small wood fragments rare. Preparation MT294, megaspores moderately
abundant, several species present; cfB. Thomsonia pseudotenella, 75% of the megaspores recovered;
cfA. T. fairlightensis sp. nov. also present.

Description. The mean and observed limits of the maximum diameter of the spore body
(i.e. excluding equatorial outgrowths and sculpture) of this trilete megaspore are 190
(268) 370 p (standard deviation 36-7 p, coefficient of variation 13-7%; 100 specimens).

342

PALAEONTOLOGY, VOLUME 12

The spore body is more or less spherical if uncompressed. The total thickness of the
two-layered exine is 6-13 /x; the inner layer is 1 -5-2-5 /x thick and the outer layer is
4-5-1 1 f-t thick. The surface of the outer layer of the spore body and the spines is pitted.
The pits appear to be a structural rather than a corrosional feature. The sculpture con-
sists of spines situated on both the proximal and distal surfaces (PI. 65, figs. 5, 8). They
are solid, rounded or irregular in cross-section, tapered, and irregularly grooved. They
show elongated vesicles below and more rounded vesicles at their apices. Low ridges
sometimes extend from their bases which may connect with each other forming muri but
a reticulum is not developed. Except near the triradiate mark the spines on the corpus
are up to 65 p long (22 p average), up to 14 ^ in maximum (basal) diameter and usually
c. 5-40 p apart; they are shortest sub-equatorially on both proximal and distal faces.
Near the triradiate mark they can be up to 1 50 /x long and 20 /x in maximum (basal)
diameter (PI. 65, fig. 2); these occasionally bifurcate towards their extremities.

The laesurae extend to the equator of the spore body and each ray is bordered by
12-16 long, usually flattened appendages. These may be connected at their bases, and
sometimes along their entire length, by a membrane. They are 80-240 p in length and
up to 50 /x in basal diameter. The equatorial radial outgrowths (PI. 67, fig. 16) are small
(maximum length 60-160 /x, maximum width 60-105 /x), more or less rectangular or
slightly tapered towards their apices. Connecting the radial outgrowths are interradial
arcuate ridges. These are occasionally extended as flanges (forming a zona) up to 50 p
wide (PI. 65, fig. 6). The outer margin of the flange is irregular.

Preservation and compression. The specimens recovered from this sample (see above)
are generally well preserved. They are usually compressed laterally or asymmetrically
laterally.

Distinction. Literature. Triletes samarus Dijkstra 1951 differs in the nature of the tri-
radiate ridge and appendages and has larger equatorial radial outgrowths; Thomsonia
midas (Dijkstra 1951) Madler 1954 and T. divisa (Dijkstra 1951) Madler 1954 have
larger equatorial radial outgrowths and different sculpture; T. granuiata Madler 1954
has a different sculpture; Triletes datura Harris 1961 has shorter triradiate appendages
and the arcuate lamellae are strongly ribbed.

Comparison. Local I literature. Dijkstra did not indicate the origin of the sample from
which he described Thomsonia pseudotenel/a , although he implied that the description
was based on observations of specimens from the Netherlands Wealden. He also noted
that he had recovered specimens of the species from Kingsclere No. 1 Borehole samples,
from depths 466-1 ,020 ft. 1 have examined twenty megaspores from a sample from depth
777 ft. (Valanginian; Hughes 1958) from this borehole. The characters of 17 of the 20
specimens are similar to those set down by Dijkstra. The other three specimens have,
however, longer body-spines and in this respect they are similar to cfB. T. pseudotenella.
On present evidence it appears that a separation of these otherwise similar spores can
be made on the basis of body-spine length, but until more evidence can indicate whether
or not the erection of a new species is justified the graded comparison prefix cfB has
been retained for the Cuckfield (CUC 971) population.

Other assemblages containing cfB. T. pseudotenella have been extracted from the
Fairlight Clay.

D. J. BATTEN: BRITISH WEALDEN MEGASPORES

343

Turma zonales (Bennie and Kidston 1886) Potonie 1956
Infraturma zonati Potonie and Kremp 1954
Genus minerisporities Potonie 1956

Type species. M. mirabilis (Miner 1935, p. 618, pi. 23, fig. 1) Potonie 1956.

cfB. M. marginatus (Dijkstra 1951) Potonie 1956

Plate 65, figs. 9-20; Plate 66, figs. 1-4; Plate 67, figs. 11,12
Sample and preparation. As for cfA. Arcellites medusus (Dijkstra 1951) Potter 1963.

