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HARVARD UNIVERSITY 

Library of the 

Museum of 

Comparative Zoology 



^^s7 



BREVIORA 



MUSEUM OF COMPARATIVE ZOOLOGY 
Harvard University 



NUMBERS 351-379 
1970-1971 



CAMBRIDGE, MASSACHUSETTS, U.S.A. 

1971 



Edited 

by 

Penelope Lasnik 



CONTENTS 

BREVIORA 
Museum of Comparative Zoology 

Numbers 351-379 

1970 

No. 351. A new species in the nomeid fish genus Psenes from 
the equatorial eastern Pacific. By Richard L. Haed- 
rich. 7 pp. June 12. 

No. 352. The Chaiiares (Argentina) Triassic reptile fauna VII, 
The postcranial skeleton of the traversodontid 
Massetognathus pascuali (Therapsida, Cynodontia). 
By Parish A. Jenkins, Jr. 28 pp. July 10. 

No. 353. Anolis jacare Boulenger, a solitary anole from the 
Andes of Venezuela. By Ernest E. Williams, Osvaldo 
A. Reig, Pablo Kiblisky, and Carlos Rivero-Blanco. 
15 pp. August 10. 

No. 354. Taxonomic and ecological notes on some Middle and 
South American lizards of the genus Ameiva 
(Teiidae). By Arthur C. Echternacht. 9 pp. 
September 18. 

No. 355. Generic relations and speciation patterns in the Cara- 
caras (Aves: Falconidae). By Francois Vuilleumier. 
29 pp. November 30. 

No. 356. On a new species in a new earthworm genus from Puerto 
Rico. By G. E. Gates. 11 pp. November 30. 

No. 357. A review of the fossil Pelomedusidae (Testudines, 
Pleurodira) of Asia. By Roger Conant Wood. 24 
pp. November 30. 

No. 358. South American anoles: Anolis apollinmis Boulenger 
1919, a relative of A. biporcatus Wiegmann (Sauria, 
Iguanidae). By Ernest E. Williams. 11 pp. 
November 30. 



No. 359. The swimbladder as a juvenile organ in stromateoid 
fishes. By Michael H. Horn. 9 pp. November 30. 

No. 360. Mammals from the early Cenozoic of Chubut, Argen- 
tina. By George Gaylord Simpson. 1 3 pp. Novem- 
ber 30. 

No. 361. Additions to knowledge of the Argyrolagidae (Mam- 
malia, Marsupialia) from the late Cenozoic of 
Argentina. By George Gaylord Simpson. 9 pp. 
November 30, 

No. 362. Addition to knowledge of Groeberia (Mammalia, 
Marsupialia) from the mid-Cenozoic of Argentina. 
By George Gaylord Simpson. 17 pp. November 30. 



1971 

No. 363. Non-specificity of host-selection in the ectoparasitic 
snail Odostomia (Menestho) bisuturalis (Say) (Gas- 
tropoda: Pyramidellidae). By Robert C. Bullock 
and Kenneth J. Boss. 7 pp. January 8. 

No. 364. A new scincid lizard from Bougainville, Solomon 
Islands. By Allen E. Greer and Fred Parker. 1 1 pp. 
January 8. 

No. 365. Characters and synonymies among the genera of ants. 
Part IV. Some genera of subfamily Myrmicinae 
(Hymenoptera: Formicidae). By William L. Brown, 
Jr. 5 pp. January 15, 

No. 366. Pulsed sound of the porpoise Lagenorhynchus australis. 
By William E. Schevill and William A. Watkins. 10 
pp. January 15. 

No. 367. Micromischodus sugillatus, a new hemiodontid characin 
fish from Brazil, and its relationship to the Chilo- 
dontidae. By Tyson R. Roberts. 25 pp. January 
15. 

No. 368. Structural habitats of West Indian Anolis lizards I. 
Lowland Jamaica. By Thomas W. and Amy 
Schoener. 53 pp. January 29. 

No. 369. Lithophaga aristata in the shell-plates of chitons (Mol- 
lusca). By Robert C. Bullock and Kenneth J. Boss. 
10 pp. January 29. 



No. 370. Ecological observations on a little known South 
American anole: Tropidodactyliis onca. By James 
P. Collins. 6 pp. March 31. 

No. 371. A new species of bromeliad-inhabiting galliwasp 
(Sauria: Anguidae) from Jamaica. By Albert 
Schwartz. 10 pp. March 31. 

No. 372. The paleontology and evolution of Cerion II: age and 
fauna of Indian shell middens on Curacao and Aruba. 
By Stephen Jay Gould. 26 pp. March 31. 

No. 373. The Chanares (Argentina) Triassic reptile fauna. VIII. 
A fragmentary skull of a large thecodont, Liipero- 
suchus fractus. By Alfred Sherwood Romer. 8 pp. 
March 31. 

No. 374. The fishes of the Malaysian family Phallostethidae 
(Atheriniformes). By Tyson R. Roberts. 27 pp. 
June 15. 

No. 375. Structural habitats of West Indian Anolis lizards II. 
Puerto Rican uplands. By Thomas W. and Amy 
Schoener. 39 pp. June 15. 

No. 376. Podocnemis venezuelensis, a new fossil pelomedusid 
(Testudines, Pleurodira) from the Pliocene of 
Venezuela and a review of the history of Podocnemis 
in South America. By Roger Conant Wood and 
Maria Lourdes Diaz de Gamero. 23 pp. June 15. 

No. 377. The Chanares (Argentina) Triassic reptile fauna IX. 
The Chaiiares Formation. By Alfred Sherwood 
Romer. 8 pp. June 15. 

No. 378. The Chanares (Argentina) Triassic reptile fauna X. 
Two new but incompletely known long-limbed 
pseudosuchians. By Alfred Sherwood Romer. 10 
pp. June 15. 

No. 379. The Chanares (Argentina) Triassic reptile fauna XL 
Two new long-snouted thecodonts, Chanaresuchus 
and GuaiosLichus. By Alfred Sherwood Romer. 22 
pp. June 15. 



INDEX OF AUTHORS 

BREVIORA 

Museum of Comparative Zoology 

Numbers 351-379 

1970-1971 

No. 

Boss, Kenneth J 363, 369 

Brown, William, Jr 365 

Bullock, Robert C 363, 369 

Collins, James P 370 

Diaz de Gamero, Maria Lourdes 376 

Echternacht, Arthur C 354 

Gates, G. E 356 

Gould, Stephen Jay 372 

Greer, Allen E 364 

Haedrich, Richard L 351 

Horn, Michael H 359 

Jenkins, Parish A., Jr 352 

KiBLisKY, Pablo 353 

Parker, Fred 364 

Reig, Osvaldo a 353 

Rivero-Blanco, Carlos 353 



No. 
Roberts, Tyson R 367^ 374 

RoMER, Alfred Sherwood 373. 377, 378, 379 

ScHEviLL, William E 366 

Schoener, Thomas W. and Amy 368. 375 

Schwartz, Albert 37I 

Simpson, George Gaylord 360, 361, 362 

Vuilleumier, Francois 355 

Watkins, William A 366 



{j'li^^^'''' . 



BREVIORA 

Mmseuim of Compsirative Zoology 

Cambridge, Mass. 12 June, 1970 Number 351 



A NEW SPECIES IN THE NOMEID FISH GENUS PSENES 
FROM THE EQUATORIAL EASTERN PACIFIC^ 

Richard L. Haedrich- 



Abstract. Psenes sio n. sp. is based on five specimens 23-66 mm SL 
from the equatorial eastern Pacific Ocean. The new species belongs to the 
species-group (others are P. pelliicidiis, P. maculatus, and P. arafurensis) 
with large, laterally compressed, knifelike teeth in the lower jaw. P. cya- 
nophrys and P. whiteleggii have small conical teeth in both jaws. The new 
species is characterised by its light color, long pelvic fins, two weak anal 
spines and 23-24 rays, 18-19 pectoral finrays, and 36-38 vertebrae. 

In a recent unpublished yet widely distributed manuscript 
(Haedrich and Horn, 1969), a new species of Psenes was included 
in a key (p. 36). It was stated explicitly that use of the name in 
the key did not constitute publication, and it was indicated that a 
formal description would soon appear in a review of the entire 
genus. Other responsibilities, however, have virtually brought this 
work to a halt, and early completion of the review does not seem 
likely. Therefore, in order to avoid the nomenclatural debacle that 
I see developing, this note has been prepared describing the new 
species. 

The specimens upon which the new species is based were made 
available by J0rgen Nielsen, and are housed in Universitetets Zoo- 
logiske Museum, Copenhagen (ZMC). They were collected by 
Dr. Nielsen on Step-I, a cruise conducted by the Scripps Institution 
of Oceanography. The manuscript has been read by Richard H. 
Backus and Giles W. Mead. Figure 1 was drawn by E. Leenders. 



1 Contribution No. 2486 from the Woods Hole Oceanographic Institution. 

2 Woods Hole Oceanographic Institution, Woods Hole, Mass., and 
Museum of Comparative Zoology, Harvard. 



2 BREVIORA No. 351 

Portions of this work were supported by a United States Govern- 
ment Grant under the Fulbright-Hays Act, the Johs. Schmidt 
Fund, and National Science Foundation grant GB- 15764. 

Among stromateoid fishes, the genus Psenes is distinguished in 
having two dorsal fins with the first dorsal originating over or 
before the pectoral insertion, persistent thoracic pelvic fins, a deep 
to moderately elongate body, and teeth present in some species on 
the palatines and/or basibranchials but never on the glossohyal. 
The genus, its relationships, and the nominal species were treated 
in a general way by Haedrich (1967), though recent findings will 
modify this account somewhat. Within Psenes, there seem to be 
two species groups. One group (including P. cyanophrys and 
P. whiteleggii) is characterized by small, conical, slightly recurved 
teeth in both the upper and lower jaw. The other group (in- 
cluding P. pellucidus, P. arajurensis, P. maciilatus and the new 
species) has small, conical, slightly recurved teeth in the upper 
jaw and large, laterally flattened, bladelike teeth in the lower jaw. 

In recognition of the considerable contributions to marine ich- 
thyology made by the Scripps Institution of Oceanography, the new 
species will be known as 

Psenes sio n. sp. 
Figure 1 

Material. Five specimens, 23-66 mm SL, all in ZMC; those 
marked with an asterisk* have been X-rayed: *1 spec, 60 mm SL, 
HOLOTYPE, Step-I sta. 23, 11°10'S 80°01'W, 17 Oct. 1960, 
2250-2345 hrs., 0-90 m, 5' net, surf. temp. 17.8°C. PARA- 
TYPES: *1 spec, 66 mm SL, Step-I sta. 80-1, 1°24'S 94°55'W, 
2/3 Dec. 1960, 2335-0230 hrs., high-speed net, battered. 2 spec, 
26 & 44 mm SL, Step-I sta. 73-1, 4°22'S 95°04'W, 2 Dec. 1960, 
0200-0500 hrs., high-speed net, very battered, smaller spec, 
cleaned-and-stained. *1 spec, 23 mm SL, Step-I sta. 80, 1°59'S 
94°55'W, 2 Dec. 1960, 2200 hrs., dipnet-nightlight, surf. temp. 
22°C. All specimens are immature. 

Diagnosis. An elongate, compressed, light-colored Psenes with 
large, compressed close-set teeth in the lower jaw, long pelvic fins, 
two weak anal spines and 23-24 rays, and 36 to 38 vertebrae. 

Description. Individual proportions and counts are presented in 
Table 1. 

The body is elongate, the maximum depth of larger specimens 



1970 NEW NOMEID FISH 3 

being around 30 per cent of the standard length, and is very com- 
pressed. The caudal peduncle is tapered, compressed, and some- 
what elongate. The musculature, though firm, is translucent, par- 
ticularly along the anal fin base and over the viscera. The two 
dorsal fins are scarcely divided. The first dorsal fin originates over 
the edge of the opercle and comprises 10 to 12 thin brittle spines, 
the second originates just behind mid-body and comprises 23 to 25 
long rays. The entire fin folds partially into a very shallow groove 
and terminates behind the end of the anal fin. The anus is at mid- 
body, in a slit. The anal fin commences shortly behind the anus 
under the third or fourth ray of the second dorsal, and is composed 
of two weak spines and 23 or 24 long rays. The muscles for ele- 
vating the anal rays can be clearly seen, as can the basal elements 
of both median fins. The pectoral fin is long and fairly broad, with 
18 or 19 rays; its base is incUned about 45° to the vertical. The 
pelvic fins are very long; they insert under the middle or end of 
the pectoral fin base and extend beyond the anal origin, and are 
composed of one short spine and five long branched rays. The 
caudal fin, broken in most specimens, is apparently long and 
forked; the small elements preceding the principal rays extend 
well forward on the peduncle. The cycloid scales are very small, 
and do not appear to extend significantly onto the bases of the 
median fins. The scales are extremely deciduous, and most are 
gone; the count of scale pockets along the lateral line of the holo- 
type is ca. 85. The skin is thin; the subdermal mucus canal system 
is but httle developed, and the body pores are very small or 
wanting. 

The head is around 35 per cent of the standard length, its profile 
sloping. The skin of the top of the head is naked, and pores are 
clearly visible, particularly those over the head of the hyomandibu- 
lar. The eye is of moderate size, located a little more than its 
diameter from the tip of the truncate snout, and does not enter 
into the profile of the head. There is apparently no adipose tissue 
around the eye, but somes does extend forward from the front of 
the eye to surround the nostrils. The two small nostrils are located 
much nearer to the tip of the snout than to the eye. The end of 
the maxillary is below the anterior border of the eye, but the angle 
of the gape is well before the eye. The premaxillary is not pro- 
tractile. The lacrimal bone is large and transparent, and covers 
the top of the maxillary. The teeth are uniserial in the jaws. The 
teeth in the upper jaw are small, conical, slightly recurved, and 
spaced; the teeth in the lower jaw are large, at least twice as long 



4 BREVioRA No. 351 

as those in the upper jaw, compressed and knifeUke with very small 
cusps, and very close-set. The vomer, palatines, and basibranchials 
appear to be toothless. The oral valves are prominent. The oper- 
cles are very thin; their margins are either entire or set with ex- 
tremely fine spinules. The striated opercle has two very weak flat 
spines; the angle of the preopercle is rounded but does not bulge 
backward. The gill-rakers are moderate, blunt, about half the 
length of the filaments, and bear fine teeth on their inner edges; the 
rakers are spaced, about 15 on the lower limb of the first arch. 
The pseudobranch is well developed, but there are no rudimentary 
rakers below it. The light yellow thymus is clearly visible. There 
are six branchiostegal rays. 

The color in alcohol is tan, darker on the back than on the sides. 
There is a suggestion of three brownish vertical bands on the after 
part of the body in some specimens. The first dorsal fin is dark, 
but all the other fins are whitish. The dark lining of the gill cavity 
shows clearly through the transparent opercles. The dark peri- 
toneum shows clearly through the thin abdominal wall. The in- 
side of the mouth is fight yellow, and the eye is grey. 

The skeleton in general is very light. This is particularly ap- 
parent in the thin transparent dermal skeleton. There is no supra- 
maxillary bone. The supraoccipital is but little developed. There 
is a wide opening between the cleithrum and the coracoid. The 
pelvic bones reach to the cleithrum. There is a large foramen in 
the scapula. The postcleithrum can be plainly seen through the 
body wall, and it extends to the lower margin of the body. There 
are 36 to 38 vertebrae, including the hypural; about 12 to 15 verte- 
brae appear to be precaudal. In the tail, there are two autogenous 
haemal spines, four hypurals, two paired uroneurals, and three 
epurals. The second and third hypurals are broad triangular plates 
much larger than any other caudal element. The first hypural bears 
an hypuropophysis. Three free interneurals precede the dorsal fin. 
The first dorsal interneural supports two spines. The two anal 
spines are weak. 

Remarks. Most species of P series are widely distributed in the 
tropical and sub-tropical parts of the world ocean. P. sio, how- 
ever, is quite restricted, and has been found only in the eastern 
Pacific from about 11° S (holotype) to perhaps 10° N (R. Rosen- 
blatt, additional Scripps specimens, in lift.). P. sio most closely 
resembles P. rnaculatus, an apparently antitropical species known 
only from sub-tropical waters in the North and South Atlantic. 

Within the range of Psenes sio, only P. cyanophrys is known to 
occur for sure. This species may be distinguished from P. sio 



1970 NEW NOMEID FISH 5 

by its small conical teeth that are similar in both jaws (as men- 
tioned above), its color pattern of fine horizontal stripes (P. sio 
has about three indistinct vertical bands), its greater maximum 
depth (43-52% SL vs. 29-41% SL in P. sio), its generally greater 
number of median fin rays (D 24-29 vs. 23-25, A 24-28 vs. 
23-24), and its fewer vertebrae (31 v^. 36-38). 

As yet unrecorded from the eastern tropical Pacific but known 
from the western parts of that ocean are Psenes pellucidus and 
P. arafurensis. The former has more median finrays and verte- 
brae (D 27-32, A 26-31, vert. 41-42) than P. sio, the latter fewer 
(D 18-22, A 20-22, vert. 31). 

Psenes whiteleggii, from the Indian Ocean and Australia, has 
conical teeth in both jaws and low median finray and vertebral 
counts (D 17-20, A 17-18, vert. 31-32). The Atlantic P. macu- 
latus, the species most similar to P. sio, has slightly fewer median 
finrays and vertebrae (D 22-24, A 22-24, vert. 35) and more 
pectoral finrays (21-22 vs. 19 in P. sio) and anal spines (III vs. 
II). The preanal distance is 58-63% SL in P. maculatus, and 
51-54% SL in P. sio. 

LITERATURE CITED 

Haedrich, Richard L. 1967. The stromateoid fishes: systematics and a 
classification. Bull. Mus. Comp. Zool., Harvard, 135(2): 31-139. 

Haedrich, Richard L., and Michael H. Horn. 1969. A key to the 
stromateoid fishes. Woods Hole Oceanographic Institution Ref. No. 
69-70, September 1969, 46 pp. Unpublished Manuscript. 

(Received 2 April 1970.) 



6 BREVIORA No. 351 



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BREVIORA 

Miiseimi of Cointipairsitive Zoology 

Cambridge. Mass. 10 July, 1970 Number 352 



THE CHANARES (ARGENTINA) TRIAS5IC REPTILE FAUNA 
VII. THE P05TCRANIAL SKELETON OF THE TRAVERSO- 
DONTID MASSETOGNATHUS PASCUALI (THERAPSIDA, 

CYNODONTIA) 

Parish A. Jenkins, Jr.^ 

Abstract. The postcranial skeleton of Massetognathus pascuali is 
described from a single nearly complete individual and four disarticulated 
specimens; manus, pes and pubis could not be described from the available 
material. M. pascuali has a postcranial skeleton morphologically similar to 
that in Pascualgnathns polanskii (an earlier traversodontid) and in African 
Triassic cynodonts. The basic skeletal pattern of all these forms differs 
from that in Exaeretodon sp., an advanced traversodontid. The specialized, 
imbricating ribs of M. pascuali are intermediate in form between those 
of P. polanskii (which are diademodontid in form) and those of Exaere- 
todon sp. (which essentially have lost the cynodont specialization). 

Although Richard Owen made the first study of a cynodont more 
than a century ago, a detailed knowledge of cynodonts has accumu- 
lated only recently. First known only from Africa, representatives 
of this advanced group of mammallike reptiles have now been 
recovered from Asia and North and South America. The most 
specialized and, during the early and middle Triassic, the most 
abundant cynodonts were the herbivorous gomphodonts. Trans- 
versely broad, multicuspid postcanine molars with heavy occlusal 
wear (often to the point of effacing the original crown pattern) 
are characteristic of the group. Romer (1967) recognized three 
gomphodont families: Diademodontidae, Traversodontidae, and 
Trirhachodontidae. Massetognathus pascuali is a traversodontid 
and is one of two species described by Romer (1967) from the 



' Department of Anatomy, Columbia University, New York, New 
York 10032 



2 BREVIORA No. 352 

Chanares Formation of Argentina. Other undoubted traversodon- 
tid genera include Traversodon from the Santa Maria Formation of 
Brasil, Exaeretodon, Proexaeretodon and Ischignathus from the 
Ischigualasto Formation of Argentina, and Scalenodon and Scal- 
enodontoides from the Manda and Molteno beds, respectively, of 
Africa. Pasciialgnathus polanskii from the Puesto Viejo Forma- 
tion of Argentina, originally classified as a diademodontid (Bona- 
parte, 1966a; 1966b), is now interpreted as a primitive traverso- 
dontid on the basis of tooth morphology (Bonaparte, 1967, and 
personal communication). 

The present account of the Massetognathus pasciiali postcranial 
skeleton is based upon the disarticulated remains of at least four 
individuals and an almost completely articulated skeleton of a fifth 
individual, all about the same size and preserved in a nodule several 
inches thick and two and one-half feet in diameter. The 1964-65 
expedition of the Museo de la Plata and Museum of Comparative 
Zoology collected the nodule from the Chanares Formation in the 
Chanares-Gualo region of western Argentina. All the skeletal 
material is catalogued as No. 3691 in the Museum of Compara- 
tive Zoology. 

Although the available postcranial material of Massetognathus 
pasciiali is incomplete, there are two reasons why even a partial 
account is important. First, some workers regard cynodonts as 
ancestral to mammals (Crompton and Jenkins, 1968; Hopson and 
Crompton, 1969). Gomphodont cynodonts are certainly not di- 
rectly related to mammals, but they undoubtedly possessed a de- 
gree of biological organization that at least approximated that of 
their carnivorous-insectivorous relatives (from some form of which 
mammals were derived). Thus all cynodonts are relevant to evalu- 
ating the reptile-mammal transition. Second, most published in- 
vestigations of cynodonts have been restricted to cranial anatomy. 
Well-preserved, generically determinate postcranial skeletons are 
rare. Of South American genera, only Belesodon (von Huene, 
1935-1942), Exaeretodon (Bonaparte, 1963a) and Pasciialgna- 
thus are known from relatively complete skeletons; the preservation 
of known Belesodon material is poor, however, and Exaeretodon 
appears to be morphologically aberrant in comparison to the gen- 
eral pattern known from other cynodonts. Postcranial material 
associated with Traversodon and Chiniquodon (von Huene, 1935 
1942) is only fragmentary, although Romer (1969) has recently 
described more complete limb bones of Chiniquodon. I have re- 
viewed the postcranial skeletons of African cynodonts (Jenkins, in 



1970 



MASSETOGNATHUS POSTCRANIAL SKELETON 



press). Of the Russian forms very little is known; some data is 
available for Permocyiiodon (Konjukova, 1946). 

Vertebral column and ribs 

The number of presacral vertebrae in Massetognathus pascuali 
is at least 23 and is here interpreted to be about 26. A hiatus in 
the lumbar series of the one nearly complete, articulated vertebral 
column is responsible for this uncertainty. Present are 7 cervicals, 
164-? dorsals, and 6 sacrals. Judging from the length of several 
articulated but incomplete caudal series, tail vertebrae numbered 
at least 17 and probably as many as 25. A count of 26 presacral 
vertebrae in M. pascuali compares with 26 in Leavachia duven- 
hagei (Broom, 1948), 27 in Thrinaxodon liorhinus (Jenkins, in 
press), 28 in Exaeretodon sp. (Bonaparte, 1963a), 29 in Cynog- 
nathus crateronotus (Seeley, 1895 ) and at least 30 in a large cyno- 
dont identified tentatively as Diademodon sp. (Brink, 1955; Jen- 
kins, in press). 

Two separately articulating atlas arches appear to conform to 
the general pattern known from African Triassic cynodonts (Jen- 
kins, in press), but their preservation is too poor to allow specific 
description or comparison. The atlas intercentrum. transversely 
elongate and ventrally convex, bears a posteriorly directed process 
or lip (1, Fig. IB). A concave articular facet on the dorsal sur- 
face of this lip contacts a median convex facet on the anterior 
aspect of the atlas centrum (f a i, Fig. 6B ) . The lateral extremities 
of the intercentrum each bear, on their dorsal surfaces, a concave 
facet that articulates with the ventral aspect of one of the two 
occipital condyles. The atlas centrum (6 mm long) is synostosed 






Figure 1. Vertebral elements in Massetognathus pascuali. A. Cervical 
vertebrae, probably the third and fourth, in lateral view. B. First or atlantal 
intercentrum in ventral view with anterior margin toward the top of the 
page. C, Anterior dorsal ("thoracic") vertebrae; vertebra on the right is 
in lateral view, on the left posterolateral view. All X 1. Abbreviations: 
fo, costal fovea for rib head; 1. posterior lip of the intercentrum; p. para- 
pophysis; t, transverse process. 



4 BREVIORA No. 352 

to the axis centrum (8.5 mm long), forming a conspicuously large 
vertebra. On the dorso-lateral aspects of the atlas centrum are two 
facets, one for each atlas arch half (f a a. Fig. 6B). Protruding 
from the median aspect of the centrum between these facets is a 
small process (d, Fig. 6B) homologous with the dens or odontoid 
process of mammals. Elsewhere (Jenkins, 1969; in press) I have 
proposed that the mammalian dens originated as a neomorphic 
process from the atlas centrum of cynodonts. The occurrence of a 
dens in Massetognathus pascuali is unequivocal and supports the 
theory that both a dens and an atlas centrum (of which the dens 
was formerly thought to be a vestige) occur together among 
cynodonts. 

The axis centrum of the one articulated cervical series is about 
9 mm long, 1 mm longer than the centra of the following cervicals. 
The axial prezygapophyses have been broken off on all specimens, 
but from the appearance of their narrow bases^ — no thicker than 
the laminae from which they protrude — they are vestigial. Axial 
postzygapophyses of normal size bear articular facets at an angle 
estimated to be 25° to the horizontal. The axial spine, a flat blade 
with a distinctly mammalian shape, exhibits a straight dorsal mar- 
gin that was probably slightly convex during hfe. The robust 
transverse processes are directed posterolaterally. 

Cervical centra are amphicoelous, as are all other centra in 
Massetognathus pascuali, with the exception of the atlas (only the 
posterior aspect bears a notochordal concavity) and possibly some 
of the smaller caudal vertebrae. In cervical vertebrae, the rim sur- 
rounding the notochordal concavity on each end is swollen, and 
this increases the concave curvature of the sides and ventral aspect 
of each centrum. A bulbous parapophysis is to be found on the 
ventrolateral aspect of each anterior rim (p. Fig. lA). If the rib 
head articulated on the apex of the parapophysis, as seems most 
likely on the basis of the large size of the process, then this condi- 
tion differs from that in species of Thrinaxodon and Cynognathus, 
in which cervical rib heads are situated intervertebrally. A median 
ventral keel, similar to that in other cynodont cervicals, traverses 
the length of each cervical centrum. 

Cervical pedicles are narrow anteroposteriorly and bear short, 
stout transverse processes (t, Fig. lA). Cervical spines, broken 
off on all but two disarticulated cervicals (Fig. lA), are trans- 
versely slender and recurved, and taper abruptly toward the apex. 
Of particular interest are the zygapophyses, which provide a basis 
for distinction between cervical and dorsal (anterior thoracic) 
vertebrae. As noted above, the axial postzygapophyseal facets are 



1970 MASSETOGNATHUS POSTCRANIAL SKELETON 5 

oriented at an angle of about 25° to the horizontal; the orientation 
of posterior facets on the third through sixth cervical are more than 
25° — probably about 35°. The distance between their lateral mar- 
gins is approximately 7 mm. The anterior articular facets of the 
seventh cervical of course conform in orientation and spacing to 
those of the foregoing series. The posterior articular facets, how- 
ever, appear to be oriented at about 45°. Those on the succeeding 
(eighth) vertebra are nearly parasagittal — i.e., within a few de- 
grees of vertical — and are only 3.5 mm apart. The articular facet 
characteristics of the eighth vertebra, continued (with gradual 
modification) through the dorsal series, definitely estabhsh a dif- 
ferent pattern. Although transitional, the seventh vertebra most 
closely resembles other neck vertebrae and thus may be regarded 
as the last cervical. Similar changes in facet orientation and 
spacing, together with other morphological changes, occur between 
the seventh and eighth vertebrae of Tlvinaxodon liorhimis and 
Cynognathiis craterouotiis (Jenkins, in press). The condition in 
Massetognathus pascuali reaffirms the fact that the "mammalian" 
number of seven cervical vertebrae was already established in 
cynodonts. 

With the exception of the atlas intercentrum, no other cervical 
intercentra have been identified. The broad grooves formed by the 
rims of adjacent centra are evidence that intercentra were present — 
as in Thrinaxodon liorhimis, for example — and the state of dis- 
articulation accounts for their postmortem loss. 

The dorsal vertebral column in cynodonts is either a relatively 
undifferentiated dorsal series (as in most reptiles) or two series — 
"thoracic" and "lumbar" (as in mammals). In certain African 
Triassic cynodonts, separation of thoracic and lumbar regions may 
be made on the basis of distinct morphological specializations of 
the posterior dorsal (= lumbar) ribs (Jenkins, in press). In other 
cynodonts (e.g., Exaeretodon sp.; Bonaparte, 1963a) the trunk 
cannot be divided into thoracic and lumbar regions because the 
posterior ribs are not specialized. Massetognathus pascuali has 
specialized "lumbar" ribs and clearly belongs to the first category. 
The exact number of thoracic and lumbar vertebrae is unknown 
because a complete vertebral column with ribs is not yet available. 
Therefore, thoracic and lumbar vertebrae will be given only a 
general description as anterior and posterior dorsals, respectively, 
although the ribs (to be discussed below) clearly give evidence of 
a differentiated series. 

The centra of anterior dorsal vertebrae are approximately 8.5 
mm long; those of posterior dorsals are about 1 1 mm long (10 mm 



6 BREVIORA No. 352 

in the one articulated specimen). The costal foveae (fo. Fig. IC) 
of anterior dorsal vertebrae form a cleft for reception of the rib 
head, which is therefore intervertebral in position. On posterior 
dorsals the rib head articulates with a parapophysis (p, Fig. 2B) 
and is not intervertebral. Transverse processes are laminar and 
bowed dorsally on anterior dorsal vertebrae (t, Fig. IC) but are 
rodlike and round in cross-section on posterior dorsals (t, Fig. 2B). 
The posterior intervertebral notch is deep throughout the dorsal 
series, the anterior notch negligible or absent. In contrast to many 
cynodonts, anapophyses are lacking. Dorsal prezygapophyses are 
robust, extending to or slightly beyond the level of the anterior 
aspect of the centrum. Articular facets on the first dorsal vertebra 
are about 3.5 mm apart and on the ninth are 4.0 mm; an abrupt 
widening takes place at some point in the middle or posterior dorsal 
series, for the articular facets of the penultimate dorsal vertebra 
are about 7 mm apart. The narrowly-spaced facets of anterior 
dorsals are nearly vertical, whereas those wider apart on the pos- 
terior dorsals are oriented at angles of as much as 45°. Neural 
spines on anterior dorsals are narrow, but unlike cervical spines, 
do not taper significantly at the apex; they incline caudad at angles 
of about 30°. Spines on posterior dorsal vertebrae are broad an- 
teroposteriorly, leaving only a narrow gap between vertebrae; their 
inclination is only a few degrees caudad. 

Sacral vertebrae successively decrease in size posteriorly. The 
centrum of the first sacral is approximately as long as those of the 
posterior dorsals (about 10 mm), while the sixth and last sacral 
centrum is some 2 mm shorter. Massive synapophyses — repre- 
senting fused parapophyses and transverse processes — arise from 
the pedicles and from the anterior half of the side of the centrum. 
The zygapophyses, proportionately less robust than in the dorsal 
series, diminish in size on successively more posterior sacrals. In 
contrast to the orientation and spacing in the posterior dorsals, 
sacral articular facets incline nearly parasagittally and are nar- 
rowly spaced. At the last dorsal-first sacral articulation, the facets 
are 5.5 mm apart, but between the third and fourth and fourth and 
fifth sacrals they are only about 2 mm apart. At the fifth-sixth 
sacral articulation the trend is reversed; the facets are spaced 
3.5 mm apart and appear to be inclined at 10° from the vertical. 
The trend toward less verticality of facets is continued into the 
caudal series. Sacral spines successively diminish in height and 
anteroposterior breadth. The spine on the first sacral is approxi- 
mately 8 mm in height and 7 mm in breadth (versus 8.5 mm height 
and 8 mm breadth for the last dorsal spine). On the fifth sacral 



i 



1970 MASSETOGNATHUS POSTCRANIAL SKELETON 7 

the same measurements are 5.5 mm and 4.2 mm respectively. This 
trend is continued into the caudal series. The apices of sacral 
spines tend to be oval in contrast to those of the posterior dorsals 
which are elongate and attentuated at each end. 

Caudal centra decrease in length from 6.5 mm at the first caudal 
to about 5 mm at the fifth. More posterior caudals preserved with 
MCZ 3691 are disarticulated, and their position cannot be posi- 
tively assigned. However, one isolated series of eleven caudals 
shows a decrease in centrum length from 5 mm (which is evidence 
that it is approximately the fifth caudal) at the first to 4 mm at 
the last (? fifteenth caudal). Other specimens show that at least the 
first five caudals bear synapophyses. Articular facets are inclined 
at approximately 45°, at least through the first five caudals. The 
width between the lateral edges of these facets decreases from 
6 mm (between the last sacral and first caudal) to 4.5 mm 
(between the fourth and fifth caudals). The terminal caudal is 
unknown. 

Massetognathus pascuali probably possessed ribs on all presacral 
vertebrae, as in other cynodonts for which adequate material is 
known. Ribs were not found in association with the first six cervi- 
cal vertebrae, although the morphology of the transverse processes 
and parapophyses on the axis through sixth cervical is clear evi- 
dence of their existence. These features cannot be verified at pres- 
ent on the atlas. The ribs of the seventh cervical appear to have 
been shorter than, but otherwise similar to, those of the anterior 
dorsal series. 

Dorsal ribs in Massetognathus pascuali are of basically two 
types: in the anterior and middle dorsal series, a freely articulating 
rib of normal costal form and proportions, and in the posterior 
dorsal series, a fused rib with a Y-shaped distal end. Unfortu- 
nately, the transitional ribs between the two types are as yet 
unknown. 

The proximal ends of anterior and middle dorsal ribs are basi- 
cally triangular. The tuberculum and capitulum form two corners 
of the triangle; the shaft arises from the third (Fig. 3A). On the 
anterior aspect of this triangular surface is a slight crest (c. Fig. 
3A) comparable to a similar feature on the anterior dorsal ribs of 
Cynognathus sp. (c. Fig. 3B. C). There is no other apparent fea- 
ture that makes this type of rib distinctive. The maximum widths of 
the shafts near their proximal ends are between 2.5 and 3 mm. The 
distal ends, as preserved, are approximately 1.5 mm thick. Ribs of 
this basic morphology (as opposed to the specialized posterior 



8 



BREVIORA 



No. 352 




Figure 2. The posterior dorsal and sacral region in Massetoguathus 
pasciiali in A, dorsal and B, lateral views. X 1. Abbreviations: a il, 
acetabular facet of the ilium; a p, anterior process of rib shaft; b, ridge 
on dorsal aspect of rib shaft; f a p, articular facet on anterior process of 
rib shaft; gr, groove on dorsal margin of ischium; il, ilium; is, ischium; 
is t, ischial tuberosity; m p, medial process on base of ilium for articulation 
with ischium and pubis; p, parapophysis; p p, posterior process of rib shaft; 
t, transverse process. 



dorsal ribs to be described next) are associated with at least the 
first thirteen dorsal vertebrae. 

The following description of the specialized posterior dorsal 
ribs is based on the penultimate and last dorsal ribs preserved in 
articulation (Fig. 2) and in addition, a few disarticulated pieces of 
similar morphology. These ribs have a short shaft that bifurcates 
into a Y-shaped terminus with two processes (ap, pp, Figs. 2, 4B). 
The anterior process is broader than the posterior and bears, on 
the dorsal surface of its tip, a rather flat, round facet (f a p, Figs. 
2A, 4B). Articulating with this facet is the end of the posterior 
process of the preceding rib. Presumably, the underside of the 



970 



MASSETOGNATHUS POSTCRANIAL SKELETON 






Figure 3. Proximal ends of dorsal ribs of A, Masseto^natliiis pascuali 
(X 2), and of B and C, Cynognatlms sp. (X V2) in anterior view. Ab- 
breviations: c, crest on anterior aspect of shaft (see text for details). 



posterior process also bears a facet. The rib as a whole projects 
laterad from the vertebral column and appears not to have had any 
ventral curvature. In lateral view (Fig. 2B) the shaft and point of 
bifurcation are at approximately the same level, but the anterior 
and posterior processes incline somewhat ventrally. A low, bony 
ridge (b. Figs. 2 A, 4B) runs obliquely onto the posterior process 
from the point of bifurcation where it is most prominent. This 
feature is comparable to a similar ridge on the ribs of Cynognatlms 
sp. (b. Fig. 4A) and other cynodonts; in the fourteenth thoracic 






Figure 4. Specialized posterior dorsal ("lumbar") ribs of various 
cynodonts. A. Cynognathus crateronotiis (British Museum of Natural 
History no. R. 2571), X V4. B, Massetogucithiis pascuali. XL C, 
Leavacliia duvenhagei (Rubidge Collection, Graaf Reinet, South Africa, 
no. 92), X V2. All dorsal views. Abbreviations: a p, anterior process 
of rib; b, ridge on dorsal aspect of rib shaft (of unknown function but 
probably homologous in the forms shown here); f a p, articular facet on 
anterior process of rib shaft; LI, L2, first and second lumbar vertebrae; 
p p, posterior process of rib shaft; T14, T15, fourteenth and fifteenth 
thoracic vertebrae. 



10 BREVIORA No. 352 

rib of C (T14, Fig. 4A), the ridge is merely a linear elevation on 
the flat costal plate. On successive ribs, however, the ridge becomes 
more prominent until, in the lumbar ribs (LI, L2, Fig. 4A), it 
reflects forward to contact the preceding rib plate (see Jenkins, in 
press). No such reflection is evident in Massetognathus pascuali, 
but the ridge morphology and general pattern of the process are 
nevertheless similar to that of the fourteenth and fifteenth thoracic 
rib plates of C 

Specialized, imbricating ribs are common but not universal 
among cynodonts. Known members of the earliest cynodont fam- 
ily, the procynosuchids, apparently did not possess this specializa- 
tion (see discussion below, however, for a possible exception). 
Galesaurids, typified by the well known Thrinaxodon liorhinus 
(Jenkins, in press), developed costal expansions on all presacral 
ribs. Members of three other families, e.g., Cynogmitlms craterono- 
tus (Cynognathidae; Seeley, 1895), Diadeinodon sp. (Diademo- 
dontidae; Jenkins, in press) and Cricodon metabolus (Triracho- 
dontidae; Crompton, 1955), possessed imbricating ribs only in the 
posterior dorsal region. The ribs in chiniquodontids (von Huene, 
1935-1942) are as yet unknown. There remains only the Traver- 
sodontidae, which Bonaparte (1963b) characterized, on the basis 
of species of Exaeretodon and supposedly Traversodon, as lacking 
synostosed ribs with overlapping processes. For this and other 
reasons, Bonaparte interpreted traversodontids as probably having 
arisen from procynosuchids along a lineage separate from that an- 
cestral to all other cynodont families (whose members possess rib 
specializations). However, Massetognathus pascuali unquestion- 
ably possesses synostosed lumbar ribs with details comparable to 
the Cynognathus-Diademodon pattern. Pascualgnathus polanskii, 
now classified as a traversodontid (Bonaparte, 1967), has lumbar 
ribs that are unquestionably diademodontid in pattern. Further- 
more, von Huene (1935-1942; 137-140) described expanded ribs 
("Facherrippen") synostosed to the lumbar vertebrae in Traverso- 
don stahleckeri. Crompton (1955) presented circumstantial evi- 
dence that the traversodont Scalenodon from the African Manda 
beds also possessed the expanded rib specialization. Yet Bona- 
parte (1963a) amply demonstrated that at least one traversodont, 
Exaeretodon sp., did not possess such specialization. Presacral ribs 
in Exaeretodon sp. are morphologically uniform and are more or 
less freely articulating (although the more "solid" attachment of 
the last three dorsal ribs, as described by Bonaparte, possibly rep- 
resents a vestige of a less mobile articulation typical of expanded 
ribs ) . In view of this unexpected association at the family level of 



1970 MASSETOGNATHUS POSTCRANIAL SKELETON 11 

forms possessing and forms lacking rib specializations, the taxo- 
nomic significance of this character should be reassessed. Further 
comment is reserved for the discussion below. 