Description. The mean and observed limits of the maximum diameter of the spore body
(i.e. excluding the zona and sculpture) of this trilete megaspore are 187 (284) 386 p
(standard deviation 41-8 p, coefficient of variation 14-7%; 100 specimens). Both the
proximal and distal faces are convex if uncompressed. The lateral diameter is 185 (248)
294 p (7 specimens). The amb is sub-circular to convexly triangular in equatorial outline.
The total thickness of the two layered exine is 3-5-5 p , the inner layer being 0-5-2 p
thick and the outer 2-4 p thick. The outer layer is pitted (PI. 66, fig. 1) and imperfectly
reticulate (PI. 65, fig. 19). The pits are a structural feature < 0-5-2 p in diameter and up
to 2 p apart. The muri of the reticulum become thinner (membraneous) above their
bases, are lowest near the triradiate mark and highest on the distal surface; their maxi-
mum basal width is 2-5 p and their maximum height is 25 p proximally and 35 p distally,
commonly being highest at their points of intersection although this is not always the
case (PI. 65, fig. 19). The lumina are rounded or irregular in shape and 4-35 p in diameter.

The triradiate mark extends to the outer margin of the zona and is bordered by pitted
elevated labra (10-70 p high and 3-5-5 p in basal width) which taper towards their
extremities and are of irregular height. The pits in the lips become holes towards the
outer margin producing a delicate lacework. The equatorial zona is pitted and struc-
turally similar to the triradiate lips; the margin is usually lacey and irregular. The
observed width of the zona interradially at the median point is 12 (30) 56 p, and the
maximum width radially ranges from 20 to 81 p (mean 47 p; 98 specimens).

Preservation and compression. The zona is more membraneous and its margin more
irregular on corroded specimens. Most specimens are flattened in polar or asymmetrical
polar aspect. Dehydration of many specimens has led to the collapse of parts of the
spore wall (usually the distal face; PI. 67, fig. 12). The collapsed wall is often concave
and pressed against the inner surface of the opposite, convex face. Separated parts of
specimens which have split apart are common. The splitting has occurred along the
triradiate mark, on the distal face just below the zona or, more rarely, on the proximal
face just above the zona.

Distinction

Local. The size of the lumina and the muri of the reticulum, the size range (partly over-
lapping) of the triradiate lips and the equatorial zona and the different structure of the
zona distinguishes this species from M. alius sp. nov.

Literature. Triletes mirabilissimus Dijkstra 1961 and Minerisporites mirabilis (Miner
1935) Potonie 1956, differ in shape and in the nature of the triradiate lips, T.

344

PALAEONTOLOGY, VOLUME 12

mirabilissimus is also larger ; Tri/etes harrisi Murray 1 939 is larger, lacks an equatorial zona
and has a thicker exine; M. institutus Marcinkiewicz 1960 and M. volucris Marcinkie-
wicz 1960 have different types of sculpture, and zona; M. venustus Singh 1964 is differ-
ently sculptured; M. macroreticulatus Singh 1964 has larger lumina and higher triradiate
lips.

Comparison

Local. Assemblages containing cfB. M. marginatus have been recovered from other
Upper Tunbridge Wells Sand samples. A single spore mass adhering to a membrane was
recovered from one of these (CUC 439).

Literature. Adequate comparison with Minerisporites marginatus (Dijkstra 1951)
Potonie 1956 is not possible since Dijkstra did not give a sufficiently detailed description
of the species; however, the assemblage described here is sufficiently similar that the
erection of a new species is not considered justified at present. Dijkstra (1951) made no
mention of having recovered his species from the English Wealden although specimens
of Minerisporites are frequently recovered from Wealden material. M. borealis (Miner
1932) Potonie 1956 is also similar but not enough details were recorded by Miner to
enable satisfactory comparison. M. richardsoni (Murray 1939) Potonie 1956 resembles
cfB. M. marginatus but the triradiate lips and equatorial zona are ribbed and the sculp-
ture is different.

Minerisporites alius sp. nov.

Plate 66, figs. 5-18; Plate 67, figs. 13, 17

Type sample. H 48 T, N. F. Hughes collection, near Pett Level, Hastings, Sussex (TQ 8872 1288), mid
Ashdown Sand; ?Valanginian. Brownish-grey (5 YR 4/1) consolidated, poorly sorted silt, general size
of coarse fraction 50 p. Megaspores extremely abundant and well preserved; 99% are M. alius sp. nov.

Diagnosis. Megaspore trilete. Mean maximum diameter of spore body (excluding zona
and sculpture) 334 p, standard deviation 32-9 p ( 100 specimens). Mean maximum diameter
of spore including zona (excluding sculpture) 413 p, standard deviation 48-5 p (100
specimens). Proximal and distal surfaces convex if uncompressed. Amb convexly

EXPLANATION OF PLATE 65

All scanning electron micrographs.

Figs. 1-8. cfB. Thomsonia pseudotenella (Dijkstra 1951) Madler 1954. 1, 2, 4, (SH)DB 11. 1, Distal
sculpture; x 500. 2, Spines increasing in length towards the triradiate mark; x 250. 4, Asym-
metrical aspect; X 100. 3, 5, 7, Second specimen, (SH)DB 11. 3, Lateral view; x 100. 5, Distal
sculpture showing pitting; x 1,000. 7, Distal sculpture; x 500. 6, Equatorial interradial zona;
x 500, third specimen, (SH)DB 11. 8, Sculpture near triradiate mark including bases of large spines
adjacent to the lips; x 500, (SH)DB 9.

Figs. 9-20. cfB. Minerisporites marginatus (Dijkstra 1951) Potonie 1956. 9, 10, 18, (SH)DB 11.
9, Distal surface; x 100. 10, Equatorial zona; x 1,000. 18, Distal sculpture; x250. 11, Specimen
with concave (collapsed) distal surface; x 100, (SH)DB 12. 12, 17, Second specimen, (SH)DB 12.

12, Oblique view; X 100. 17, Proximal sculpture; x 500. 13, 15, Second specimen, (SH)DB 11.

13, Proximal polar view; X 100. 15, x 250. 14, Distal sculpture; x 500, third specimen, (SH)DB

11. 16, 20, Fourth specimen, (SH)DB 11. 16, Distal sculpture; x 1,000. 20, Specimen in lateral

view; X 100. 19, Distal sculpture; x 1,000, third specimen, (SH)DB 12.

Palaeontology, Vol. 12

PLATE 65

mmm m

$5^v*

BATTEN, Early Cretaceous megaspores

D. J. BATTEN: BRITISH WEALDEN MEGASPORES

345

triangular in equatorial outline. Total thickness of two layered exine, 3-7 p; inner layer
0-5-2 /x thick ; outer layer pitted, 2-5-5 /x thick. Sculpture, usually an imperfect reticulum.
The reticulum of the proximal face is smaller meshed than the distal (PI. 66, fig. 18)
and the muri near the triradiate mark are lower than on the remainder of the spore.
The maximum width of the muri between their connections is 4 /x on the proximal face,
and 7 p distally. The muri are tapered, irregular in height, and are highest distally
(maximum height, 17 /x on the proximal face and 55 p on the distal face). The lumina on
the proximal face are rounded, polygonal, or irregular in shape and 7-40 p in diameter.
On the distal face, the lumina are usually similar in shape although they may be rather
more angular (PI. 66, figs. 11, 14) and can be up to 80 ft in maximum diameter.

The triradiate mark extends to the outer margin of the zona and is bordered by ele-
vated lips 3-6 ft thick at their base on each side of the laesurae, tapering to their extremi-
ties. The lips are pitted; the pits become fovea towards the outer margin producing a
delicate lacework. The lip margins are usually irregular, commonly with flattened hair-
like appendages or irregular elongations up to 80 ft long extending from them (PI. 66,
figs. 12, 13, 17; PI. 67, fig. 17). The equatorial zona is scabrate, pitted, similar in nature
to the triradiate lips (PI. 66, figs. 6, 15). Hairs or elongations like those on the triradiate
lips may extend from the outer margin. The range of the maximum width of the zona
interradially at the median point is 30 (50) 79 ft (84 specimens) and radially is 40 (73)
126 ft (91 specimens).