Sacral ribs in Massetognathiis pascuali have an essentially con- 
fluent capitulum and tuberculum, a short shaft and an expanded 
distal end for articulation with the iliac blade. Proximally each rib 
is synostosed to its corresponding vertebra. If I may judge from 
the disarticulated condition of every known sacroiliac joint, liga- 
ments and cartilage must have been chiefly responsible for binding 
the ilium and sacral ribs. The concave distal ends of the sacral ribs 
conform to the gently convex internal surface of the ilium, but 
they do not appear to form any osseous interdigitation by which 
sacroiliac joints are commonly reinforced. Viewed from above, the 
distal end of the first sacral rib (Si, left side. Fig. 2A) is Y-shaped 
with processes directed anterolaterad and posterolaterad. Articu- 
lating with the dorsal surface of the anterolateral process is the 
posterior process of the last dorsal (lumbar) rib. The second sacral 
rib has the largest distal expansion; irregularly shaped and widest 
anteriorly, the expansion is 7 mm long in one well preserved speci- 
men. The third, fourth and fifth ribs bear more or less symmetrical 
distal expansions that are successively smaller caudally. The first 
four sacral rib shafts are oriented more or less laterally, the fifth 
slightly anterolaterally. The sixth and last sacral rib bears a shaft 
that is directed posterolaterally and a bifurcated, Y-shaped termi- 
nus resembling that of posterior dorsal ribs. Its iliac articular sur- 
face is narrow and strap shaped; the rib and vertebra could well be 
interpreted as the first caudal were it not for its position opposite 
the posterior tip of the ihac blade (S6, Fig. 2A). While it is appar- 
ent that the width between the distal ends of this pair of ribs 
(20 mm) is much less than that of the fourth and fifth sacrals 
(27 mm), the intervening gap could well have been completed by 
ligaments. This interpretation of the sixth sacral vertebra and ribs 
may be open to future modification, but on present evidence ap- 
pears to be the most probable. 

Only the first three caudal ribs are preserved. All are synostosed, 
their shafts directly posterolaterally. The first is only 8 mm long 
(Cdl, Fig. 2A), with two blunt processes on its terminus resembling 
a stunted version of the last sacral rib. As far as can be deter- 
mined, terminal processes were not developed on the second and 
third caudal ribs, which are 5 mm or less in length. Ribs on suc- 
ceeding vertebrae must have been very small and probably did not 
occur in the posterior caudal series. 



12 



BREVIORA 



No. 352 



Shoulder Girdle 

Available interclavicles of Massetognatlius pascuali are incom- 
plete, although there is sufficient material to conclude that the 
morphology is very similar to that in Thrinaxodon liorhinus and 
different from that in Exaeretodon sp. In outline the interclavicle 
is cruciate with an elongate posterior ramus (pr, Fig. 5A). The 
entire bone, although basically a flat plate, is bowed ventrally from 
front to back. Two ridges, one longitudinal, the other transverse, 
divide the ventral surface of the interclavicle into quadrants. The 
two anterior quadrants (c c. Fig. 5A) are shallow concavities for 
reception of the proximal ends of the clavicles. The ridges are 



#^f 





prox 

Figure 5. A, The interclavicle and B, the right clavicle of Massetog- 
nathus pascuali, both in ventral view. X 1. Abbreviations: ca, concavity 
for acromion; c c, concavity for proximal end of the clavicle; dist, distal 
end of clavicle; f, ventral flange on distal end of clavicle; pr. posterior 
ramus of interclavicle; prox, proximal end of clavicle. 



most prominent at their intersection. With the exception of the 
posterior part of the longitudinal ridge, which gradually fades out, 
the ridges become more salient toward the margins. There is no 
evidence that the longitudinal ridge was a deep keel as in Exaereto- 
don sp. (Bonaparte, 1963a). The posterior ramus in M. pascuali 
is similar in length and form to that in galesaurids, and is unlike the 
very short ramus of Exaeretodon sp. 

The Massetognathus pascuali clavicle is robust. The proximal 
two-thirds are more or less straight (Fig. 5B), the distal third 
curving sharply posterodorsally. The broad, flat plate on the proxi- 
mal end articulates with the previously described concavity (c c. 
Fig. 5A) in the interclavicle. Along the ventral aspect of the distal 



1970 MASSETOGNATHUS POSTCRANIAL SKELETON 13 

third runs a flange (f, Fig. 5B) similar to that noted in African 
Triassic cynodonts (Jenkins, in press) and Exaeretodon sp. (Bona- 
parte, 1963a). This flange continues to the distal end where it 
contributes to the formation of a concavity (ca, Fig. 5B) for re- 
ception of the acromion. The clavicle is essentially identical to 
that in galesaurids. 

The scapula, coracoid, and procoracoid in Massetognathiis pas- 
ciicili are firmly synostosed, although the joints can readily be dis- 
tinguished (Fig. 6A). The scapular blade, elongate and narrow, 
bears a distinct concavity on its lateral surface — a fossa presumably 
for the supracoracoideus muscle, the infraspinatus homologue of 
mammals. The anterior margin of the blade is reflected sharply 
laterally, the posterior margin somewhat less so. An acromion 
process as such is not preserved on any of the scapulae; this ab- 
sence may be due to postmortem damage to a delicate process or 
to the fact that the clavicular concavity simply fitted to the convex 
edge of the anterior scapular base (ac, Fig. 6A). The scapular 
half of the glenoid is a hemicircular and shghtly convex facet that 
faces posteroventrally and somewhat laterally. 

The coracoid is basically triangular in lateral view (co. Fig. 6A). 
The posterior end forms an elongate, attenuated process terminated 
by a tubercle for the origin of the coracoid head of the triceps (co 
tr, Fig. 6A ) . The process is morphologically similar to the same 
feature in Pascualgnathus pokmskii and in African Triassic cyno- 
donts, but differs in form from that in Exaeretodon sp. as inter- 
preted by Bonaparte ( 1963a). Between the glenoid and the triceps 
tubercle, the superior margin of the coracoid is about 2 mm wide 
and is slightly concave from front to back. The slightly convex 
inferior margin is, in contrast, extremely thin bone, and, as a con- 
sequence, is invariably damaged postmortem. A saddle-shaped 
facet, concave dorsoventrally and convex transversely, constitutes 
the coracoid half of the glenoid. 

The procoracoid (pr, Fig. 6A) appears to be an irregularly 
shaped, flat plate, but in no available specimen are the free mar- 
gins complete. There are so many basic similarities in the scapu- 
locoracoid of Massetognathiis pascuali and African cynodonts that 
a complete procoracoid of the former would probably have the 
same oval shape characteristic of the latter. A crescentic depres- 
sion on the lateral aspect along the inferior margin may represent 
the biceps origin. Above lies the round procoracoid foramen 
(f pr. Fig. 6A) sculptured in a ventrolateral direction to facilitate 
passage of its nerve and blood vessels. The evidence as to 
whether the procoracoid participated in the glenoid is equivocal. I 



14 



BREVIORA 



No. 352 



believe that the procoracoid probably supported articular cartilage 
at the very anterior extremity of the glenoid (see left glenoid, 
Fig. 6A), but there is no certainty of the procoracoid contribu- 
ting to the shoulder joint as there is for some African Triassic 
cvnodonts. 




970 MASSETOGNATHUS POSTCRANIAL SKELETON 15 



Figure 6. Elements of the postcranial skeleton of Massetogiuithiis 
pasciiali, drawn as preserved in situ. A, Incomplete left shoulder girdle and 
forelimbs seen from the left side. B. Lateral view of axis. C, Dorsal view 
of left humerus. D, Medial view of left radius and ulna. All X 1. Ab- 
breviations: ac, area of clavicular articulation (distinct acromion process 
not developed); cl. clavicle; co, coracoid; co tr, tubercle for coracoid head 
of triceps; cp. capitellum; d, dens; d f. distal flange on radius; dp, delto- 
pectoral flange; f a a, atlas centrum facet for atlas arch; f a i, atlas 
centrum facet for atlas intercentrum; f ec, ectepicondylar foramen; f en, 
entepicondylar foramen; f pr, procoracoid foramen; g, groove possibly 
representing teres major insertion or the origin of one of the humeral 
triceps heads; h, humeral head; hu, humerus; 1, ridge possibly representing 
insertion of the teres minor; 1 t, lesser tuberosity; p f, proximal flange on 
radius; pr. procoracoid; ra, radius; s, scapula; ul, ulna; ul f, ulnar flange. 



16 BREVIORA No. 352 

Forelimb 

Principal characteristics of the humerus of Massetognathus pas- 
ciuili are the relatively broad expansion of the proximal and distal 
ends, and the large deltopectoral flange. The proximal end of the 
shaft is bowed dorsally and the head is oriented to a more dorsal 
position. The well-rounded head (h, Fig. 6C) possesses greatest 
curvature along its dorsoventral axis. As preserved, the articular 
surface is confluent medially whh the lesser tuberosity (1 t, Fig. 
6C) and laterally with the proximal margin of the deltopectoral 
flange. The greater tuberosity presumably arose in the mammalian 
lineage between the head and the proximal margin of the delto- 
pectoral crest, but in M. pasciiali there is no evidence of a distinct 
tubercle. The greatest width of the proximal end, from the lesser 
tuberosity to the region of the presumptive greater tuberosity, 
measures approximately one-third the total length of the humerus. 
The broad deltopectoral flange is slightly more than half the total 
length of the humerus. The free edge of the flange thickens and 
everts (laterally) at its proximal and distal extremities, but along 
the middle part is rather thin and flat. From the region of the pre- 
sumptive greater tuberosity a low, bony ridge runs obliquely across 
the flange toward the shaft (1, Fig. 6C). An identical ridge on the 
humeri of certain African Triassic cynodonts has been interpreted 
as possibly representing the insertion of a teres minor (Jenkins, in 
press). On the posterodorsal aspect of the shaft is a groove pos- 
sibly representing the insertion of the teres major or the origin of 
one of the humeral triceps heads (g. Fig. 6C); Bonaparte ( 1966b) 
interpreted a rugosity at this site in Pascualgnathus polcmskii as the 
origin of the medial triceps head. 

The distal end of the humerus is triangular in dorsal view, its 
maximum breadth being approximately 40 per cent of the humeral 
length. Arising from the robust ectepicondylar region, a thin supra- 
condylar flange runs proximally as well as somewhat dorsally. The 
flange, pierced in its proximal half by a small ectepicondylar fora- 
men (f ec, Fig. 6A, C), becomes a low crest at the middle of the 
shaft and is continuous with the ridge (1, Fig. 6C) described above. 
A stout bar of bone arising from the entepicondylar region encloses 
an elongate, oval entepicondylar foramen (f en. Fig. 6A, C). The 
capitellum (cp, Fig. 6A) is bulbous and contributes to the thick- 
ness of the ectepicondylar region. The trochlea immediately 
adjacent is a broad, shallow groove; the principal axis of this 
groove is dorsoventral, as expected, but it is also slightly 
oblique — the dorsal part being more laterally situated than the 



1970 MASSETOGNATHUS POSTCRANIAL SKELETON 17 

ventral part. Morphologically, the humerus of M. pasciudi is essen- 
tially identical to that in Pasciuil^naihus polcmskii and galesaurids; 
apparent differences with galesaurids, e.g., the greater roundness 
of the head and capitellum, are due to the better ossification in 
M. pascuali and P. polcmskii. As Bonaparte (1963a) noted, the 
humerus of Exaeretodon sp. is more similar to the dicynodont 
or gorgonopsid pattern than to that typical of galesaurids, and 
thus stands in contrast to the conventional cynodont humerus of 
M. pascuali. 

The radius has a slight sigmoidal curvature (which facilitates its 
crossing over the anterior aspect of the ulna) and expanded proxi- 
mal and distal ends. The nearly circular proximal articular facet 
forms a shallow concavity, in which the greatest curvature is an- 
teroposterior (as is its reciprocal surface on the capitellum). On 
the posteromedial aspect of the proximal end is an excrescence that 
bears a facet (f u. Fig. 6D) apparently for articulation with the 
ulna. From this excrescence, a distinct flange (p f. Fig. 6D) runs 
distally to about the midpoint of the shaft. On better preserved 
material of African Triassic cynodonts, I interpreted a similar 
flange as possibly being associated with the biceps insertion and 
the radio-ulnar interosseous ligament (Jenkins, in press). Bona- 
parte (1963a) interpreted a similar feature in Exaeretodon sp. as 
marking the position of the interosseous ligament. The distal end 
of the radius expands gradually to the distal articular facet which 
is oval (long axis transverse) and shallowly concave. A distal 
flange ( d f. Fig. 6D ) arises near the midpoint of the shaft essen- 
tially as a continuation of the attenuating proximal flange described 
above. Beginning on the posterior aspect of the shaft, the distal 
flange takes a spiral course toward the lateral aspect as it enlarges 
distally. Its position is suggestive of the attachment of an inter- 
muscular septum separating flexor and extensor muscle groups. 

The ulna, like the radius, is sigmoidally shaped but is expanded 
only at its proximal end (Fig. 6D). The relatively shallow semi- 
lunar notch represents the typical cynodont condition — basically 
oval in outline, but with a rather straight medial margin and a 
nearly hemicircular lateral margin. An olecranon process is not 
present or at least was not ossified; the proximal end of the ulna, 
where such a process would be developed, is broad and rugose. 
The transversely narrow shaft of the ulna bears on its anteromedial 
aspect a flange (ul f. Fig. 6D) that extends from the semilunar 
notch to the distal articular facet. In all probability this flange rep- 
resents the ulnar attachment of the interosseous ligament. The 
lateral surface of the shaft reveals one large, spoon-shaped fossa 
proximally, and on the medial surface two fossae, one proximal, 
the other distal. All three fossae are wefl represented in African 



18 BREVIORA No. 352 

Triassic cynodonts, and I have proposed (Jenkins, in press) that 
they represent origins of various manual flexor and extensor mus- 
cles. The distal articular facet, convex from front to back, is broad 
anteriorly and narrow posteriorly and thus is triangular in outline. 
Both the radius and ulna of M. pascuali, as far as available mate- 
rial permits comparison, are extremely similar to their counterparts 
among galesaurids and in Pascualgnathus polanskii. Although 
definite similarities exist with the antebrachial elements of Exaere- 
todon sp., the essential identity of the M. /7<;/.vcwa//-galesaurid pat- 
tern is incontrovertible. 

Only an incomplete and disarticulated series of seven or eight 
carpals of Massetognathus pascuali is known, but these are so 
poorly preserved, and good comparative material is so scanty, that 
no constructive observations on the manus can be made at this 
time. 

Pelvis 

A complete pelvis of Massetognathus pascuali is not yet avail- 
able, although enough is known of the ilium and ischium for pre- 
liminary description and comparison with other forms. The ilium 
bears an elongate, vertical blade, spatulate in front and lanceolate 
behind (il. Fig. 2). The lateral aspect of the blade is concave, 
especially anteriorly. The shape of blade, as well as the relative 
proportions of the pre- and postacetabular regions, is most similar 
to that in Pascualgnathus polanskii and is comparable to that of 
galesaurids, cynognathids, and diademodontids; Exaeretodon sp., 
on the other hand, has an iliac blade quite unlike the foregoing 
(Bonaparte, 1963a). The base of the iliac blade in M. pascuali is 
constricted into a short neck, below which are medial and lateral 
processes. The medial process (m p. Fig. 2B) bears two articular 
surfaces — one each for the pubis and ischium — which intersect at 
an angle of about 150°. The lateral process bears a nearly circular, 
concave facet that represents the iliac contribution to the acetabu- 
lum (a il. Fig. 2B). The facet is oriented principally in a postero- 
ventral direction but with a slight lateral eversion. 

Only the dorsal half of the ischium is available for examination 
(is. Fig. 2). The concave acetabular surface faces anterolaterally 
and is oriented essentially vertically. The postacetabular part of the 
ischium constitutes a broad plate that ventrally meets its counter- 
part of the opposite side. A longitudinal groove (gr. Fig. 2) on 
the dorsal margin of this plate terminates posteriorly at an ischial 
tuberosity (is t. Fig. 2). 

Available pubes have been extensively damaged postmortem. 



970 



MASSETOGNATHUS POSTCRANIAL SKELETON 



19 



The pubic contribution to the acetabulum is considerably smaller 
than that of the ischium. Neither the obturator fenestra nor the 
ventral aspect of the pelvic basin is preserved. 

The bony acetabulum is relatively shallow — a little more than 
5 mm deep. The continuous, sharp rim around the acetabulum de- 
fines a more circular socket than that known in African Triassic 
genera. In all other details, the pelvis of Massetognathus pasciiali 
appears to be morphologically similar to that in Pascualgnathus 
polanskii, galesaurids, and even larger African Triassic forms. 

Hindlimb 

The femur (Figs. 7, 8A) is a moderately slender bone, except 
for the expanded proximal end, which bears robust trochanters. 
The femoral head, bulbous and almost hemispherical as in mam- 
mals, is reflected medially but also somewhat dorsally by virtue of 
the dorsal bowing of the proximal end of the shaft (Fig. 8 A ) . The 
protuberant trochanter major (tr mj, Figs. 7, 8A) measures about 
5 mm in thickness. A pear-shaped area of smooth bone on its apex 
may represent the principal site of muscle attachment or of a sub- 
tendinous bursa. The bone surface immediately adjacent to the 
apex is rugose. The trochanter minor (tr mn. Figs. 7, 8A) forms 
an elongate flange that arises abruptly near the intertrochanteric 



tr mj 




tr mn tr mn 




tr mj 



Figure 7. Reconstruction of a left femur in Massetognathus pasciiali 
in A, ventral, and B, dorsal views. X 1. Abbreviations: i f. intertrochanteric 
fossa; tr mj. trochanter major: tr mn. trochanter minor. 



20 



BREVIORA 



No. 352 



fossa (i f. Fig. 7) and gradually disappears slightly distal to the 
shaft's midpoint. In cross-section, the middle of the shaft is essen- 
tially rectangular; its thickness from extensor (dorsal) to flexor 
(ventral) surfaces is about 6 mm, from the medial to lateral sur- 
faces 4.5 mm. The distal end of the femur expands gradually but 
asymmetrically, the lateral condyle being broader and farther offset 
from the femoral axis than the medial. The medial condyle pro- 
jects more ventrally than does the lateral condyle. The fibula ap- 
pears to have articulated on the lateral epicondylar region where a 
shallow groove (f f, Fig. 8A) occurs. The femur of Massetog- 
nathus pascuoli is morphologically comparable to the femora of 
Pascualgnathus pokmskii and even the larger African genera in 
which ossification of the extremities was well developed (Jenkins, 
in press). In smaller forms, such as galesaurids, the femur appears 
to be diiTerent because of the lack of ossification of the extremities 
and trochanters. 

The tibia is a transversely slender bone, bowed somewhat an- 
teriorly. The two proximal articular facets, oval in outline and 
shallowly concave, are separated by a low, median ridge. The 




B 




Figure 8. Elements of the hindlimb of Massetognathiis pascuoli. drawn 
as preserved in situ. A. Right femur, tibia and fibula in lateral view. B. 
Left tibia in medial view. All X 1. Abbreviations: f f. facet for articula- 
tion with fibula; fl, fibular flange for femoral articulation; f t, lateral tibial 
fossa of uncertain significance; g t, groove on medial aspect of tibia; 1 t. 
lineation on lateral aspect of tibia; tr mj, trochanter major; tr mn. 
trochanter minor. 



1970 MASSETOGNATHUS POSTCRANIAL SKELETON 21 

lateral margin of the lateral facet is thickened and protuberant, and 
it appears likely that part of the proximal fibula articulated here. 
On the proximal end of the lateral aspect of the shaft is a deep 
fossa (f t, Fig. 8A) of uncertain significance; from the posterior 
margin of this fossa a faint lineation (1 t. Fig. 8A) runs obliquely 
across the shaft to merge with the narrow anterior margin of the 
shaft. Also of uncertain significance is a slightly curved groove 
(g t. Fig. 8B) along the middle of the shaft's medial aspect. The 
distal extremity of the tibia has a marked lateral expansion that 
sufficiently widens at the terminus to accommodate a broad, 
slightly convex facet for the astragalus. 

The fibula, a very slender-shafted bone with enlarged extremi- 
ties, is bowed laterally. The shaft appears to have been wider 
transversely than anteroposteriorly. On the one complete speci- 
men, a shallow groove running the length of the shaft along its 
medial aspect can be detected. A flange on the proximal end 
(fl. Fig. 8A) probably contacted a groove on the lateral epicon- 
dylar region of the femur; the remainder of the proximal fibula 
articulated with the tibia. The distal end, like the proximal, broad- 
ens anteroposteriorly and is inflected somewhat medially. All 
features of both tibia and fibula found in MassetognatJius pascuali 
are duplicated in galesaurids and even in the larger African Triassic 
genera. The tibia and fibula of Exaeretodon sp., by contrast, de- 
part from the uniform pattern of other cynodonts by being pro- 
portionally more massive. 

Nothing can be described of the pes of Massetognathus pascuali 
from the available material. 

Discussion 

Massetognathus pascuali, about 50 cm in length from head to 
tail, was a cynodont of relatively slender build (Fig. 9). The short- 
ness of the limbs relative to the approximated trunk length gives 
the body a "low-slung" appearance. The head seems dispropor- 
tionately large for the body, but a relatively massive head is a 
common cynodont characteristic. 

The postcranial skeleton of Massetognathus pascuali is basically 
like that in galesaurids, diademodontids, cynognathids and Pas- 
cualgnathus polanskii. Limited morphological diversity appears to 
be the rule for the postcranial skeletons of Triassic cynodonts. 
Exaeretodon, however, is an exception; the postcranial skeleton in 
this genus differs in major details from the pattern characteristic 
of other Triassic cynodonts. Bonaparte (1963a) recognized post- 
cranial specializations in his original description and implied that 



22 



BREVIORA 



No. 352 







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1970 MASSETOGNATHUS POSTCRANIAL SKELETON 23 

similar features might also be characteristic of other traversodon- 
tids. From similarities between the genera Exaeretodon and Lea- 
vachia, Bonaparte further inferred that traversodontids possibly 
evolved from procynosuchids in a lineage separate from that giving 
rise to other cynodont families. These conclusions, credible on 
evidence available in 1963, now require modification, because 
P. polanskii and M. pasciiali demonstrate that Exaeretodon is a 
specialized traversodontid. Such specialization is not surprising in 
view of the fact that this genus lived later in the Triassic than any 
form with which it has been compared. Limb bones in Exaereto- 
don sp. are more robust than in other cynodonts (Fig. 10), no 
doubt in relation to its unusually large size. Some Exaeretodon 
features are unknown in other cynodonts. For example, a deep, 
sagittal keel occurs on an unusually short interclavicle; an extra 
trochanteric process runs distally from the trochanter major along 
the ventral aspect of the femur (Bonaparte, 1963a; a similar 
process, identified as a trochanter minor by Parrington (1961), is 
known in a whaitsid therocephalian and in a scaloposaurid bauri- 
amorph). Furthermore, the lack of rib specialization is a unique 
feature for a Triassic cynodont. Thus, as a specialized traverso- 
dontid, Exaeretodon is no longer as relevant to the problem of 
traversodontid origins as it was when other traversodontid genera 
were poorly known. 

Two facts bear on the problem of traversodontid origins. First, 
morphological similarities between the postcranial skeletons of 
Massetognathus pasciiali, Pasciialgnathiis polanskii, and African 
Triassic cynodonts are evidence of close phylogenetic relationship. 
Similarities between the skull and specialized ribs of P. polanskii 
and Diadeinodon (see Bonaparte 1966b) raise the likelihood that 
traversodontids and diademodontids were derived from a common 
stock. Second, the paucity of information available on the pro- 
cynosuchid postcranial skeleton does not appear to be useful in 
evaluating relationships with other cynodont families. Bonaparte 
( 1963a) compared the postcranial morphology of Exaeretodon sp. 
and Leavachia duvenhagei and on this basis suggested the possibility 
that traversodontids and procynosuchids were directly related. The 
difficulty of this approach may be illustrated with respect to the 
forelimb in which, for example, Bonaparte noted similarity between 
the radius and ulna of Exaeretodon sp. and L. duvenhagei. The 
radius and ulna of E. duvenhagei are, in fact, poorly known and in 
relative proportions do not resemble those in Exaeretodon sp. more 
than those of African Triassic cynodonts (Fig. 10). Similarities 
cited by Bonaparte between the manus of Exaeretodon sp. and 



24 



BREVIORA 



No. 352 




1970 MASSETOGNATHUS POSTCRANIAL SKELETON 25 



Figure 10. Diagrammatic comparison of postcranial bones in various 
major groups of cynodonts. Leavachia, in part modified from Broom 
(1948) and in part drawn from stereoscopic photographs, represents 
Procynosuchidae. The galesaurid and cynognathid-diademodontid pat- 
terns are taken from Jenkins (in press); cynognathids and diademodontids 
are sufficiently alike in their postcranial morphology to be represented 
here by a single pattern. The Exaeretodon material is drawn from Bona- 
parte (1963b). All bones have been reduced to a standard dimension to 
illustrate proportional differences. 



26 BREVIORA No. 352 

L. diivenhagei are of equivocal significance in view of the almost 
total lack of information on the manus of other cynodonts. Bona- 
parte's contention that the humeri of Exaeretodon sp. and L. dii- 
venhagei are proportioned alike is valid, but the dissimilarity to 
those in other cynodonts is not so great as to make this comparison 
especially significant (Fig. 10). Bonaparte admitted that the 
scapulocoracoid of Exaeretodon sp. is more like that in Cynog- 
nathus sp. than that in L. diivenhagei. This resemblance, in Fig- 
ure 10 at least, is not particularly marked, ahhough the speciahzed 
character of the scapulocoracoid in Exaeretodon sp. is evident. 
Thus, comparisons between forelimb features of several cynodont 
families provide no evidence of special affinity between traverso- 
dontids and procynosuchids. 

The iliac blade of Massetognathus pascuali has a long posterior 
process like that in African Triassic cynodonts (Fig. 10) and 
Pascualgnathiis polanskii. In contrast, the same process in Exaere- 
todon sp. is relatively short (Fig. 10), and as a consequence the 
blade as a whole has a more mammahan shape (Bonaparte, 
1963a). The iliac blade in the type of Leavachia diivenhagei ap- 
pears to have a short posterior process (Fig. 10; Broom, 1948) but 
also appears to be somewhat damaged. Thus a long posterior 
process may have existed in procynosuchids, and on present evi- 
dence, at least, the ilia of Exaeretodon sp. and L. duvenhagei do 
not indicate special affinity between the two. 

Bonaparte (1963a) cited the absence of specialized ribs in 
Exaeretodon sp. and Leavachia duvenhagei as possible evidence of 
a close relationship between traversodontids and procynosuchids. 
The subsequent discovery of specialized ribs in Massetognathus 
pascuali and the reclassification of Pascualgnathiis polanskii (which 
has specialized ribs of the Diademodon pattern) make this observa- 
tion no longer significant. It is interesting, however, that in the 
type of Leavachia duvenhagei (Rubidge Collection No. 92, Graaf 
Reinet, South Africa) the last dorsal rib appears to be laterally 
oriented (Fig. 4C), much as in M. pascuali and in other cynodonts 
with specialized ribs. On the dorsal aspect of the shaft is a ridge 
(b, Fig. 4C) comparable in position and orientation to a similar 
ridge in M. pascuali, cynognathids. and diademodontids (b. Fig. 
4A, B). Furthermore. Konjukova (1946) figured a specimen of 
the procynosuchid Permocynodon, incompletely prepared from the 
ventral aspect. The posterior dorsal ribs are directed anterolaterad 
(as in Thrinaxodon, for example) and the shafts appear to be 
wider than those of more anterior dorsal ribs. The capitular articu- 
lations of posterior dorsal ribs in Permocynodon are relatively 
broad, a feature typical of cynodonts in which the posterior dorsal 



1970 MASSETOGNATHUS POSTCRANIAL SKELETON 27 

ribs are synostosed. On this incomplete evidence, it appears pos- 
sible that rib specialization was already underway in procyno- 
suchids and was further modified in the various cynodont families 
descended from them. 

Hopson and Crompton (1969), in a discussion of the origin of 
mammals, observe that galesaurids such as Thrinaxodon liorhinus 
would be ideal candidates for mammalian ancestors were it not for 
the presence of specialized ribs. These authors suggest that Exaere- 
todon is relevant to this problem because its nonspecialized ribs 
may represent a reversion from a specialized pattern, and similar 
trends may have occurred in galesaurids. There is now substantial 
evidence favoring the view that rib specialization was gradually lost 
in traversodontids. P. polanskii, the earliest traversodontid for 
which ribs are known, has a costal morphology of a Diadeinodon 
pattern. M. pascuali, temporally intermediate between P. polanskii 
and Exaeretodon sp., has ribs with less extensive specialization. 
Thus the ribs of Exaeretodon sp. apparently represent a reversion 
to a nonspecialized condition, and are not primitively nonspecial- 
ized as originally suggested by Bonaparte (1963a). That such a 
loss occurred in one family of cynodonts increases the possibility 
that a similar reversion occurred in advanced galesaurids — or their 
descendants — during the reptile-mammal transition. 

ACKNOWLEDGMENTS 

I am grateful to Professor Alfred S. Romer of Harvard Univer- 
sity for enabling me to participate in the Chanares faunal studies. 
Professor Romer, together with Professor Rosendo Pascual, Uni- 
versidad de la Plata (Argentina), generously consented to my re- 
quest to describe Massetognathus pascuali as a sequel to my work 
on African cynodonts. Professor Romer furthermore provided 
preparational facilities and staff, skillfully supervised by Mr. Arnold 
D. Lewis, with the result that the material was presented to me in 
excellent condition. Dr. Jose F. Bonaparte of the Institute Miguel 
Lillo de Tucuman (Argentina) kindly read the manuscript and 
clarified several important points of cynodont anatomy and rela- 
tionships. Figures 6 and 8 were prepared by Mr. Robert J. 
Demarest. I thank Dr. James A. Hopson of the University of 
Chicago for making available his collection of stereoscopic photo- 
graphs of Traversodon, and Dr. James Kitching of the Bernard 
Price Institute for Palaeontological Research (Johannesburg) for 
verifying some features on a specimen of Leavachia. 

The collection of the Chanares material was aided by National 
Science Foundation Grant GB-2454; preparation and publication 
of the results has been supported by grants GB-46 1 5 and GB-8 171. 



28 BREVIORA No. 352 

LITERATURE CITED 

Bonaparte, J. F. 1963a. Descripcion del esqueleto postcraneano de 

Exaeretodon. Acta Geol. Lilloana, 4: 5-52. 
1963b. La familia Traversodontidae. Acta Geol. Lilloana, 

4: 163-194. 
1966a. Sobre nuevos terapsidos Triasicos hallados en el 



centro de la Provincia de Mendoza, Argentina. Acta Geol. Lilloana. 
8: 91-100. 
1966b. Una niieva "fauna" Triasica de Argentina (The- 



rapsida: Cynodontia, Dicyncdontia) consideraciones filogeneticas y 
paleobiogeograficas. Ameghiniana, 4: 243-296. 
1967. Los tetrapodos Triasicos de Argentina. First Inter- 



national Symposium on Gondwana Stratigraphy and Paleontology, 

Mar del Plata. 
Brink, A. S. 1955. A study on the skeleton of Diculenwdon. Palaeont. 

Afr.. 3: 3-39. 
Broom, R. 1948. A contribution to our knowledge of the vertebrates 

of the Karroo Beds of South Africa. Trans. Roy. Soc. Edinburgh, 

61: 577-629. 
Crompton, a. W. 1955. On some Triassic cynodonts from Tanganyika. 

Proc. Zool. Soc. London. 125: 617-669. 
Crompton. A. W., and F. A. Jenkins, Jr. 1968. Molar occlusion in 

Late Triassic mammals. Biol. Rev., 43: 427-458. 
HoPSON, J. A., AND A. W. Crompton. 1969. Origin of mammals. In 

T. Dobzhansky, et ai. (eds. ), Evolutionary Biology, Vol. 111. New 

York: Appleton-Century-Crofts, pp. 15-72. 
HuENE, F. VON. 1935-1942. Die fossilien Reptilien der siidamerikanischen 

Gondwanalandes. Munich, C. H. Beck'sche Verlagsbuchhandlung, 

332 pp. 
Jenkins, F. A. Jr. 1969. The evolution and development of the dens of 

the mammalian axis. Anat. Rec, 164: 173-184. 
In press. The postcranial anatomy of African cynodonts 

and problems in the early evolution of the mammalian postcranial 

skeleton. Bull. Peabody Mus. Nat. Hist., Yale. 
KoNJUKOVA, E. D. 1946. New data on Perniocynodon siishkiiii Woodw., 

a cynodont member of the Northern Dvina fauna. Dokl. Akad. Nauk, 

54: 527-530. 
Parrington, F. R. 1961. The evolution of the mammalian femur. Proc. 

Zool. Soc. London. 137: 285-298. 
RoMER, A. S. 1967. The Chanares (Argentina) Triassic reptile fauna. 

III. Two new gomphodonts, Massctogiuttluis pasciiali and M. teniggii. 

Breviora, No. 264: 1-25. 
1969. The Brazilian Triassic cynodont reptiles Belesodon 

and Chiniqiiodoii. Breviora, No. 332: 1-16. 
Seeley, H. G. 1895. Researches on the structure, organization and 

classification of fossil Reptilia. Part IX, Section 5. On the skeleton in 

new Cynodontia from the Karroo rocks. Phil. Trans. R. Soc, Ser. B, 

186: 59-148. 

(Received 8 January 1970.) 



BREVIORA 



leseiiiini of Comtipsirative Zoology 

Cambridge, Mass. 10 August, 1970 Number 353 

Anolis iacare Boulenger, a "solitcry" anole from the Andes 

of Venezuela 



Ernest E. Williams,^ 
Osvaldo A. Reig,!^- 
Pablo Kiblisky,- and 
Carlos Rivero-Blanco'^ 

Abstract. Anolis jacare Boulenger is the sole member of its genus in 
the Andes of Merida in Venezuela. In external morphology, size, and to 
some extent in behavior, it resembles its congeners on the one anole islands 
of the Lesser Antilles. The karyotype of A. jacare. however, demonstrates 
that it is not closely related to either of the two Lesser Antillean stocks 
which it resembles and these we know not to be closely related to each 
other. The similarity of A. jacare to the two Lesser Antillean stocks and 
of these to each other seems to be due to selection for a similar ecological 
type. 



In 1903 Boulenger described Anolis jacare from several speci- 
mens in a collection made by S. Briceno at Merida, Venezuela, 
at an elevation of 1 600 meters. As all too frequently happens in 
Boulenger's work, the description was altogether without com- 
parison or note on relationship. 

Since its description additional specimens have been taken, all 
in the Venezuelan Andes, but there has been little discussion of the 
species. There has never been any question of its validity. 



1 Museum of Comparative Zoology. Harvard University, Cambridge, Mass. 
02138 

2 Institute de Zoologia Tropical, Universidad Central de Venezuela, Aptdo. 
59058. Caracas. Venezuela 

■= Jardin Zoologico "El Pinar." Cota 905, Caracas, Venezuela 



BREVIORA 



No. 353 



Schmidt (1939: 9) mentioned a peculiar feature of the spscies, 
the double row of keeled scales forming the dorsal caudal margin. 
This is a feature which A. jacare shares with some South American 
species and with the very distantly related A. harkeri of Mexico. 
In 1960 Etheridge placed jacare in the latijrons series of his alpha 
section of the genus Anolis. This section, distinguished by the 
absence of transverse processes on the caudal vertebrae, represents 
an old endemic South American stock, which today shares South 
America with more recent (beta section) invaders from Central 
America. 




Figure 1. Anolis jacare. Dorsal view of head. AMNH 13444. 



No previous mention of A. jacare has cited its most interesting 
feature: alone of native South American species, it shows a 
close resemblance to West Indian species, specifically those of the 
Lesser Antilles. In fact, its resemblance to Anolis leachii, except 
in size, is such that even an experienced student of Anolis, pre- 
sented with a specimen of jacare without locality, is very likely to 
confuse it with A. leachii. 

Table 1 compares A. jacare to A. leachii and to the Leeward 
Island species more similar in adult size. A. marmoratiis. 

When A . jacare is closely examined, of course, there should be 
no real possibility of confusing it with A. leachii. The dorsal 
squamation of the tail, larger dewlap, relatively larger ventrals. 
smaller scales on the snout, etc., permit easy recognition of v4. 



1970 ANOLIS JACARE 3 

jacare. On general appearance, however, relationship will still 
seem plausible. 

However, in terms of geography, close relationship of jacare of 
the Andes of Venezuela and leachii of the northern Lesser Antilles 
is prima facie unlikely. In addition, there is good evidence that 
the biniaculatus group (Gorman and Atkins. 1969) is derived 
from the still more distant Puerto Rican stock and that it is to this 
Puerto Rican stock or a still more primitive group that any phy- 
letically meaningful resemblance would be expected. 

Geographically, the roquet group in the southern Lesser Antilles 
would be a little more plausible as close relatives of jacare than the 
biniaculatus group. Gorman and Atkins (1969) have commented 
on the close external resemblance of the roquet and biniaculatus 
groups. Earlier, Underwood (1959) was able to find only the 
most trivial scale differences between the two groups. However, 
on all the characters by which Underwood was able to separate 
the roquet and bimaculatus groups, jacare fits the bimaculatus 
group. 

With the eight Venezuelan species geographically closest, jacare 
shows little similarity. (None of the eight appear to overlap the 
distribution of jacare at all.) Five of the eight {chrysolepis, 
auratus, juscoauratus, tropidogaster, biporcatus) belong to the 
beta division of Anolis (Etheridge, 1960) and are neither osteo- 
logically nor in squamation close to jacare. The three remaining 
species {squamulatus, punctatus, tigrinus) are referred by 
Etheridge (1960) to the same group as jacare (the latifrons series 
of the alpha section of Anolis). However, these again show no 
evidence of close relationship. Squamulatus and tigrinus are very 
different from jacare in size {squamulatus a giant, tigrinus a 
dwarf), and punctatus is conspicuously specialized in the swollen 
snout of the male. All differ significantly from jacare in scale 
characters. 

There are indeed no South American or other continental 
snecies to which A. jacare shows important resemblances. We are 
left, therefore, with the external similarities to the bimacidatus 
species group and, less marked, to the roquet species group. If 
these resemblances go deeper, we appear to be faced with a zoo- 
geographic puzzle which may need a difficult and complex solution. 

It has seemed worthwhile, therefore, to broaden the study of 
A. jacare to include such more recently utilized characters as 
karyotype and ecology. The remainder of this paper deals with 
the results of these analyses. 



4 BREVIORA No. 353 

Chromososome analysis (O. A. Reig and P. Kiblisky): 

Four male and three female individuals have been worked for 
chromosome analysis. Our report is based on the four male 
individuals. We failed to get results with one of the females, and 
the other two were sent to Dr. George Gorman, who, by the use 
of a blood culture microtechnique, obtained a chromosome count 
agreeing with our results ( personal communication ) . The male 
specimens have been deposited in the Collection of Herpetology 
of the Museum of Natural History of Caracas (MCNC 5601- 
5604). Those studied by Dr. George Gorman are in the Museum 
of Vertebrate Zoology, University of California. 