Holotype. Slide preparation MT 391/2, LI 4T3 111-3; pi. 67, fig. 13.

Description. The observed limits of the maximum diameter of the spore body are 245-
406 ft (coefficient of variation 9-8%). The observed limits of the maximum diameter of
the spore including the zona are 297-565 ft (coefficient of variation 1 1 -8%). The pitting
of the ektexine is a structural feature.

Preservation and compression. The muri are reduced in height, especially between con-
nections, on corroded specimens. Specimens are usually compressed in polar or asym-
metrical polar aspect. Dehydration of the spore has led to the collapse of parts of the
spore wall of some specimens. Specimens with parted lips were not found although
many of the fragments present have resulted from breakage along the laesurae as well
as along the equator. A spore mass was recovered.

Distinction

Local. M. alius is distinguished from cfB. M. marginatus chiefly by the different nature
of the reticulum and the margin of the triradiate lips.

Literature. TrUetes mirabilissimus Dijkstra 1961 and Minerisporites inirabi/is{ Miner 1935)
Potonie 1956 differ in shape and in the nature of triradiate lips, T. mirabilissimus is
also larger; T. harrisi Murray 1939 is larger, lacks an equatorial zona and has a thicker
exine; M. institutus Marcinkiewicz 1960 and M. volucris Marcinkiewicz have different
types of sculpture and zonas; M. venustus Singh 1964 has a different sculpture.

Comparison. Literature. M. marginatus (Dijkstra 1951) Potonie 1956 resembles M. alius
but the equatorial zona is narrower, the reticulate sculpture poorly defined and the
lumina smaller in diameter; M. borealis (Miner 1931) Potonie 1956 is similar but as

346

PALAEONTOLOGY, VOLUME 12

mentioned before, not enough details were recorded by Miner to enable accurate com-
parison; M. richardsoni (Murray 1939) Potonie 1956 is like M. alius but is somewhat
larger and the sculpture is slightly different, the equatorial zona is generally narrower and
the triradiate lips lower although the size ranges of these characters overlap ; the proximal
reticulum of M. macroreticulatus Singh 1964 is not reduced as in M. alius but in other
respects the species is similar.

FEATURES OF WEALDEN MEGASPORES REVEALED OR CLARIFIED
BY SCANNING ELECTRON MICROSCOPY

Since cfA. A. medusus has a very thick exine, optical examination of its surface is
particularly difficult. The anastomosing rods of sporopollenin on the appendages and
the spongy nature of the outer layer of the spore body are difficult to resolve optically,
but they are clearly discernible in scanning micrographs (PI. 62, figs. 7, 1 1 ; PI. 63, fig. 1).
These remarks also hold true for cfB. A. medusus. In both cases, the rings of thickening
on the outer surface of the exine (PI. 62, fig. 1 1 ; PI. 63, fig. 8) are not resolved by light
microscopy.

Micrographs elucidate the exact nature and configuration of the muri (PI. 63, figs. 10,
12, 14, 15) and the structure of the triradiate appendages (PI. 63, fig. 9) of Thomsonia
alata. They established that the pitting of the exine is a structural feature rather than one
of corrosion (PI. 63, fig. 13). They show the surface sculpture of the spines of cfB. Thom-
sonia pseudotenella (PI. 65, fig. 5) and the nature of the reticulum of T. fair/ightensis
(PI. 64, fig. 10). The irregular form and configuration of the muri of cfB. Minerisporites
marginatus (PI. 65, figs. 14, 16-19) and M. alius (PI. 66, figs. 8-1 1, 17) is clarified and the
structure of the outer margin of the zona of these species is revealed (PI. 65, fig. 10; PI. 66,
fig. 6).

POSSIBLE AFFINITIES AND ASSOCIATIONS OF THE MEGASPORES

Hughes (1955) proposed an aquatic habitat for Arcellites medusus and morphologic-
ally similar spores. A relationship with the Hydropterideae (Marsiliaceae) was suggested
by Dijkstra (1951) and supported by others. A. medusus may have been orientated neck-
downwards when floating in water. This orientation was suggested by Ellis and Tschudy

EXPLANATION OF PLATE 66

All scanning electron micrographs.

Figs. 1-4. cfB. Minerisporites marginatus (Dijkstra 1951) Potonie 1956. 1, Distal sculpture, part of
reticulum showing pitting; x 2,000, (SH)DB 7. 2, Proximal sculpture; x 1,000, (SH)DB II.
3, Inflated; X 100, second specimen, (SH)DB 11. 4, Collapsed (concave) proximal face; x 100,
third specimen, (SH)DB 11.

Figs. 5-18. Minerisporites alius sp. nov. 5, 6, 9, 13, (SH)DB 11. 5, Proximal face; x 100. 6, Outer
margin of zona; x 2,500. 9, Proximal sculpture; x 500. 13, Proximal sculpture and triradiate lips
with hairs extending from them; x250. 7, 10, (SH)DB 10. 7, Lateral view; x 100. 10, Proximal
sculpture; x 1,000. 8, 1 1, 14, Second specimen, (SH)DB 11. 8, Distal surface; x 100. II, Distal
sculpture; x 250. 14, Distal sculpture; X 503. 12, Proximal polar view; x 100, (SH)DB 2. 15, Part
of zona; x 1000, second specimen, (SH)DB 10. 16, Concave (collapsed) distal surface; x 100,

third specimen, (SH)DB 10. 17, Slightly concave proximal surface; x 100, (SH)DB 3. 18, Specimen
compressed laterally; X 100, (SH)DB 9.

Palaeontology , Vol. 12

PLATE 66

BATTEN, Early Cretaceous megaspores

D. J. BATTEN: BRITISH WEALDEN MEGASPORES

347

(1964) for A. discifonnis , a morphologically similar spore. A. medusus may have been
dispersed in masses (see cfA. A. medusus description) or as isolated specimens. Since the
specimens in the masses are not smaller or in any way different from isolated forms it
is unlikely that they are immature. It is probable that their body appendages became
interlocked in the sporangium so that when the sporangium dehisced they were not
always separated. The function of the neck of Arcel/ites medusus is not definitely known
but Ellis and Tschudy (1964) suggested that the neck of A. discifonnis functioned in
a similar way to that of modern Marsilia.

The spores described have not been found in tetrads but a spore mass of Minerisporites
alius adhering to a cuticle membrane was recovered. Harris (1961) has pointed out that
the occurrence of spores in this manner indicates that they were produced in large
numbers in a cutinized sporangium as in Lepidostrobus. Hall (1963) suggested that
Minerisporites may have been produced by either (an) offshore aquatic or near-shore
terrestrial species of Isoetes.

Although the miospore/megaspore assemblage from which Thomsonia fairlightensis
was described, is a diverse one, only specimens of elliptical ?monolete miospores have
been found between their triradiate lips (in several topotype specimens). Unfortunately
the structure and the convoluted nature of the lips obscures most of the spore exine
detail. They appear to be monolete, elliptical in shape, 17-25 p in maximum diameter
and scabrate. The fact that other spore species are not found within the lips is significant
in that it appears that they occurred there naturally and not by accident. They have not
been recognized in the dispersed miospore preparation concerned; an explanation could
be that the megaspores were transported subsequent to trapping the miospores. Jung
(1958) and Dettmann (1961) have found similar although somewhat larger spores with
thicker exines, in close association with species of Nathorstisporites Jung 1958 from the
Early Mesozoic.

Monolete grains (of the type on PI. 67, fig. 15) and fern spores are abundant in some
of the palynological facies rich in megaspores; the monolete spores may constitute up
to 90% of the miospores present and some significance can be attached to their presence
in these assemblages since they are rarely recorded from other facies. It may be that their
presence is due merely to the fact that the depositional environment was suitable for
their preservation. On the other hand, it is possible that some of the megaspores and
monolete grains were derived from the same parent plant or that the parent plants were
ecologically related. Some species of megaspores have also been noted to occur together
frequently.