Our animals were injected with 0.5 cc Colchicine Merck (solu- 
tion 5 mg per cc ) 2-3 hours before killing. Testes were re- 
moved, minced with scalpel, and pretreated for 20 minutes in a 
hypotonic solution of sodium citrate 0.7%. The material was 
centrifuged at 800 rpm and the pellet resuspended in 3/1 alcohol- 
acetic fixative. After a new centrifugation, the pellet was changed 
to 2/1 fixative. Spreads were obtained by air-drying on chilled 
slides or by squashing, then stained with acetolactic orcein. 
Giemsa and Feulgen, and mounted in Canadian balsam. Chromo- 
somes were observed with a Wild M-20 microscope, and each 
appropriate metaphase or meiotic prophase was recorded and 
sketched. Numerous additional cells were also counted and ob- 
served. Selected cells from those recorded were photographed 
with high contrast Copy Kodak film, and karyotypes were con- 
structed from enlarged prints. A total of 50 cells was recorded, 
as listed below: 



Specimen Nr. MCNC 5601 

Specimen Nr. MCNC 5602 

Specimen Nr. MCNC 5603 

Specimen Nr. MCNC 5604 

All specimens 41 8 1 

Results 

The diploid chromosome complement of Anolis jacare is com- 
posed of 32 chromosomes (Figs. 3 and 4). Of them, 12 are 
macrochromosomes and 20 are microchromosomes. The diaki- 
neses (Fig. 5 ) show six large bivalents and ten very small bivalents. 
Chromosome number and structure are identical in all the studied 
specimens. The six pairs of macrochromosomes do not gradually 



ipermalos^onicd 








i)U'l<iplia\cs 


D 


akineses 


Metaphases II 


9 




3 




4 




1 


1 


15 




1 




13 




3 





1970 ANOLIS JACARE 5 

decrease in size but can be divided into tliree groups (Fig. I). 
Group A is formed by three pairs of large metacentric and sub- 
metacentric chromosomes. (In the following, we use the nomen- 
clature proposed by Levan, Fregda, and Sandberg, 1964.) Pair 
A-1 comprises sin chromosomes, whereas pairs A-2 and A-3 are 
//^-chromosomes. Chromosomes of pair B-1 are around 4/5 the 
length of those of pair A-3. Pairs B-1 and B-2 are easily 
distinguishable in size. Group C comprises one pair of small si 
chromosomes (r = 3.66), clearly smaller than those of pair B-2 
and three times larger than the largest chromosome of the set 
of the microchromosomes. A small difference in size and arm 
ratio was found in the chromosomes of this pair in all the cells 
where the shape of these chromosomes was clear enough, so that 
the pair might tentatively be considered as heteromorphic. 
Whether or not the presumptive heteromorphic pair is to be 
interpreted as an X-Y sexual system cannot be solved in the 
absence of good female metaphases. In two of the chromosome 
spreads obtained by Gorman, the female karyotype also shows 
heteromorphism in this pair. Moreover, the ring-shaped form of 
the corresponding bivalent in male diakinesis does not seem to fit 
with the X-Y hypothesis. The 20 pairs of microchromosomes 
steadily decrease in size and seem to have terminal (/) or sub- 
terminal (st) centromeres. 

Gorman (1965), Gorman and Atkins (1967, 1968a) and 
Gorman, Atkins and Holzinger (1967) have demonstrated that 
a karyotype of six pairs of macrochromosomes and twelve pairs 
of microchromosomes is shared by most of the studied species of 
iguanid lizards, including the anoles of the alpha group of 
Etheridge ( 1960) other than those of the bimaculatus series. The 
anoles of the beta group of Etheridge depart from this "standard" 
iguanid karyotype in showing seven pairs of macrochromosomes 
and a variable number of microchromosomes. Within the alpha 
group, the species of the bimaculatus series known in chromosome 
constitution {bimaculatus, leachii, gingivinus, and marmoratus) 
(see Gorman, 1965; Gorman and Atkins, 1966) are peculiar in 
having quite another kind of karyotype. In these species there is 
no sharp distinction between macro- and microchromosomes. 
There are from 18 to 20 chromosomes gradually decreasing in 
size that continue in five or six pairs of dotlike microchromosomes. 

Anolis jacare departs from both the beta anoles and alpha 
anoles of the bimaculatus series in retaining the "standard" set of 
six pairs of macrochromosomes, easily distinguishable from the 



6 BREVIORA No. 353 

microchromosome set. The morphological similarities referred 
to above with members of the bimaculatus series are thus not 
supported by chromosome evidence, but this evidence agrees with 
the osteological evidence in indicating that this species belongs to 
the alpha group. Within the non-biinaculatus series alpha anoles 
so far known in chromosome structure, however, a considerable 
variation occurs in details of structure of the macrochromosome 
set and in the number of microchromosomes. Anolis roquet, 
equestris, carolinensis, and cybotes are different from Anolis jacare 
in showing 22 or 24 microchromosomes and a steady decrease in 
size of the macrochromosomes, the only distinguishable break in 
size in these being between the fifth and the sixth pairs. Anolis 
cooki, pulchellus, cristatellus and scriptus of the cristatellus series 
(Gorman, Thomas, and Atkins, 1968) show the two sharp breaks 
in the macrochromosomes that are also observed in A. jacare, but 
in them the second break falls between the fourth and the fifth 
pairs instead of between the fifth and the sixth pairs as in A. jacare. 
In addition, those species of the cristatellus series mentioned above 
have heteromorphic sex chromosomes and only from 15 to 18 
microchromosomes. A. trinitatis and A. aeneus of the primitive 
latijrons series agree with A. jacare in the two size discontinuities 
among the macrochromosomes. They have, however, 24 and 22 
microchromosomes respectively, and the first break in the macro- 
chromosomes falls between the second and the third pair. More- 
over, the first pair of macrochromosomes is metacentric in all the 
illustrated karyotypes of alpha anoles, whereas it is submetacentric 
in A. jacare. 

Anolis jacare thus seems to be an isolated species within the 
alpha group on the basis of the pattern of the size discontinuities 
among the macrochromosomes and the unique number of 20 
microchromosomes. It is suggestive that a distinction of three 
groups within the macrochromosomes falling in the same order as 
in A. jacare can also be observed in the species of the beta anoles 
of the grahami and chrysolepis series so far reported (Gorman, 
1965; Gorman and Atkins, 1967). There is, however, a sharp 
difference between the macrochromosome set of these species and 
that of A. jacare: in the former the group C comprises two pairs 
instead of one pair as in the latter, the number of pairs of macro- 
chromosomes thus amounting to a total of seven, as in all of the 
beta anoles. 



1970 ANOLIS JACARE 7 

Given the widespread occurrence of six pairs of macrochromo- 
somes in alpha anoles and most iguanids, we are inclined to evalu- 
ate differences in number of the macrochromosome set as more 
important than structural rearrangements within this portion of the 
karyotype. For this reason, and because A. jcicare is clearly an 
aipha Anolis on ostcological grounds, the similarities it shows with 
some of the beta anoles in chromosome structure are better in- 
terpreted as a departure from the "standard" iguanid karyotype 
that converged with some of the modifications shown in the anoles 
of the grahami and chrysolepis series. Admittedly, the amount 
of this convergence may be considerable. It would be possible to 
derive the karyotype of A. jacare from that of A. chrysolepis by 
centromeric fissions in the last pair of macrochromosomes of the 
latter, leading to two pairs of microchromosomes with terminal 
centromeres. This process would result in a complement with 
six pairs of macrochromosomes separable into three distinct 
groups, and in ten pairs of microchromosomes, exactly as in /I. 
jacare. The osteological evidence, however, does not support any 
close relationships between these two species. 

The chromosome analysis thus indicates that Anolis jacare is an 
alpha Anolis that has departed significantly from other members 
of this group in chromosome number and structure, though main- 
taining the standard iguanid karyotypic feature of six pairs of 
macrochromosomes. 
Observations in life (C. Rivero-Blanco and E. E. Williams): 

Since no information of any ecological sort had ever been pro- 
vided for Anolis jacare, it was as important an objective of the 
expedition to Merida to provide this information as to obtain 
chromosome data. 

Only twelve anoles were collected during a period of three days 
of active search. All were obtained on medium and large-sized 
trees bordering the small Rio Milla just outside the city of Merida 
(1639 meters above sea level). Several other areas within and 
outside the city of Merida were carefully examined. 

The general area is classified as Premontane Humid Forest in 
the scheme of L. R. Holdridge (J. J. Ewel and A. Madriz. 1968). 
The mean annual temperature is 19.1° C and the annual rainfall 
1791 mm. 

The two actual collection sites (Fig. 2) were roadside localities 
and were subject to more or less penetration by the sun, especially 
so in site 1 where trees were partly separated, less so in site 2 
where the canopy was closed. In the first site, the anoles were 



8 



BREVIORA 



No. 353 



seen and collected on the branches of "majagua" (Heliocarpus 
popoyensis, Tiliaceae) and "guamo" {Inga sp., Leguminosae), at 
the second on "anime" {Montanea quadrangularis, Compositae) 
and on a very large tree 10-15 meters high, not identified, since 
leaves and flowers were not collected. 




Figure 2. Map of the collecting sites for A nulls jacarc along the Rio 
Milia outside Merida. 



Collecting was done with the aid of a 5 meter long telescopic 
fishing rod with a nylon noose. The animals were not shy but 
avoided the noose by moving around the branch or further along 
the branch or to other branches along the trunk or out on the finer 
twigs. Two escaped high into the canopy; others did not move at 



1970 ANOLIS JACARE 9 

all. The number of animals seen varied from none on many trees 
to four on one guamo tree. Few of those seen escaped the noose. 

We have no belief that we have even the beginning of knowledge 
of the population density of this species. The animals were difficult 
to see and commonly lay along branches, and only twice were 
they seen on the main trunk of the trees. They obviously ranged 
widely within the trees they inhabited, including very high in the 
crown. The first specimen taken came from a guamo tree that 
was examined several times every day and even one night. It was 
this tree that, on the last afternoon, provided three additional ani- 
mals to give a final result of two males and two females on a 
tree no more than six meters high and not especially complex. 
This result was possible only because, during the last afternoon, 
we had the help of a young local boy who was an excellent climber 
and who was able to spot from a higher position animals that could 
not be seen from below because of their resting position on 
branches. 

In summary, this is an animal inhabiting primarily the crown 
and its branches, though not avoiding the trunk. It is not re- 
stricted to shade; several individuals seen were in partial sun or 
moved into sun without reluctance. It has no evident competitors. 
No other lizards were seen in the collecting area either on the 
trees or on the ground. Elsewhere in the vicinity other lizards 
were found: Polychrus, in a hedge, and Aiueiva and Cnemido- 
phorus, on the ground. 

Discussion (E. E. WiUiams): 

The karyotypic evidence clearly demonstrates a strong separa- 
tion between jacare and either of the stocks of Lesser Antillean 
anoles. Equally there is sharp difference between jacare and the 
few mainland alphas that have been studied thus far (Gorman, 
personal communication). On the face of the evidence, A. jacare 
seems to occupy a rather isolated phyletic position. 

It may be of interest and importance here that A . jacare is dis- 
tributionally isolated also and that, very unusually for South 
American anoles, it is not known to be sympatric with any con- 
geners in any part of its known range. 

There are other South American species that extend beyond 
the range of their congeners somewhere at the periphery of their 
range. A. jacare is special in that so far as known its whole range 
is outside contact with any other anole. 

Recent studies by T. Schoener (1970) have shown that in the 
Lesser Antilles, "solitary" species, i.e., species without sympatric 



10 BREVIORA No. 353 

congeners, tend to be very similar in size and habitus. There also 
appears to be a broadened unsp:ciaiized ecology characteristic 
of these "solitary" anoles. We have noted above that the 
bimaculatiis and roquet species groups are extraordinarily similar 
in scale characters. We emphasize now that they are so in spite 
of the fact that they are products of two quite separate invasions 
of the West Indies and are very distinct in karyotype and bio- 
ci'icm'stry. 

Schoener infers, and we may agree with him, that some common 
selective factor must be at work to keep (or evolve) external 
similarity when wide underlying differences exist. That common 
selective factor would appear to be the negative one of the absence, 
or extreme limitation, of the number of congeners. 

Certainly on the larger islands of the Greater Antilles a con- 
trary rule exists: syntopic anoles are very diverse in morphology 
or size or both. 

The modification of a species in the absence of congeners or 
other competitors in its general niche is sometimes spoken of as 
"release." In morphology, at least, it is proper to speak of a more 
positive selection than that implied by that essentially negative 
term. A certain size seems clearly optimal and presumably the 
features of squamation must likewise be held under selective 
control. 

In ecological behavior, "release" seems a more descriptive term, 
since the wider range of habitat permitted a species in the absence 
of close competitors concords better with our intuitive sense of the 
meaning of release. 

In the Lesser Antilles, there is often only one species per island 
and, except for instances of very recent importation and their very 
local occurrence (e.g., wattsi on St. Lucia, Underwood, 1959. 
1962), there is a maximum of two species per island. These are 
relatively old islands and the species on them are well differen- 
tiated. They afford the classic and best examples of "solitary" 
anoles. 

A. jo.care, however, is as isolated in the Andes of Merida as the 
solitary anoles of the Lesser Antillean islands. It is effectively on 
a mainland island; it is interesting therefore, but not unexpected, 
however, to find it resembling and behaving like an island anole — 
a solitary anole of an old small island. 

The resemblances, then, of A. jacare to A. leachii or A. luar- 
moratus are to be explained in terms of adaptation to similar selec- 
tive pressures. We need not, in fact, seek any complex zoogeo- 
graphic solution to the similarity of one anole on island mountains 



1970 



ANOLIS JACARE 



11 



to one on a distant island; the similarity is non-phyletic, strictly 
convergent. 





TABLE 


1 




snout-vent 
length of 
adult -' 


jacarc 

73 mm 


leach a 
96 mm 


intirnioraliis 
77 mm 


scales acioss 
snout 


6-8 


4-5 


4-5 


scales between 
semicircles 


0-2 


0-1 


0-1 


loreal rows 


4-5 


4-5 


4-5 


scales between 
interparietal 
and semi- 
circles 


1-3 


1-2 


1-2 


supralabials to 
center of eye 


6-9 


7-8 


7-8 


mental 

number of 
sublabials in 
contact with 
infralabials 


not deeper 
than wide 

3-5 


not deeper 
than wide 

2-4 


deeper than 
wide 

2-4 


scales between 
sublabials in 
contact with 
mentals 


4 


4-6 


3-4 


ventrals 


smooth 


smooth 


feebly keeled 



lamellae under 
phalanges ii and 
iii of fourth toe 

tail 



dewlap 
color 



19-25 

compressed 
but without 
crest, 2 
dorsal rows 

large 

green with 
variable dark 
vermiculations 



26-32 

compressed, 
with strong 
crest in 
males 

small 



24-30 

Compressed, with 
weak dorsal crest 
in males 



large 



green with dark green with light 
vermiculations vermiculations 
but these on head in males 

stronger on head only 
than on body 



12 BREVIORA No. 353 

ACKNOWLEDGMENTS 

The expedition to obtain and study A uoUs jaccire was supported 
by the Instituto de Zoologia Tropical, Universidad Central de- 
Venezuela, and by National Science Foundation Grant GB 6944 
to Ernest E. Williams. Thanks are also due to Ingrid LcJbig for 
help in laboratory work, and to Pedro Durand for facilities provided 
at the Universidad de los Andes during the work in Mcrida. We 
are indebted to George Gorman for communicating to us data on 
the karyotypes of two female A . jacare. 

REFERENCES 

BouLENGER, G. A. 1903. On some batrachians and reptiles from 
Venezuela. Ann. Mag. Nat. Hist., ser. 7. 11: 481-484. 

Etheridge, R. 1960. The relationships of the anoles ( Reptilia:Saiiria: 
Iguanidae) an interpretation based on skeletal morphology. Ann Arbor, 
Michigan: University Microfilms, xiii -f 236 pp. 

Ewel, J. J., AND A. Madriz. 1968. Zonas de Vida de Venezuela. 
Ediciones del Fondo Nacional de Investigaciones Agropecuarias. 
Caracas. 265 pp + Mapa Ecologico de Venezula. 

Gorman, G. C. 1965. Interspecific karyotypic variation as a systematic 
character in the genus Anolis (Sauria: Iguanidae). Nature 208: 95-97. 

Gorman, G. C, and L. Atkins. 1966. Chromosomal heteromorphism 
in some male lizards of the genus Anolis. Amer. Nat. 100: 579-583. 

1967. The relationships of the Anolis of the roquet species 

group (Sauria; Iguanidae). II. Comparative chromosome cytology. 
Syst. Zool. 16: 137-143. 

1968a. New karyotypic data for 16 species of Anolis 



(Sauria: Iguanidae) from Cuba. Jamaica and the Cayman Islands. 
Herpetologica 24: 13-21. 
1968b. Confirmation of an X-Y sex determining mech- 



anism in lizards (Anolis). Copeia 1968: 159-160. 
1968c. Natural hybridization between two sibling species 



of Anolis lizards: chromosome cytology. Science 159: 1358-1360. 
1969. The zoogeography of Lesser Antillean Anolis 



lizards — an analysis based upon chromosomes and lactic dehydro- 
genases. Bull. Mus. Comp. Zool. 138: 53-80. 

Gorman, G. C, L. Atkins, and T. Holzinger. 1967. New karyotypic 
data on 15 genera of lizards in the family Iguanidae, with a discus- 
sion of taxonomic and cytological implications. Cytogenetics 6: 
286-299. 



1970 ANOLIS JACARE 13 

Gorman. G. C. R. Thomas, and L. Atkins. 1968. Intra- and inter- 
specific chromosome variation in the lizard Anolis cristate I Ins and its 
closest relatives. Breviora 293: 1-13. 

Levan, a.. K. Fredga. and A. A. Sandberg. 1964. Nomenclature for 
centromeric position on chromosomes. Hereditas 52: 201-220. 

Schmidt, K. P. 1939. A new lizard from Mexico with a note on the 
genus Norops. Zool. Ser.. Field Mus. Nat. Hist. 24: 7-10. 

ScHOENER, T. W. 1970. Size patterns in West Indian Anolis Lizards. II. 
Correlations with sizes of particular sympatric species displacement 
and convergence. Amer. Nat. 104: 155-173. 

Underwood, G. 1959. The anoles of the Eastern Caribbean (Sauria, 
Iguanidae). Part III. Revisionary notes. Bull. Mus. Comp. Zool. 
121: 187-226. 

___. 1962. Reptiles of the Eastern Caribbean. Caribbean 

Affairs (N.S.) 1: 1-192. 

(Received 17 April 1970.) 



14 BREVIORA No. 353 

A^ A2 A3 ^ -*\ » U ^ 

XX XX .. ^^W 



B1 B2 CI 



• • • 






Figure 3. Spermatogonia! metaphase and karyotype of AiioUs jacarc. 
Specimen no. MCNC 5601. cell no. A-167 T5 C2. Scale: 10 micra. 



M }t n «V^ 



• • 



« » 



Figure 4. Spermatogonial metaphase and karyotype of Aiiolis jacare. 
Specimen no. MCNC 5604. cell no. A-)71 T.^ C2. Scale: 10 micra. 



970 



ANOLIS JACARE 



LS 



w*- 




Figure 5. Diakinesis of Aiuilis hicarc. Specimen no. MCNC 5603, eel 
no. A-170 T7 CI. 



• ..^ \^IX-'' 



^■^-rj.^*^ 






W~'f'^' 



-^ml 



^: 






■%,. 



~ "^' 



j^;;.-.k. 



Figure 6. Rio Milla. Merida (site 1 of Fig. 2). To the right of the hght 
pest is the guamo (Inga sp.) in which two males and two females were 
collected. The other trees to the right are majagua (Heliocarpus 
pupayensis) where other specimens were collected 



BREVIORA 



Musenaiiii of Compsirative Zoology 

Cambridge, Mass. 18 September, 1970 Number 354 

TAXONOMIC AND ECOLOGICAL NOTES ON SOME 

MIDDLE AND SOUTH AMERICAN LIZARDS OF THE 

GENUS Ameiva (TEIIDAE) 

Arthur C. Echternacht 



Abstract. The taxonomy of two Middle American and one South 
American Ameiva (Sauria, Teiidae) is discussed. Ameiva festiva niceforoi 
Dunn is accorded species rank, A. f. miadis Barbour and Loveridge is for- 
mally designated a subspecies of A. undiilata. and A. iiiuliilata thomasi 
Smith and Laufe is placed in the synonymy of A. chaitzami Stuart. Diag- 
noses and statements of range are provided for each, and ecological in- 
formation is presented for miadis. The condition of the median parietal 
(divided or not) is shown to be unstable in Ameiva and useless for diag- 
nosing species in Middle America. 

INTRODUCTION 

In the course of my studies of geographic variation in the 
Middle American species of the lizard genus Ameiva, I have found 
that certain taxa require reallocation and that diagnoses presented 
with the original descriptions of some are either in error or mis- 
leading. It is the purpose of this paper to clarify the taxonomic 
positions of three of these taxa. A diagnosis is presented for 
each, and ecological information is included where warranted. 

Acknowledgements. I am indebted to the following persons 
for the loan of specimens in their care: W. E. Duellman, Univer- 
sity of Kansas Museum of Natural History (KU); R. F. Inger 
and H. Marx, Field Museum of Natural History (FMNH); E. V. 
Malnate, Academy of Natural Sciences of Philadelphia (ANSP); 
J. R. Meyer (Private Collection); J. A. Peters and G. R. Zug, 
United States National Museum (USNM); C. F. Walker and L. 
C. Stuart, University of Michigan Museum of Zoology (UMMZ); 
R. G. Zweifel, American Museum of Natural History (AMNH); 



2 BREVIORA No. 354 

and E. E. Williams, Museum of Comparative Zoology (MCZ). 
W. E. Duellman and E. E. Williams read and criticized the manu- 
script. 

Ameiva niceforoi Dunn 

Ameiva f estiva niceforoi Dunn, Notulae Naturae no. 126: 1-2, 1943 
(Holotype: ANSP 24300. Type Locality: "Sasaima, in the eastern Andes, 
75 km northwest of Bogota, altitude 1200 meters," Colombia. Collector: 
Hermano Niceforo Maria). 

Diagnosis. Ameiva niceforoi can be distinguished from its 
congeners by the following combination of characters: Small size 
(maximum observed snout-vent length |SVL] 82 mm for males, 
75 mm for females) ; central gular scales much enlarged, surround- 
ing scales diminishing in size gradually toward the periphery of 
the gular region; frontal and frontoparietal scales entire; three 
parietal scales; total number of femoral pores moderate; number 
of dorsal granules around the body (GAB) and occiput to rump 
(GOR) low; no preanal spurs; broad middorsal stripe bordered 
laterally by a fine white stripe; black dorsolateral stripe bordered 
ventrally by a fine white stripe; no narrow, light-colored vertebral 
stripe. 

Range. Knovv'n only from the type locality and from Honda, 
Departamento Tolima, Colombia. 

Remarks. Dunn (1943) diagnosed Ameiva f estiva niceforoi 
( =A. niceforoi) as "A form of f estiva, identical with it in size, 
proportions, and in scalation, but remarkably different in mark- 
ings." In addition to color pattern (Fig. lA), niceforoi differs 
from fesiiva in a number of characters of scutellation. In color 
pattern, niceforoi is virtually identical to female or subadult male 
A. leptophrys but differs from leptoplvys in numerous scale char- 
acters. Some pertinent differences among the three species are 
summarized in Table 1. Because geographic variation is marked 
(Echternacht, 1970), means of characters of scutellation for an 
entire species tend to mask similarities between niceforoi and 
samples of other species drawn from nearby localities. For this 
reason, means for nearby samples are given as well as those for 
the entire species. In addition to the total number of femoral 
pores, GAB and GOR, niceforoi differs from leptophrys in the 
arrangement of scales peripheral to the enlarged central gulars. In 
leptoplvys the posterior gular scales are much reduced in size 



1970 



NOTES ON AMEIVA 




Figure 1. (A) Ameiva niceforoi, paratype (ANSP 24303: Sasaima, 
Depto. Cundinamarca, Colombia), snout-vent length 77 mm. (B) Ameiva 
undulata miadis, holotype (MCZ 26970: Isla del Maiz Grande, Depto. 
Zelaya, Nicaragua), 126 mm. (C) Ameiva chaitzami, paratype (MCZ 
52170 [formerly UMMZ 90642]: Along Cahabon-Languin trail ca. 2 km 
N Finca Canihor, Depto. Alta Verapaz, Guatemala), 69 mm. All males. 



relative to the anterior gulars. Ameiva niceforoi and festiva are 
similar in this respect. 

No other South American species of Ameiva seems to be closely 
related to any of the three species discussed above. An Ameiva 
similar to niceforoi could have given rise to either leptophrys or 
festiva or to both, but the present chaotic situation with respect 
to the taxonomy of Ameiva in South America (Medem, 1969) pre- 
cludes decisive conclusions concerning phylogenetic relationships. 
Studies in progress are designed to clarify this situation. 

Other than the type series (ANSP 22784, 24300-303), only 
three specimens of Ameiva niceforoi are known: USNM 93500- 
93501 (Topotypes) and AMNH 35300 from Honda, Depto. 
Tolima, Colombia. 



BREVIORA 



No. 354 



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1970 NOTES ON AMEIVA 5 

Ameiva undulata miadis Barbour and Loveridge 

Ameiva f estiva miadis Barbour and Loveridge, Bull. Mus. Comp. Zool., 
69: 141-142, 1929 (Holotype: MCZ 26970. Type Locality: "Great Corn 
Island" [=Isla del Maiz Grande], Depto. Zelaya. Nicaragua. Collector: 
James L. Peters). 

Ameiva undulata miadis, Dunn, Proc. Acad. Nat. Sci. Philadelphia, 92: 
115, 1940. Villa, Rev. Biol. Trop., 15: 119, 1968. 

Diagnosis. Ameiva undulata miadis (Fig. IB) can be dis- 
tinguished from A. f estiva and other subspecies of A. undulata 
on the basis of its unique color pattern: No narrow, light-colored 
vertebral stripe; lateral pattern of blue (males) or gray-brown 
(females) bars on a black background extending from mid- 
dorsal stripe to enlarged ventral scutes; broad middorsal stripe 
from occiput onto tail, much disrupted by transverse black blotches 
that are often continuous with the black background color of the 
flanks; sexual dimorphism in color, but not pattern, in adults. 

Range. Known only from Islas del Maiz, Depto. Zelaya, Nica- 
ragua. 

Remarks. With the exceptions noted above, Ameiva undulata 
miadis is similar to other subspecies of undulata that have barred 
flanks (see Echternacht, 1970). Dunn (1940) and Villa (1968) 
have briefly alluded to the relationship of miadis with undulata 

Barbour and Loveridge (1929) considered Ameiva festiva 
miadis ( ^A. undulata miadis) to be intermediate between A. 
festiva and A. ruthveni ( =A. leptophrys) . Color pattern alone 
distinguishes miadis from leptophrys, but in addition, the peri- 
pheral gular scales of undulata are like those described for niceforoi 
above and differ from those of leptophrys in the same manner. 
Also, in leptophrys the postnasals are not in contact with the pre- 
frontal scales, whereas in undulata these scales are in contact. 

The nearest known mainland populations of Ameiva festiva are 
at Bluefields, Depto. Zelaya, Nicaragua, about 85 kilometers west 
of Isla del Maiz Grande. Ameiva festiva from Bluefields are 
typical of the species in having a well-defined vertebral stripe in 
ah but large adults and in having little barring on the flanks. 
Nearest known populations of leptophrys are in the southeastern 
lowlands of Costa Rica, and the nearest populations of undulata 
are in northeastern Honduras, western Nicaragua, and northwest- 
ern Costa Rica. Four specimens of undulata (ANSP 15438- 
15441) from Huaunta Haulover, Depto. Zelaya, Nicaragua, about 



BREVIORA 



No. 354 



150 kilometers north-northwest of Isla del Maiz Grande, may in- 
dicate an isolated population there. In color pattern, the undulata 
from Islas del Maiz most closely resemble those from near Cata- 
camas, Depto. Olancho, Honduras. In these Honduranian 
Ameiva, the middorsal stripe is heavily blotched, but the blotches 
are never continuous onto the flanks. 

Island populations of Middle American Ameiva (with the ex- 
ception of qiiadnlineata) tend to have a relatively high GAB count 
when compared to mainland samples of the same species (see 
Echternacht, 1970). Although the mean for this character does 
not differ statistically from those of certain mainland samples 
examined, it is the highest recorded for the species {A. undulata: 
X = 149.5, standard deviation of the mean = 16.5, range = 

108-202, N = 918. A. u. miadis: x = 186.3 ± 9.3, range = 
165-202, N = 42). 

Nothing has been reported of the ecology of Ameiva undulata 
miadis. I was able to make some observations on June 4-8, 1966. 
The lizard is very common on Isla del Maiz Grande and I found it 
particularly abundant in clearings within the coconut groves that 
cover the island (Fig. 2). It was also common in the shrub and 







'i.. -^ *t,. ., ,.^5^-s. 




Figure 2. Habitat of Ameiva undulata miadis on Isla del Maiz Grande, 
Depto. Zelaya, Nicaragua. June 1966. 



1970 NOTES ON AMEIVA 7 

grassy vegetation along the airstrip and in clearings around build- 
ings. None were seen on open beaches. Individuals often were 
encountered basking or foraging on or around fallen palm fronds. 
Activity extended from dawn until dusk, but more lizards were 
seen early in the day than in late afternoon. The lizards were not 
active in rain. Hatchlings with clearly dehneated umbilical scars 
were observed. The chin, gular region, and anteriormost part of 
the chest of many males was bright reddish orange. In others, 
this area was pale blue. Such dichromatism is widespread among 
species of Ameiva and may be associated with reproductive con- 
dition. Evidence is lacking on this point. English-speaking resi- 
dents of the island refer to the Ameiva simply as "lizard," al- 
though they have specific names for Iguana iguana and Cteno- 
saura similis, both of which are common. 

Ameiva chaitzami Stuart 

Ameiva chaitzami Stuart, Proc. Biol. Soc. Washington, 55: 143, 1942 
(Holotype: UMMZ 90638. Type Locality: "Along Cahabon-Languin trail 
about 2 km north of Finca Canihor . . . , Alta Verapaz, Guatemala." Col- 
lector: L. C. Stuart). 

Ameiva imdulata thomasi Smith and Laufe, Univ. Kansas Sci. Bull., 31: 
47-50, pi. lA, 1946 (Holotype: FMNH 100006. Type Locality: "La Liber- 
tad, Chiapas, near Rio Cuilco where it crosses the Guatemalan border," 
Mexico. Collector: Henry D. Thomas). New synonymy. 

Diagnosis. Ameiva chaitzami (Fig. IC) can be distinguished 
from its congeners by the following combination of characters: 
Small size (maximum observed SVL 85 mm for males, 75 mm for 
females); central gular scales enlarged, in longitudinal series; 
gradual reduction in size of scales radiating outward from the 
central gulars; prefrontals in contact with postnasals; three parietal 
scales (four if median parietal divided); transverse row of abrupt- 
ly enlarged mesoptychial scales; usually eight transverse rows of 
ventral scutes at midbody; moderately narrow middorsal stripe 
(mean width in terms of granules 37.1, N = 61); no narrow, 
well-defined vertebral stripe; often a dark secondary stripe medial 
to the dorsolateral light stripes; dorsolateral blotches of adult 
males fused to the dorsolateral light stripe so that the latter has 
a well-defined dorsal border, an irregular ventral border. The 
latter character alone will distinguish chaitzami from undulata 
with certainty. 



8 BREVIORA No. 354 

Range. Valleys of the upper tributaries of the Rio Grijalva 
in Chiapas, Mexico, and west-central Guatemala, from the vicin- 
ity of Finca Canihor, Depto. Alta Verapaz, Guatemala, and near 
Poptiin, Depto. El Peten, Guatemala. 

Remarks. Stuart (1942) diagnosed Ameiva chaitzami as "An 
Ameiva almost identical with Ameiva nndulata stuarti Smith from 
which it may readily be distinguished by the fact that the median 
parietal is divided longitudinally to produce four instead of three 
parietals." The posterior scales on the dorsal surface of the head 
is an unstable character among Middle American species of 
Ameiva, and diagnoses based on scales in the area are unreliable 
(Echternacht, 1970). Considering nndulata only, I noted the 
median parietal to be divided or semidivided in 22.4 per cent of 
1043 specimens obtained from throughout the range of the species. 
This is probably a conservative estimate of the frequency of oc- 
currence of this condition, because the information was not noted 
early in the study. There seem to be no geographic trends as- 
sociated with the condition of the median parietal. At least 38 
of 45 samples contained individuals with divided or semidivided 
median parietals. Samples having a high frequency of occurrence 
of division were as follows: near Chinandega, Depto. Chinandega, 
Nicaragua (55 per cent, N = 31); Piedras Negras, Depto. El 
Peten, Guatemala (72 per cent, N = 32); Canihor, Depto. Alta 
Verapaz, Guatemala (50 per cent, N = 30); near Panajachel, 
Depto. Sololii, Guatemala (48 per cent, N = 29); Sabana de 
San Quintin, Chiapas, Mexico (100 per cent, N = 10); near Las 
Tazas and Florida, Chiapas, Mexico (90 per cent, N = 30). 
Three samples of chaitzami yielded the following frequencies: 
Comitan, Chiapas, Mexico, 3 per cent (N = 30); near San An- 
tonio Huista, Depto. Huehuetenango, Guatemala, 10 per cent 
(N = 31 ); near Finca Canihor, Depto. Alta Verapaz, Guatemala, 
and near Poptun, Depto. El Peten, Guatemala, 89 per cent (N = 
9). Six of the nine in the last sample constitute the type series. 
At the type locality and at Poptun, chaitzami is sympatric with 
A . imdidata hartwegi Smith, a large subspecies quite distinct in color 
pattern and scutellation from chaitzami. The samples from Canihor 
and Piedras Negras, Guatemala, and from Sabana de San Quintin, 
Chiapas, are hartwegi. Elsewhere within its range, samples of 
hartwegi have from 13 to 30 per cent of individuals with divided 
or semidivided median parietals. It is noteworthy that the holo- 
type of hartwegi (FMNH 108600), obtained across the Rio Usu- 
macinta from Piedras Negras, has a divided median parietal. 



1970 NOTES ON AMEIVA 9 

Smith and Laufe (1946) discussed the evolution of Aineiva 
undidata and recognized several new subspecies, but they ap- 
parently did not examine specimens of chaitzami. The description 
of A. u. thomasi (Smith and Laufe, 1946) agrees with that of 
Stuart (1942) for chaitzami in most respects. I have examined 
the type specimens of both and consider them to be conspecific. 
The samples cited above from Comitan and near San Antonio 
Huista are from within the range of thomasi as described by 
Smith and Laufe (1946). 

LITERATURE CITED 

Dunn, E. R. 1940. New and noteworthy herpetological material from 
Panama. Proc. Acad. Nat. Sci. Philadelphia, 92: 105-122. 

. 1943. A new race of Ameiva f estiva from Colombia. Notu- 

lae Naturae no. 126, 2 pp. 

EcHTERNACHT, A. C. 1970. A review of Middle American lizards of the 
genus Ameiva (Teiidae) with emphasis on geographic variation. Un- 
published Ph.D. Dissertation, University of Kansas, Lawrence, Kansas. 

Medem, F. 1969 (1968). El desarrollo de la Herpetologia en Colombia. 
Rev. Acad. Colombiana Cienc. Exactas Fis. Natur., 13(50): 149-199. 

Barbour, T., and A. Loveridge. 1929. Vertebrates from the Corn Is- 
lands. Reptiles and Amphibians. Bull. Mus. Comp. Zool., 69: 138-146. 

Stuart, L. C. 1942. Comments on the iindiilata group of Ameiva 
(Sauria). Proc. Biol. Soc. Washington. 55: 143-150. 

Smith, H. M., and L. E. Laufe. 1946. A summary of Mexican lizards 
of the genus Ameiva. Univ. Kansas Sci. Bull., 31(2): 7-73. 

Villa, J. D. 1968. A new colubrid snake from the Corn Islands, Nic- 
aragua. Rev. Biol. Trop., 15: 117-121. 

(Received 13 June 1970.) 



BREVIORA 

Miasemim of Coimpsirsitive Zoology 

Cambridge, Mass. 30 November, 1970 Number 355 



GENERIC RELATIONS AND 

SPECIATION PATTERNS IN THE CARACARAS 

(AVES: FALCONIDAE) 

Francois Vuilleumier^ 



Abstract. The caracaras are a group of American Falconidae occurring 
from temperate and subtropical North America southward to extreme south- 
ern South America and the Falkland Islands. The taxa of caracaras appear 
to be closely interrelated. It is suggested that they be classified in two 
genera: Daptrius (forest caracaras; two sympatric species), and Polybonis 
(nonforest caracaras; two species-groups: the chimachima and planciis 
species-groups, with two and three species, respectively). Former classifica- 
tion advocated the use of four genera. Speciation is long completed in 
Daptrius and in the Polybonis chimachima species-group. In the Polybonis 
planciis species-group, however, several phenomena are evidence of active 
species formation. Geographical isolates exist that are morphologically 
differentiated enough to be considered borderline cases between species and 
subspecies. Some of the cases of geographical isolation in the caracaras can 
be related to climatic and vegetational changes following glacial events of 
the Pleistocene. 

INTRODUCTION 

This paper constitutes the fourth of a series stemming from 
studies on speciation in Andean birds (see Vuilleumier, 1968, 
1969, 1970). 

I shall discuss, first, the generic classification of the caracaras, 
and secondly, the patterns of distribution, geographical variation 
and speciation in these birds, with particular emphasis on the 
Andean taxa. I shall deal either with problems not, or only litde, 
covered by Brown and Amadon (1968) in their recent book, or 

1 Biology Department, University of Massachusetts, 100 Arlington Street, 
Boston, Massachusetts 02116. 



2 BREVIORA No. 355 

with controversial issues, especially when my own conclusions differ 
from theirs. 

The data were obtained from examination of about 250 skins 
and some skeletons; and from field studies on the habitat prefer- 
ences, general behavior, and distribution of five taxa of caracaras 
made over a period totaling thirteen months during trips to South 
America in 1964, 1965, and 1967-68. 

THE CARACARAS 

The 7 to 10 or 11 species of caracaras can be distinguished 
from other Falconidae more by their vulture-like external morpho- 
logical characters and associated scavenging habits, than by clear- 
cut anatomical characters (Friedmann, 1950: 719). They differ 
from true falcons, however, in their habit of building their own 
nest, as pointed out by Brown and Amadon (1968: 23, 104). The 
problem of whether the caracaras should be accorded taxonomic 
rank within the Falconidae, and if so, which one (e.g., subfamily, 
tribe), will not be discussed here. 

The species of caracaras have traditionally been placed in four 
genera (see, e.g., Peters, 1931; Hellmayr and Conover, 1949; 
Friedmann, 1950; de Schauensee, 1966; Brown and Amadon, 
1968): Daptrius Vieillot, 1816, with two species; Milvago Spix, 
1824, with two species; Phalcoboenus d'Orbigny, 1834, with two 
to four species; and Poly bonis Vieillot, 1816, with one to three 
species. (The long controversy over the names Polyborus versus 
Caracara Merrem, 1826, was resolved by Amadon (1954), who 
showed that "Vieillot's diagnosis of Polyborus applies to the Cara- 
caras," so that "the diagnosis sustains the name." Caracara must, 
therefore, go into synonymy, and the issue can be considered 
closed.) 

As a group, the caracaras are distributed from temperate North 
America southward to Central and South America, ranging as far 
south as the Falklands and the islands off Tierra del Fuego. Sev- 
eral species have very broad ranges, especially Polyborus plancus, 
the distribution of which encompasses almost that of the entire 
group. Other species are, on the contrary, quite localized geo- 
graphically. For example, the extinct Polyborus lutosus occurred 
only on Guadalupe Island off Baja California, and the living Phal- 
coboenus australis breeds on a handful of small islands off the 
southern coast of Tierra del Fuego and on the Falklands. 



1970 SPECIATION IN THE CARACARAS 3 

Correlated with the broad distribution of the caracaras is their 
ecological diversity. As a group, these birds inhabit most vegeta- 
tion formations found in their geographical range, from desert 
scrub to tropical lowland wet forest, and including the highest 
zones of Andean vegetation. About the only major type of vegeta- 
tion not favored by caracaras is montane tropical wet forest (or 
cloud forest). 

All the taxa of caracaras are scavengers, but should perhaps be 
viewed as omnivorous, since their diet also includes live prey (ver- 
tebrates and invertebrates) and vegetal matter (see, e.g., Hud- 
son, 1920: 62-88; Wetmore, 1926: 92-96; Haverschmidt, 1962: 
157-158; Friedmann, 1927: 157; Friedmann and Smith, 1950: 
450-451, and 1955: 486-487; Brown and Amadon, 1968). Among 
the most notable food specializations of the caracaras is the habit 
of Polyborus planciis of attacking domestic animals the size of 
sheep (Johnson, 1965: 263), and the marked predilection shown 
by Daptrius americanus for colonial wasps (Skutch, 1959). 