DISTRIBUTION OF WEALDEN MEGASPORES

The presence of megaspores in Wealden sediments is probably due to water transport
and it is assumed that most represent the presence of lycopods growing on the delta.
Their spores could have dropped directly into an aquatic environment or could have
been washed in along with other plant debris during times of heavy rain and flooding.
Presumably many were transported over relatively short distances although their dis-
persal range must have partially depended on whether the spores were dispersed as
isolated specimens or in masses, and whether they were adapted to floating. Forms like
Arcellites medusus , probably produced by aquatic plants as mentioned earlier, may

348

PALAEONTOLOGY, VOLUME 12

have been commonly dispersed as entangled masses which could have floated for some
time; the expanded extremities of the appendages of A. medusus probably functioned as
air bladders thus assisting flotation. The flotation of other forms such as Thomsonia
alata was probably assisted by their pronounced equatorial outgrowths. It is likely that
the distribution of forms lacking prominent equatorial outgrowths or bladders probably
depended to a greater extent on their weight. Some of the coarser silts and fine sands
contain only a few large forms with thick exines, smaller lighter grains presumably hav-
ing been transported further afield.

It is possible, with experience, to foretell with reasonable accuracy whether a Wealden
rock sample will yield megaspores but predicting their (relative) abundance is more
difficult. Pure sands contain few if any but an increase in the amount of finer material
in a fine sand is usually accompanied by an increase in the numbers of megaspores.
Poor sorting will also be accompanied by a larger number of megaspores since their
chances of survival are improved (Dijkstra 1949).

Assemblages with an abundance of megaspores have been recovered from unaltered,
unsorted, grey (N4-N7) or brownish grey (5 YR 4/1) non-calcareous silts which contain
both sand and clay and relatively few small plant fragments. (If the plant fragments
(wood and cuticle) are large and abundant, fewer megaspores are usually recovered (as
noted by Hughes 1958) although several species may be present. There is therefore a
direct relationship between the abundance of megaspores and the presence of plant
debris.) Very small miospores (< 30 p. in maximum diameter) are common (3-30% of
the miospore assemblage) or frequent (> 30%) in the miospore preparations, indicating
a lack of current activity.

Most of the spores in this facies are probably of local origin, the parent plants having
grown near, around and even in the body of water; few, if any, were transported from

EXPLANATION OF PLATE 67

Figs. I, 2, 4, 9, 10. cfA. Arcellites medusus (Dijkstra 1951) Potter 1963. 1, Oblique view, neck not

clearly visible, swellings and ridges connecting bases of appendages, x 100; MT 395/8, LI 43-9
1 17-6. 2, Lateral view, neck prominent but partly obscured by appendages, spore body slightly
compressed in polar aspect, x 100; MT 395/9, LI 34-3 1 14-7. 4, Triradiate mark at base of damaged
neck, X400; MT 395/9, LI 31 -7 115-9. 9, Base of deformed but entire appendage, most of length

out of focus, X 500; MT 395/9, LI 25-1 120-8. 10, Part of sectioned specimen showing two exine

layers, base of neck and bases of some appendages, x 500; DBS/4A, LI 50-9 124-7.

Figs. 3, 8. Thomsonia alata sp. nov. 3, Holotype, x50; MT 395/14, LI 41-7 116-2. 8, Flattened

appendages extending from triradiate lips connected by a 'lacey’ membrane for most of their
length, x 100; MT 395/10, LI 23-0 119-3.

Figs. 5-7. cfB. Arcellites medusus (Dijkstra 1951) Potter 1963. 5, Lateral view, x200; MT 395/8,

LI 38-8 118-9. 6, Lateral view, x 100; MT 395/8, LI 42-9 1 19-3. 7, Lateral view, small (shrunken ?)

corpus, membraneous appendages, x 100; MT 395/8, LI 42-2, 117-3.

Figs. 11, 12. cfA. Minerisporites marginatus (Dijkstra 1951) Potonie 1956. 11, Polar view, x 100;
MT 395/1, LI 33-9 128-2. 12, Section of specimen with collapsed distal wall, x500; SDB/1B,

LI 35-2 120-7.

Figs. 13, 17. Minerisporites alius sp. nov. 13, Holotype, polar view, X 100; MT 391/2, LI 41-3 11 L3.
17, 'Hairs’ extending from the triradiate lips, x500; MT 391/2, LI 540 111 -3.

Fig. 14. Thomsonia fairlightensis sp. nov. Holotype, lateral view x 100; MT 025/3, LI 51 -4 1 1 8-4.

Fig. 1 5. Monolete spore, x 500; T391/1, LI 31-3 121-3.

Fig. 16. cfB. Thomsonia pseudotenella (Dijkstra 1951) Miidler 1954, polar view; MT 294/1, LI 32-2
117-2; x 100.

Palaeontology , Vol. 12

PLATE 67

BATTEN, Early Cretaceous megaspores

D. J. BATTEN: BRITISH WEALDEN MEGASPORES

349

further afield. This suggestion is supported not only by the lithology and the composition
of the palynological facies, but also by the fact that the spores are better preserved than
usual, indicating that they have not been subjected to much transportation and oxida-
tion. The deposition of sediment often appears to have been rapid (probably the result
of flood downwash) since the wood fragments are disposed at all angles and there is no
sign of bedding. The absence of water-worn fragments and the marked local dominance
of certain species also indicates that the parent plants were near at hand. Presumably
the deposition occurred in shallow fresh or oligohaline water. Possible environments of
deposition are ponds and lakes into which flood waters and downwash brought coarse
detritus ; lagoons into which some of the water from a main river channel entered, rapidly
dropping much of its suspended load; channels abandoned by a stream (channel-fills)
and bar swalefill deposits. Apparently the depositional environments were unfavourable
for the development of bottom life, perhaps because of a low oxygen content or because
deposition took place too rapidly; the sediments are usually undisturbed, lacking in
animal remains, burrows, rootlets, and other structures.

Megaspores also occur in many of the sorted medium- and coarse-grained silts,
although seldom are they an important component, probably because the sorting has
played a major part in their distribution. Sediments which accumulated in relatively
high energy environments contain few if any but they are usually present and sometimes
common in sediments that were deposited in lower energy environments, for example,
laminated and cross-bedded (and sometimes bioturbated) fine sands and silts with silty
clay partings. Pyrite may be present in these facies, some of the wood and cuticle being
partly pyritized and some of the spore exines being damaged by corrosion. Mica is also
a common constituent. Some assemblages show evidence of reworking; many or all of
the spores have thinner exines than usual and torn specimens and fragments are common.

Many sediments, such as pure sand, as mentioned earlier, or clay are unlikely to pro-
duce megaspores. They are for instance noticeably less common in the more clayey
formations of the Wealden, such as the Wadhurst. Calcareous sediments and those
which contain shells (e.g. ostracods and bivalves) or much pyrite are usually barren.

Acknowledgements. I thank Mr. N. F. Hughes for advice and criticism, and Miss M. Chappell for
reading the manuscript. The micrographs were obtained on a ‘Stereoscan’ microscope at the Depart-
ment of Geology, Leicester University; I am grateful to Mr. G. L. C. McTurk who operated it.

REFERENCES

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spore wall of Lycopodium clavatum as revealed by the electron microscope. Svensk. bot. Tidskr.,
Stockholm, 48, 151-61, 2 pi.

cookson, i. c., and dettmann, m. e. 1958. Cretaceous ‘megaspores’ and a closely associated micro-
spore from the Austrialian region. Micropaleontology, New York, 4, 39-49, 2 pi.
dettmann, m. e. 1961. Lower Mesozoic megaspores from Tasmania and South Australia. Ibid. 7,
71-86, 4 pi.

dijkstra, s. J. 1949. Megaspores and some other fossils from the Aachenian (Senonian) in South
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1951. Wealden megaspores and their stratigraphical value. Ibid. 5, 7-21, 2 pi.

- 1959. On megaspores, charophyta fruits and some other small fossils from the Cretaceous.
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ellis, c. h., and tschudy, r. h. 1964. The Cretaceous megaspore genus Arcellites Miner. Micropaleon-
tology, New York, 10, 73-9, 1 pi.

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PALAEONTOLOGY, VOLUME 12

hall, j. w. 1963. Megaspores and other fossils in the Dakota formation (Cenomanian) of Iowa (U.S.A.)
Pollen et Spores, Paris, 5, 425^13, 7 pi.