Most caracaras are social, at least during the nonbreeding sea- 
son, and form intraspecific flocks that appear to be feeding associa- 
tions. The larger-sized species may form smaller flocks than the 
smaller ones. Thus the largest flock of the osprey-sized Polyborus 
plancus I have observed comprised about 15 birds, while I have 
often seen much larger flocks of the kestrel-sized Milvago chimango. 
The intraspecific gregariousness of some of the smaller species may 
also extend to the breeding season. Drury (personal communica- 
tion ) observed a colony of Milvago chimango where the nests were 
only about 30 feet (ten meters) apart. The caracaras also form 
associations with vertebrates other than birds. In Patagonia, Mil- 
vago chimango flocks are frequent near cattle and horses; I even 
saw one bird sitting on the flank of a lying horse, pecking from time 
to time at the skin, perhaps to eat ticks. Hudson (1920: 70) men- 
tioned that M. chimango "follows the plough," thus playing the 
part of gulls {Lams) elsewhere. The habit of following moving 
vehicles from which scraps of food can be collected has been 
observed in Phalcoboenus megalopterus along the Yungas Road 
in La Paz, Bolivia (Niethammer, 1953: 265; personal observa- 
tion), and in Polyborus plancus along a railroad in the Bolivian 
Chaco (Eisentraut, 1935: 391). The gregarious behavior exhib- 
ited by the caracaras may be correlated to a large extent with their 
scavenging habits, yet, from my own observations, I would judge 
their behavior to be much more plastic and diverse than that of 



4 BREVIORA No. 355 

other scavengers such as Old World or New World vultures 
(Cathartidae and Aegypiinae, respectively). 

ANALYSIS OF SOME CHARACTERS OF THE CARACARAS 

Size 

The caracaras vary considerably in size, as several authors 
(Friedmann, 1950; Brown and Amadon, 1968) have already 
pointed out. This variation is obvious if wing length, in the ab- 
sence of data on weights, is used as an indicator of overall body 
size (Table 1). Taxonomists have often been bothered by size 
differences between species, and have been reluctant to place in 
the same genus closely related species which differed conspicuously 
in size but in few, or no, other characters. This attitude might 
have been prevalent among the ornithologists who worked with 
caracaras, because the two smallest species belong in the genus 
Milvago and the largest species in Phalcoboenus and Polyborus. 
Yet the two species of Daptrius bridge the gap between these ex- 
tremes. I therefore believe that size should not be given undue 
weight in the supraspecific classification of the caracaras. In other 
Falconidae, notably in the genus Falco, similarly large size differ- 
ences between species have not prevented their inclusion in the 
same genus. 

Proportions 

In a number of bird taxa, a proportionately short tarsus is cor- 
related with arboreal habits, and a long tarsus with more terrestrial 
habits. Most species of caracaras are both arboreal and terrestrial, 
but some definite trends toward one or the other of these habits 
exist, especially in regard to feeding habits. Thus Polyborus and 
Milvago are often seen perched on trees, and they breed in trees, 
but they do a lot, perhaps most, of their foraging for food on the 
ground. The species of Phalcoboenus (with the possible exception 
of P. albogularis) seem to forage entirely on the ground, and breed 
in cliffs and rocky slopes; they do on occasion perch on buildings. 
The species of Daptrius seem at variance with the other three 
genera because they do some, perhaps even a substantial, portion 
of their foraging for food in trees. 

From this summary one would thus expect the species of Dap- 
trius, which are more arboreal than the other caracaras, to have 
proportionately shorter tarsi than other species. Figure 1 shows a 



1970 



SPFXIATION IN THE CARACARAS 









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6 BREVIORA No. 355 

scatter diagram of tarsus length plotted against wing length (rep- 
resenting body size in the absence of weight data) in the caracaras. 
The two species of Milvago, although overlapping considerably in 
wing length, show little overlap in tarsus length. The southern 
species, M. chimango, is decidedly longer-legged than the northern 
one, M. chimachima. This difference, especially in regard to the 
zone of sympatry of the two species, is discussed again below in 
the section on speciation in these birds. Dapthiis ater has somewhat 
longer wings than either species of Milvago, but its tarsal measure- 
ments overlap fully with those of M. chimachima. Yet D. ater 
would seem more arboreal than M. chimachima. The arboreal 
Daptrius americanus overlaps with the more terrestrial Phalco- 
boenus megaloptenis, P. albogularis, and Polyborus plancus in 
wing length, but has a much smaller tarsus. In this case the differ- 
ence in tarsus size appears to correspond to a difference in habits. 



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caracaras. 



1970 SPECIATION IN THE CARACARAS 7 

It is worthy of note that the species of Phalcoboemis closest to D. 
americamis in tarsus length is P. albogularis (see Fig. 1) said by 
Olrog (1948: 478; 1950: 520) to occur in forests and thus to 
diverge from the habitat preferred by P. megalopterus. 

On the basis of the proportions of tarsus and wing lengths plotted 
on Figure 1 , Milvago chimango, M. chimachima, and Daptrius ater 
would form one group of species closely similar to each other, over- 
lapping greatly in both wing and tarsus length. A second such 
group would include Phalcoboemis and Polyborus, while Daptrius 
americanus appears clearly distinct from all other species, yet inter- 
mediate between the two groups. 

Interspecific variation in tail length is summarized in Table 2. 
When handling skins, Daptrius americamis appears distinctly longer 
tailed than the other species of caracaras. If the tail/wing ratios, 
instead of the absolute tail lengths, are compared among the species 
of caracaras, then a smooth variation is detected, from the propor- 
tionately short-tailed Polyborus plancus and Phalcoboemis mega- 
lopterus to the long-tailed Milvago chimachima and Daptrius 
americamis. No groups of caracaras can be established on the 
basis of relative tail length. 

TABLE 2 

Variation in tail length, expressed in percent of wing length, 
among the caracaras. The taxa are ranked in order of increasing 
tail/wing ratio. Both sexes, and adult and subadult birds included. 



Taxon 


Tail/ Wing 


X 100 


Sample Size 




Range 


Mean 




plancus 


50.8-58.1 


53.9 


42 


megalopterus 


53.1-57.4 


55.5 


13 


carunculatus 




55.6 


1 


chimango 


54.8-58.7 


57.3 


5 


albogularis 


54.1-64.7 


58.4 


5 


australis 


57.5-61.5 


59.4 


4 


ater 


58.4-63.5 


61.1 


6 


lutosus 




62.7 


1 


chimachima 


60.9-70.2 


66.2 


25 


americanus 


62.2-74.6 


68.4 


36 



8 BREVIORA No. 355 

Plumage Color and Pattern 

Good descriptions of both adult and immature plumages of 
caracaras have been given by Friedmann (1950) and Brown and 
Amadon (1968), who should be consulted for full details. The 
main colors of aduh and immature plumages are summarized in 
Table 1. 

Adult caracaras vary from a brown, rather unpatterned plumage 
(such as is found in a variety of birds of prey) to a highly pat- 
terned plumage. Thus Milvago chimango has a brown plumage, 
variegated somewhat with barrings, reminiscent of the plumage of 
some kites of the genus Milvus. The plumages of both species of 
Daptrius, and of the three Andean species of Phalcoboenus (carun- 
culatus, megalopterus, and albogularis) are very different from 
those of the other caracaras. These birds are strikingly marked 
with black and white patterns, and remind one of gallinaceous 
birds such as Crax. 

Immature caracaras are less varied in their plumages. Most of 
them are brownish with patterns of barring or streaking, with the 
exception of the immature Daptrius americanus, which is like the 
adult. The dimorphism between immature and adult can be very 
well marked, as in Phalcoboenus carunculatus, P. megalopterus, 
and P. albogularis; or poorly marked, as in Daptrius americanus 
or Milvago chimango; or intermediate, as in Polyborus plancus and 
P. lutosus. 

In spite of the variation in plumage color and pattern exhibited 
by the different species of caracaras, certain basic resemblances are 
evident in the group as a whole when adult and immature plumages 
are compared together. For example, the immatures of Milvago 
chimachima, Phalcoboenus carunculatus, P. megalopterus, P. albo- 
gularis, Polyborus lutosus and P. plancus are all very similar to 
one another, as they are to the adult of Milvago chimango. Thus, 
regardless of the intraspecific variabihty between immatures and 
adults on the one hand, and the interspecific variability among 
adults on the other, Milvago, Phalcoboenus, and Polyborus all 
appear to have similarities in plumage color and pattern. 

In every genus except Polyborus, there is a dichotomy between 
one or more species that have different immature and adult plum- 
ages, and one or more species that have quite similar immature and 
adult plumages. This dichotomy is obvious in Milvago, with 



1970 SPECIATION IN THE CARACARAS 9 

chimanfio plumages much alike, and chimachima unlike; in Phal- 
coboenus, with australis plumages much alike, and with canincu- 
latus-megalopterus-albogularis plumages very different. The dicho- 
tomy is still present, but much less obvious, in Daptrius, with 
americanus plumages alike and ater plumages slightly different. 
Correlation between this dichotomy and patterns of geographical 
distribution among closely related species is not readily apparent. 
In Milvago and Phalcoboemis , the species which differ least in their 
adult and immature plumages are the two southern ones; but in 
Milvago alone, there is an important geographical overlap between 
chimango and chimachima, whereas there is no or only a very nar- 
row overlap between the southern australis and the more northern 
carunculatus-megalopterus-albogularis complex. In Daptrius (di- 
chotomy poorly marked), there is almost complete overlap between 
the ranges of the two species, since the range of ater is almost 
entirely contained within that of americanus. In Polyborus (no, 
or almost no dichotomy ) , lutosus and plancus are entirely allopat- 
ric. (The possible ecological significance of the immature and adult 
dimorphism is discussed below under habitat preferences.) 

If one were to consider the immature-hke plumage of some sex- 
ually mature birds as being a primitive condition, and the strikingly 
different plumage in other mature birds as an advanced one (i.e., 
secondarily developed during the evolutionary history of the cara- 
caras), then Polyborus and Daptrius might be thought to be more 
primitive than the other two genera. If a brownish, barred and 
streaked immature plumage were considered a more primitive con- 
dition, then Daptrius is more advanced in this character than the 
three other genera, because in that genus, immatures are hardly 
different from adults, being also conspicuously patterned in black 
and white. 

Naked Facial Skin 

Every species in the genera Polyborus, Phalcoboenus, and Dap- 
trius has brightly colored naked skin between the bill and the eye, 
and often around the eye or even the throat. In the genus Milvago, 
only M. chimachima has naked facial skin; M. chimango has a fully 
feathered head. The area of unfeathered skin varies from species 
to species among those that have naked facial skin. In the species 
of Phalcoboenus, this variation is geographical. In Phalcoboenus 
carunculatus (Colombia and Ecuador), the surface of facial skin 
is extensive, and the throat is even adorned by fleshy wattles. In 



10 BREVIORA No. 355 

p. megalopterus (Peru, Bolivia, and northern Chile-Argentina), 
only the lores are unfeathered, while the throat is largely feathered. 
In P. albogularis (Patagonia), the extent of bare loral skin is 
smaller than in megalopterus. Finally, in P. australis (southernmost 
islands of South America), the facial skin is almost entirely feath- 
ered, but there are wattles on the breast instead. The difference 
between P. australis and P. carunculatus-megalopterus-albogularis 
may be related to the fact that australis is sympatric with Polyborus 
plancus, a species having extensive naked facial skin, whereas the 
other three species of Phalcoboenus are the only caracaras in their 
respective ranges. 

The naked facial skin in the caracaras varies from salmon pink 
to rose-red and from yellowish to bright red (see Table 1). This 
variation is both intra- and interspecific. I have seen the facial 
skin of one individual of Polyborus plancus change, in a few sec- 
onds, from pale yellow to salmon-pink and finally to vivid red. 
Such a rapid change cannot easily be ascribed to hormonal influ- 
ences, but is more likely to be due to a sudden flush of blood to the 
superficial vessels of the skin. Brown and Amadon (1968: 738) 
mention a reverse change in P. plancus: "bare facial skin carmine 
red, changing to yellow when excited." 

The variation in facial skin color in the caracaras (Table 1) 
seems too extensive within species, and too restricted between 
species (differences between, say, yellow and orange, or orange and 
red seem relatively slight) to be important as a species-specific 
means of recognition. Presence or absence, together with color 
and area of unfeathered skin might, however, play such a role 
among true sympatric species, e.g., Phalcoboenus australis and 
Polyborus plancus already cited, or Milvago chimango and M. 
chimachima. 

Nostril Shape 

I have examined skulls of Polyborus plancus (several speci- 
mens), Phalcoboenus australis (4), Daptrius sp. (1 ), and Milvago 
sp. (3). Polyborus plancus has slanted, elongated nostrils (bean- 
shaped), while Phalcoboenus australis, Daptrius sp., and Milvago 
sp. all have rounded nostrils. This difference is also visible on the 
cere of study skins and seems to be confined to Polyborus (Table 
1 ) , since only P. lutosus and P. plancus have bean-shaped nostrils. 
Swann (1925: 66) and Friedmann (1950: 545-546) used this 



1970 SPECIATION IN THE CARACARAS 11 

difference in nostril shape, together with other characters, as diag- 
nostic features to key out the genera of caracaras. I do not know 
what the biological significance of this difference may be. 

Habitat Preferences 

The preferred habitats of Milvago, Phalcoboenus, and Polyborus 
include a variety of nonforest types: open scrub, grassy pampas, 
tussock-grassland, pastures, treeless cultivated farmland, open 
thorny chaco, savanna woodland, and open plantations. Phalco- 
boenus albogularis may be an exception, since Olrog (1948: 478; 
1950: 520) reports it as a forest bird. 

Both species of Daptrius are inhabitants of tropical forest and 
contrast markedly with the other caracaras in this feature. The 
distribution of ater and americamis corresponds to the distribution 
of wet lowland rain forest in Central and South America, but the 
actual preference of these species seems to be less for the forest 
interior than for more open situations within or along the forest: 
river banks, small clearings, secondary growth, mangroves, and 
tree-tops. The plumage pattern of both species of Daptrius, espe- 
cially D. americamis, is most similar to that of adults of Phalco- 
boenus carunculatus and P. megalopterus, which inhabit high 
Andean steppes, an environment that differs in every respect from 
that of Daptrius. This basic morphological similarity among taxa 
of widely distinct ecological preferences seems to be more easily 
understandable on an hypothesis of close relationship than on one 
of convergent evolution. The fact that the species of Phalcoboenus 
mentioned above have a very different immature plumage, while 
those of Daptrius are far less dimorphic between adult and imma- 
ture, might be a correlate of environmental differences between the 
two genera. In the open habitats of the high Andes there is never 
more than one species of caracara at any one locality (diversity 
= 1 ) . Because congeneric competitors are absent, the sharp 
dimorphism between adults and immatures of Phalcoboenus may 
consequently reflect the results of slightly relaxed selective pres- 
sures. In the tropical lowland forests, however, there are two 
sympatric species of caracaras (diversity = 2), so that selection 
through interspecific competition might possibly limit the range of 
intraspecific variability, thus resulting in the evolution of similarity 
(monomorphism) between immatures and adults of Daptrius. The 
difference in size (character divergence) between the two species 



12 BREVIORA No. 355 

of Daptrius, which are sympatric, may be relevant here. Being so 
different from each other (no overlap in range of wing lengths), 
they should compete very little for food (see Schoener, 1 965 ) . The 
interspecific difference in size, together with the lack of dimorphism 
between age categories in Daptrius, may be roughly equivalent 
ecologically to the striking dimorphism within high Andean Phal- 
coboenus, which do not have any sympatric congeners. In Milvago, 
where the two species are largely allopatric, one observes a con- 
siderable overlap in wing lengths between the two, but one of the 
species is conspicuously dimorphic (chimachima) , whereas the 
other is not. Therefore, the situation in Milvago appears inter- 
mediate to that in both Daptrius and Phalcoboenus. I beheve this 
intermediacy is also found in the habitats occupied by Milvago 
(such as open woodland, savannas) that are more or less inter- 
mediate between lowland wet forest (occupied by Daptrius) and 
barren high Andean steppes (occupied by Phalcoboenus). 

Summary of Character A nalysis 

If the characters discussed above are examined separately, the 
variation among some of them shows the following possible group- 
ing within the caracaras. (a) Polyborus is distinct in nostril shape 
from the other genera, (b) Daptrius and Phalcoboenus are closer 
to each other than to other genera since both have a strikingly 
patterned black and white adult plumage, (c) The immature plum- 
ages of Milvago, Phalcoboenus and Polyborus appear extremely 
similar to one another, and differ, as a group, from those of Dap- 
trius. If both adult and immature plumages are used, together with 
habitat preferences, the two species of Daptrius appear to stand 
out against most other species. First, the immature plumage of 
Daptrius, when distinct from that of the adult (as in D. ater), is 
quite different from the brownish, streaked or barred immature 
plumage of all other species except Phalcoboenus australis. Sec- 
ondly, the forest habitat of the species of Daptrius differs from the 
nonforest habitats of the species in the other genera, with the pos- 
sible exception of Phalcoboenus albogularis. (The remaining char- 
acters [naked facial skin and size] seem of httle or no use in 
estabUshing groups within the caracaras.) 

I can only conclude from this analysis that all caracaras appear 
to be closely interrelated, but that Daptrius is less similar to the 
other three genera than these are to each other. 



1970 SPECIATION IN THE CARACARAS 13 

CLASSIFICATION 

The splitting of the caracaras into four genera, endorsed by most 
taxonomists, does not seem to reflect properly the close relation- 
ships of these birds. Since the lumping of all caracaras into a single 
genus may be going somewhat too far in the opposite direction, I 
suggest here a third possibiUty, which is to put the caracaras in- 
habiting nonforest habitats in a single genus (Polyborus, including 
Milvago and Phalcoboemis) and to keep the forest caracaras in a 
second genus (Daptrius). Further subdivisions within the non- 
forest caracaras can be made by using species-groups and super- 
species, which do not burden the nomenclature with additional 
names (as pointed out by Cain, 1954), yet permit a finer hierarchy 
between the genus and species levels. 

I present below a classification outline of the caracaras, includ- 
ing species-groups and superspecies. Each species-group represents 
a former genus. The grouping of some species in a superspecies 
(included in braces) is given here in anticipation of the discussion 
on speciation in the next section of this paper. The sequence of 
taxa in this list is arbitrary, and does not pretend to suggest that 
some taxa are more primitive than others, since such decisions 
would be guess work. 

Genus Dap /m/5 Vieillot, 1816 (forest caracaras) 
D. ater Vieillot, 1816 
D. americanus (Boddaert, 1783) 

Genus Polyborus Vieillot, 1816 (nonforest caracaras) 

1 . chimachima species-group 

P. chimachima Vieillot, 1816 
P. chimango Vieillot, 1816 

2. plancus species-group 

P. plancus (Miller, Mil) (includes lutosus Ridgway, 
1876, considered by some authors as a separate species) 

australis superspecies 
iP. australis (Gmelin, 1788) 

\p. megalopterus (Meyen, 1834) (includes carunculatus 
(Des Murs, 1853), and albogularis Gould, 1837, con- 
sidered by some authors as two separate species) 



14 BREVIORA No. 355 

VARIATION AND SPECIATION IN DAPTRIUS 

Of the two species of Daptrius, only D. americanus shows geo- 
graphical variation. This variation seems to be a cline of diminish- 
ing size, as measured by wing length, from Guatemala southward 
through Central America to South America. According to Brown 
and Amadon (1968), the populations from "southern Brazil" may 
show an increase in wing length over those from farther north in 
South America. This increase is in fact quite sharp, and is illus- 
trated by Figure 2. The disjunction may reflect absence of gene 
flow between birds from the Amazon Valley and those from the 
uplands of Brazil. The birds Hving in the coastal forests of south- 
ern Brazil and in the gallery forests of the Parana-Paraguay drain- 
age system of south-central Brazil may be ecologically isolated 
from birds living in forests of the Amazon Valley by parts of the 
central Brazilian plateau, which are covered by extensive open 
savannas and campos. 

Any inferences that might be drawn about the possible evolu- 
tionary history of this genus are prevented by the considerable 
sympatry between ater and americanus (see map 76 in Brown and 
Amadon, 1968). 



320 330 340 350 360 370 360 390 400 4 10 
I \ \ \ \ 1 \ 1 \ 1 



Guatem,, Hond.Nicar. Cos, Rica 



Ecuador. Peru 



Brazil (Goias, Mato Grosso) 



Figure 2. Geographical variation of wing length in Daptrius americanus. 
Measurements are in miHimeters. Horizontal bars: range of measurements; 
vertical bars: means. 



1970 SPECIATION IN THE CARACARAS 15 

VARIATION AND SPECIATION IN POLYBORUS 
1. The chimachima Species-Group 

The two species of this group, which constitute the former genus 
Milvago, are largely allopatric. Polyborus chimachima occurs in 
southern Central America (Costa Rica and Panama) and in South 
America from Colombia and Venezuela in the north to northern 
Argentina in the south, and P. chimango from northern Argentina 
southward to southernmost South America. They are sympatric, 
however, over a relatively broad zone, including Rio Grande do 
Sul in southern Brazil, parts of northern Argentina, Uruguay, and 
Paraguay, and southern Bolivia westward to the foothills of the 
Andes. 

Polyborus chimachima shows color and size variation. Tail and 
culmen length appear to vary clinally, and to increase from south 
to north, whereas the reverse seems to be true of wing length (see 
Fig. 3). 

Polyborus chimango shows geographical variation that seems to 
conform to eco-geographical rules, since the southernmost birds 
are the largest (Bergmann's rule), and the birds occurring along 
the wet, forested Andean slopes are darker than those living in the 
drier, grassy and shrubby plains of central Argentina (Gloger's 
rule). 

Geographical variation in P. chimango has been recognized tax- 
onomically by the naming of three subspecies. Two of them, temu- 
coensis (Andean slopes birds) and chimango (open plains birds) 
intergrade broadly. The third subspecies, juegiensis, seems re- 
stricted to the island of Tierra del Fuego, but is probably merely 
the southward end of a north to south cline of increasing size. 
Interestingly, the southern populations, from Tierra del Fuego and 
the mainland of southern Patagonia, appear to leave their breeding 
grounds to migrate northward as far as northern Argentina (Olrog, 
1962: 112-113) in the southern hemisphere winter. 

Although P. chimachima and P. chimango are undoubtedly very 
close relatives, they have diverged morphologically rather consider- 
ably. One of the differences has been mentioned earlier: the im- 
mature plumage of chimango is very similar to that of the adults, 
whereas the immature chimachima is quite unlike the adult. An- 
other difference between the two species may be ecological. As I 



16 



BREVIORA 



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1970 SPECIATION IN THE CARACARAS 17 

judge from personal observations and literature records, P. chima- 
chima may generally prefer somewhat denser, more wooded, habi- 
tats than P. chimango, but no study of a possible habitat segrega- 
tion has been undertaken in the area of sympatry. If tarsus length 
reflects whether a bird is more or less arboreal, then variation 
between P. chimachima and P. chimango in this character is in- 
structive. That P. chimachima populations have shorter tarsi than 
those of P. chimango (see Fig. 3) suggests that the latter may be 
less arboreal than the former. Whether this difference is true 
character divergence should be examined carefully. 

Brown and Amadon (1968: 739) say that the two species "may 
be regarded as a super-species." Even if a broad superspecies con- 
cept is embraced, it seems to me that the zone of overlap, con- 
sidered together with the morphological differentiation between 
chimachima and chimango, clearly suggests that these two taxa are 
past the species borderline, and that application of the superspecies 
concept to their case may no longer be correct. As far as I know, 
hybridization does not take place between the two species where 
they are sympatric; a field study of the pair in their overlap zone 
would nevertheless be rewarding. 

It seems most likely that the pair of species chimachima and 
chimango has originated by a straightforward process of splitting 
of one ancestral population into two. Yet secondary sympatry is 
too extensive to permit more speculation about the original 
isolation. 

2. The planciis Species-Group 

This group consists of P. plancus and the P. australis super- 
species. The birds of this group are medium to large, and have 
brownish immature plumage with dark streaking and/or barring. 
The P. plancus species-group includes both the former genera 
Polybonis and Phalcoboemis. Brown and Amadon (1968: 730) 
remarked that "Phalcoboemis australis is in all respects inter- 
mediate" between Polyborus and Phalcoboenus, yet they kept the 
two genera distinct. 

P. plancus is essentially a lowland species, while the members of 
the P. australis superspecies occur mostly in the Andes, in some 
localities at high altitudes. Where plancus meets members of the 
australis superspecies, as on the Falkland Islands and on islands 
off Tierra del Fuego, the two may live in habitat co-occupancy, 
but their ecological relationships have not been studied. In any 



18 BREVIORA No. 355 

event, sympatry in the P. plancus species-group is very limited and 
geographically peripheral. 

Polyborus plancus 

Polybonis plancus has a broad distribution from the southern 
United States and Mexico to Tierra del Fuego and the Falkland 
Islands and exhibits extensive geographical variation. The birds 
from Florida, isolated from the remainder of the mainland North 
American birds, are closer geographically and morphologically to 
the Cuban ones (both are included in the subspecies auduboni) . 
The birds of the population living on the Tres Marias Islands off 
western Mexico (subspecies pallid us) are morphologically differ- 
entiated from the nearest mainland populations (for a discussion 
of the characters of palUdus, see Grant, 1965: 12-14). The con- 
tinental population living from eastern Panama southward to 
northwestern Peru near the Upper Maranon and Amazon Rivers 
(subspecies cheriway) are well marked. There is intergradation 
between cheriway and southern South American birds (subspecies 
plancus) in Brazil (see Hellmayr and Conover, 1949: 283-284). 

The extinct Polyborus lutosus lived on Guadalupe Island (see 
e.g., Abbott, 1933; Greenway, 1958). The adults looked very 
similar to plancus, but white was replaced by brown, and there 
was no black on the abdomen; the immature was brown and 
streaked. This insular population was certainly well marked; it 
is considered here as having been a strong subspecies of plancus. 
Brown and Amadon (1968: 736) maintained lutosus as a separate 
species. 
The australis Superspecies 

The four nominal species (the former genus Phalcoboenus) in- 
cluded in this superspecies are Andean and Patagonian in distribu- 
tion (Fig. 4). One of the species, australis, occurs only on islands 
off southern South America. The three others, carunculatus, mega- 
lopterus, and albogidaris, occur along the Andean cordillera, from 
Colombia to Tierra del Fuego. 

Polyborus australis is larger than the three other species, but 
resembles them in several other respects. The pattern of breast and 
abdominal streaks in the adults is especially reminiscent of the 
geographically distant carunculatus. P. australis breeds on the 
Falklands, where, according to Cawkell and Hamilton (1961), its 
numbers have decreased in the recent past. It also breeds on sev- 
eral islands off Tierra del Fuego (Staten and Navarino), and on 
islands of the Cape Horn Archipelago (for example, Grevy, Bayly, 



1970 



SPECIATION IN THE CARACARAS 



19 





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A question mark represents the alleged occurrence of albogulans at Puente 
del Inca, Mendoza (see Hellmayr and Conover, 1949: 217-218). Labeled 
localities are identified in the text. 



20 BREVIORA No. 355 

Freycinet, Hershel: Olrog: 1950: 520). Reynolds (1932) ob- 
served one P. australis on Woodcock Island in the Beagle Channel, 
and Olrog (1948: 478) saw it at Yendegaia, along the southern 
coast of Tierra del Fuego, where he also collected P. megalopterus 
albogularis (see Fig. 4). This observation (not mentioned by 
Brown and Amadon, 1968: 731 ) implies that P. australis and P. 
megalopterus albogularis are narrowly sympatric on the main island 
of Tierra del Fuego, but this suggestion needs careful checking in 
the field. P. australis is sympatric with P. plancus on some islands 
off Tierra del Fuego and the Falklands. 

Polyborus carunculatus, megalopterus, and albogularis are here 
treated as three subspecies of a single species, as previously advo- 
cated by Hellmayr and Conover (1949: 276-277), and adopted 
later by some students of South American birds (e.g., Olrog, 1963; 
Koepcke, 1964; and Johnson, 1965). (The name megalopterus 
Meyen, 1834, has priority over albogularis Gould, 1837, and 
should be used as the specific name, contra Hellmayr and Conover, 
1949.) Other authors, however, have maintained the three taxa 
as separate species (e.g., Amadon, 1964: 14; de Schauensee, 1966; 
Brown and Amadon, 1968). 

The divergence of opinion about the taxonomic status of these 
three taxa has hinged on two things: first, the striking interspecific 
adult plumage color differences, and secondly, the allopatry of the 
taxa. A third factor, namely the absence of intermediate specimens 
between any two of these forms, has been invoked by some authors 
to justify their treating the three as species. Brown and Amadon 
(1968: 371), for instance, stated: "the two [taxa] that are the 
most similar, albogularis and megalopterus, are not known to inter- 
grade rather [sic] there seems to be a slight gap between their 
ranges, suggesting friction." A few specimens, however, do seem 
to be intermediate between carunculatus and tnegalopterus on the 
one hand, and between megalopterus and albogularis on the other, 
as discussed below. 

The characters that vary from one to the other of the three taxa, 
carunculatus, megalopterus and albogularis, are: the amount of 
white at the tip of the primaries, the degree of curliness of the crest 
feathers, the extent of bare skin on the throat, and the coloration 
of the underparts. The two northern taxa, carunculatus and mega- 
lopterus, live in high Andean grassland and scrub above the timber 
line, at altitudes usually higher than 3000-3500 meters. Both of 
these forms are common birds where they live, and can be seen 



1970 SPECIATION IN THE CARACARAS 21 

daily in small groups or singly (personal observation). The popu- 
lations of carunculatus are geographically isolated from those of 
we-^alopterus by a hiatus that includes the low Andes of northern 
Peru, the depression of the Upper Maranon Valley and other val- 
leys in northern Peru (see Fig. 4). Birds north of this gap {carun- 
culatus) have the throat and breast black with white longitudinal 
streaks or spots, and the abdomen white. South of the gap, birds 
{megalopterus) have throat and breast black without white spotting 
or streaking, and a white abdomen. 

These morphological differences, considered in the light of the 
ecological barrier lying between the two taxa, might be interpreted 
as reflecting a period of geographical isolation during which differ- 
ential selection acted on populations cut off from free gene flow. 
Absence of gene flow, however, seems surprising in view of the 
good flying abilities and the relative abundance of birds of this 
group. It is therefore noteworthy that Zimmer (1930: 248) found 
three adult males of megalopterus from Peru, all showing "an 
interesting progression in the direction of carunculatus." Two of 
the three specimens (from Macate, Department Ancash, and 
Panao, Department Huanuco, see Fig. 4), have small, pale or 
whitish spots on the lower breast; the third specimen (from Junin, 
farther south) lacks breast spots. Zimmer's description of the three 
birds should be consulted for additional details. 

These data seem to indicate that gene flow is indeed possible 
between Ecuadorian carunculatus and Peruvian megalopterus. 
Further intensive collecting of these birds in northern Peru is badly 
needed. The total number of specimens of either carunculatus or 
megalopterus from areas close to the barrier of northern Peru is 
low, so hybrid specimens might appear to be much rarer than they 
really are. 

What about the situation between megalopterus and albogularis? 
The northern megalopterus is a common bird in the high Andean 
scrub vegetation of the Argentine-Chilean cordilleras. The south- 
ern albogularis seems to occur in Nothojagus forests rather than 
open vegetation types (see Olrog, 1948: 478; 1950: 520; Philippi 
et al., 1954: 39). There seems to be a distributional hiatus (see 
Fig. 4) between the northernmost records of albogularis (in 
Neuquen, fide Olrog, 1963: 116) and the southernmost ones of 
megalopterus (in Talca, fide Johnson, 1965: 265). We do not 
know, however, whether this gap is real or not, because of the 
general scarcity of collections made in the "hiatus" area. In any 



22 BREvioRA No. 355 

event, what is real is the fact that no ecological barrier interrupts 
the distribution of megalopterus and that of alhogularis in the way 
the northern Peruvian low does between megalopterus and carun- 
culatus. The situation seems therefore more complex ecologically, 
and deserves field study. 

From these considerations, contact should be possible between 
megalopterus and alhogularis, and if they are not reproductively 
isolated, gene flow should occur between them. In February, 1965, 
at 1950 m on Cerro Catedral, near Nahuel Huapi, Rio Negro, 
Argentina (see Fig. 4), I observed two adult Polyborus that were 
attracted by a small garbage dump near the Refugio Lynch. One 
of them had the throat and breast black, in contrast with the white 
of the abdomen (megalopterus-likQ phenotype). The second had 
both a white throat and breast, with only the sides of the breast 
black, not forming a black pectoral band (albogularis-YikQ pheno- 
type). This observation might have been of a mixed pair, but 
unfortunately the birds could not be collected. 

The possibility of mixed pairs and of offspring from them, seems 
to be shown by two adult birds that exhibit what appears to be 
intermediacy between megalopterus and alhogularis. One of these 
birds, an adult male taken in February, 1 896, in Chubut, southern 
Argentina, was described by Scott (1910) as Ihycter circumcinctus. 
The underparts of this specimen are as follows: the throat is white, 
followed by "a band of black below the throat patch more or less 
variegated by white on some of the feathers; this band is about an 
inch in width; lower part of the under neck pure white, the black 
of the sides of the neck confining the white of this region to a 
narrow area, widening into the pure white of the breast." This bird 
appears to be like a specimen of alhogularis with a narrow black 
breast band. The second of these birds, an adult male from Nahuel 
Huapi (see Fig. 4), is mentioned by Hellmayr and Conover (1949: 
277). This specimen (British Museum 99.1.27.229) has a distinct, 
interrupted breastband. 

The same conclusion seems, therefore, to follow from these 
scanty data as from those on carunculatus and megalopterus: con- 
tact between megalopterus and alhogularis seems a reality since at 
least two specimens are somewhat intermediate between the two 
taxa, and since birds from the two phenotypes were sighted to- 
gether. Amadon, however, speaking of Scott's "circumcinctus," 
said that it "may be a mutant rather than a true genetic intergrade" 
(1964: 15). This hypothesis seems unlikely to me. Since speci- 
mens of alhogularis are relatively rare in museums, the two birds 



1970 SPECIATION IN THE CARACARAS 23 

with a black pectoral band represent a relatively high frequency of 
the black-banded phenotype, perhaps as many as 1 in 10 or 1 in 
15 — a number too high to be accounted for solely on the basis of 
recurrent mutation. A third possible interpretation would be that 
there is a polymorphism involving breast color. If this were true, 
then obviously megalopterus and albogidaris should be considered 
members of the same species. 

For the time being, I believe the best interpretation of the situa- 
tion in this complex to be that the three taxa, although clearly dif- 
ferentiated morphologically as adults, have not achieved compbte 
reproductive isolation, so that when two of them come in contact, 
whether across a barrier (carunculatus with megalopterus) or not 
(megalopterus and albogularis) , they produce hybrids. The tax- 
onomic solution I propose in this paper is to consider all three 
taxa conspecific, although I realize that this lumping may be a 
little premature in view of the paucity of data. If additional study 
should reveal that hybridization is very limited, even though there 
may be plenty of opportunity for it to take place, then it would be 
justified to maintain the three taxa as species, although it would 
be necessary to emphasize that they are really semispecies: a truly 
intermediate stage in the speciation process. 

DISCUSSION 

The caracaras are interesting to the student of speciation, be- 
cause they offer a variety of phenomena that are interpreted as 
intermediate in the process of species formation (see Table 3). 
They can be summarized as follows. In Daptrius americanus, the 
populations from southern Brazil may be geographically isolated 
from other populations farther north in South America. In Poly- 
borus plancus can be seen phenomena of incipient spsciation. 
Isolated populations, both insular (Tres Marias Islands, Cuba) 
and continental, exist, showing varying degrees of morphological 
differentiation. The most differentiated population (lutosus) was 
wholly insular, yet was of no evolutionary significance for further 
speciation since it is now extinct. The other insular populations, 
on the Tres Marias Islands and Cuba, are much less differentiated 
than lutosus, the Cuban one even being similar morphologically to 
the Florida population. On the continent, populations from north- 
em South America (cheriway) are sufficiently differentiated from 
southern South American ones (plancus) for some ornithologists 



24 



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1970 SPECIATION IN THE CARACARAS 25 

to have treated them as species. There is some evidence that (sec- 
ondary? ) hybridization takes place near the mouth of the Amazon 
where they come into contact. 

The taxa of the Polyborus australis superspecies present another 
"stage" of the speciation process, in that one of the members of 
the superspecies, australis, is sufficiently distinct to be considered 
unhesitatingly as a species. The three remaining members, how- 
ever, present interesting situations. In one instance, differentiation 
seems to have taken place across an ecological barrier (the low 
area of the northern Peruvian Andes), yet hybridization appears 
to occur in spite of this gap. In the second instance, no barrier is 
evident today, and some hybridization seems to occur. The south- 
ernmost taxon of this complex {albogularis) apparendy meets 
australis in Tierra del Fuego. 

In the Polyborus chimachima species-group, speciation is com- 
pleted, and the two species overlap now over a considerable area, 
although they are allopatric over the major portions of their respec- 
tive ranges. Finally, the two species of the genus Daptrius are so 
different morphologically and show so much sympatry that recon- 
struction of their history is impossible. 

Although six of the seven species I recognize in the caracaras 
have extensive geographical distributions, the existing patterns of 
speciation, or incipient speciation, seem to indicate that multiphca- 
tion of species has occurred mostly through the formation, and 
subsequent differentiation, of small or relatively small peripheral 
isolates. The present isolates of Daptrius americanus and Polyborus 
plancus are restricted to small areas around the periphery of the 
range of the species, and the geographical location of Polyborus 
australis relative to Polyborus megalopterus seems to suggest for- 
mer peripheral isolation of the first named species. Differentiation 
within P. megalopterus does not seem to correspond as clearly to 
a pattern of isolation in peripheral areas, although the central 
populations {megalopterus) do have a much broader distribution 
than either the northern (carunculatus) or southern (albogularis) 
ones. 

The previous summary of speciation in the caracaras shows that 
this process is most actively taking place along the Andes, where 
the various members of the Polyborus australis superspecies live. 
In the other, lowland, taxa, the speciation process is either com- 
pleted (as in Daptrius or the Polyborus chimachima species-group) 
or is not as pronounced {Polyborus plancus, Daptrius americanus) . 



26 BREVIORA No. 355 

It is tempting to relate the apparently greater evolutionary activity 
in the Andean caracaras to the recent geological history of this 
Cordillera. The high Andean grasslands and scrub habitats (paramo 
and puna) where Polyborus megalopterus now lives are undoubt- 
edly the most recent environments of the Andes, and cannot be 
older than the latest phases of uplift, which brought the mountains 
to their present tremendous altitudes during the Pho-Pleistocene 
(see Childs and Beebe, 1963; Steinmann, 1930; Ahlfeld and 
Branisa, 1960; and Briiggen, 1950; for summaries of the geological 
development of the Andes). The differentiation within P. megalop- 
terus most probably occurred during the Pleistocene glaciations, 
although to attempt the dating of such processes is almost complete 
guess work. However, if we recall that during glacial episodes, the 
temperature depression lowered the altitude of the upper vegeta- 
tion zones, where P. megalopterus lives, then it becomes possible 
to envision the separation of a northern isolate (proto-carunculatus) 
in Ecuador at interglacial time, when the altitudinal raising of this 
treeless zone occurred, thus increasing the effectiveness of a natural 
barrier such as the Upper Maranon Valley and northern Peruvian 
low for birds living on either side of it. The isolation of caruncu- 
latus from megalopterus, or, rather, of proto-carunculatus from 
proto-me galopterus, might, then, have happened during an inter- 
glacial. It is, of course, not possible to suggest which of the several 
interglacial periods was responsible for such an event. 

Similar glacial-interglacial oscillations may have permitted the 
separation of proto-megalopterus and proto-australis in extreme 
southern South America. During the maximum glacial, extreme 
southern South America was covered with an ice-sheet (Caldenius, 
1932; Polanski, 1965) which probably forced Andean biota to 
"retreat" considerably northward. At the same time, however, the 
Falkland Islands were left unglaciated, and, furthermore, were of 
greater area than today because of a concurrent lowering in sea- 
level. It seems therefore possible that during the maximum glacia- 
tion the southernmost populations of the stock common to mega- 
lopterus and australis remained on a Falkland refuge, where they 
were geographically isolated from mainland populations by the ice 
barrier, added to the sea barrier. If such a separation did indeed 
take place during the maximum glaciation, which is attributed to 
the late Pleistocene (Wiirm or Wisconsin) (see Polanski, 1965), 
then the splitting of an ancestral stock into the modern australis 
(having evolved from a population in a southern insular refuge) 



1970 SPECIATION IN THE CARACARAS 27 

and megalopterus (having remained in Andean Patagonia, but con- 
siderably farther north than its present-day southernmost limit) 
may have taken place as recently as 50,000 to 80,000 years ago. 
Of course, it is also possible that the original separation took place 
during an earlier, somewhat less extensive, glacial episode, but 
since the maximum glaciation apparently obliterated earlier re- 
mains, it is futile to speculate any further about the possible course 
of this event. 

ACKNOWLEDGMENTS 

I thank Ernst Mayr for his continued advice throughout my 
studies of speciation in Andean birds. He and Dean Amadon 
criticized an earlier version of this paper. W. John Smith and 
William H. Drury, Jr. kindly allowed me to use their field notes 
on several species. 

Field work was financed by the Frank M. Chapman Memorial 
Fund of the American Museum of Natural History, the National 
Science Foundation (grants G-19729 and GB-3167 to the Com- 
mittee on Evolutionary Biology of Harvard University), the Society 
of the Sigma Xi, and the Bourse federate de voyages of the Societe 
helvetique des sciences naturelles (Switzerland). 

I am grateful to the following persons, who helped me in various 
ways during my examination of specimens: Jean Dorst (Museum 
national d'histoire naturelle, Paris), I. C. J. Galbraith (British 
Museum, Natural History), Father Antonio Olivares (Instituto de 
Ciencias Naturales, Bogota), Raymond A. Paynter, Jr. (Museum 
of Comparative Zoology), and the late R. A. Philippi (Museo 
Nacional, Santiago). Finally, I acknowledge the assistance of 
Warren Hubley during the course of this study. 

BIBLIOGRAPHY 

Abbott, C. G. 1933. Closing history of the Guadalupe Caracara. Condor, 
35: 10-14. 

Ahlfeld, F., and L. Branisa. 1960. Geologia de Bolivia. La Paz, Insti- 
tuto Boliviano del Petroleo, Editorial Don Bosco. 245 pp. 

Amadon, D. 1954. On the correct names for the caracaras and for the 
Long-winged Harrier. Auk, 71: 203-204. 

1964. Taxonomic notes on birds of prey. Amer. Mus. Novi- 

tates, No. 2166: 1-24. 

Brown, L., and D. Amadon. 1968. Eagles, Hawks, and Falcons of the 
World. 2 Vols. New York, McGraw-Hill Co. 945 pp. 



28 BREVIORA No. 355 

Bruggen, J. 1950. Fundamentos de la geologia de Chile. Santiago, Insti- 

tuto Geografico Militar. 374 pp. 
Cain, A. J. 1954. Subdivisions of the genus Ptilinopus (Aves, Columbae). 

Bull. British Mus. (Nat. Hist.), Zool. 2 (8): 265-284. 
Caldenius, C. C. 1932. Las glaciaciones cuaternarias en la Patagonia y 

Tierra del Fuego. Geogr. Annaler, 14: 1-164. 
Cawkell, E. M., and J. E. Hamilton. 1961. The birds of the Falkland 

Islands. Ibis, 103a: 1-27. 
Childs, O. E., and B. W. Beebe (Eds.). 1963. Backbone of the Americas. 

Amer. Assoc. Petroleum Geol., Memoir 2. 320 pp. 
EiSENTRAUT, M. 1935. Biologische Studien im bolivianischen Chaco. 

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367-443. 
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. 1950. The birds of North and Middle America. Part XI. 

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Haverschmidt, F. 1962. Notes on the feeding habits and food of some 

hawks of Surinam. Condor, 64: 154-158. 
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Cabo de Hornos. Acta Zool. Lilloana, 9: 505-532. 



1970 SPECIATION IN THE CARACARAS 29 
. 1962. Notas ornitologicas sobre la coleccion del Institute 



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BREVIORA 



Mnaseiiamn of Coimparative Zoology 

Cambridge, Mass, 30 November, 1970 Number 356 

On new species in a new earthworm genus 
from Puerto Rico^ 

G. E. Gates2 



Abstract. A new genus of earthworms, Estherella (family Glossosco- 
lecidae), with new species montana (type species) and nemoralis, is 
described from Puerto Rico, and its remarkable structural modification is 
discussed. 

A seemingly impossible evolutionary modification was shown 
by several worms received 25-30 years ago. Immaturity, amputa- 
tion, maceration, and paucity of specimens prevented completion 
of species descriptions to desired standards. Unfortunately subse- 
quent material never became available. Various attempts to secure 
it were futile. This contribution now is proferred in hope of 
awakening interest in: 1) An evolutionary development that some 
zoologists categorically maintain is impossible. 2 ) The mostly 
unknown earthworm faunas of Caribbean Islands. 

Glossoscolecidae 
Estherella gen. nov. 

Definition. Digestive system, with a gizzard in iii, three pairs of 
calciferous glands in v-vii, each gland sausage-shaped, vertically 
placed alongside gut, with a short duct from dorsal end opening 
into esophagus just lateral to the supra-esophageal vessel, in- 
testinal origin in region of xix-xx, with a lamelliform typhlosole, 
without caeca and supra-intestinal glands. Vascular system, with 
a single dorsal trunk aborted in front of hearts of iv, complete 
ventral and subneural trunks, the latter adherent to parietes, a 
supra-esophageal trunk in v-xiv, paired latero-esophageal trunks 

1 From research financed by the National Science Foundation. 

2 Zoology Department, University of Maine, Orono. 



2 BREVIORA No. 356 

in iii-ix with connectives to supra-esophageal in v-vii. Hearts, in 
iv-vii lateral, in viii latero-esophageal. Nephridia, holoic and 
vesiculate. Nephropores, obvious, in a regular longitudinal rank 
on each side in region of CD. Pigment, none. Septa, present from 
3/4. Prostomium, none, replaced by a protrusible proboscis. Setae, 
eight per segment, in regular longitudinal ranks. 

Quadrithecal, spermathecae adiverticulate, pores in region of 
CD, at 5/6-6/7. 

Type species, E. montana n. sp. 

Distribution. Puerto Rico. 

Estherella montana sp. nov. 

Puerto Rico, El Yunque Mountain. Wet cloud forest at 
± 2500 feet. May 1938. 3-0-0. P. J. Darlington per G. E. 
Pickford. (Mus. Comp. Zool.) About 2200 feet, an anterior 
fragment, C. W. Richmond & L. Stejneger. (U. S. Nad. Mus.) 
External characteristics. Length, 50-60 mm (juveniles), 175 
mm (posterior amputee of 148 segments). Diameter, 4 mm 
(juveniles), 12 mm (amputee). Segments of 54 mm juvenile, 
188. Color, white (long alcoholic preservation). Peristomium, 
much shorter than ii but of about the same appearance externally 
as subsequent segments. Intersegmental furrows, distinct. Seg- 
mental length, gradually increasing posteriorly to region of vii-ix. 
Secondary annulation, a presetal and a postsetal secondary furrow 
in each of ix-xxvi, postsetal secondaries unrecognized behind 
xxvi. Nephropores, obvious, present from ii, well behind inter- 
segmental furrows but usually less than half way toward segmental 
equators, at or near C. Setae, paired, ventral couples first certainly 
recognizable in v, lateral couples in region of xv, in region of xxx 
CD slightly < AB much < AA < BC, posteriorly A A ca. - BC, 
still further back AA ^ BC. Dorsal pores, none. 

Quadrithecal, spermathecal pores, minute, superficial, in CD, 
at 5/6-6/7. Other genital apertures, unrecognizable. Genital 
tumescences, transversely and shortly elliptical, indistinctly de- 
limited, each with two circular areas of epidermal translucence at 
center of which is a follicle aperture, a,b/xw-\xi\. Region ot AA, 
rather deeply depressed through xv-xxiv. 

Internal anatomy. Septa, 4/5-13/14 thickly muscular to 
muscular, funnel-shaped, large, apices well posteriorly, 14/15 and 
following septa slightly strengthened by muscular fibers. Septum 
3/4, a delicate transparent membrane bearing on its posterior face 



1970 NEW EARTHWORM GENUS 3 

one pair of nephridia and on its anterior face two other pairs of 
tubules, with insertion on gut immediately behind gizzard. Pig- 
ment, if once present in body wall, completely leached by pre- 
servative. A large, empty canal, ellipitical in cross section, 
apparently completely circumferential, in anterior portion of body 
wall in each of i-x. Canal size, decreasing posteriorly. Brain, in 
ii. Nerve cord sheath, massively muscularized (Fig. 1) anteriorly 
but so as to leave a greyish translucent line visible at mD and 
mV in the cord between segmental ganglia (Fig. 2). 

Buccal cavity, in i dorsally of small juveniles, seemingly pro- 
vided, though only temporarily, with a suckerlike pad somewhat 
resembling the withdrawn and depressed condition of the prosto- 
mium in various megadriles, in ii dorsally with a circular aperture 
into a tunnel containing a presumably protrusible proboscis 1-2 
mm long. Gut from level of intersegmental furrow 2/3 to septum 
4/5, ca. 30 mm long, sigmoid, comprising a pharynx (4 mm 
long), a bulb (5 mm thick dorsoventrally and with a glandular 
chamber anteriorly), a slender esophagus (14+ mm long) with 
closely crowded, low longitudinal ridges on its inner wall, a sort 
of conical crop (5 mm long) with circular ridges on its inner wail, 
and a powerful gizzard (6 mm long) referable to iii. 

Calciferous glands, in contact with each other mesially under 
the gut, in vii ducts longer but concealed by adherence of 7/8 
(near apex of its funnel) to the gut. Typhlosole, present from 
region of xxiv-xxvi, 10 mm high (3 mm, small juvenile), rolled 
up on itself like a scroll, ending in region of 125th segment (132d 
of 188). Lateral typhlosoles, not lamelliform, rounded and pro- 
tuberant ridges in first one or two typhlosolar segments. 

Ventral blood vessel, high up in coelom and near gut in v-xi at 
least. Extra-esophageals. interconnected by a transverse vessel 
just in front of 4/5 and just under the ventral trunk, anteriorly 
passing up and branching among nephridia associated with 3/4. 
Supra-esophageal, with a large branch on each side in v and vi 
that bifurcates, one branch to a calciferous gland near the duct, 
the other passing down along anterolateral aspect of the gland to 
an extra-esophageal trunk, connected also with extra-esophageals 
by a pair of vessels, seemingly on posterior face of 7/8 but mostly 
within the septum. Hearts, of iv-vii slender and lateral, of viii 
apparently latero-esophageal — posterior bifurcations to dorsal 
trunk slender and empty, anterior branches filled with blood and 
obviously joining the supra-esophageal. 



4 BREVIORA No. 356 

Nephridial ducts (of anterior segments), passing down through 
longitudinal muscle layer and then turning forward to cross the 
circumferential intra-parietal canal, thence anteriorly widened and 
with more opaque (muscularized?) wall. 

Spermathecae, rudimentary, adiverticulate, within the longi- 
tudinal muscle layer. , 

Remarks. Small juveniles are assumed to be of the same species 
as the large worm from the same mountain. 

Rudimentary state of the spermathecae and absence of macro- 
scopically recognizable gonads, funnels, and seminal vesicles, in- 
dicate that even the large worm was juvenile though maximum 
diameter for the species may have been attained. 

The parietal insertion of the delicate septum 3/4 had become 
unrecognizable presumably as a result of pinning out the specimen 
after a longitudinal incision had been made near the mid-dorsal 
line. 

Any connection between nephridial ducts and the circumferential 
intraparietal canals would have been too small to recognize in 
dissection, and microtome sections were unsatisfactory. The 
canals were crossed diagonally by delicate fibers (or septa?). 
Similar canals had been observed at least once before, but records 
were destroyed during World War II. 

Abortion of dorsal trunk in front of hearts of iv and posteriorly 
in that segment was found in each dissected specimen considered 
herein. That and other characters already mentioned in the generic 
definition do not need mention again in species descriptions. 

Photographs of nerve cord sections were provided by Prof. E. 
Carpenter. 

E. nemoralis sp. nov. 

Puerto Rico. Luquillo Forest (Caribbean National Forest), 
La Mina Recreational Area, at 1800 feet, February 22, 1947., 
2 macerated specimens (several younger specimens possibly of 
the same species, also macerated.) R. Kenk. (U. S. Natl. Mus.) 
External characteristics. Length, 250 mm. Diameter, 9 mm. 
Segments, 220 (at 195/196 a tail regenerate with terminal anus). 
Color, possibly red originally, even after long alcoholic preserva- 
tion dorsum with a slight reddish tinge, except in regenerate. 
Nephropores, obvious, present from ii, in CD. Setae, closely 
paired throughout, AB = CD, AA > BC, DD ca. = VzC, ventral 



1970 NEW EARTHWORM GENUS 5 

couples of some segments modified (? but genital tumescences not 
recognized). 

Clitellum, perhaps represented by a dark brown coloration in 
xv-xxii, xxiii/eq, which is conspicuously lacking in a small area 
around each nephropore, no epidermal tumescence recognizable. 
Ouadrithecal, pores minute, superficial, each at center of a small 
tubercle at C and at or immediately in front of 5/6-6/7. Female 
pores, postsetal in AB of xii(?). 

Internal anatomy. Septa, 4/5-6/7 very thickly muscular, a 
transparent, funnel-shaped membrane bearing three pairs of 
nephridia inserted on the gut just behind the gizzard almost im- 
mediately in front of 4/5 presumably being 3/4, 7/8 lacking or 
else inserted on parietes over intersegmental furrow 8/9. 

Calciferous glands, without a central lumen but with a honey- 
comb appearance in cross sections, each with a small distal 
appendage. 

Supra-esophageal, bifurcating posteriorly in xiv, giving off two 
pairs of vessels, one immediately behind the other and both just 
in front of the septum in each of v-vii, the posterior of each pair 
giving ofl" branches to the calciferous gland and ventrally joining 
the extra-esophageal trunk of it^ side, the anterior vessels passing 
onto stalks of calciferous glands and down through the glands into 
the terminal appendages. Extra-esophageal, first visible in region 
of 3/4 as a result of union of several large vessels, with several 
branches to each calciferous gland of its side. Subneural trunk, 
large, zigzag-looped, closed ends of loops visible beyond both sides 
of the nerve cord, bifurcating just in front of subpharyngeal gang- 
lion (one specimen) or in region of xvii (one), each branch 
passing anteriorly in a zigzagged course lateral to the cord but 
connected with its twin on the opposite side by numerous trans- 
verse vessels. Ventral trunk, high up in coelom as in E. montana. 
Hearts, large, two pairs, possibly latero-esophageal and attributable 
to viii-ix (?). 

Testis sac (or sacs?) filled with coagulum, surrounding or 
including hearts belonging in viii (?). 

Spermathecae, sessile, ducts confined to body wall, ampullae 
small, protruding only slightly into coelomic cavities of vi and vii. 

Remarks. Intersegmental furrows, in spite of the maceration, 
are distinct, and septa 4/5-6/7 are inserted on the parietes directly 
over intersegmental furrows 4/5-6/7. 

Thickness of the subneural trunk is greater than that of the nerve 
cord even in regions of segmental ganglia. 



6 BREVIORA No. 356 

The cuticle was loose and setae had been pulled out of their 
follicles. 

Repetition in the description of characters shared identically 
with E. montana seems unnecessary. Mention should be made of 
the fact that a proboscis and circumferential parietal canals were 
not seen. 

This species is distinguished from E. montana by absence of the 
marked muscularity in the nerve cord sheath. 

Estherella sp. 

Puerto Rico. Luquillo Forest (Caribbean National Forest), 

La Mina Recreational Area, 1800 feet, February 22, 1947, 1 

macerated specimen. R. Kenk. (U. S. Natl. Mus.) 

External characteristics. Size, 150 by 7 mm. Nephropores, 

obvious, present from ii, in CD. Setae, paired throughout (ventral 

couples modified in some clitellar segments?). 

Qitellum, xv-xxii (and xxiii?). Tubercula pubertatis, longi- 
tudinal bands of translucence, just lateral to B, each demarcated 
laterally by a deep furrow. Female pores, postsetal in /4B of xii(?). 
Internal anatomy. Male funnels, one pair, iridescent, imbedded 
in coagulum apparently also containing hearts of viii and possibly 
in sacs (or a testis sac?). Spermathecal ampullae, spheroidal, 
without spermatozoal iridescence, slightly protuberant into 
coelomic cavities from the angles of septal insertions and parietes. 
Remarks. Setae had been pulled out of their follicles as in the 
types of nemoralis. Gonads and female funnels were not found. 
Structure, so far as could be determined, is the same as is shared 
by the two preceding species. 

The reason for anticipating a third species is the maturity at a 
size smaller than is expected for the other two. 

SYSTEMATICS 

Cephalization has had little attention from oligochaetologists 
and perhaps least of all in connection with a family in which one 
manner of evolutionary modification seemingly had its most ex- 
tensive, as well as perhaps least appreciated development. 

Metamerism in oligochaetes sometimes has been said to be 
homonomous, i.e., similar throughout the body. Typically, the 
soma is in anteroposterior segments, each of which, at least in 
earlier stages of evolution, has four pairs of setae, a pair of 



1970 NEW EARTHWORM GENUS 7 

nephridia. and a section of the gut. Such a segment is demarcated 
externally from each of its two contiguous neighbors by inter- 
segmental furrows, circumferential lines where the epidermis is 
thinnest. Internally, a segment is deUmited by transverse parti- 
lions, the intersegmental septa. The latter, typically, are in exactly 
the same anteroposterior levels as the intersegmental furrows. 
Peristomium and periproct, according to such definitions, are not 
segments, though for practical purposes are counted as such. 

Differentiation in a relatively short anterior portion of the soma 
of special digestive organs such as gizzards, calciferous glands, 
etc., and localization of gonads are aspects of oligochaete cephali- 
zation so universal as not even to have been thought to be involved. 
More usually considered were abortions, as of follicle and nephri- 
dial anlage, and disappearance of septa and intersegmental fur- 
rows, i.e., those structures existence of which enables recognition 
of segments. Slight (or at least seeming) diplacements of septal 
insertions on the parietes have been known for some time. Recog- 
nized but recently (Gates, 1943: 92) was a seemingly posterior 
dislocation of the parietal insertion of septum 9/10, in Pontoscolex 
corethrurus (Miiller, 1857), to a position over site of inter- 
segmental furrow 10/11. Failure to recognize that dislocation was 
responsible in part for assignment of certain organs in systematic 
descriptions to wrong segments. How many other errors of that 
sort were made in past characterizations of glossoscolecids remains 
to be learned. 

Appearance of deep, secondary, and even tertiary furrows hardly 
distinguishable from the primary intersegmentals, in association 
with abortions of setae and nephridia, also has been responsible 
for errors in determination of organ locations. Such mistakes are 
unfortunate, as knowledge of exact organ position along the ante- 
roposterior axis is of first importance for megadrile systematics 
and phylogeny. Absence of data as to segmental location of the 
gonads in the Puerto Rico species is not so regrettable as would 
formerly have been thought since it is now known that "andry" 
often, and sometimes even "gyny," does vary intragenerically. 

Fortunately, the worms now under consideration, in spite of 
the poor condition, are free of external modifications that might 
lead to wrong determinations of organ locations. Sctal follicles, 
to be sure, have been aborted in some of the anteriormost seg- 
ments, but compensation is provided by the nephropores which 
not only are all present but also are obvious. Secondary and 



8 BREVIORA No. 356 

tertiary furrowing is lacking, and the anterior segments are clearly 
demarcated by unmistakable intersegmental furrows. The first 
two segments have the normal appearance of externally exposed 
epidermis. No evidence was found for the existence of an actual 
pre-oral vestibule comprising one or two rudimentary segments 
no longer exposed regularly to the external environment. Further- 
more, the unusual condition next to be discussed characterizes 
every individual of two, or possibly even three, species. Individual 
abnormality or defective anterior regeneration accordingly cannot 
be invoked as was contended when a single Panama specimen was 
described (Gates, 1968) with a similar condition. 

The powerful gizzard, being in front of a membrane that, be- 
cause of nephridial relationships, must be regarded as septum 3/4, 
is unusually anterior. With the single exception of the above- 
mentioned Panama species, a megadrile gizzard has not hitherto 
been found in front of segment v and often is further back in the 
esophagus. Other organs also are too far forward. The last pair 
of hearts is in viii, whereas the first pair of real hearts usually is 
in ix. Calciferous glands are present in v only in the Panamanian 
Thamnodriloides yimkeri Gates, 1968. Lastly, testes are at least two 
segments in front of where they would normally be expected. 

Accordingly, much more is involved than forward displacement 
(homoeosis) of a single organ but rather a condition in which 
all organs of the cephalic region from gizzard posteriorly are three 
segments in front of their expected positions (regional homoeosis). 

An initial or very early stage in an evolutionary development 
that may have reached its climax in the Puerto Rico and Panama 
worms is provided by P. corethrurus. In that species an inter- 
segmental furrow between the first and second segments has di- 
appeared along with the prostomium. The now rather flaccid 
fusion metamere is small. Proof of what happened is provided in 
many specimens by retention of the setae belonging to ii which are 
now near the first intersegmental furrow that morphologically is 
2/3. With loss of those setae, as in some individuals of the species, 
the gizzard would have to be referred to v instead of vi. Organs 
behind the gizzard also would be one segment anterior to their 
usual position. Abortion of two further segments by the same 
process under way in P. corethrurus would provide the regional 
homoeoses of the Puerto Rico and Panama genera. Although 
body wall and associated nephridia were markedly reduced or 
deleted, the digestive system was not correspondingly shortened. 



1970 NEW EARTHWORM GENUS 9 

On the contrary, there has been so much elongation as to require 
very considerable enlargement of associated septa into posteriorly 
directed funnel-shapes. What happened in the nervous system may 
prove to be interesting also. 

Although homoesoses are identical, the digestive systems and 
especially structure of the calciferous glands show that the two 
fore-shortened genera are not closely related. Puerto Rican worms 
may have evolved from a stock with calciferous glands in viii-x. 
Genera so characterized are unknown. Related forms should be 
sought to the south as the glossoscolecids evolved in tropical South 
America. Puerto Rico now appears to be the northern limit of 
generic endemism. 

Completion of a development somewhat hke that now under 
way in P. corethrurus may be responsible for attribution of testes 
in Thamnodriliis matapi Righi, 1969, to segments ix and x instead 
of the expected x and xi. 

REFERENCES 

Gates, G. E. 1943. On some American and Oriental earthworms. 

Ohio Jour. Sci., 43: 97-116. 
. 1968. On a glossoscolecid earthworm from Panama and 

its genus. Megadrilogica, 1: 1-15. 



10 



BREVIORA 



No. 356 




1970 NEW EARTHWORM GENUS 11 



LIST OF ILLUSTRATIONS 



Figure 1. E. montana. Transverse section of nerve cord anteriorly to 
show muscularization of the sheath. 

Figure 2. E. montana. Transverse section of nerve cord anteriorly to 
show the condition responsible for the appearance of a greyish translucent 
line at mD and mV. 

Figure 3. E. montana. Transverse section of nerve cord anteriorly to 
show giant cells ventrally. 



BREVIORA 

MiLiiseiiinn of Coimpsirsitive Zoology 

Cambridge, Mass. 30 November, 1970 Number 357 

A review of the fossil Pelomedusidae (Testudines, 
Pleurodira) of Asia 

Roger Conant Wood 



Abstract. The taxonomic status of the three Asiatic chelonian genera 
that have been described as pelomedusids is reviewed. Of these, "Podoc- 
neinis" imiica, although possibly a member of the family, is so poorly known 
that familial assignment is not presently possible. Carteremys leithii and 
Shwehoemys pilgrimi both appear to be valid palomedusid species. On 
the basis of new material S. pilgrimi is redescribed and, in addition, a new 
species of this genus from the Miocene of Baluchistan, S. gaffneyi, is 
proposed. 

INTRODUCTION 

Living pelomedusid turtles are restricted to sub-Saharan Africa, 
Madagascar, and South America. But paleontological evidence 
indicates that pelomedusids formerly had a much more cosmo- 
politan distribution; fossil representatives of this family occur in 
North and South America, Europe, Africa, and Asia. 

The purpose of the present paper is to review the extinct Asiatic 
chelonian genera that have been described as pelomedusids as 
well as to put on record two new fossil pelomedusid skulls from 
Asia, one referable to Shwehoemys pilgrimi and the other repre- 
senting a new species of the same genus. 

Abbreviations used in this paper are: 
ANSP — Academy of Natural Sciences, Philadelphia 
BMNH — British Museum (Natural History) 
GSI — Geological Survey of India 
MCZ — Museum of Comparative Zoology, Harvard University 

I have not seen the material described by Lydekker, Swinton, 
and Williams that is contained in the collections of the Geological 
Survey of India, but it is for the most part well figured in the 
literature. Photographs of the type of Shwehoemys pilgrimi 
Swinton have been available. 



2 BREVIORA No. 357 

PREVIOUSLY DESCRIBED ASIATIC PELOMEDUSIDS 

Very few fossil pelomedusids have been described from any- 
where in Asia, and none of these is particularly well known on the 
basis of published material. 

"Podocnemis*"' indica Lydekker 1887. This species was de- 
scribed on the basis of a fairly complete carapace and on some 
miscellaneous plastral fragments found at Nila in the Salt Range 
of West Pakistan. Lydekker was uncertain about the age of "P". 
indica but concluded (1887: 59) that it was probably of ". . . low- 
est eocene . . . and may . . . correspond to the Cemaysian stage 
of Reims, and the Puerco group of the United States." Since it 
is now generally recognized that the Cernay beds are of late 
Paleocene age and the Puerco beds of early Paleocene age, "P." 
indica may actually be of Paleocene rather than Eocene age. Both 
Paleocene and early Eocene deposits occur in the Tertiary sequence 
of the Salt Range (Krishnan, 1960: 494), and too much uncer- 
tainty exists as to the exact stratigraphic horizon from which the 
only known specimen of "P." indica was obtained to resolve the 
question of its age beyond all doubt. Invertebrates found in 
association with the two chelonians {"Podocnemis" and Hemi- 
chelys) described from this locality ". . . indicate that the bed 
in which they were found is either of marine or estuarine origin; 
and this is confirmed by the chelonians, one of which is covered 
with the 'spaf of oysters, while sharks' teeth are embedded in the 
matrix of the other" (Lydekker, 1887; 59-60). 

Preservation of the carapace of "P." indica is rather poor; 
Lydekker noted (1887: 60) that ". . . both specimens [from 
Nila] . . . were in a much broken condition, and . . . required all 
[the preparator's] skill to render them fit for description." 
Lydekker's restoration of the carapace (1887, plate 13) indicates 
that its most distinctive feature is a peak along the midline of the 
neurals, with the pleurals on either side apparently sloping away 
flatly rather than on a curve. The nuchal bone appears to be 
unusual in that its postero-lateral sides are considerably longer 
than its antero-lateral ones. The nuchal is rather small and does 
not transgress the lateral boundaries of the first vertebral scute. 
There are seven neurals; the first five are all longer than broad, 
whereas the last two are broader than long. Two pleurals (the 
seventh and eighth) meet in the midline between the last neural 
and the suprapygal. No indentation occurs at the midline along 



1970 ASIATIC FOSSIL PELOMEDUSIDAE 3 

the anterior margin of the carapace and a cervical scute^ is lacking. 
Whereas the first vertebral is nearly twice as wide as it is long, 
the second and third vertebrals are both longer than broad. 
Lydekker estimated (1887: 63) that the overall length of the 
carapace must have been approximately 35 inches (87 centi- 
meters), exceptionally large for a fossil pelomedusid. Critical 
taxonomic evidence, such as whether or not the pelvis was fused to 
the shell, the presence or absence of mesoplastra, and the scute 
pattern on the anterior plastral lobe, is not preserved. Conse- 
quently, there is no assurance that "P." indica is actually a pelo- 
medusid, let alone a member of the genus Podocnemis. Neverthe- 
less, its midline ridge and straight loping sides are somewhat remi- 
niscent of the carapace structure of a recently discovered shell of 
Shweboemys from Egypt (see p. 00), and the number, shape, and 
arrangement of its neurals is typical of many pelomedusids, as is 
its lack of a cervical scute. Therefore, it does not seem altogether 
unlikely that "P." indica may represent the remains of some kind 
of pelomedusid, although it probably is not a member of the genus 
Podocnemis. Until more complete specimens of this taxon are 
discovered, I do not think that a better identification of this speci- 
men is possible than Pelomedusidae? incertae sedis. 

Cartereniys leithii (Carter 1852). A second Asiatic pelome- 
dusid taxon, "Hydraspis" leithii, was recovered from Intertrappean 
beds near Bombay, India. Some uncertainty exists as to the age of 
these sediments. Lydekker (1887: 60) regarded them as "lower 
eocene." Referring to the age of the volcanics within which the 
Intertrappean beds occur, Wadia (1953: 302) stated that "... it 
is quite apparent that the Deccan Traps cannot be older than the 
Danian stage of the uppermost Cretaceous [now Paleocene], while 
. . . they cannot be much younger than the Eocene." According 
to Krishnan (1960: 483-486), paleontological evidence afforded 
by fossils contained within the Intertrappean beds is not par- 
ticularly helpful for dating, but on other grounds he concluded 
that the Deccan Traps ranged in age from late Cretaceous to, 
perhaps, Ohgocene. Robinson (1970: 245) has expressed similar 
views, stating that the Intertrappeans are ". . . probably mainly early 



ij have here adopted the term suggested by Zangerl (1969: 315) for 
this particular scute to avoid the confusing redundancy arising from the 
conventional procedure of referring to both it and the underlying bone as 
the nuchal. 



4 BREVIORA No. 357 

Tertiary in age. . ." Since the Intertrappeans of the Bombay 
region are confined to the upper part of the Deccan Traps (Pascoe, 
1964: 1385), their attribution to the Eocene would not be unrea- 
sonable. Krishnan (1960: 482), Pascoe (1964: 1385) and 
Robinson (1970: 245) all agree that the Bombay Intertrappeans 
were laid down in fresh water, Pascoe further suggesting (1964: 
1386) that the depositional environment was a shallow marsh. 

Carteremys leithii was a small species; the only two complete 
carapaces for which measurements have been recorded are IVk 
and 8 inches (18-20 centimeters) in length (Carter, 1852: 187; 
Williams, 1953: 6). Carter's original description was based on 
material that is now unfortunately lost (Williams, 1953: 2). Only 
three other specimens that can be referred to this species with 
reasonable confidence have subsequently been discovered 
(Williams, 1953: 6, and plate 3). The total number of neurals 
is uncertain, although there are at least five. Evidently no cervical 
scute was present, and the first vertebral was much smaller than 
the second. The outer surface of the shell is covered with fine 
sculpturing. In several respects the plastron is quite distinctive: 
it is relatively narrow, with a semicircular anterior lobe projecting 
well forward of the front of the carapace; between the broadly 
rounded xiphiplastral tips is a very shallow anal notch, not com- 
parable in its shape to those of any pelomedusid with which I am 
familiar; and the outlines of the pelvic scars on the xiphiplastron 
are also unusual. In spite of Williams' suggestion (1953: 4) that 
small, laterally placed mesoplastra, a characteristic pelomedusid 
feature, may have been present, there is no conclusive evidence 
bearing on this point. None of the three existing specimens (all 
belonging to the collections of the Geological Survey of India) is 
sufficiently complete to demonstrate the presence or absence of 
these structures (WiUiams, 1953: 6). Trapeziform gulars were 
widely separated by an extremely broad intergular scute that 
extended posteriorly to the humero-pectoral sulcus and thus pre- 
vented the humerals from meeting in the midline also. The most 
notable feature of the skull is the extensive emargination of the 
roof from behind, a condition typical of most pelomedusids. A 
well-developed jugal-quadratojugal bar is present. Although the 
extremity of the mandibular rostrum was broken off in the 
material Carter described, it is clear from what was preserved 
that there must have been a broad, robust symphysis at the mid- 
line of the lower jaw. 



1970 ASIATIC FOSSIL PELOMEDUSIDAE 5 

Long regarded as a chelid, "Hydraspis" leithii was eventually 
redescribed and designated as the type of a new pelomedusid genus 
by Williams (1953: 3-4). A combination of several characters — 
the absence of a cervical scute, the relative proportions of the first 
and second vertebrals, the remarkably large intergular, and the 
lack of a parieto-squamosal arch combined with the presence of 
a jugal-quadratojugal bar — led Williams to conclude that this 
species could not be a cheHd. These characters, together with the 
inferred existence of small, laterally placed mesoplastra, per- 
suaded him that Carteremys was in fact a pelomedusid. On the 
basis of the data presented in Table 1, I agree with Williams' 
conclusion. If we disregard for a moment the question of whether 
or not mesoplastra were present in Carteremys, then we see that 
for all the characters tabulated, this genus and pelomedusids agree. 
In contrast, none of the other families share more than two 
characters with Carteremys. This comparison strongly suggests 
that Carteremys is a pelomedusid. Should it eventually be possible 
to determine that Carteremys had mesoplastra, the evidence would 
overwhelmingly favor this determination. 

Lydekker (1890: 22-23, fig. 2) referred an epiplastral frag- 
ment, probably from Intertrappean beds and therefore possibly 
of Eocene age, to "Hydraspis" leithii. Differing from Carteremys 
in size and in gular-intergular proportions, this specimen may well 
represent an unknown taxon, but too little is known of it to permit 
useful discussion. 

Shweboemys pilgrimi Swinton 1939. The type, and until now 
only known specimen, of this species is a partial skull of Pliocene 
or Pleistocene age from Burma (Swinton, 1939). Swinton be- 
lieved that nasal bones, although not preserved on the specimen 
he described, must have been present originally. Were this sup- 
position true, his placement of the genus in the Pelomedusidae 
would be suspect because one of the diagnostic characters of the 
family is the absence of nasals (cf. Romer, 1956: 515). Evidently 
Swinton was either unaware of the significance of this character 
or else he did not consider it to be of great importance; at any 
rate, he did not discuss its bearing on taxonomy. Nevertheless, 
other observations led him to conclude (1939: 551) that 
Slnveboetnys is a pelomedusid: 'in brief, the interest of the speci- 
men is that in superior and lateral aspect there is little to dis- 
tinguish it from the genus Podocnemis, while in palatal view it 
has much similarity to Stereogenys. There is no doubt that it 



BREVIORA No. 357 



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1970 ASIATIC FOSSIL PELOMEDUSIDAE 7 

differs from both genera and is a new form belonging to the family 
Peiomedusidae." 

NEW ASIATIC PELOMEDUSID MATERIAL 

The recent recognition of a second, slightly more complete 
specimen of Shweboemys pilgrimi by Mr. C. A. Walker in the 
collections of the British Museum (Natural History) has provided 
new information which confirms Swinton's familial determination. 
Further supporting evidence is furnished by the new species of 
Shweboemys from the Miocene of Baluchistan (West Pakistan) 
described below. In addition, recent Yale University paleonto- 
logical expeditions to the Fayum Depression of Egypt have pro- 
duced conclusive evidence showing that "Podocnemis" antiqua 
Andrews 1903 from the late Eocene Qasr el-Sagha Formation is 
referable to Shweboemys. A detailed description of this species, 
the only one represented by both skull and shell material, is being 
prepared for publication elsewhere, but I include the diagnostic 
characters of its shell in the emended diagnosis. 

Shweboemys Swinton 1939 

Type species. Shweboemys pilgrimi Swinton 1939. 

Emended diagnosis. Skull with broad secondary palate formed 
by medial expansion of maxillae and palatines, with narrow median 
cleft extending posteriorly from behind premaxillae; outer border 
of palatines not parallel to midline axis, but diverging from it at 
an angle of approximately thirty degrees; laterally projecting, 
prominent ectopterygoid processes; enlarged carotid charmels; 
basisphenoid not covered by pterygoids ventrally. Carapace cordi- 
form in outline, tapering to a point posteriorly; pleurals flat rather 
than curved, sloping away from continuous midline ridge at gentle 
angle; ventral surface of plastron completely flat; anterior lobe of 
plastron very short and semicircular; posterior lobe narrower and 
approximately one and one-half times longer than anterior; 
outer margin of posterior lobe straight rather than curved, slanting 
inward toward rear. 

Referred species. Shweboemys antiqua (Andrews) 1903, S. 
gaffneyi sp. no v. 

Distribution. Late Eocene, Fayum Depression, Egypt; early 
Miocene, Bugti HiUs, West Pakistan; Pliocene or Pleistocene, 
Burma. 



8 BREVIORA No. 357 

The skull of Shweboemys is very similar to that of Stereogenys 
but differs in several significant respects: the pterygoids do not 
completely cover the basisphenoid ventrally; the lateral margins of 
the palatines are not parallel to the midline axis; and the secondary 
palate is less elongate, not extending back as far as the ectoptery- 
goid processes. 

Swinton's decision to base a new pelomedusid genus and species 
on his Burmese specimen was founded on his belief that the skull 
combined features of both Podocnetnis and Stereogenys without 
being more like one than the other (see p. 5). That the palatal 
structure of Shweboemys is very similar to that of Stereogenys and 
different from that of Podocnemis is indisputable, but Swinton's 
remark that the dorsal and lateral aspects of Shweboemys are 
virtually identical to the comparable regions of Podocnemis and 
unlike those of Stereogenys is an overstatement. Swinton (1939: 
550) evidently compared the type of Shweboemys pilgrimi only 
with Andrews' original description (1901: 442) of the type skull 
of Stereogenys cromeri, which is somewhat crushed dorso-ventrally 
in the facial region as Andrews himself noted (1901 : 443n). An- 
other specimen (BMNH — R.3189), which Andrews later (1906: 
301 and plate 25, fig. 1 ) referred to this species, is not flattened' 
and reveals that virtually all of the characters used by Swinton 
(1939: 550) to differentiate Stereogenys from Shweboemys — the 
relative positions of the orbits and external nares, shape of the 
orbits, and breadth as well as flatness of the skull — are artifacts 
of preservation rather than taxonomically significant features. 
Swinton also claimed (1939: 550) that the facial bones of 
Stereogenys were more slender than those of Shweboemys. The 
difference in thickness is easily explained, however. The type of 
Shweboemys pilgrimi is considerably larger than that of Stereogenys 
cromeri (12.5 versus slightly more than 8 centimeters from the 
snout to the occipital condyle) and the thicker bones merely reflect 
greater size. In dorsal and lateral aspects, therefore, the skuU of a 
Shweboemys does not resemble that of Podocnemis more than it 
does that of Stereogenys. 



1 If anything, in terms of distortion, this skull may perhaps be some- 
what compressed laterally. 



1970 ASIATIC FOSSIL PELOMEDUSIDAE 9 

Shweboemys pilgrimi Swinton 1939 
(Plates I, IIA, IIIA, IVA) 

Type. GSI 17255, an incomplete skull. The original description 
of this specimen was accompanied only by some rather crude 
sketches (Swinton, 1939, text-figures 1 and 2). Photographs of 
the type showing comparable views are therefore reproduced as 
Plate I. 

Hypodigm. The type and BMNH— R. 8432, a slightly more 
complete skull lacking the anterior portions of the premaxillae, 
both ectopterygoid processes, part of the left and all of the right 
paroccipital process, and, to whatever extent it may have been 
developed, the supratemporal roof. 

Horizon and locality. Pliocene or Pleistocene, Irrawaddy beds, 
one mile NNE of Mauktet, Shwebo District, Burma. 