Harris, t. m. 1961. The Yorkshire Jurassic Flora, 1. Thallophyta-Pteridophyta. Brit. Mus. (Nat. Hist.),
London, 212 pp.

hughes, n. f. 1955. Wealden plant microfossils. Geol. Mag., Flertford, 92, 201-17, 3 pi.

1958. Palaeontological evidence for the age of the English Wealden. Ibid. 95, 41-9.

hughes, n. f., dettmann, m. e., and playford, g. 1962. Sections of some Carboniferous dispersed
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and moody-stuart, J. c. 1967. Proposed method of recording pre-Quaternary palynological

data. Rev. Palaeobotan. Palynol., Amsterdam, 3, 347-58, 1 pi.

jung, w. 1958. Zur Biologie und Morphologie einiger disperser Megasporen, vergleichbar mit solchen
von Lycostrobus scotti aus dem Rhat-Lias Frankens. Geol. Bl. Nordost-Bayern, Erlangen, 8, 114-30,
1 pi.

kemp, e. m. 1968. Probable Angiosperm pollen from the British Barremian to Albian strata. Palaeon-
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lees, G. m., and taitt, a. h. 1945. The geological results of the search for oilfields in Great Britain.
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madler, K., 1954. Azolla aus dem Quartar und Tertiar sowie ihre Bedeutung fiir die Taxionomie
alterer Sporen. Geol. Jb., Hannover, 70, 143-58, 1 pi.

martens, p. 1960. Sur une structure microscopique orientee dans la paroi megasporale d’une Sela-
ginelle. C.r. hebd. Seanc. Acad. Sci. Paris, Paris, 250, 1599-1602, 1774-5, 2 pi.

Murray, n. 1939. The microflora of the Upper and Lower Estuarine Series of the East Midlands. Geol.
mag., Hertford, 76, 478-89.

pettit, j. m. 1966. Exine structures in some fossil and recent spores and pollen as revealed by light and
electron microscopy. Bull. Br. Mus. (Nat. Hist.), London, 13, 221-57, 21 pi.

potter, d. r. 1963. An emendation of the sporomorph Arcellites Miner, 1935. Ok la. Geol. Notes,
Norman, 23, 227-30, 1 pi.

singh, c. 1964. Microflora of the Lower Cretaceous Mannville Group, east-central Alberta. Bull. Res.
Counc. Alberta, Edmonton, 15, 239 pp., 29 pi.

stainier, f. 1965. Structure et infrastructure des parois sporales chez deux Selaginelles (Selaginella
myosurus and S. krausiana). Cellule, Louvain, 65, 221-44, 5 pi.

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104+xii pp., 6 pi.

D. J. BATTEN
Department of Geology
Sedgwick Museum

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PALAEONTOLOGY

VOLUME 12 ' PART 2>

CONTENTS

A new species of Babinka (Bivalvia) from the Lower Ordovician of Oland,
Sweden. By helen soot-ryen 174

Lower Devonian Hexagonaria (Rugosa) from the Armorican Massif of
Western France. By J. E. sorauf 178

Benthonic Foraminifera from the Maestrichtian Chalk of Galicia Bank,
west of Spain. By M. J. fisher 189

Upper Silurian and Lower Devonian spore assemblages from the Welsh Border-
land and South Wales. By j. b. richardson and t. r. lister 201

A new British Carboniferous calamite cone Paracalamostachys spadiciformis.

By B. A. THOMAS 253

A Lower Carboniferous conodont fauna from East Cornwall. By s. c.
MATTHEWS 262

Two conodont faunas from the Lower Carboniferous of Chudleigh, South
Devon. By s. c. Matthews 276

Skeletal structure and growth in the Fenestellidae (Bryozoa). By R. tavener-
SMITH 281

The cross-bladed fabrics of the shells of Terrakea solida (Etheridge and Dun)
and Streptorhynchus pelicanensis Fletcher. By J. Armstrong 310

The interpretation of growth and form in serial sections through brac-
hiopods, exemplified by the trigonorhynchiid septalium. By p. westbroek 321

Some British Wealden megaspores and their facies distribution. By d. j.
batten 333

PRINTED IN GREAT BRITAIN AT THE UNIVERSITY PRESS, OXFORD
BY VIVIAN RIDLER, PRINTER TO THE UNIVERSITY

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