Swinton's determination of a Pliocene age for the type (1939: 
548) is questionable because he failed to state — perhaps because 
the information did not exist — at what level within the Irrawaddy 
sediments the specimen was found. It is generally recognized that 
there are two faunal horizons within the Irrawaddy beds, a lower 
one of Pliocene age and an upper one of Pleistocene age (Stamp, 
1922: 498; Colbert, 1938: 267; Krishnan, 1960: 554). Un- 
determined chelonian remains have been reported from the lower 
beds near Yenangyaung (Stamp, 1922: 498), but these have never 
been formally described. Fossil turtle fragments have also been 
recovered from the upper Irrawaddy beds (Colbert, 1943: 417). 
One of these, MCZ 1890 (MCZ 6305 in Colbert) represents the 
left epiplastron of a very large tortoise while another (ANSP 
14644)^ according to Colbert, may be a trionychid. No pelome- 
dusid remains have been recognized among these specimens. 
Whether the Irrawaddy beds of the Shwebo District, whose admin- 
istrative center, the municipality of Shwebo, lies some 130-140 
miles to the northeast of Yenangyaung, represent only the upper 
part or the lower part of this sedimentary unit, or a mixture 
of both, is unknown. Consequently, the absence of any reasonably 
precise stratigraphic data for Swinton's specimen does not permit 
a decision as to its age. Unfortunately, nothing is known about 
the provenance, other than "Burma," of BMNH — R. 8432. Its 
morphological identity with the type of 5. pilgrimi leads me to 
believe that the two skulls are of essentially the same age. 



10 BREVIORA No. 357 

Emended diagnosis. Interorbital width slightly greater than di- 
ameter of orbits; orbits circular, directed forward; maxillary tomia 
curving upwards toward midline to form broad, semicircular notch; 
medial borders of palatine flanges nearly parallel to each other as 
far back as the opening for internal nares; little or no contact be- 
tween pterygoids at midline; precondylar fossa lunate; trigeminal 
foramen facing antero-laterally, situated low on wall of brain case; 
breadth between postero-lateral corners of palatines equal to 40 
per cent of skull length from snout to occipital condyle. 

Not only does the British Museum specimen provide new infor- 
mation about parts of the skull that were not preserved in the 
type, but it also permits an important correction of Swinton's 
description. The snout region of BMNH — R. 8432 is little dam- 
aged and it is possible to determine unequivocally that, contrary 
to his belief, nasals were lacking, as in all pelomedusids. 

The type as preserved is 4V2 inches (11.4 centimeters) long 
according to Swinton. A comparable portion of the British 
Museum specimen measures 9.3 centimeters in length. The total 
length of this skull (from snout to occipital condyle) is approxi- 
mately 10.2 centimeters. With this information it is possible to 
calculate the total estimated length of the type skull, assuming that 
there were no significant ontogenetic changes in proportion, as 
12.5 centimeters. Such large skulls indicate that adult representa- 
tives of Shweboemys pilgrimi must have been imposing creatures, 
roughly equivalent in size to Podocnemis expansa, the largest of 
the living pelomedusid species. 

The most persuasive indication that Swinton adduced to support 
his contention that Shweboemys was a pelomedusid is its palatal 
structure, which resembles that of Stereogenys more than that of 
any other known turtle. This, however, is not a diagnostic 
character, since it occurs elsewhere within the family only in 
Bothremys and is rather widespread among cryptodires. 

For taxonomic purposes, therefore, the most significant addi- 
tional information provided by the British Museum skull is the 
evidence that enlarged carotid channels were present (Fig. lA). 
Such structures are known only in the pelomedusid genera 
Podocnemis and Stereogenys and are not known in any other 
turtle group. Much more substantial grounds now exist, con- 
sequently, to confirm Swinton's belief that Shweboemys is truly a 
pelomedusid. 



1970 



ASIATIC FOSSIL PELOMEDUSIDAE 



11 





Figure 1. Palatal views of: A — Shweboemys pilgrimi (BMNH — R. 
8432); B— Shweboemys gaffneyi (BMNH— R. 8570). Solid parallel lines 
represent areas of breakage. Matrix is indicated by randomly arranged 
Vs. Stippled areas cover region in which thin sheets of surface bone have 
broken off, thus making exact determination of position of sutures difficult. 
Abbreviations: PM = premaxilla; M = maxilla; Pal = palatine; Pt = 
pterygoid; Bs = basisphenoid; Bo = basioccipital; Eo = exoccipital; So = 
supraoccipital; Etp = ectopterygoid process; cc = carotid channel. 



12 BREVIORA No. 357 

There does not appear to be any contact between the pterygoids 
at the midHne, although less than perfect preservation on the 
ventral surface of the basicranium of BMNH — R. 8432 necessi- 
tates consideration of the possibility that these bones may have 
barely met in an undamaged specimen (see Plate II A and Fig. 
lA). Even if the pterygoids actually did meet at the midline, 
their junction was clearly not extensive.^ Among pelomedusids, 
this particular configuration is found only in this species and its 
African relative, Shweboetuys antiqua. Another distinctive char- 
acter is the position of the foramen for the trigeminal nerve 
(Plate IIIA), which Swinton (1939: 551) was unable to detect 
in the type specimen because of poor preservation. Instead of 
being situated above the floor of the brain case and directed later- 
ally, as in nearly all other pelomedusids, it is positioned much 
lower and faces antero-laterally. In Bothremys cooki this foramen 
is evidently situated as far down on the side of the brain case as 
in Shweboemys pHgrimi, but it does not seem to have been directed 
antero-laterally (Galfney and Zangerl, 1968: 220, figs. 13, 14, 
and 16). 

Breakage of the anterior ends of the premaxillae prevents an 
exact determination of the shape of the external nares (Fig. 2A). 
As preserved, the narial opening is ellipical, with its transverse 
axis the longest. Damage to this same region also leaves some 
question as to the actual shape of the upper jaw. Conceivably, it 
may have had a downward curving beak, as in adult specimens of 
Pelusios niger, or have simply been notched, as in many other 
pelomedusids. Alternatively, its present rounded contour may 
actually reflect its original shape. Whatever the case, it is clear 
that there was a strong median indentation of some kind at the 
midline. 

Although the scroll-like outer portion of the laterally projecting 
ectopterygoid processes have not been preserved in either speci- 
men of Shweboemys pilgrimi, these structures did exist. Evidence 
to this effect is preserved on BMNH — R. 8432, where the basal 
portion of these protuberances can be seen on both sides. 



1 Contrary to Swinton's statement (1939: 550), no portion of the 
pterygoids is preserved on the holotype. What he evidently interpreted as 
the palatine-pterygoid suture appears to be a transverse crack across the 
ventral surface of the palatines (Plate lA). 



1970 



ASIATIC FOSSIL PELOMEDUSIDAE 



13 




3 CM 




3 CM 



Figure 2. Facial views of: A — Shweboemys pilgrimi (BMNH — R. 
8432); B—Shweboemys gaffneyi (BMNH— R. 8570). Solid parallel lines 
represent areas of breakage. 



 



14 



BREVIORA 



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1970 ASIATIC FOSSIL PELOMEDUSIDAE 15 

Scute sulci can be detected on the roof of the British Museum 
skull (Fig. 3). The anterior border of the interparietal overlapped 
slightly onto the postero-lateral corners of the frontal bones and 
was bow-shaped, more like that of Podocnemis sextiiberculata 
{cj. Siebenrock, 1902, fig. 9) than any other pelomedusid known 
to me. Behind the orbit a scute intervened between the maxillary 
and frontal scutes. Whether this was an enlarged masseteric scute, 
as in Podocnemis diimeriliana, or a subocular scute, as in most of 
the other species of Podocnemis (Williams, 1954), is uncertain. 

Shweboemys gaffneyi sp. nov.^ 
(Plates MB, IIIB, IVB) 

Type. BMNH — R. 8570, a partial skull lacking the premaxillae, 
most of the prefrontals, the bones of the cheek region, the quad- 
rates and squamosals, the supraoccipital crest, and whatever 
supratemporal roofing there may have been. 

Hypodigm. The type, only. 

Horizon and locality. Early Miocene, Bugti Hills, Baluchistan, 
West Pakistan. 

No locahty or stratigraphic data are associated with this speci- 
men, but apparently it was obtained by C. Forster-Cooper during 
one of his two expeditions to the area around Dera Bugti during 
the years 1910 and 1911 and would therefore be of the age and 
from the general region cited above. It was subsequently given to 
Professor D.M.S. Watson for description, who in turn passed it 
on to Dr. E. E. Williams for the same purpose. Other commit- 
ments having prevented either from formally describing this 
interesting skull, the task has now fallen to me. 

Pilgrim (1908: 144) briefly mentioned that chelonian remains 
are not uncommon in the Miocene sediments of the Bugti region. 
Unfortunately, none of these have ever been described. Knowl- 
edge of their existence nevertheless reinforces the probabihty that 
the skull under consideration is of the age of and from the locality 
given above. 

Diagnosis. Differing from S. pilgrimi in : interorbital width less 
than diameter of orbits; tomial margins of upper jaw (so far as 
preserved) horizontal, not notched; medial borders of palatine 



1 The species is named for Dr. Eugene Gaffney in recognition of his 
work on pelomedusid turtles. 



16 BREVIORA No. 357 

flanges curving away from midline; breadth between postero- 
lateral corners of palatines equal to 50 per cent of skull length 
from snout to occipital condyle; broad contact between pterygoids 
at midline; precondylar fossa semicircular; foramen for trigeminal 
nerve situated relatively higher on ascending wall of brain case 
and directed laterally. Differing from S. antiqua in: lack of fore- 
head groove; orbits round rather than oval; no median notch in 
upper jaw; broad contact between pterygoids at midline; size 
much greater. 

In total length, this skull is slightly longer than the smaller of 
the two specimens of Shweboemys pilgrimi (10.5 versus 10.2 
centimeters for the distance from the snout to the occipital 
condyle). The width at the postero-lateral corners of the palatines 
is significantly greater, however, indicating that the skull of S. 
gaffneyi was proportionately wider. Compared to S. pilgrimi, the 
orbits of the new species are also proportionately much larger. 
The increase has been achieved primarily by dorsal emargination 
of the external face of the maxilla. The diameter of the orbits in 
S. pilgrimi is essentially the same as the distance across the maxilla 
from the base of the orbit to the tomium. In contrast, the diameter 
cf the orbits in S. gaffneyi is nearly twice as great. Because the 
premaxillae are missing, it is impossible to reconstruct the shape 
of the upper jaw at the midline. There may have been some kind 
of median notch, but if so it must have been relatively small and 
thus quite unlike that of S. pilgrimi (see Fig. 2B). 

The two Asiatic species differ somewhat in the structure of their 
secondary palates. In S. gaffneyi, the secondary palate is broader 
than it is long, whereas in S. pilgrimi this region is slightly longer 
than wide (cf. Figs. lA and B). For analyzing proportional dif- 
ferences, direct comparisons may be made between comparable 
measurements of the two British Museum skulls of Shweboemys, 
each representing one of the Asiatic species, since they are both 
of nearly the same length and are equally well preserved in the 
region under consideration. At the point where the sutures be- 
tween the maxillae and the palatines reach the outermost extent 
of the secondary palates, the distance across the secondary palate 
of the type of S. gaffneyi is 7.2 centimeters, whereas this same 
distance in BMNH — R. 8432 is 6.1 centimeters. But the length 
of this structure is 5.3 centimeters in the former and 6.7 in the 
latter. Another difference, of unknown biological significance, 
involves the pitting on the ventral surface of the secondary palate. 



1970 ASIATIC FOSSIL PELOMEDUSIDAE 17 

In both species, these pits appear to be more abundant on the 
maxillae than on the palatines. The maxillary pits, however, seem 
to be deeper, larger in diameter, and fewer in number in 5. 
gaffneyi (see Plate II). 

No scute sulci are clearly discernible on the preserved part of 
the skull roof of 5. gaffneyi. Linear depressions, which might be 
interpreted as scute furrows, follow the courses of the fronto- 
parietal and fronto-postorbital bone sutures. But a similar groove 
running antero-posteriorly along the midline does not have a 
homologue in any other pelomedusid. Thus I am dubious that any 
of these indentations necessarily corresponds in position to the 
actual boundaries between scutes. 

The position of the trigeminal nerve foramina and the extent 
to which the pterygoids meet on the ventral surface of the skull in 
5. gaffneyi are typically pelomedusid and clearly serve to differenti- 
ate this species from 5. pilgrimi, which is specialized in these 
characters. The skull of S. gaffneyi exhibits no features that would 
bar the species from the ancestry of S. pilgrimi. 

The skull of S. gaffneyi differs from that of 5. antiqua in a num- 
ber of respects, of which a few may be mentioned here, pending 
detailed description of the Fayum species. Size is the most obvious 
(although not necessarily the most significant taxonomically ) dif- 
ference between the two: the distance from the snout to the 
occipital condyle in S. gaffneyi is more than one and one-half 
times longer than in 5. antiqua ( 10.5 versus 6.6 centimeters). The 
orbits of S. gaffneyi are round and directed forward, those of S. 
antiqua are oval and face laterally. There is a forehead groove 
between the orbits of the latter but not of the former. As in S. 
pilgrimi, and in strong contrast to 5. gaffneyi, there is little or no 
contact between the pterygoids at the midline in 5. antiqua. 

DISCUSSION 

Of the small number of Asiatic fossil pelomedusids hitherto 
described, one, "Podocnemis" indica, is not well enough known 
at the present time to merit formal taxonomic assignment. How- 
ever, Carteremys probably was a pelomedusid, and Shwebuemys 
certainly was. 

The relationships of Carteremys within the Pelomedusidae are 
uncertain. On the basis of skull structure, Shweboemys appears 
to have been more closely related to Stereogenys than to any other 



18 BREVIORA No. 357 

pelomedusid. Within the genus, Shweboemys pilgrimi may well 
have been derived more or less directly from 5. gaffneyi, and 
there is no reason why this latter species could not in turn have 
been directly descended from S. antiqua. Occurrences of this 
genus are separated by such great distances and represented by 
such a paucity of material, however, that future discoveries may 
reveal that this interpretation is overly simplistic. 

Shweboemys is the only pelomedusid genus so far known to 
have established a successful, enduring lineage outside of Africa 
or South America. The Shweboemys lineage appears to have been 
restricted to southern Asia and Africa; no pelomedusid has thus 
far been reported, even questionably, from central or eastern Asia. 
The localities where the two Asiatic species of this genus occur 
are very widely separated geographically and no representative 
has been recorded from the intervening (and considerably 
younger) Siwalik deposits of India. Nothing, however, has been 
published on Siwalik fossil turtles for more than three-quarters of 
a century. Those described by Lydekker (1885), apart from the 
large testudinids, show relationships to the recent turtle fauna of 
India, but available collections need to be examined thoroughly 
with an eye to the possible presence of pelomedusid remains. 

Some inferences are possible concerning the ecology of the two 
Asiatic species of Shweboemys: the Irrawaddy beds are fluviatile 
in origin (Krishnan, 1960: 498), so that this species was evidently 
not a marine form.^ In view of the fact that all pelomedusids 
(except for one or possibly two undescribed fossil genera from 
Africa) are aquatic, S. pilgrimi was probably a freshwater rather 
than a terrestrial turtle. Pilgrim (1908: 159) referred to the 
Bugti beds from which S. gaffneyi was presumably recovered as 
a '^freshwater formation" and Krishnan (1960: 492) regarded 
them as being fluviatile, so that this species was in all likelihood 
also a freshwater rather than a marine form. Moreover, the 
specialized palatal structures of these two species have definite im- 
plications regarding their feeding habits. Like some living triony- 
chids with enlarged secondary palates, their diet may have con- 
sisted largely or perhaps even exclusively of molluscs of one sort 
or another. 



1 1 am suggesting elsewhere that the pelomedusids were of marine origin. 



1970 ASIATIC FOSSIL PELOMEDUSIDAE 19 

ACKNOWLEDGMENTS 

I am particularly grateful to Mr. C. A. Walker of the British 
Museum (Natural History) for bringing to my attention the skull 
of Shweboemys pilgrimi belonging to that institution. To the 
authorities of the British Museum (Natural History) I am indebted 
for permission to describe this specimen as well as the type of 
S. gaffneyi. I am also much obliged to Professor Bryan Patterson 
and Dr. E. E. Williams for critically reading this manuscript, to 
Professor B. Kummel for help concerning the stratigraphy of West 
Pakistan and Burma, and to Mr. A. D. Lewis for his skillful 
preparation work on both of the British Museum skulls. The 
photographs of the type of 5. pilgrimi reproduced in Plate 1 were 
sent to Dr. E. E. Williams by the authorities of the Geological 
Survey of India. The figures were drawn by Mr. Laszlo Meszoly. 
Finally, I would like to express my appreciation to the National 
Geographic Society for their generous financial support of my 
research on pelomedusid turtles. 

LITERATURE CITED 

Andrews, C. W. 1901. Preliminary note on some recently discovered 

extinct vertebrates from Egypt. (Part II.) Geol. Mag., 8: 436-444. 
. 1906. A descriptive catalog of the Tertiary Vertebrata of 

the Fayum, Egypt. Brit. Mus. (Nat. Hist.), London. 324 pp. 
Carter, H. J. 1852. Geology of the Island of Bombay. Jour. Bombay 

Branch Roy. Asiatic Soc, 4, 16: 161-215. 
Colbert, E. H. 1938. Fossil mammals from Burma in the American 

Museum of Natural History. Bull. American Mus. Nat. Hist. 74, art. 

6: 255-436. 
1943. Research on early man in Burma, Part III: 

Pleistocene vertebrates collected in Burma by the American Southeast 

Asiatic expedition. Trans. American Phil. Soc, n.s., 32, part 3: 

395-429. 
Gaffney, E. S.. and R. Zangerl. 1968. A revision of the chelonian 

genus Bothremys (Pleurodira: Pelomedusidae), Fieldiana (Geol.), 16 

(7): 193-239. 
Krishnan, M. S. 1960. Geology of India and Burma (4th ed.). Madras. 

Higgenbothams (Private) Ltd. 604 pp. 

Lydekker, R. 1885. Indian Tertiary and post-Tertiary Vertebrata. 

Siwalik and Narbada Chelonia. Mem. Geol. Surv. India, Palaeont. 

Indica, sen 10, 3, part 6: 155-208, pis. 18-27. 
1887. Indian Tertiary and post-Tertiary Vertebrata. 

Eocene Chelonia from the Salt Range. Mem. Geol. Surv. India, 

Palaeont. Indica, ser. 10, 4, part 3: 59-65, pis. 12-13. 



20 BREVIORA No. 357 
1890. Note on certain vertebrate remains from the Nagpur 



District. Records Geol. Surv. India, 23: 20-24. 
Pascoe, E. H. 1964. A manual of the geology of India and Burma, 
3 (3rd ed.). Geol. Surv. India: XXIV and pp. 1345-2130. 

Pilgrim, G. E. 1908. The Tertiary and post-Tertiary freshwater de- 
posits of Baluchistan and Sind, with notices of new vertebrates. 
Records Geol. Surv. India, 37, part 2: 139-166, pis. 2-4. 

Robinson, P. L. 1970. The Indian Gondwana formations — a review. 
l.U.G.S. First Symposium on Gondwana Stratigraphy: 201-268. 

RoMER, A. S. 1956. Osteology of the Reptiles. Chicago, The University 

of Chicago Press. 772 pp. 
SiEBENROCK, F. 1902. Zur systematik der schildkroten-gattung Podoc- 

nemis Wagl. Sitz. der kaiserl. Akad. der Wiss. in Wien, Math.-Naturw. 

Classe, 111, abt. 1: 1-14. 
Stamp, L. D. 1922. An outline of the Tertiary geology of Burma. Geol. 

Mag., 59 (11): 481-501. 
SwiNTON, W. E. 1939. A new fossil fresh-water tortoise from Burma. 

Rec. Geol. Surv. India, 74, pt. 4: 548-551. 
Wadia, D. N. 1953. Geology of India (3rd ed.). London, Macmillan 

and Co. 531 pp. 
Williams, E. E. 1953. Fossils and the distribution of chelyid turtles, 

1. "Hydraspis leithii" (Carter) in the Eocene of India is a pelomedusid. 

Breviora, no. 13: 1-8, pis. 1-3. 
^__ 1954. A key and description of the living species of the 

genus Podocnemis {sensii Boulenger) (Testudines, Pelomedusidae). 

Bull. Mus. Comp. Zool., Ill, (8): 279-295. 
Zangerl, R. 1969. The turtle shell. In Biology of the Reptilia, /. 

Morphology A (C. Gans, ed.) London and New York, Academic Press. 

311-339. 



970 



ASIATIC FOSSIL PELOMEDUSIDAE 



21 



-'-r^np^ 





.^i*^^*^"^' 




»>• 



B 



I. Type specimen oi SJnveboemys pilgrimi (GSI 17255): A — 
palatal view of skull; B — dorsal view. Approximately Va natural 
size. 



22 



BREVIORA 



No. 357 









! 


 


1 11 


Hj CM 


 


■1 


^^^^1 • •'\^' " 


A 












*^"^^^^§L^^- 








^'' -«<■•■ >^^o|^^3H|^t^ 


k 








b 






"** "*** ^^BSiBt 






ilraMI^T'^ 










^^^^s 


»^«w 








■J^ 


■J^^^Pk 


'^^^^^^m^B^^-, «-v» --t^^t "•» '^^H 


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II. Palatal views of: A — Shweboemys pilgrimi (BMNH- 
R. 8432); "R— Shweboemys gafjneyi (BMNH— R. 8570). 



1970 



ASIATIC FOSSIL PELOMEDUSIDAE 



23 






III. Lateral views of: A — Shweboemys pilgrimi (BMNH- 
R. 8432); B— Shweboemys gaffneyi (BMNH— R. 8570). tgf 
trieeminal nerve foramen. 



24 



BREVIORA 



No. 357 







CM 




IV. Dorsal views of: A — Siiweboemys pilgiimi (BMNH — R. 
8432); B—Shweboemys gaffneyi (BMNH— R. 8570). 



BREVIORA 



Miaseium of Comparative Zoology 

Cambridge, Mass. 30 November, 1970 Number 358 

South American anoles: Anolis apollinoris Boulenger 1919, 
a relative of A. biporcatus Wiegmann (Sauria, Iguanidae) 



Ernest E. Williams 

Abstract. Anolis apollinaris is a central Andean derivative of A. bipor- 
catus, probably from an earlier invasion of South America than that which 
has provided the present Colombian, Ecuadorian, and western Venezuelan 
populations of the latter species. 

Anolis apollinaris Boulenger 1919 was described from a unique 
type, a female, said to come from "near Bogota." The description 
made no mention of relationships. 

The next mention of the species was made by Burt and Burt 
(1931: 255), who referred numerous Colombian specimens in the 
American Museum to this species. They suggested that the species 
belonged to the "chrysolepis stock" but also said that their speci- 
mens closely resembled A. gemmosus of Ecuador with which they 
believed A . apollinaris "may prove to be identical or subspecifically 
allied." An examination of the type of apollinaris in the British 
Museum shows that these statements of relationships are entirely 
mistaken and that the specimens referred to the species by Burt 
and Burt — one specimen received in exchange from the American 
Museum by the Museum of Comparative Zoology — are mis- 
identified.^ 



1 The type of A. gemmosus O'Shaughnessy has also been examined. It 
is not of chrysolepis stock nor related at all closely to the two species mis- 
identified by Burt and Burt as A. apollinaris. The affinities of A. gemmosus 
are with A. fasciatus Boulenger and A. andianus Boulenger. 



2 BREVIORA No. 358 

A correct judgment on the affinities of A. apollinaris was made 
by E. R. Dunn in 1944 (p. 25), who at that time reported: 

"The Instituto de La Salle has a specimen of this lizard (de- 
scribed from 'near Bogota') from Paime, Cundinamarca, 1038 
meters. A number of students have overlooked the statement that 
this is a large Anolis (type head-body length 106 mm) and mis- 
applied the name. Thus the "Anolis apollinaris" of Burt and Burt 
(1921 I sic J, p. 255) is not Boulenger's species but a composite of 
two smaller species, incomperliis Barbour from Villavicencio and 
mariaruin Barbour from Medellin^ True apollinaris is allied to 
solijer of Santa Marta and copei of Central America." 

The two latter names are now regarded as synonyms of bipor- 
catus (see Williams, 1966) and it is with this species, which ranges 
from Mexico to Ecuador, that apollinaris requires comparison. 

Brother Niceforo Maria of the Instituto La Salle tells me that 
Dunn's specimen of A. apollinaris was one of many specimens 
destroyed in a fire at the Institute in 1948. Fortunately, a number 
of previously unreported specimens have been discovered, one in 
the Institut Royale (Brussels), a series in the Zoologische Staat- 
sammlung (Munich) and three, indeed, in more recent collections 
of the Instituto La Salle (ILS), and two more in the American 
Museum of Natural History (AMNH). 

On the basis of these new specimens and the type specimen at 
the British Museum (BM), I present a revised standard descrip- 
tion of the species: 

Anolis apollinaris Boulenger 

Type. BMNH 1919.3.6.7 (1946.8-13.22), from near Bogota, 
Cundinamarca, Colombia. 

Referred specimens. (All Colombia.) Antioquia (all Cauca 
Valley): AMNH 38725, Sabanalarga; ILS 81, Puerto Antioquia. 
Caldas: ILS 101, Pueblo Rico. Cundinamarca: Brussels 3580, La 
Esperanza, 1250 m; ILS 65, Paime; ILS 106, Quipile; Munich 
427-432, San Pablo, west side of cordillera between Bogota and 
La Dorada. "Western Colombia": AMNH 4844. 



1 A. incompertus Barbour is a composite species: specimens from 
Villavicencio are A. chrysolepis scypheus Cope and, from near Bogota. A. 
tropidogaster Hallowell. A. mariaruin Barbour is a synonym of A. antonii 
Boulenger. All types have been examined. 



1970 



ANOLIS APOLLINARIS 




u 






d 

Z, 

B 

Xi 

o 

c 

3 












2 



BREVIORA 



No. 358 



Diagnosis. Allied to biporcatus Wiegmann and its subspecies 
parvauritus Williams but differing in color, in one or no scales 
separating nasal from rostral, and in a modally higher number of 
lamellae under phalanges ii and iii of the fourth toe. 

Head. Head scales small, sharply uni- or tricarinate. Ten to 
thirteen scales across snout between second canthals. A distinct 
frontal depression, scales within it not smaller than surrounding 
scales. Five to nine scales border rostral posteriorly. Circumnasal 
scale separated from rostral by one small scale or in contact. Six 
to seven scales between circumnasals dorsally. 

Supraorbital semicircles separated from each other by 2-4 scales, 
from the supraocular disk by one row of smaller scales. Supra- 
ocular disk not very distinct, of 4-12 keeled scales grading laterally 
into granules. One to three overlapping elongate supraciliary scales, 
continued posteriorly by granules. Anterior corner of supraocular 
filled by larger subgranular scales. Canthus sharp, of 6-7 over- 
lapping scales, the first and second or second and third the largest. 
Five to seven loreal rows, subequal or the uppermost largest. Tem- 
poral scales granular. A distinct double line of enlarged inter- 
temporal scales. Supratemporals granular, slightly smaller than 




Figure 2. Anolis apollinaris Munich No. 422. Dorsal view of head. 



1970 ANOLIS APOLLINARIS 5 

temporals. Scales surrounding interparietal moderately to abruptly 
enlarged, swollen, largest anteriorly and laterally. Interparietal less 
than or greater than ear, separated from semicircles by 3-4 scales 
on each side. 

Suboculars separated from supralabials by one row of scales (or 
narrowly in contact), anteriorly separated from canthal ridge by 
one scale, posteriorly continued by an indistinct double row of 
smaller scales. Seven to eight supralabials to center of eye. 

Mental slightly wider than long, in contact with 4-8 scales be- 
tween supralabials posteriorly. Sublabials not well differentiated. 
Central throat scales quadrangular, swollen, gradually increasing 
in size laterally. 

Dewlap. Dewlap in male large with close-packed scales. A 
gular fold only in female, moderate, scales rather closely packed. 

Trunk. Middorsals slightly enlarged, swollen, keeled. Dorsal 
and flank scales keeled, subequal. Ventrals larger, weakly keeled, 
imbricate, not mucronate. 

Limbs. Largest fore and hind limb scales strongly unicarinate, 
except at knee and elbow, smaller than largest ventrals. Supra- 
digital scales multicarinate. Twenty-four to twenty-seven lamellae 
under phalanges ii and iii of fourth toe. 

Tail. Slightly compressed, almost evenly scaled all round. Ver- 
ticils indistinct. All scales keeled. Enlarged postanals in male. 

Size. Type: 106 mm snout-vent length. 

Comparison. Table 1 lists the major features differentiating A. 
apollinaris and A. biporcatus. I comment on each of these features 
below: 

1. Scales in narial area. The exact pattern of the scales sur- 
rounding the naris and their relation to the rostral have been 
repeatedly used in lizards generally (e.g., geckos), and this pattern 
has also proved empirically very useful at the species level in 
Anclis. Published examples of the utility of this character at the 
species level are Ruibal and Williams (1961 ) and Lazell (1964). 
Although, like all squamation characters in Anolis, these patterns 
are subject to some intraspecies variation, they are rather surpris- 
ingly constant. Frequently a single pattern is consistently main- 
tained; this is usually a simple one. More complex patterns tend 
to greater variation but the variations are readily derivable from 
the modal condition (Fig. 3). The pattern of apollinaris is always 
simpler than that of biporcatus and may be more primitive. (The 
judgment that this pattern may be more primitive is based not upon 



BREVIORA 



No. 358 







Figure 3. Nasal rostral relationships. Upper left: Anolis biporcatus 
biporcatiis, MCZ 15426. Upper right: A. b. parvaiiritus, MCZ 78942. 
Lower left: A. apollinaris, Munich 422. Lower right: A. fraseri, MCZ 
43772. 



its simplicity but upon its association with other characters re- 
garded as primitive and on its occurrence in species regarded on 
other grounds as primitive.) The variation in apollinaris is in the 
direction of the pattern in biporcatus, but there is no overlap. This 
is a sharp and clear distinction. 

2. Supraciliary scales (Fig. 4). Again the pattern of this area 
tends to be species specific and again the condition in apollinaris 
tends to be simpler and perhaps more primitive than that of bipor- 
catus. The common pattern in biporcatus is indeed unusual (though 
not unique). Two patterns are common for the supracihary region 
of anoles: (1) one or more elongate supraciliaries followed by un- 
differentiated granules; (2) one or more elongate supraciliaries 
followed by a double series of enlarged scales rather even in size. 



970 



ANOLIS APOLLINARIS 





Figure 4. Supraciliary area. Top: Anolis apoUinaris, Munich 422. 
Lower left: A. b. biporcatiis, MCZ 15426. Lower right: A. fraseri, MCZ 

43772. 



A. biporcatiis, exhibiting several rather short supraciharies grading 
into large scales that tend to grade again into granules, presents a 
condition hardly more frequent than that of A . fraseri with its series 
of quadrate scales along the whole supraciliary margin, the first of 
these sometimes elongate. 

3. Scales around interparietal. In general, the degree of 
enlargement of scales around the interparietal is a good specific 
character in Anolis. Particularly valuable may be the degree of 
enlargement of the scales posterior to the interparietal as compared 
with the adjacent dorsal or supratemporal scales. There may be 
rapid intergradation of enlarged scales lateral to the interparietal 
into much smaller dorsal and supratemporal scales, or the scales 
behind the interparietal may be sharply and conspicuously larger 
than dorsal or supratemporal scales (as in some apoUinaris). The 
two subspecies of A. biporcatus difl'er in this regard. A. apoUinaris 
is variable; perhaps the variation is geographic, but there is not 
enough material to say. 

4. Ear shape and position. The ear of apoUinaris is quite dif- 
ferent from that of either southern or northern biporcatus. It is 



8 BREVIORA No. 358 

closer in size to that of southern biporcatus but quite distinct in its 
obliquity, a rather unusual feature. 

5. Ventral keeling. This character is minor. Keeled ventrals 
may be a good species character, but there are many instances of 
intraspecies variability, both geographic and (typically qualitatively 
less extreme) at a single locality. A. apollinaris has the ventrals 
more weakly keeled than either subspecies of biporcatus. 

6. Toe lamellae. The number of toe lamellae is an extremely 
useful character in Anolis and very characteristic of species. It is, 
however, subject to variability (a range of 6 or 7 is quite usual) 
and overlap is, as in the present case, frequent. A. apollinaris 
tends to a higher number of toe lamellae than either subspecies 
of biporcatus. 

7. Color. I have no descriptions of color in life of apollinaris 
and the varying colors of biporcatus as preserved (it is uniform 
green in life) do not make comparison very easy. Boulenger de- 
scribed the type female as "Dark olive above and on the sides, 
with a fine blackish network, head and a vertebral band pale, the 
latter with narrow transverse processes; small round light spots on 
the sides and tail; forearm, tibia and lower parts pale green." 

The Brussels specimen has preserved its pattern rather well. 
Description follows: Head greyish. A dark streak from back of 
eye to shoulder, there merging with dark flanks. Below this, labials 
and nape lighter, their color continuous with the smudged grey of 
the throat. A hght brown middorsal zone, irregularly darker lat- 
erally, bordered on each side by a narrow grey line. Flanks dark 
brown with indications of white spots or broken narrow vertical 
white bars. Forelimbs obscurely annulate, hind limbs boldly so. 
Tail above with longitudinally oval light spots with irregularly dark 
centers. Belly lighter than any part of dorsum but still heavily 
infuscated. Tail below lighter still. 

The new specimens resemble the Brussels specimen in head 
coloration, as the British Museum type now does; presumably the 
latter differs from Boulenger's description as a result of change 
during preservation. 

A. apollinaris, when compared with A. biporcatus, differs in few 
and superficially trivial ways. The ventrals are less strongly keeled. 
There are fewer scales between nostril and rostral: one or more 
rather than two or three. The color is quite unlike anything 1 have 
seen in biporcatus. I am neither confident that this form is a full 



1970 ANOLIS APOLLINARIS 9 

species nor convinced that it is not. It is certainly not to be con- 
fused with Mexican or Central American biporcatus, nor with the 
south Colombian-Ecuadorian population, nor does it resemble the 
two Venezuelan specimens of that species. Whether it is distinct 
from, or intergrades with, some of the other Colombian or the 
Ecuadorian populations is a matter for future discovery. Provi- 
sionally, since it was described as a species, it may remain so 
allocated. 

A. biporcatus has the distribution of a recent immigrant into 
South America, extending from Panama through the Choco region 
of Colombia down into Ecuador west of the Andes and extending 
eastward through the Santa Marta Mountains into western Vene- 
zuela. A. apollinaris, now recorded from Antioquia, Caldas, and 
Cundinamarca, may be supposed to have arisen from A. bipor- 
catus by isolation and subsequent minor modification in the central 
Andean regions of Colombia. Since it has some primitive features 
(e.g., nasal-rostral relationship) and since it has reached species 
status, it may represent an earlier invasion of South America than 
that which resulted m A. b. parvauritus Williams and the Vene- 
zuelan specimens oi A. b. biporcatus. 

REFERENCES 

BouLENGER, G. A. 1919. Descriptions of two new lizards and a new frog 
from the Andes of Colombia. Proc. Zool. Soc. London, 1919: 79-80. 

Burt, C. E., and M. D. Burt. 1931. South American lizards in the col- 
lection of the American Museum of Natural History. Bull. American 
Mus. Nat. Hist. 61: 227-395. 

Dunn, E. R. 1944. Herpetology of the Bogota area. Revista Acad. Co- 
lombiana Cienc. 6: 68-81. 

Lazell. J. D., Jr. 1964. The anoles (Sauria, Iguanidae) of the Guade- 
loupeen Archipelago. Bull. Mus. Comp. Zool. 131: 359-401. 

RuiBAL. R., AND E. E. Williams. 1961. The taxonomy of the Anolis 
honwlechis complex of Cuba. Bull. Mus. Comp. Zool. 125: 209-246. 

Williams, E. E. 1966. South American anoles: Anolis biporcatus and 
Anolis fraseri (Sauria, Iguanidae) compared. Mus. Comp. Zool., 
Breviora No. 239: 1-14. 

(Received 9 June 1970.) 



10 



BREVIORA 



No. 358 




■10 



O' 



-:^/0' 



Figure 5. Map of the distribution of Anolis apollinaris in central 
Colombia. 



1970 



ANOLIS APOLLINARIS 



11 



TABLE 1 



apollinaris b. biporcatus 

scales across snout 9-13 7-11 



b. parvauritus 
8-13 



scales between nasal 
and rostral 



0-1 



2-3 



2-3 



scales between supra- 
orbital semicircles 



2-4 



1-4 



0-3 



supraciliaries 



1-2 elongate plus usually 3-4 short as in biporcatus 
series of small supraciliaries 
scales of rather plus a series of 
uniform size small scales of 

variable size 



scales behind 
interparietal 



variable, slightly abruptly larger 
to abruptly larger than dorsals 
than dorsals 



grading gradually 
into dorsals 



scales separating 
interparietal from 
semicircles 



3-5 



3-6 



3-7 



loreal rows 



5-8 



5-10 



6-9 



supralabials to 
center of eye 



ear 



7-8 



8-11 



small to moderate moderate to 
large, vertical 



7-12 



small 



ventrals 



weakly keeled 



strongly keeled, 
mucronate 



strongly keeled, 
mucronate 



lamaellae under 
phalanges ii and iii 
of fourth toe 



25-27 



22-26 



22-26 



BREVIORA 



MiaseiLaitii of Comparative Zoology 

Cambridge, Mass. 30 November, 1970 Number 359 

The Swimbladder as a Juvenile Organ 
in Stromateoid Fishes 

Michael H. Horn^ 



Abstract. The swimbladder regresses in 14 of the 15 genera of strom- 
ateoid fishes and apparently in each case before maturity is reached. In 
one genus the swimbladder is absent. The organ appears to be completely 
functional and is present in juvenile fishes that inhabit the surface layers 
of the ocean, often in association with jellyfish medusae or floating objects. 
In the transition from the juvenile to the adult habitat and mode of life, 
the swimbladder regresses to a nonfunctional state, and other morphological 
changes occur. 

A detailed study in progress of the state and structure of the 
swimbladder in stromateoid fishes in relation to their evolution 
and ecology shows that the organ regresses with age in 14 of the 
15 genera comprising this suborder of perciform teleosts. The 
regression of the swimbladder occurs at different ages, depending 
upon the species in question and seems to be correlated with other 
morphological changes and with certain changes in mode of life. 
Thus, the state of the swimbladder may be useful in predicting 
or determining at what age or size a particular species undergoes 
a shift in habitat or way of life. 

The suborder Stromateoidei consists of six families (Haedrich 
& Horn, 1969), the members of which range in maximum size 
from about 30 to about 120 centimeters. It is a fairly diverse 
group of temperate and tropical marine fishes, which, as adults, 
variously occupy a wide range of depths in coastal and oceanic 
waters. The Stromateidae occur at all depths over the continental 
shelf. The Ariommidae are benthic or benthopelagic on the shelf. 



1 Present address: Department of Biological Science, California State 
College, Fullerton, California 92631. 



2 BREVIORA No. 359 

The Centrolophidae are either coastal, as in Hyperoglyphe and 
Seriolella, or oceanic at various depths, as in Centrolophiis and 
Icichthys. The Nomeidae, Tetragonuridae, and Amarsipidae are 
oceanic usually in epi- or mesopelagic layers. However, as occurs 
in many other marine fishes, the larvae and juveniles of stroma- 
teoids are pelagic in the surface layers, mostly in the upper 100 
meters. 

Stromateoid fishes commonly undergo marked changes when 
approaching maturity, and these changes are often associated with 
the migration from the surface layers to the deeper layers where 
the fishes live as adults (Haedrich, 1969). Along with certain 
changes in body proportions (see Haedrich, 1967; and Horn, 
1970), including, frequently, changes in the length of paired fins, 
the swimbladder regresses. This regression and the significance of 
the swimbladder in the life of young fishes are discussed below. 

MATERIALS AND METHODS 

Specimens examined are from the collections of the British 
Museum (Natural History); the Zoological Museum, Copen- 
hagen; and, the Woods Hole Oceanographic Institution. The 
fishes from the last institution will ultimately be deposited in the 
Museum of Comparative Zoology, Harvard University. Specimen 
data will be included in a forthcoming comprehensive paper on 
stromateoid swimbladders. 

Swimbladder volumes were calculated treating the bladder as 
an ellipsoid. Body volumes were determined by displacement in 
water. Ten per cent was allowed for shrinkage of the preserved 
material, and volume determinations were made from swimblad- 
ders that were in most cases well expanded. The number of retial 
capillaries was estimated from thin sections of swimbladders. 

RESULTS AND DISCUSSION 

Very little mention has been made of the swimbladder in 
stromateoids. Jordan & Evermann (1896) stated that the organ 
was "usually absent" in the Stromateidae. Fowler (1936) indi- 
cated that it was "present or absent" in his treatment of several 
stromateoid genera. Grey (1955) reported it to be absent in 
Tetragonurus. Haedrich (1967) cited its presence in Ariomma. 
While I have not yet examined every species, I have found a 
swimbladder to be present in all genera except Pampus. 



1970 



SWIMBLADDER OF JUVENILE STROMATEOIDS 



The swimbladder in stromateoids (Fig. 1) is euphysoclystous, 
i.e., with a distinct gas-resorbing area — a posterior chamber 
separated from the anterior by a diaphragm — and has unipolar 
retia that are either medial or posterior in position. It is generally 
of a relatively simple type found in a number of perciform fishes 
(N. B. Marshall, personal communication). 




Figure 1. Ventral (slightly flattened) view of the swimbladder of 
Nomeus gronovii, 26.4 mm SL; rm = rete mirabile; rv = retial vein; 
ra = retial artery; gg = gas gland; ac = anterior chamber; dm = dia- 
phragm; pc = posterior chamber. (X 33) 



The swimbladder in these fishes is relatively small and fre- 
quently below the 3.1-5.7 range of percentage volumes calculated 
by Alexander (1966) to be necessary for neutral buoyancy in 
sea water (Table 1). Measurements of swimbladder percentage 
volume for Hyperoglyphe, Cubiceps, and Ariomma show the 
organ to be within the above range, but in other genera, notably 
Schedophiliis and Nomeus, the percentage volume may be as low 
as 0.5 or 0.6 per cent. Some calculated values may be lower 
than normal because of the swimbladder being in a slightly con- 
tracted state. The organ does appear to be completely developed 
and almost certainly functional. The blood supply is complete, 
and the surface area of the gas gland and the length of the retia 
in relation to swimbladder size (Table 1 ) compare closely with 
the range of values calculated by Marshall (1960: tables 3, 4, & 
5) for deep-sea fishes with well-developed swimbladders. The 
organ is fully formed in the smallest individuals (9 mm SL) that 
have been examined. Regression to a nonfunctional state occurs, 
apparently in all species, before maturity is reached. 



BREVIORA 



No. 359 



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1970 SWIMBLADDER OF JUVENILE STROMATEOIDS 5 

Being fully developed and certainly capable of hydrostatic ad- 
justment, the stromateoid swimbladder seems very unlikely to be 
merely an evolutionary remnant. The clue to its significance 
appears to lie in the behavior of the juveniles. The young of all 
or nearly all of the species live in the surface layers and fre- 
quently in association with jellyfish medusae or other animate or 
inanimate floating objects. Protection is presumably provided by 
the medusae or floating objects, and the fishes feed upon the 
small invertebrates concentrated around the objects or upon the 
jellyfishes themselves. This existence seems to require both con- 
siderable maneuverability and the ability to hover and remain 
motionless in midwater. I have observed young Peprilus triacan- 
thus hovering beneath and near the tentacles of the sea nettle, 
Chrysaora qiiinquecinha, and they show little locomotor activity 
except for backing of water by the pectoral fins. Mansueti (1963) 
has made similar observations on Peprilus alepidotus {= P. 
paru.). Few, if any, of the stromateoid genera which consort 
with medusae are completely immune to jellyfish toxins but merely 
avoid the tentacles, according to observations made by Mansueti 
(1963) on P. alepidotus, by Maul (1964) on Mupus {-Schedo- 
philus), and myself on P. triacanthus. Lane (1960) reports that 
Nomeus gronovii can survive doses of Physalia toxin as much as 
ten times that which would kill other fishes of the same general 
size and type; however, Nomeus still exhibits considerable agility 
in avoiding the tentacles of Physalia. 

The swimbladder, even if smaU, would provide a degree of 
buoyancy, although not necessarily complete neutral buoyancy. 
During the period of life in which the fishes have a gas bladder, 
the skeleton is not well ossified and the musculature may not be 
completely developed; thus, the juveniles probably have a lower 
specific gravity than the adults. In those adults with soft muscula- 
ture and light ossification, such as Schedophilus, the swimbladder 
probably becomes unimportant and uneconomical because of a 
change in mode of life, even though, as in juveniles, a small volume 
of gas would provide nearly neutral buoyancy. Using Alexan- 
der's (1966) formula for calculating the percentage swimbladder 
volume necessary to achieve hydrostatic equilibrium, I find that 
only a 1 per cent reduction in specific gravity of the fish lowers the 
required percentage volume from 3.1 per cent, the lower figure 
in Alexander's calculated range, to 2.2 per cent. The latter figure 
is within or near the range of volumes for most of the stromateoid 



6 BREVIORA No. 359 

genera (Table 1). Also, the more firmly muscled and more 
heavily ossified fishes, such as Hyperoglyphe, have greater swim- 
bladder volumes than those with softer muscles and lighter bones, 
such as Schedophiliis (Table 1 ). An exception is Nomeus, which 
has relatively firm musculature but a small swimbladder. 

The regression of the swimbladder is a gradual process, with 
the sac diminishing and the gas gland becoming a small yellowish 
mass before being completely resorbed. The mass representing 
the regressed gas gland may persist in the mesentery beneath the 
kidney for a considerable period of time after the swimbladder 
becomes nonfunctional. In none of the stromateoids does the 
swimbladder appear to become fat-filled upon regression as it 
does in some deep-sea fishes (Marshall, 1960). 

It is meaningful to consider the duration that the swimbladder 
remains functional in the different stromateoid genera in rela- 
tion to the time of change in habitat and mode of life. Nomeus 
among the stromateoids appears to have the most intimate and 
enduring association with jellyfishes, usually with the siphono- 
phore, Physalia. The fish may remain with Physalia throughout 
its life, although this is uncertain. Significantly, Nomeus retains 
what seems to be a functional swimbladder longer than any other 
stromateoid that has been examined. The largest specimen I have 
studied (142.7 mm SL) had a relatively large sac with a some- 
what contracted gas gland and was captured at the surface with 
Physalia. It has not been possible to determine whether or not 
the large specimens that have been found with Physalia were 
mature. 

The swimbladder of Peprilus triacanthus is usually completely 
regressed by the time the fish reaches a length of 100 mm SL, 
and this is about the size at which it has completely abandoned 
jellyfish medusae. Large individuals (> 100 mm SL) of P. tria- 
canthus do not hover as do the juveniles but swim continuously. 
The pecioral fins increase in relative length with age and are used 
more extensively for propulsion in adults than in juveniles. The 
angle through which the pectorals are adducted apparently pro- 
vides lift. (The locomotion and buoyancy of P. triacanthus are 
being considered in a separate study.) Continuous swimming 
with some degree of pectoral propulsion is probably the rule in 
adult stromateoids. 

In Stromateus fiatola, the swimbladder is greatly regressed at 
a fish length of 75 mm SL, a size at which the fish seems to have 



1970 SWIMBLADDER OF JUVENILE STROMATEOIDS 7 

ended its association with medusae (Mansueti, 1963: 60). In 
the size interval of 75 to 100 mm SL, this species loses the pelvic 
fins, and its coloration changes from a vertically-banded pattern 
to a more uniform one in which there are often dorsal spots. 

Tetragoniirus is a strictly oceanic genus (Grey, 1955), and its 
swimbladder is considerably regressed when the fish reaches a 
size of 50 mm SL. The young have been found associated with 
medusae in the surface waters (Mansueti, 1963: 60). According 
to Haedrich ( 1967), the adults are probably members of the meso- 
or bathypelagic fauna. 

Finally, Pampus, a coastal genus and the one considered by 
Haedrich (1967) to be the most advanced of the stromateids, 
evidently has no swimbladder. Whether fishes of this genus as- 
sociate with medusae as frequently as other stromateids is not 
known. There are indications that they do not. According to 
Suyehiro (1942), P. argenteus does feed to a certain extent on 
jellyfishes in Japanese waters. However, studies by Kuthalingam 
(1963) and Nath (1966) show that both juveniles and adults of 
this species off the Indian coast are macroplankton feeders whose 
diet largely depends upon seasonal changes in abundance of crus- 
taceans and polychaetes; this may indicate that the young do 
not regularly associate with medusae. Also, the pectoral fins of 
Pampus become quite long early in life and do not greatly increase 
in relative length with age as they do in Peprilus, another stro- 
mateid, and certain other genera. At a fish size of 30 mm SL, 
the pectoral length of Pampus argenteus is about 40 per cent of 
the standard length compared to only about 30 per cent in Pep- 
rilus paru, which has a very similar body shape. The pectoral 
length in Peprilus triacanthus of the same size is about 25 per 
cent of standard length. The relative length of the pectorals has 
increased to 40 per cent in P. paru and to about 35 per cent in 
P. triacanthus at a size of 80 mm SL. Thus, assuming that hover- 
ing beneath objects and possession of a swimbladder are related 
and that increased pectoral length is important in continuous swim- 
ming, it seems that members of the genus Pampus acquire the adult 
mode of locomotion and habit at an earlier stage than most other 
stromateoids and, in so doing, completely dispense with the swim- 
bladder. 

A number of other fishes have regressed, age-dependent swim- 
bladders. These include such shallow-water marine fishes as cer- 
tain gobies, blennies, flatfishes, and most muraenid eels (N. B. 



8 BREViORA No. 359 

Marshall, personal communication ) and also some deep-sea fishes, 
such as certain species of Cyclothone and Stomias, whose swim- 
bladders, upon regressing, become invested with fat (Marshall, 
1960). As in stromateoids, the regression of the organ in these 
fishes is probably associated with habitat and/or internal changes. 
Swimbladder regression is eventually to be the subject of a general 
review. 

Yet to be examined is the state of development of the swim- 
bladder in newly-hatched stromateoid larvae. Since it is fully 
formed in fishes as small as 9 mm SL, the organ must develop 
quite early. The swimbladder may be of considerable importance 
to larvae in orientation and in positioning the body for food- 
capturing, although it is not known when the larvae begin to feed. 
Indeed, the swimbladder, as I judge from its particularly early 
regression in some stromateoids, may have its greatest functional 
significance in the larvae and smallest juveniles. 

ACKNOWLEDGMENTS 

1 sincerely thank N. B. Marshall and Richard L. Haedrich for 
reading and ofi'ering suggestions on the manuscript. I am also 
grateful to Dr. Marshall for valuable advice on swimbladders 
and for providing space and facilities in the British Museum (Na- 
tural History). This work was supported by a NATO Postdoctoral 
Fellowship awarded by the National Science Foundation. 

LITERATURE CITED 

Alexander, R. McN. 1966. Physical aspects of swimbladder function. 

Biol. Rev., 41 (1): 141-176. 
Fowler, H. W. 1936. The marine fishes of West Africa, based on the 

collection of the American Museum Congo Expedition, 1909-1915. 

Part 11. Bull. American Mus. Natur. Hist., 70(2): 607-1493. 
Grey, M. 1955. The fishes of the genus Tetragoniirus Risso. DANA- 

Report No. 41: 1-75. 
Haedrich, R. L. 1967. The stromateoid fishes: systematics and a classi- 
fication. Bull. Mus. Comp. Zool., 135(2): 31-139. 
1969. A new family of aberrant stromateoid fishes from 

the equatorial Indo-Pacific. DANA-Report No. 76: 1-14. 
Haedrich, R. L., and M. H. Horn. 1969. A key to the stromateoid 

fishes. WHOl Tech. Rept. No. 69-70, 46 pp. UNPUBLISHED 

MANUSCRIPT. 



1970 SWIMBLADDER OF JUVENILE STROMATEOIDS 9 

Horn, M. H. 1970. Systematics and biology of the stromateid fishes of 
the genus Peprilii.s. Bull. Mus. Comp. Zool., 140(5): 165-262. 

Jordan. D. S., and B. W. Evermann. 1896. The fishes of North and 
Middle America: a descriptive catalogue of the species of fish-like 
vertebrates found in the waters of Ncrlh America north of the Isthmus 
of Panama. Part 1. Bull. U. S. Nat. Mus., No. 47: 1-1234. 

KuTHALiNGAM, M. D. K. 1963. Observations on the fishery and biology 
of the silver pomfret, Pampiis argenteiis (Euphrasen), from the Bay 
of Bengal. Indian J. Fish.. 10(1): 59-74. 

Lane, C. E. 1960. The Portuguese man-of-war. Sci. Amer., 202(3): 
158-168. 

Mansueti, R. 1963. Symbiotic behavior between small fishes and jelly- 
fishes, with new data on that between the stromateid, Pepriliis alepi- 
dotus, and the scyphomedusa, Chrysaora qiiinqiiecirrha. Copeia, 1963 
(1): 40-80. 

Marshall, N. B. 1960. Swimbladder structure of deep-sea fishes in rela- 
tion to their systematics and biology. Discovery Rept., 31: 1-122. 

Maul, G. E. 1964. Observations on young live Miipus tnaculatus 
(Giinther) and Miipiis oralis (Valenciennes). Copeia, 1964 (1): 
93-97. 

Nath, p. R. 1966. Biology and seasonal distribution of the pelagic food 
fishes of Travancore coast. Kerala Univ. Pub., India, 1-140. 

SuYEHiRO, Y. 1942. A study on the digestive system and feeding habits 
of fish. Japan. J. Zool., 10 (1): 1-303. 



BREVIORA 



Muisenajnini of Comparative Zoology 

Cambridge, Mass. 30 November, 1970 Number 360 



MAMMALS FROM THE EARLY CENOZOIC OF 
CHUBUT, ARGENTINA 

George Gaylord Simpson 

Abstract. Angelocabrenis daptes, new genus and species (Mammalia, 
Marsupialia, Borhyaenidae), Coelostylodon florentinoameghinoi, new genus 
and species (Mammalia, Notoungulata, ?Isotemnidae) and Coelostylodon 
caroloameghinoi, new species, are described from the Casamayor forma- 
tion, probably early Eocene. Knowledge of upper premolars of Didolodiis 
(Mammalia, Condylarthra. Didolodontidae) is increased and the status of 
Acoelodiis (Mammalia, Notoungulata, Acoelodidae) is discussed. The latter 
genus and the family based on it are essentially indeterminate, and previous 
usage of the names is unjustified. 

INTRODUCTION 

A visit to Mar del Plata, Provincia de Buenos Aires, Argentina, 
early in 1970 enabled me for the second time to examine parts of 
the important collections of fossil mammals in the Museo Munici- 
pal de Ciencias Naturales of that municipality. In collections from 
the Casamayoran Stage of Chubut, three specimens were found to 
be of particular interest and to make especially important con- 
tributions to knowledge. The Director of the Museo, Sr. Galileo 
J. Scaglia, very kindly permitted me to study those specimens and 
to publish descriptions and discussions of them, presented here- 
with. I am again and increasingly indebted to Sr. Scaglia and to the 
whole staff of the Museo for their courtesy and cooperation. The 
accompanying illustrations were prepared by RaVae Marsh. 

In the following, MMP precedes catalogue numbers of the 
Museo Municipal de Ciencias Naturales de Mar del Plata and 
MACN those of the Museo Argentino de Ciencias Naturales "Ber- 
nardino Rivadavia," Buenos Aires. 

While carrying out the research for this paper I was employed 
jointly by the Museum of Comparative Zoology and the Univer- 
sity of Arizona. 



2 BREVIORA No. 360 

Order Marsupialia lUiger 

Family Borhyaenidae Ameghino 

Angelocabrerus, new genus 

Etymology. For the late Angel Cabrera, a great mammalogist, 
who, among many other things, wrote an important study of bor- 
hyaenids. This kind of nomenclature is Ameghinian and is con- 
sonant with the related Arminiheringia. I have ventured to give 
the compound an appropriately mascuUne ending. 

Type-species. Angelocabrerus daptes, new species, infra. 

Known distribution. Casamayoran, Argentine Patagonia. 

Diagnosis. Specialized borhyaenines. Canines with closed, 
rapidly tapering roots; short, heavy, fully enameled crowns. P., 
one-cusped, heavy, with small distinct talonid. M 1.4 essentially 
two-cusped, with paraconid anterior and only slightly lingual to 
the larger protoconid. No trace of metaconid. Talonids un- 
basined, reduced to very slight, simple ledges. Protoconids and 
paraconids truncated with wear on M^.g, becoming sharp points on 
M4 with protoconid a high slender needle. 

Discussion. As far as known, the dentition is similar to that 
of the much later (Santacrucian) Borhyaena and by the same token 
is also similar to the contemporary Casamayoran Arminiheringia. 
The talonid reduction seems to have gone even further in Angelo- 
cabrerus than in the other genera. The lower canine is unlike that 
of Arminiheringia, with a shorter closed root and more fully 
enameled crown. The way in which M^ wears, quite distinctive 
from either Arminiheringia or Borhyaena, would seem to imply 
different occlusion and hence different structure in the unknown 
upper teeth, M^.^ , with which M^ occluded. This wear is much 
as in Plesiofelis, considered by Cabrera (1927: 274-278) Des- 
eadan in age and synonymous with Pharsophorus but almost cer- 
tainly Mustersan and probably distinct from Pharsophorus. How- 
ever, in Plesiofelis the molar talonids are considerably less re- 
duced than in Angelocabrerus. 

In Arminiheringia auceta, the only adequately known species 
of its genus, there is a rapid increase in size of the molars pos- 
teriorly, M4 being about twice as large as M^. The figures (some- 
how omitted in Simpson, 1948) are here given in Table 1. It is 
there shown that the increase is much less in Angelocabrerus dap- 
tes, with M4 only about half again as large as M^. The increase 



1970 EARLY CENOZOIC CHUBUT 3 

is even less in Borhyaena. As far as the evidence goes, Angeloca- 
hrerus could be ancestral to Borhyaena, and in that case the rate 
of evolution in known parts must have been extremely slow. 
Knowledge of the present genus is too incomplete, however, to 
warrant a firm conclusion. 

As in Arminiheringia and Borhyaena but to even more marked 
degree, Pg is a large and heavy tooth. It here approximates M , in 
dimensions. It has a single main cusp, with a long anterior and 
short, nearly vertical posterior slope. There is a minute cuspule 
at the anterior base. There is a distinct but small, shelflike talonid 
with a single cuspule. This is absent in Borhyaena and also in the 
only known specimen of Arminiheringia that might show it, but 
the latter is so worn that a small talonid could have been present 
originally. Except for the points already mentioned, the lower 
molars are like Arminiheringia and Borhyaena in structure. 

Angelocabrerus daptes, new species. 

Etymology. Greek daptes, eater, gnawer, from the inferred 
carnivorous, possibly ossifragous habits of the animals. 

Holotype. MMP 967M, part of right mandibular ramus with 
M2.4, left Pg, Ml, and M. probably of the same individual, two 
lower canines somewhat broken, and small caniniform tooth and 
tip of another doubtfully associated. 

Hypodigm. Holotype only. 

Horizon and locality. Casamayoran, south of Lago Colhue- 
Huapi, Chubut, Argentina. The specimen was a surface find high 
in the beds, and derivation from an overlying formation is pos- 
sible but quite improbable. 

Diagnosis. Only known species of the genus as diagnosed 
above. 

Discussion. The loose left M. has somewhat darker enamel 
and is slightly less worn than the right M. in the mandibular frag- 
ment. Its color and wear are more consonant with those of the 
loose teeth identified as left Pg and M^. However, there can be 
little serious doubt that those and the two loose lower canines do 
in fact belong to the same individual as the mandibular fragment. 
All were found together, they are congruent in size and structure, 
and they add up to a unique specimen of a group extremely rare 
in these beds. The two slender caniniform teeth are dubious and 
I do question whether they belong to the same animal. 



BREVIORA 



No. 360 



The diagnosis and discussion of the genus and the illustrations 
make further description unnecessary. 






Figure 1. Angelocabrerus daptes, new genus and species. Holotype, 
MMP 967M. Right M2-4. A, buccal view. B, occlusal view. C, lingual 
view. X 1. 



Order Condylarthra Cope 

Family Didolodontidae Scott 

Didolodus sp. indet. 

Specimen. MMP 696M, fragment of right maxilla with 



2-4 



Horizon and locality. Casamayoran of Caiiadon Vaca, tribu- 
tary to the left (northwest) bank of the Rio Chico, Chubut, Ar- 
gentina. 



1970 



EARLY CENOZOIC CHUBUT 






Figure 2. Angelocabrerus daptes, new genus and species. Holotype, 
MMP 967M. Left P^ - M,. A, lingual view. B, occlusal view. C, buccal 
view. XI. 




Figure 3. Angelocabrerus daptes, new genus and species. Holotype, 
MMP 967M. Lower canine. X 1. 



BREVIORA 



No. 360 



Discussion. This specimen is interesting because it shows the 
coronal structure of P^'^ of Didolodus in relatively little worn 
condition and because the proportions of these teeth are distinctive. 

Comparison is mainly with MACN 10690, holotype of Didolo- 
dus multicuspis Ameghino, the only other specimen of Didolodus 
known to me that includes P^^. It is figured in Simpson, 1948, 
text figures 25 and 26 and plate 10, figures 1 and 2. MACN 10738 
includes P-, which has not been figured but was included in my 
description of D. multicuspis (Simpson, 1948: 101). AMNH 
2847 is a P'^ referred to D. minor by me (Simpson, 1948: 103) 
but not separately described or figured. 

As shown in Table 2, P- and P^ are each shorter than in the 
holotype by 7 per cent, which does not in itself suggest specific dis- 
tinction, and P^ has almost the same length in the two specimens. 
However, all three teeth are more notably narrower in MMP 
696M, by 16 per cent, 20 per cent, and 19 per cent for P-, P^, 
and P^ respectively. A result is that all three teeth are longer 
relative to their widths in MMP 696M. This is especially notice- 




Figure 4. Didolodus sp. MMP 696M. Right PS-i, occlusal view. X 3. 



able in P"^, which is distinctly transverse in MACN 10690 but 
equidimensional in MMP 696M. P=^ of AMNH 28471, referred 
to D. minor, is even more transverse than in the holotype of D. 
multicuspis. Its width slightly exceeds that of P^ in MMP 696M, 
although its length is decidedly (25 per cent) shorter. The in- 
dividual represented by MMP 696M was probably closer to D. 
multicuspis in over-all size, but the differences in some dimensions 
and in proportions make reference doubtful either to that species 
or to D. minor. At the same time, they do not warrant definition 
of a new species, which in any case should preferably not be based 
on upper premolars, for which there is so little comparative 
material. 



1970 EARLY CENOZOIC CHUBUT 7 

Specimens of known origin referable to D. midticiispis without 
much doubt are all from south of Lago Colhue-Huapi, and those 
similarly referable to D. minor are from Canadon Vaca. MMP 
696M is from Canadon Vaca but probably does not belong to D. 
minor. Specimens and field data for Didolodus are still far from 
sufficient for identification of populations within the genus and for 
determination of their distribution. 

P- of MMP 696M, unlike the less well-preserved specimens 
previously known, is seen to have two distinct external cusps, con- 
nate above the tips but still separated by grooves. These are at 
least descriptively paracone and metacone, and the metacone is 
only slightly lower and smaller than the paracone. The tooth is 
completely surrounded by a cingulum, but this is feeble on the 
middle of the labial face. The lingual slope from paracone plus 
metacone to the labial cingulum is sUghtly uneven, but is without 
really distinct cusps. P^ and P^ also have distinct paracone and 
metacone but, unusually, the metacone is lower and smaller rela- 
tive to the paracone progressively from P- to P^. P^ and P^ have 
well-developed protocones, and the cingula do not cross their lin- 
gual faces. A distinct cingular cusp or style is present on each 
tooth anterior and slightly labial to the paracone and there is a 
similar but smaller and less distinct cuspule posterior to the meta- 
cone. Each tooth has a distinct protoconule but no metaconule. 
There is no hypocone. It is also unusual that P^ is distinctly 
shorter than P-^ although wider. 

The structure of P- in this specimen seems to be rather different 
from that in the holotype of D. multicuspis and more molariform. 
Except for dimensions and proportions, apparent differences in 
structure of P ^"^ are possibly due only to the more worn condition 
of the holotype of D. multicuspis. 

Although far from identical, there is considerable resemblance 
between P^-^ of MMP 696M and the homologous teeth of North 
American Phenacodus. A fairly close ancestral relationship is con- 
firmed to that extent. However, considerable independent evolu- 
tion is also suggested. For example, P^-^^ especially, of MMP 
696M, are more distinctly molariform than their homologues in 
Phenacodus. 



8 



BREVIORA 



No. 360 



Order Notoungulata Roth 

Family Isotemnidae Ameghino 

Coelostylodon, new genus 

Etymology. Greek koilos, hollow, stylos, pillar, odon, tooth. 
The name is meant to recall former reference to Acoelodiis and 
resemblance to Pleurostylodon. It is also consonant with much 
Ameghinian nomenclature. 

Type-species. Coelostylodon florentinoameghinoi, new species, 
injra. 

Known distribution. Casamayoran, Argentine Patagonia. 

Diagnosis. Primitive notoungulates with complete, nearly 
closed dentition. Upper canine small and fully incisiform. Cheek 
teeth brachydont, P--M^ soon wearing so that crown presents a 
single fossa, without complex folds or anterior opening. M^-^ 
with flattened, slightly bifid lingual faces. M^^ with slight para- 
style and paracone folds and very feeble metacone swelling on 
ectolophs, no mesostyle. M^ subtriangular, with short but distinct 
metaloph, longer than M' or M- and almost as long as broad. 





Figure 5. Coelostylodon florentinoameghinoi, new genus and species. 
Holotype, MMP 1723M. Right C and pa - M^. X W2. 



Discussion. This genus is essentially that called Acoelodus 
by Ameghino (1901: 467) and discussed by me (Simpson, 1967: 
57) under that name, but that apphcation of the name can no 
longer be sustained. The type-species of Acoelodus is A. oppositus 
Ameghino, 1897 (p. 454). The holotype of that species is MACN 
10770, a fragment of a left mandibular ramus with much worn 
P 2.3 and part of Pj. That specimen is essentially indeterminate. 
In 1901 Ameghino referred to the species a poorly preserved skull, 
MACN 10753, and redefined the genus essentially on the basis of 



1970 EARLY CENOZOIC — CHUBUT 9 

that specimen. Desiring to validate as much as possible of Ame- 
ghino's nomenclature, I accepted the reference and redefinition, 
taking MACN 10753 as essentially a neotype in Ameghino's usage 
and designating it as such (Simpson, 1967: 58). However, that 
action is invalid under the present code of nomenclature (Stoll 
et al., 1964, Article 75) because in fact the holotype, MACN 
10770, has not been lost or destroyed. 

If now there were a reasonable probability that the referred skull 
and the holotype belong to the same genus and species, the type 
designation would have no practical importance and one could 
continue to use the name Acoelodus for the genus and A. oppositus 
for the species represented by the referred skull. In fact, however, 
as I already mentioned in previous discussion (1967), there is no 
good evidence that the two specimens are of the same genus and 
species, and there is some contrary evidence. The contrary evi- 
dence is weightier than I previously indicated. If the comparative 
sizes of P 2.3 and P^-^ jn Acoelodus were approximately as in 
Pleurostylodon, a reasonable assumption, then P ^-s of the skull 
MACN 10753 are some 22 to 44 per cent larger in various dimen- 
sions than would be expected from the holotype of Acoelodus 
oppositus and are also different in relative sizes and proportions. 
It is thus highly improbable that the two specimens are conspecific, 
and if they are not conspecific, there is no reason to consider them 
congeneric. 

The genus represented by the holotype of Acoelodus oppositus 
is indeterminate, a notoungulate incertae sedis as far as my knowl- 
edge and judgment go. The genus represented by MACN 10753 
is determinate and is distinct from any other for which there is 
comparable material known to me. This conclusion is reinforced 
by discovery of another specimen, MMP 723M, that can be re- 
ferred to the same genus as MACN 10753 but is specifically dis- 
tinct. In order to avoid possible further confusion with Acoelodus, 
the species represented by MMP 723M is made type-species for 
the new generic name. 

In order to avoid still another confusion, it must be noted that 
none of Ameghino's figures labeled "Acoelodus oppositus" in sev- 
eral of his publications are conspecific or congeneric either with 
the holotype of that species or with MACN 10753 (for details and 
discussion see Simpson, 1967: 58-59). 

Ameghino considered Acoelodus as closely related to Oldfield- 
thomasia and so placed the latter in his family Acoelodidae, but 



10 BREVIORA No. 360 

that was based on specimens dubiously or incorrectly referred to 
Acoelodus, including at least one that in fact belongs in Oldfield- 
thomasia. Since the holotype of the type-species of Acoelodus is 
not identifiable as to family, the name Acoelodidae has no estab- 
lished significance. For that reason, I named a family Oldfield- 
thomasiidae for Oldfieldthomasia and its probable relatives (Simp- 
son, 1945: 126). In revision of the Casamayoran fauna, I put 
MACN 10753, under the incorrect reference name Acoelodus 
oppositus, in the Oldfieldthomasiidae. The genus Coelo stylo don, 
to which that specimen is now referred as holotype of C. caro- 
loameghinoi, is of uncertain family position. It differs from all 
adequately characterized previously named genera of both the 
Oldfieldthomasiidae and the Isotemnidae, but has resemblances to 
both families. Present reference to the Isotemnidae is very tentative. 
The upper molar structure is most nearly similar to that of Pleu- 
rostylodon, an isotemnid, among adequately known genera, but 
Coelostylodon differs from Pleurostylodon and other isotemnids in 
its small, incisiform canine and various other details. The canine 
is more like that of Oldfieldthomasia, but the molars are quite 
different. 

Coelostylodon florentinoameghinoi , new species 

Etymology. For Florentino Ameghino, famed describer of 
most of the Casamayoran fauna. Combination of given and family 
names is a nomenclatural device that he often used. 

Holotype. MMP 723M, nearly complete but badly crushed 
skull. 

Hypodigm. The holotype only. 

Horizon and locality. Lowest Casamayoran beds in the bar- 
ranca south of Lago Colhue-Huapi, Chubut. 

Diagnosis. Significantly larger than C. caroloameghinoi (see 
Table 3 ) . Posterolabial angle of M^ less projecting. 

Discussion. The teeth are deeply worn in both of the holo- 
types now referred to this genus. As preserved, there is no 
marked, discernible difference in structure of the cheek teeth. 
MMP 723M clearly has the small canine considered characteristic 
of the genus. P^^^are almost completely fragmented, but seem to 
have been quite small, perhaps more so, relatively, than in MACN 
10753. The posterolabial corner of M^ does not project so dis- 
tinctly as in MACN 10753. 



1970 EARLY CENOZOIC CHUBUT 1 1 

The skull is too badly crushed to make out much significant de- 
tail. It seems to have been a primitive, unspecialized notoungulatc 
skull generally similar to that of Pleurostylodon. 

Coelostylodon caroloameghinoi , new species. 

Acoelodus oppositus, in error, Ameghino, 1901: 365; Simpson, 
1967: 58 and plate 11, fig. 1. 

Etymology. For Carlos Ameghino, who discovered the Casa- 
mayoran fauna and found the holotype of this species. 

Holotype. MACN 10753, poorly preserved anterior part of 
skull. 

Hypodigm. The holotype only. 

Horizon and locality. Casamayoran, barranca south of Lago 
Colhue-Huapi. 

Diagnosis. Significantly smaller than C. florentinoameghinoi 
(see Table 3). Posterolabial angle of M^ sharply produced 
posteriorly (or distally). 

Discussion. In 1901 and thereafter Ameghino based his con- 
cept of Acoelodus oppositus mainly on this specimen, but he did 
not figure it, and none of the specimens figured by him as Acoe- 
lodus oppositus belong to the present genus or species. The holo- 
type is adequately figured in my previous memoir, as cited above. 

REFERENCES 

Ameghino, F. 1897. Mammiferes cretaces de I'Argentine. Deuxieme 
contribution a la connaissance de la fauna mammalogique des couches 
a Pyrotherium. Inst. Geog. Argentina, 18: 406-429, 431-521. 

. 1901. Notices preliminaires sur des ongules des terrains 

cretaces de Patagonia. Bol. Acad. Nac. Cien. Cordoba, 16: 350-426. 

Cabrera, A. 1927. Datos para el conocimiento de los dasiuroideos fosiles 
argentinos. Rev. Mus. La Plata, 30: 271-315. 

Simpson, G. G. 1945. The principles of classification and a classification 
of mammals. Bull. American Mus. Nat. Hist., 85: i-xvi, 1-350. 

. 1948. The beginning of the Age of Mammals in South 

America. Part 1. Bull. American Mus. Nat. Hist., 91: 1-232. 

. 1967. The beginning of the Age of Mammals in South 



America. Part 2. Bull. American Mus. Nat. Hist., 137: 1-259. 

Sinclair, W. J. 1906. Marsupialia of the Santa Cruz beds. Repts. Prince- 
ton Univ. Exped. Patagonia, 1896-1899, vol. IV, part III: 333-460. 

Stole, N. R., et al. 1964. International code of zoological nomenclature 
adopted by the XV International Congress of Zoology. International 
Trust for Zoological Nomenclature, London. 



12 BREVIORA No. 360 



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1970 



EARLY CENOZOIC CHUBUT 



13 



TABLE 2 



Measurements in millimeters of upper premolars of Didolodus. 



p2 



p3 



p4 



Length 

Width 

L/W 

Length 

Width 

L/W 

Length 

Width 

L/W 



D. luulticuspis 
MACN 10690 

7.6 
7.4 
1.03 

7.5 
9.5 
.79 

7.0 
10.0 
.70 



D. minor 
AMNH 28471 



5.7 
7.8 
.58 



D. sp. 
MMP696M 

7.1 
6.2 
1.15 

7.6 
7.6 

1.00 

6.5 

8.1 
.80 



TABLE 3 

Comparative measurements in millimeters of dentitions of holo- 
types of Coelostylodon florentinoameghinoi and C. carolo- 
ameghinoi. 



p4 



Ml 



M2 



M3 



Length 
Width 

Length 
Width 

Length 
Width 

Length 
Width 



C florentinoameghinoi 


C caroloameghinoi 


MMP723M 


MACN 10753 


9.9 


7.5 


12.5 


9.9 


Ca.lO 


8.0 


15.4 


11.5 


12.6 


8.5 


17.0 


11.8 


15.1 


10.0 


15.4 


10.7 



BREVIORA 

Mnaseiam of Compsirative Zoology 



Cambridge. Mass. 30 November, 1970 Number 361 

ADDITIONS TO KNOWLEDGE OF THE ARGYROLAGIDAE 

(MAMMALIA, MARSUPIALIA) FROM THE LATE 

CENOZOIC OF ARGENTINA 

GEORGE GAYLORD SIMPSON 

Abstract. A recent monograph of the Argyrolagidae is supplemented 
by observations on specimens not previously seen by the author. The 
holotype of Argyrolagiis palineri confirms previously published data. An 
additional specimen of Argyrolagiis scagliai adds to i<nowledge of the 
coronal pattern of lower molars. Argyrolagiis parodii is a hitherto dubious 
species the holotype of which was destroyed. A second specimen is made 
neotype; it validates the species and permits redefinition. 

A monograph of the Argyrolagidae (Simpson, 1970) was com- 
pleted early in 1968 and an addendum included late in that year. 
Early in 1970 a visit to Argentina made possible the study of 
several specimens not available or not known to me when the 
monograph and addendum were written. These add significantly 
to knowledge of the family. 

For the facilities for making and the privilege of publishing 
these observations I am greatly indebted to the authorities of the 
Museo de La Plata and especially to Dr. Rosendo Pascual and 
Sr. Jorge Zetti. The accompanying photographs were made under 
the direction of Sr. Zetti and provided for this publication by the 
Museo. In Buenos Aires Sr. Guillermo del Corro courteously 
made available the type of Argyrolagiis palmeri. The drawing was 
made by RaVae Marsh from a sketch by me. While making this 
study I was employed jointly by Harvard University and the Uni- 
versity of Arizona. 

In the following all measurements are in miUimeters: L r=z length 
(anteroposterior or mesiodistal). W = width (bucco-lingual). 
Ljj = length of trigonid. Lp = length of talonid. W^ =r width of 
trigonid. Wj, = width of talonid. MACN = Museo Argentino de 



2 BREVIORA No. 361 

Ciencias Naturales "Bernardino Rivadavia." MLP ■=. Facultad 
de Ciencias Naturales y Museo de La Plata. MM? = Museo 
Municipal de Ciencias Naturales de Mar del Plata. 

Family Argyrolagidae Ameghino, 1904 

Genus Argyrolagus Ameghino, 1904 

Argyrolagus palmeri Ameghino, 1904 

Holotype. MACN A53-4, part of left mandibular ramus, ori- 
ginally with I J and M ^.4, collected by Carlos Ameghino at Monte 
Hermoso in 1904. 

Remarks. For other formal data see Simpson, 1970: 11. 
When that account was written I had not seen the type, which is 
in the Ameghino Collection in Buenos Aires and catalogued as 
above. I^ has been lost since the specimen was figured by F. 
Ameghino (1906, fig. 221) and L. Kraglievich (1931, fig. 2). 
Both of those figures represent the specimen accurately. New 
measurements on the specimen agree reasonably well with those 
taken from the earlier figures (given in Simpson, 1970, Table 1 ), 
see present Table 1. 

Argyrolagus scagliai Simpson, 1970 

Addition to hypodigni. MPL 49-1X-7-1, right mandibular la- 
mus with alveoli of I ,0 and P. and all of Mi,. "Miramar, prov. 
de Bs. Aires," probably Chapadmalal formation. Presented to 
the MLP by the widow of Dr. Santiago Roth in August, 1924. 

Description. For formal data on the species see Simpson, 
1970: 12. This specimen has M^.^ beautifully preserved and less 
worn than in others known. In this genus the hypselodont molars 
rapidly lose the coronal pattern by wear and become columns with 
characteristic outline but no internal structure. Here even Mj, 
although somewhat worn, preserves some coronal features. M^ 
is also fully erupted and beginning to wear. The teeth do not 
taper in the alveoli and would not increase in size with wear. The 
dimensions of the exposed ends of these young teeth are com- 
parable with those of old individuals of the species (see Table 2). 
All the molars retain traces of a fossettid in the trigonid. M, has 
a somewhat more complex outline than in other, individually older 
specimens considered to be of the same species (see Fig. 2). 
Most of the crown is horizontally truncated by wear, but there is 
a steeply sloping anterolingual wear facet. On the anterior face 



1970 



ARGYROLAGIDAE 



there is a well-developed cingulum, not yet worn, enclosing a small 
pocket. The preservation makes possible separate trigonid and 
talonid measurements in Table 3. 







A. 




B. 




C. 



Figure 1. Argyrolagus scaglicii Simpson, 1970. M.L.P. No. 49-1X-7-1. 
right mandibular ramus with M ^,^ . A, buccal view. B. occlusal view. 
C, lingual view. Approximately X 4i/4. 



BREVIORA No. 361 




Figure 2. Argyrolagus scagliai Simpson, 1970. M.L.P. No.49-IX-21, 
right M^. Occlusal view, diagrammatic sketch. Approximately X 10. 



Argyrolagus parodii Rusconi, 1933 

Neotype. MLP 62-V11-27-81, right mandibular ramus with 
I^, alveolus of I., and PfM,, from the Playa las Palomas, near 
the Balneario Chapadmalal. Collected by the personnel of MLP 
in August, 1961. 

Revised diagnosis. Smaller than A. palmeri or A. scagliai. 
Trigonids somewhat more triangular, paraconids medial. Talonids 
relatively short. Labial and lingual sulci directly opposite. Talonid 
of Mj somewhat reduced, but decidedly larger than in Microtra- 
gulus. Buccal extension of coronoid crest strong. 

Discussion. In a letter written shortly before his lamented 
death, Sr. Rusconi informed me that the holotype of this species, 
in his private collection, had been destroyed. The available figures 
and description of that holotype are somewhat equivocal, as dis- 
cussed in Simpson, 1970: 14-15. There is little doubt, however, 
that MLP 62-Vn-27-81 does belong to the same species. It is 
very close to the size indicated by Rusconi in text and figures, as 
here shown in Table 4, and it also shares the most likely morpho- 
logical distinctions of the holotype. The present specimen can 
be confidently referred to Argyrolagus and it shows that A. parodii 
is distinct from any other known species — both points left in 
some doubt by the destruction of the holotype. This case meets 
all the conditions for designation of a neotype set forth in Article 
75(a) of the International Code of Zoological Nomenclature 
adopted by the XV International Congress of Zoology, and the 
present treatment supplies all the qualifying conditions specified in 
Article 75(c) of the Code. 

The locality where the holotype was found is not precisely 
known but was somewhere along the shore four or five kilometers 



1970 



ARGYROLAGIDAE 




Figure 3. Argyrolagiis parodii Rusconi, 1933. Neotype, M.L.P. No. 
62-V!!-27-81. right mandibular ramus with I^ and P.^ - M,. A, buccal 
view. B, occlusal view. C, lingual view. Approximately X 6. 



BREVIORA 



No. 361 



northeast of Miramar, Buenos Aires Province. The neotype is 
from the same sequence of exposures on the shore about llVz 
to 13V2 kilometers farther northeast. The holotype was probably 
from the Chapadmalal formation, as restricted, but possibly 
Vorohue. (See J. L. Kraglievich, 1952.) There is no clearly 




/ '-*'S 



n 
^ 



'I 




,i.r 



I""*' 



A. 



B. 



c. 



D. 



Figure 4. Argyrolagidae, genus and species undetermined. M.L.P. No. 
59-IX-28-98, right tibiofibula lacking unfused portion of fibula. A, lateral 
view. B, anterior view. C, medial view. D, posterior view. Approximately 
X 2. 



1970 ARGYROLAGIDAE 7 

established difference between the faunas of the two formations. 
The neotype is almost certainly from the restricted Chapadmalal 
formation. The two are probably of the same age, and in any 
case can hardly have a faunally appreciable difference in age. 

The specimen now made neotype of Argyrolagus parodii is the 
one figured, without catalog reference, as Microtragulus argentinus 
by Ringuelet (1966, plate X, figs. I, J) and used as a basis {Ibid., 
pp. 58-59) for redefinition of the genus Microtragulus (taken as 
a synonym of Argyrolagus) and the family Microtragulidae 
(equated with Argyrolagidae). As previously pointed out (Simp- 
son, 1970: 65-67), the redefinitions are valid for the specimen in 
question but are too restricted for the genus and family as wholes. 

The preceding diagnosis and accompanying measurements 
(Table 4) and photographs (Fig. 3) make detailed description 
unnecessary. 

Argyrolagidae gen. et sp. indet. 

MLP 59-IX-28-98 is a tibiofibula lacking the free part of the 
fibula, collected by Dr. J. Frenguelli from the "Chapadmalense" 
of Baliza Chica, northeast of Miramar. At this locality it would be 
either from a very high level in the Chapadmalal formation, re- 
stricted, or from the overlying Vorohue formation. Its length is 
53.5 mm, compared with 60.4 mm for MMP 7855, holotype of 
Argyrolagus scagliai. It also differs from the latter in that the 
proximal part of the cnemial crest ends abruptly slightly below 
rather than at the articular surfaces and also ends abruptly distally 
rather than passing gradually into the shaft. This specimen may 
belong to Microtragulus reigi, but association cannot now be estab- 
lished. 



REFERENCES 

Ameghino, F. 1906. Les formations sedimentaires du Cretace superieur 
et du Tertiaire de Patagonie. Ann. Mus. Nac. Buenos Aires, ser. 3, 8: 
1-568. Also published, with Spanish translation, as volume 16 of the 
Obras (Ameghino, 1913-1936). 

Kraglievich, L. 1931. Cuatro notas paleontologicas, sobre Octomylodon 
aversus Amegh., Argyrolagus palmeri Amegh., Tetrastyhis montanus 
Amegh., y Munizia paranensis. Rev. Soc. Argentina Cien. Nat., 10: 
22-266. Also in the Obras (Kraglievich, 1940: 581-602). 



8 BREVIORA No. 361 

Kraglievich, J. L. 1952. El perfil geologico de Chapadmalal y Miramar, 

Provincia de Buenos Aires. Rev. Mus. Municipal Cien. Nat. y. Tradic. 

Mar del Plata, 1 : 8-37. 
RiNGUELET, A. B. DE. 1953. Marsupialia. In A. V. Borello, ed., Paleon- 

tografia Bonaerense, Comis. Invest. Cien.. Prov. Buenos Aires, La Plata, 

fascicule IV: 46-59. 

RuscoNi, C. 1933. New Pliocene remains of diprotodont marsupials from 

Argentina. Jour. Mammal., 14: 244-250. 
__. 1936. La supuesta afinidad de Argyrolagiis con los Typotheria. 

Bol. Acad. Nac. Cin. Cordoba, 33: 173-182. 

Simpson, G. G. 1970. The Argyrolagidae, extinct South American Mar- 
supials. Bull. Mus. Comp. Zool., 139: 1-86. 



1970 ARGYROLAGIDAE 9 

TABLE 1 
Measurements of teeth of holotype of Ar^yrola^us palmeri 

M, M,. M3 M4 LMu4 

L W L W L VV L W 

MACN A53-4 1.9 1.1 2.1 1.3 2.0 1.3 2.0 1.1 7.8 

TABLE 2 
Comparative measurements of teeth of Argyrolagus scagUai 

M, M2 Ma M4 LMi^ 

L W L W L W L VV 
Holotvpe, MMP 7855 1.7 1.4 2.0 1.7 2.0 1.6 2.2 1.2 8.5 

MLP49. IX. 7.1 1.8 1.7 2.3 1.9 2.3 1.8 2.2 1.4 8.6 



TABLE 3 

Trigonid and talonid measurements of Argyrolagus scagliai, MLP 

49.IX.7.1. 

Ml M-. Ms M4 

La Lp Wa Wp La Lp W^ Wp L^ Lp Wa Wp L^ Lp W^ Wp 

1.2 0.6 1.6 1.7 1.4 0.9 1.9 1.9 1.5 0.8 1.8 1.6 1.3 0.9 1.4 1.3 



TABLE 4 

Measurements of destroyed holotype of Argyrolagus parodii, from 
text and figures of Rusconi, and of neotype MLP 62-VII.27.81. 



Holotype: 

Rusconi, 1933, te.xt 

Rusconi, 1933, fig. la 

Rusconi, 1936, fig. 12 — 

Neotype 1.6 1.4 1.8 1.5 1.7 1.4 1.7 1.1 6.7 



M, 


M-. 


M3 


A 


^4 


LM, 


L W 


L \V 


L W 


L 


\v 




— —  


— — 


1.9 — 


1.3 


— 


— 


— — 


— — 


1.8 1.6 


1.6 


1.2 


— 


— — 


— — 


1.6 1.4 


1.6 


1.2 


— 



BREVIORA 

Mmseiuiiiii of Compsirative Zoology 



Cambridge, Mass. 30 November, 1970 Number 362 

ADDITION TO KNOWLEDGE OF GROEBERIA 

(MAMMALIA, MARSUPIALIA) FROM THE 

MID-CENOZOIC OF ARGENTINA 

George Gaylord Simpson 

Abstract. Groeberia pattersoni, new species, from the Divisadero 
Largo formation, is based on the second known specimen of that genus. 
Some information on the hitherto unknown skull of genus and family is 
provided. Reference to the Marsupialia is supported, but affinities within 
the Marsupialia remain dubious. 

The extraordinary fossil marsupial genus Groeberia has hitherto 
been known from a single specimen, a fragmentary mandible, 
named and described by Patterson (1952). A second specimen 
was found by Dr. Edgardo Rolleri of the Yacimientos Petroliferos 
Fiscales (Argentine government petroleum bureau) and deposited 
in 1968 in the Museo de La Plata. Dr. Rosendo Pascual kindly 
referred it to me for study, which I carried out in La Plata early 
in 1970, and for publication, here presented. Sr. Jorge Zetti, as- 
sistant to Dr. Pascual, facilitated the study and arranged for photo- 
graphs, provided by the Museo for this publication. The accom- 
panying drawings were made by RaVae Marsh on the basis of 
sketches by me. I am also indebted to Dr. A. J. Amos, Dean of 
the Faculty of Natural Sciences and the Museum of La Plata, and 
to Sr. G. J. Scaglia, Director of the Museo Municipal de Ciencias 
Naturales of Mar del Plata, who sent the holotype of G. minoprioi 
on loan to La Plata for direct comparison with the present speci- 
men. 

The research for this paper was performed while I was employed 
jointly by the University of Arizona and the Museum of Com- 
parative Zoology. 



2 BREVioRA No. 362 

Class Mammalia Linnaeus, 1758 

Order Marsupialia Illiger, 1811 

Family Groeberiidae Patterson, 1952 

Genus Groeberia Patterson, 1952 

Groeberia pattersoni, new species 

Etymology. For Bryan Patterson, who named and described 
the genus and its type-species, G. ininoprioi. 

Holotype. Museo de La Plata No. 68-VI-27-1, partial skull 
and mandible. 

Hypodigm. Holotype only. 

Horizon and locality. Divisadero Largo formation, [in the 
general vicinity of] Mina Atala, Mendoza, Argentina. 

Diagnosis. Anterosuperior part of symphysis much more 
slender and incisors smaller than in G. minoprioi. M 3.4 also, but 
less, smaller. See Table 1. 

Identification. The holotype of the type-species Groeberia 
minoprioi includes most of the mandibular symphysis and incisors, 
left Mo. .J , and broken bases of M, and M, (see Patterson, 1952). 
The present specimen also preserves most of the symphysis and 
lower incisors and has the broken bases of left M 3.4. These parts 
are morphologically closely similar in the two specimens and quite 
unlike any other animal known to me. Reference to the same genus 
is indicated. Both are from the Divisadero Largo formation and 



'&'- 



TABLE 1 



Comparative measurements in millimeters of holotypes of 
Groeberia minoprioi and G. pattersoni. 





G. minoprioi 


G. pattersoni 


Transverse at narrowest 






part of symphysis, at 






postincisive diastema 


ca. 5.8 


ca. 3.4 


Transverse, across both 






incisors at alveoli 


ca. 5.8 


ca. 3.4 


M3 Length 


2.3 


ca. 1.8 


M., Width 


1.6 


ca. 1.4 


M^ Length 


ca. 2.3 


ca. 1.5 


M^ Width 


ca. 1.8 


ca. 1.3 



Measurements of M.. of G. pattersoni and of M^ of both speci- 
mens are on broken bases of teeth and are rough approximations. 



1970 GROEBERIA 3 

near the same locality: the holotype of G. minoprioi from one-half 
kilometer east of the Cerro Divisadero Largo (Patterson, 1952: 
3) and that of G. pattersoni recorded as "Mina Atala," which 
would be about IVi kilometers northeast of the previous locality 
but which must be a rough approximation, as the Mina Atala is 
not on the Divisadero Largo formation. 

The holotype of G. minoprioi is from Minoprio's stratum F 
(see map and stratigraphic discussion in Simpson, Minoprio, and 
Patterson, 1962). The level of the present specimen is not so 
precisely known. Although no faunal change has been demon- 
strated within the formation, its deposition may have covered a 
considerable span of time and the two specimens may not be very 
closely contemporaneous. There is some presumption that speci- 
mens so similar in morphology and provenience are conspecific, 
but, as far as I know, the difference in slenderness of the sym- 
physis and sizes of the teeth are greater than within adults of 
any one species of marsupials. This difference can hardly be due 
to greater age of the holotype of C. minoprioi. The incisors of the 
holotype of G. pattersoni do not taper in the alveoli, hence they 
could age considerably without increasing in diameter at the alveoh. 
Although measurements are imprecise, the length of M^ is about 
50 per cent longer in the holotype of G. minoprioi, and these 
brachydont teeth do not grow after eruption. The holotype of G. 
pattersoni evidently had all teeth erupted and some skull sutures 
closed, as in fully adult animals. Thus specific separation is in- 
dicated. 

Age. Simpson, Minoprio, and Patterson (1962: 290) con- 
cluded that "the age of the Divisadero Largo fauna is approxi- 
mately early Deseadan or latest pre-Deseadan," but that knowledge 
at that time did not warrant basing on it the apparently missing 
mammalian age-stage between Mustersan and Deseadan. How- 
ever, on evidence not fully stated, Pascual, Ortega, Gondar, and 
Tonni (1965) proposed a "Divisaderense" (in English, Divisa- 
deran) mammal age-stage as intermediate between Mustersan and 
Deseadan and separated from each by a hiatus. They tentatively 
correlated it with the Ludian of Europe and Duchesnian of North 
America as latest Eocene. As those authors also did recosnize. 
the data do not really permit close correlation, and I believe that 
all one can now say is that the age in terms of the European epochs 
may be somewhere around late Eocene or early Oligocene, hence, 
in terms of absolute age, more or less middle Cenozoic. 



4 BREVIORA No. 362 

Description. As found, the specimen included at least the 
anterior part of the skull and most of the mandible in articulation. 
Some time before the specimen came into the control of the Museo 
de La Plata, the skull and mandible were separated and both were 
severely damaged. Nevertheless, what remains adds considerably 
to knowledge of this remarkable and enigmatic genus. 

The two lower incisors are preserved for a length of about 12 
mm within their alveoli. The anterior ends are broken and the 
posterior ends have been ground smooth, presenting the appear- 
ance seen in Figure IB. The pulp cavity is here open, and there 
is no sign of root formation, so these teeth were clearly hypselo- 
dont/ as in G. minoprioi. The teeth curve so that the posterior 
parts were nearly horizontal, in an odd medial posterior projection 
of the symphsis, and the extra-alveolar parts would have been 
nearly vertical. Enamel is lacking on the medial and dorsal faces, 
and at this depth in the alveoli even the dentine has not quite 
closed the pulp cavity dorsally. Heavy enamel occurs ventrally, 
and this extends, thinning as it goes, onto the lateral faces, more 
so than in the extra-alveolar parts of the incisors of the holotype 
of G. minoprioi. 

There is a short diastema posterior to the lower incisors and 
then a series of cheek teeth, probably four as in G. minoprioi, al- 
though here they cannot be definitely counted. The bases of what 
are almost certainly the last two cheek teeth can be made out, but 
the crowns are not visible. These teeth are brachydont as in G. 
minoprioi and similar in outline but perhaps slightly less elongate. 
There are two pairs of upper incisors, here designated I' and 1- 
for convenience, although their ancestral homologies are unknown. 



1 Dictionaries give "hypselodont" as a variant of "hypsodont," and the 
most recent authoritative odontology, Peyer (1968), uses "hypselodont" 
in place of "hypsodont." It is, however, more convenient to adopt a dis- 
tinction sometimes made by mammaiogists, especially paleomammalogists. 
I define as hypsodont a tooth that eventually develops one or more roots 
but that has a crown definitely higher than those roots or than any of its 
horizontal dimensions and, as hypselodont, a tooth that never forms a 
root but continues to grow and to extrude new parts from the alveolus 
throughout life. Peyer was not a mammalogist and devoted relatively 
little attention to mammal teeth. Other odontologists have often oriented 
their work on groups, especially Homo, in which hypselodont teeth (in 
my sense) do not occur. The distinction is of great functional importance. 



1970 



GROEBERIA 





B. 



bone 

enamel 

dentine 

matrix in 
pulp cavity 



Figure I. Grocheria pattersoni, new species. Holotype, M.L.P. No. 
68-VI-27-1. A, sketch and measurements of wear surface of P, approxi- 
mately X 6. B, sketch of posterior (intra-alveolar) exposure of paired 
lower incisors, approximately X 5. 



P is a large, strongly curved tooth with an alveolus extending 
posterodorsally far back in the facial region to above the infra- 
orbital foramen. It and I- are probably both hypselodont. The 
cross section is peculiar, with an oblique, long, slightly convex, 
buccal, enamel-covered face; a flat, anteroposterior, enamelless, 
anteromedial face; and a likewise enamelless, concave, postero- 
medial face. The three faces meet at definite angles, approximately 
right angles at both ends of the anteromedial face but strongly 
acute between the buccal and posteromedial faces. (See Fig. lA.) 
The enamel is nearly smooth but with slight wavy longitudinal rib- 
bing. Right and left P are close to each other on their medial 
faces. 

I- is much smaller than P, measuring about 1.1 mm across the 
buccal face as compared with about 2.5 mm for P. I- is also 
enameled on the buccal face, and probably not elsewhere. The 
cross section cannot be clearly determined as the specimen is 
preserved. I- is less curved longitudinally than P and although 



BREVIORA 



No. 362 



the extra-alveolar parts of the two are in contact, the alveoli di- 
verge. In the most probable orientation of the skull, the extruded 
part of P is slightly recumbent and that of I- is nearly vertical. 




Figure 2. Groeheria pattersoni. new species. Hololype. M.L.P. No. 
68-VI-27-1. Fragment of symphysis with parts of lower incisors. A, 
supero-pcsterior or lingual view. B, infero-anterior or genial view. C, right 
lateral view (in more anatomical orientation the anterior parts of the in- 
cisors would be nearly vertical). Approximately X 4. 



1970 



C.ROEBERIA 




'mx-mx 
suture? 



IFO 
foramen ? 



Buccal 
to M^ 



Mx- Ju 
suture ? 



Figure 3. Groehcria pcittersoni. new species. Holotype. M.L.P. No. 
68-VI-27-1. Anterior part of skull, left lateral view, photograph and ex- 
planatory sketch. "Buccal to M-^" indicates a point on matrix, formerly 
covered by the zygoma, medial to which is a broken cheek tooth identi- 
fied as probably M'\ IFO = infraorbital. Mx-Ju = maxillo-jugal. NA 
= nasal. OR = orbit. Pmx-mx = premaxillo-maxillary. Approximately 
X 4. 



8 



BREVIORA 



No. 362 




IFO forame 




HR 



Mx-Ju 
suture ? 



Figure 4. Groeberia pattersoni, new species. Holotype. M.L.P. No. 
68-VI-27-1. Anterior part of skull, right lateral view, photograph and 
explanatory sketch. CO = fragment of coronoid process of mandible. DPZ 
= descending plate of zygoma. HR = fragment of horizontal ramus of 
mandible. IFO = infraorbital. Mx-Ju i=: maxillo-jugal. OR = orbit. 
Approximately X 4. 



1 970 



GROEBERIA 





4"'; 






'^ 








•^i 




B. 



Figure 5. Groeheria pattersoni, new species. Holotype M.L.P. No. 
68-VI-27-1. Anterior part of slcull. A, dorsal view. B. palatal view. Ap- 
proximately X 4. 



10 



BREVIORA 



No. 362 



There is a diastema posterior to I- and then cheek teeth, but noth- 
ing definite can be made out for the latter, except that they are 
small and brachydont. 

The preorbital part of the skull is notably short and deep. In 
the most probable orientation, it (or the snout) is convex dor- 
sally as a whole and curves downward anteriorly. The nasals are 
accordingly downcurved and end shortly anterior to P. The infra- 
orbital foramen is not definitely visible as the specimen is pre- 
served, but must be of moderate size and in a normal position on 
the face anteroventral to the orbit and about half way between it 
and 1-, where there is a depression obscured by matrix on the 
specimen. On the left side, what is probably part of the pre- 
maxillo-maxillary suture is visible just anterior to that depression. 

The orbit is rather small and relatively anterior in position, its 
anterior rim probably in advance of the cheek teeth and certainly 
well in advance of what is identified as M-\ The stout root of the 
zygoma below the orbit had an expanded suborbital process or 
plate, the full extent of which cannot be determined. On both 
sides, a possible but uncertain maxillo-jugal suture can be seen 




Figure 6. Groeberia pattersoni, new species. Holotype, M.L.F. No. 
68-VI-27-1. Anterior part of skull, anterior view. Approximately X 4. 



1970 GROEBERIA I 1 

below the ventral border of the orbit. Posterior to this, and hence 
on the jugal if the possible suture is such, is a small ventral postor- 
bital process. Uncertainly but probably, there was no dorsal post- 
orbital process, and the orbit was therefore probably open. 

The palatal surface is both poorly exposed and poorly preserved, 
so that little can be made out there with sufficient probability. 
However, its dorsal (intranasal) surface is partly exposed, and 
some details can be made out in cross section at the broken pos- 
terior surface of the specimen. A palatal vacuity was probably 
absent or small if present. It appears that the palate between the 
cheek teeth was deeply arched (concave ventrally). The coro- 
noid process of the mandible can be seen lateral to a posterior 
tooth, perhaps M'' or M^, and lateral to that a section of a deep 
(vertically) but thin (laterally) zygoma. (See diagram, Fig. 7.) 

palate {^probable 
zygoma \^ K^ cartilage 



mandible 



Figure 7. Groeberia pattersoni, new species. Holotype, M.L.P. No. 
68-VI-27-1. Rough diagram of section at posterior break of specimen as 
preserved. Not to scale. 



Affinities. This specimen adds considerably to data bearing 
on affinities of the genus, without settling the matter. Patterson's 
(1952: 3) judgment that Groeberia should be distinguished at the 
family level, as Groeberiidae, is strongly confirmed. 

Patterson's evidence that Groeberia is a marsupial was in small 
part positive, largely negative, and partly indirect. The present 
specimen adds no positive evidence, strengthens the negative evi- 
dence, and does not change the indirect evidence. The only 
really positive evidence from the holotype of G. ininoprioi for 
marsupial affinities in general (as distinct from caenolestoid affin- 
ities in particular, see below) is the probably inflected angle of 
the mandible. Even this is not quite certain, because the angle 
itself is not known, but a crest that would have led to it does 
decidedly suggest inflection. An inflected angle is strong, but not 
conclusive, evidence, as a few marsupials do not have the angle 
inflected and a few placentals do. G. minoprioi may have had four 




12 BREVIORA No. 362 

lower molars, and that would again be strong but not fully con- 
clusive evidence, but the possibility that its cheek teeth include 
one premolar and three molars is not entirely excluded. The 
known parts of the skull of C pattersoni have no evident features 
strongly characteristic either of marsupials or of placentals. The 
absence of palatal vacuities would be more like most placentals, 
but it is uncertain and there are a number of marsupials without 
such vacuities. 

The negative evidence is that Groeberia has no known features 
that would make reference to the Marsupia'ia impossible or highly 
improbable but does have known features that make reference 
to any other order highly improbable. Here the new specimen 
confirms and adds somewhat. The habitus is more or less rodent- 
like, but the two upper incisors are unlike those of any rodent. 
They are somewhat like those of lagomorphs, but the cheek teeth, 
even what little can be seen of them in this specimen, definitely 
rule out pertinence to that group. Limited resemblances of the 
mandible to those of certain primates, such as the early Cenozoic 
Chiromyoides, as mentioned by Patterson, or the living Daiiben- 
tonia, become even less possibly significant in the light of what is 
now known of the skull. The skull is unknown in Chiromyoides, 
but its upper incisors are entirely unlike those now known in Groe- 
beria and the skulls of other plesiadapids are also quite dilTerent 
(see especially Russell, 1964). There is an interesting resemblance 
between the short, deep faces of Daubentonia and Groeberia, but 
this is quite clearly functionally convergent and the two diff'er 
markedly in other respects and in facial details. Almost all other 
placental orders have basic diagnostic features absent in Groe- 
beria or strongly contradicted in this genus. 

If Groeberia was a placental, it must almost perforce have 
evolved independently and uniquely from ancestors as primitive 
and undifferentiated as those now known from the late Cretaceous 
and, in decreasing numbers and generality, quite early Cenozoic. 
Here one turns to the indirect and yet cogent evidence: that no 
such placentals are known from South America; that equally pri- 
mitive and undifferentiated marsupials are known from there; that 
those marsupials did diverge in independent and unique lines; and 
that derivation of Groeberia from a potent and definitely South 
American source is at least a likely hypothesis. 

Patterson's views on the affinities of Groeberia were buttressed 
by evidence for referring it to the Caenolestoidea. That evidence. 



1970 GROEBERIA 13 

from the single poorly preserved fragment of mandible then known, 
was as follows: 

1 . One greatly enlarged lower incisor, with enamel on an- 
terior face and alveolus (or "parte basal") parallel to 

median line of symphysis (not to the horizontal ramus or 
tooth row). 

2. Strong salient coronoid process. 

3. Molars with short talonids with posterior entoconid and 
hypoconid, united by a transverse crest, a short crista 
obliqiia, and a shallow basin. 

4. Molar trigonids with one lingual (probable metaconid) 
and two labial cusps (probable paraconid and protoco- 
nid), as in caenolestoids except Caenolestinae. 

5. Trigonids and talonids subequal, as in Palaeothentinae 
and Abderitinae. 

6. Masseteric crest absent; very poorly defined in Palaeothen- 
tinae. 

7. Inflection of lower border beginning anterior to cheek 
teeth; usually posterior to cheek teeth in Caenolestoidea 
but beneath M^ in Parabderites bicrispatus. 

This was a valid analysis of the admittedly deficient evidence, 
but the conclusion may be retroactively queried in the light of 
present knowledge. As to (1 ), no unquestioned caenolestoids have 
hypselcdont incisors comparable to these in form or function, but 
the placing of the alveoli is an interesting point. (2) is not par- 
ticularly diagnostic. Regarding (3)-(5), the molar structure is 
difiicult to make out on the specimen, but I believe that Patterson 
has correctly interpreted it. However, it diff'ers characteristically 
from probably ancestral didelphid structure in litde more than the 
more labial position of the paraconid, an occlusal adjustment that 
could well arise more than once. (6) is somewhat dubious and 
is not diagnostic for caenolestoids. (7) dift'ers from caenolestoids 
more than it resembles them. 

A reasonable but inconclusive case was presented on the basis 
then available and pending acquisition of further knowledge. The 
still quite limited further knowledge now acquired does not flatly 
contradict that case, but neither does it strengthen it, and it even 
weakens it to some extent. I see no special resemblance of known 
parts of G. pattersoni to any unquestionable caenolestoid. On the 
contrary, the extreme abbreviation of the face, the reduction of 
the incisors to two, and their truly gliriform, hypselodont nature 



14 BREVIORA No. 362 

are almost the opposite of known trends in the Caenolestoidea. 
Even the Polydolopidae, superficially most seemingly rodentlike 
of undoubted caenolestoids, are not really very rodentlike in habi- 
tus and evolved in a direction very unlike that of Groeberia (see 
especially Simpson, 1948; Paula Couto, 1952). 

Patterson (1952: 6) who com'pdL^td Groeberia \n\\\\ Argyrokiiius 
and concluded that they are not specially related beyond their both 
being marsupials. With greatly increased information on Argyro- 
logiis, I agreed (Simpson, 1970), and the present addition to 
knowledge of Groeberia does not change that opinion. Indeed, the 
contrasts between Argyrolagiis and Groeberia, both somewhat 
rodentlike, are remarkable. Argyrolagiis has an extremely elon- 
gate, shallow rostrum and face, very posterior orbit, short, shal- 
low zygoma, hypselodont cheek teeth. Groeberia has extremely 
short, deep rostrum and face, very anterior orbit, long deep 
zygoma, brachydont cheek teeth. 

Almost complete knowledge of dentition and skeleton of Argyro- 
lagiis contradicted previous opinion that it might be a caenolestoid 
and required placing it in a separate superfamily. I suspect that 
the same might happen if we had equally good information on 
Groeberia, but we do not. This knowledge is still so scanty that 
I believe it would be unreasonable or, at best, premature at this 
point to classify the Groeberiidae other than as Marsupialia in- 
certae sedis. 

Proposals have long been made to divide the marsupials into 
suborders, and recently, to divide them into two or more orders. 
If suborders Polydactyla and Syndactyla were recognized, I would 
predict that discovery of foot bones would aline Groeberia with 
the polydactyls. If Polyprotodonta and Diprotodonta were recog- 
nized, Groeberia would be descriptively, typologically, or pheneti- 
cally diprotodont, but I believe that would be profoundly mis- 
leading because it inevitably suggests connection with the Austral- 
ian diprotodonts, and Groeberia is not so incertae sedis as all 
that. It has no suggestion at all of Australian affinities. The 
ordinal system of Ride ( 1964) has no sure ordinal place for it, as 
the evidence that it may be a "paucituberculate" (caenolestoid) 
is insufficient, but reference to the Marsupicarnivora would be 
rather anomalous (although like all marsupials it doubtless arose 
from the group so named by Ride), and pertinence to the Pera- 
melina or Diprotodonta (seiisii Ride) is out of the question. 
Kirsch's (1968) arrangement also has no sufficiently likely place 
for Groeberia in any one of his orders. 



1970 GROEBERIA 15 

Bioloij;}'. In the absence of postcranial remains, nothing can 
be safely inferred as to body build, hmb proportions, or locomo- 
tion in Groeberia. Biological inferences are further limited by the 
absence of specimens of the neurocranium and by the imperfec- 
tions of the only two specimens known. The following are the 
principal characters of probable functional importance that are 
known: 

1 . Face and snout short. 

2. Face and mandible deep. 

3. infraorbital foramen small. 

4. Orbit relatively anterior. 

5. Orbit of moderate size. 

6. Masseteric origin on zygoma. 

7. Heavy hypselodont incisors with labial enamel. 
(S. 1' recumbent. 

9. Short lower diastema near alveolar level. 

10. Comparatively small, brachydont cheek teeth. 

1 I . Large coronoid process. 

12. Small (no?) masseteric crest. 

13. Inverted angle. 

The habitus is rodentlike at first sight, but no living rodent and 
in fact no other animal, living or fossil, known to me combines 
all those characteristics. 3, 6, 11, and 13 are usual and 4, 5, and 
10 common in marsupials; all but 13 are also fairly common in 
placentals. 1, 2, 7 and 8 occur in the other known marsupials 
that are most rodentlike, the Australian wombats. They are lack- 
ing in caenolestoids, also somewhat but much less rodentlike in 
some genera. With only the partial exception of 13, all these 
characters occur in one placental rodent or another, but not in 
this combination. For example some caviomorphs, such as 
Echbnys, have characters 5, 7, 8, 10 and a functional modification 
of 13. but notably differ in 3, 6. 9. 11 and 12. Aplodontia has 
3, 4, 6, 7, moderate 8, I 1 and moderate 12, but differs markedly 
in 1,2, 5, 9, 10, and 13. Xenis (a sciurid) agrees well in 1, 
3, 4, 7, 8, and 10, but less well in 2 and 9, and not at all in 
5, 6, 11, 12, and 13. 

There is no doubt that Groeberia was a powerful gnawer, at 
least as much so as hares, rodents, wombats, or Daubentonia. Its 
incisors were not merely a pincer apparatus as in all known caeno- 
lestoids and all diprotodonts (phalangeroids) except the wombats. 
They are decidedly more adapted to gnawing than in the argyro- 
lagoids, even though the latter, unlike caenolestoids, also have 



16 BREVIORA No. 362 

hypselodont incisors. Gnawing is strongly connected with food 
gathering in recent animals, but not exclusively so. On the other 
hand, Groeheiias small area of brachydont cheek teeth is very 
different from the hypselodont teeth of wombats, argyrolagoids, 
and many rodents, and is more nearly comparable with the cheek 
dentition of caenolestoids, squirrels, and Daubentonia. The com- 
bination suggests a food obtained by gnawing but prepared for 
deglutition by crushing or comminution without grinding. Pos- 
sibilities are bark or wood-boring insects or fruits or nuts with 
hard shells. However, some murids with strong gnawing apparatus 
and limited, brachydont cheek teeth are virtually omnivorous or 
even carnivorous. I see no way to correlate Groeberias unique 
combination of characters with an equally unique diet or with 
any closely specific way of life. 

No rodents are known in the Divisadero Largo or any earlier 
South American formation. Simpson, Minoprio, and Patterson 
(1962: 289) mentioned the possibility that the presence of the 
rodentlike marsupial Groeberia indicated age before rodents 
reached that area, hence pre-Deseadan. The ecological aspect of 
that suggestion would still hold even if the determination of the 
relative time of entry of rodents proved to be incorrect. (There 
is still no opposing evidence.) The rodent habitus surely evolved 
elsewhere and was in being when the first rodents entered South 
America, whether in the Deseadan or, as is quite likely, somewhat 
earlier. On the other hand, the ancestral habitus of Groeberia 
almost certainly evolved in South America before rodents reached 
there, convergent to some extent toward the absent rodents and 
entering niches with some points of similarity. 

Zoogeography. It is the most reasonable hypothesis that the 
Groeberidae did evolve in South America, even though their pos- 
sible relationship to the Caenolestoidea is quite dubious, and there 
is no suggestion of special descendant relationship (involving 
specialization) to any other South American group. Origin from 
South American didelphoids is as likely as any other, if not more 
so. There is no special resemblance to any Australian marsupials 
suggestive of genetic affinity beyond the remote ancestry of all 
marsupials. No marsupials are known from Africa and any idea 
of connection there would be purely gratuitous at present. 

Nevertheless it is strange that three of the most peculiar, most 
specialized known groups of South American marsupials appear 
in the presently available record without known ancestors, only to 



1970 GROEBERIA 17 

vanish again immediately (geologically speaking) or soon there- 
after: Groeberiidae, only in the Divisadero Largo formation; Nec- 
rolestidae, only in the Santa Cruz formation; and Argyrolagidae, 
only from Huayquerian to Uquian. A possible clue is that all 
these faunas are in Temperate Zone Argentina and that earlier 
faunas are as yet very inadequately known farther north on the 
continent. It is a reasonable hypothesis, as yet without direct 
evidence, that these groups evolved in what are now (and quite 
likely were then) the tropics and are picked up in our record only 
when they spread rather briefly to what was for them a marginal 
area. 

REFERENCES 

KiRSCH, J. A. W. 1968. Prodromus of the comparative serology of 
Marsupialia. Nature, 217: 418-420. 

Pascual, R.. E. J. Ortega Hinojosa, D. Gondar, and E. Tonni. 1965. 
Las Edades del Cenozoico mamalifero de la Argentina, con especial 
atencion a aquellas del Territorio Bonaerense. Prov. de Buenos Aires, 
Sep. An. Com. Invest. Cient. Bs. As., VI: 165-193. 

Patterson. B. 1952. Un nuevo y extraordinario marsupial deseadiano. 

Rev. Mus. Municipal Cien. Nat. y Tradic, Mar del Plata, 1: 49-44. 
Paula Couto, C. de. 1952. Fossil mammals from the beginning of 

the Cenozoic in Brazil. Marsupialia: Polydolopidae and Borhyaenidae. 

American Mus. Novitates. No. 1559: 1-27. 

Peyer, B. 1968. Comparative Odontology. (R. Zangerl. ed.) Chicago, 
Univ. of Chicago Press. 

Ride. W. D. L. 1964. A review of Australian fossil marsupials. Jour. 

Roy. Soc. Western Australia, 47: 97-131. 
Russell, D. E. 1964. Les Mammiferes Paleocenes d'Europe. Memoires 

du Mus. Nat. D'Histoire Nat.. Serie C, Sciences de la Terre, XIII: 

1-324. 

Simpson, G. G. 1948. The beginning of the Age of Mammals in South 
America. Bull. American Mus. Nat. Hist., 91: 1-232. 

, 1970. The Argyrolagidae. extinct South American 

marsupials. Mus. Comp. Zool.. 139 (1): 1-86. 

Simpson. G. G., J. L. Minoprio, and B. Patterson. 1962. The mam- 
malian fauna of the Divisadero Largo formation, Mendoza, Argentina. 
Bull. Mus. Comp. Zool.. 127 (4): 239-293. 



BREVIORA 



Miiseiuiiti of Compsirative Zoology 

Cambridge, Mass. 8 January, 1971 Number 363 

NON-SPECIFICITY OF HOST-SELECTION IN THE 

ECTOPARASITIC SNAIL ODOSTOMIA (MENESTHO) 

BISUTURALIS (SAY) (GASTROPODA: PYRAMIDELLIDAE) 

Robert C. Bullock and Kenneth J. Boss 



Abstract. Ectoparasitic pyramidellid gastropods have often been 
considered host-specific, although a few species have been reported to feed 
on a variety of hosts under laboratory conditions. A large population of 
Odostomia (Menestho) bisuturalis (Say) at Duxbury Beach, Massachu- 
setts, provided an ideal opportunity to study the association of this ecto- 
parasite with the various moUusks found in the vicinity. Our results re- 
vealed that O. bisuturalis was associated with seven species of moUusks, 
most commonly Nassariiis obsoletiis (Say) and Mytilus editlis Linnaeus. 
The great abundance of O. bisuturalis and the fact that Crassostrea vir- 
ginica (Gmelin), its usual natural host, was absent from the study area, 
appear to account for the non-host-specificity observed. 

INTRODUCTION 

The host-specificity of the ectoparasitic snails of the family 
Pyramidellidae has been the subject of several papers during the 
last decade. Early observations led some workers, notably Fretter 
and Graham (1949; 1962), to state that these ectoparasites were 
host-specific. More recent studies have revealed that under labora- 
tory conditions certain pyramidellids actually feed on a variety of 
hosts (Ankel and Christensen, 1963; Scheltema, 1965; Robertson, 
personal communication), although possible host-preference may 
be a factor (Boss and Merrill, 1965). The observations reported 
here suggest that some species of pyramidellids are not host- 
specific. 

What actually constitutes a true parasitic relationship has been 
questioned (Robertson and Orr, 1961; Dehlinger, unpublished 
MS). While observations of pyramidellids associated with 



2 BREViORA No. 363 

various organisms indicate, by their proximity or physical contact, 
possible parasite-host relationships, most authors have been 
wary of such evidence. Robertson (personal communication) 
stated that the presence of an Odostomia on a possible host may 
only reflect the pyramidelUd's need for a suitable substrate. This 
view is supported by some of our observations and those of Schel- 
tema (1965), who noted O. bisuturalis clinging to the under sur- 
faces of stones in a region where Littorina littorea L., a "labora- 
tory host" for this species, was abundant. Recent workers have 
indicated what constitutes a true parasitic relationship: insertion 
of the proboscis and action of the buccal pump (Robertson, per- 
sonal communication; Scheltema, 1965) or when the parasite is 
"less than V& in. from the edge of the mantle of the host" 
(Boss and Merrill, 1965). Although the former is a more exact 
method, we have necessarily followed Boss and Merrill (1965), 
since our observations were made during the low tide period when 
the ectoparasites were not actively feeding on exposed hosts. 

OBSERVATIONS 

An abundance of Odostomia (Menestho) bisuturalis (Say, 
1822) was noted on the tidal flat on the harbor side of Duxbury 
Beach, Massachusetts, in June, 1969. Sampling at several stations 
along the beach during a -1.6 tide on 3 June and subsequent 
visits to the study area provided ample field evidence of the occur- 
rence of this snail on numerous intertidal moUuscan hosts. 

The Odostomia were not limited to a particular region of the 
tidal flat, for they were found from below the low-water mark to 
the upper portion of the intertidal zone. Quantitative samples 
were taken in the region at the east end of the Duxbury Beach 
bridge. All moUusks collected were carefully examined for the 
presence of Odostomia. O. bisuturalis, the only pyramidellid 
found, was collected from seven different species of moUusks: 
Littorina littorea (L.), Urosalpinx cinereus (Say), Crepidula con- 
vexa Say, Crepidula fornicata (L.), Nassarius obsoletus (Say), 
Nassarius trivittatus (Say), and Mytilus edulis Linnaeus. They 
were also observed on the egg capsules of Nassarius sp. and Poli- 
nices sp., and on empty shefls. 

O. bisuturalis was most abundant on three hosts: Mytilus edulis, 
which formed large mats on the mud flats, and on the snails Nas- 
sarius obsoletus and Littorina littorea, which occasionally had 



1970 ECTOPARASITIC ODOSTOMIA 3 

from one to three ectoparasites on the operculum or on the Hp of 
the shell. The Mytilus that were observed in water often had a 
number of ectoparasites situated on the margins of the mantle, 
away from the hinge, similar to the position assumed in Odostomia 
scalaris MacGillivray on Mytilus in Europe. However, most of 
the Mytilus population at Duxbury was exposed at low tide and 
the ectoparasites had migrated to moist areas within the Mytilus 
mat. In the laboratory we have observed O. bisuturalis feeding 
on Mytilus. 

Table I shows the relative abundance of Odostomia on three 
hosts. In the case of Nassarius obsoletus several items should be 
noted: 1) the parasites occurred on samples with a large mean 
length in a frequency of one Odostomia to three or four Nassarius; 
2) smaller individuals of Nassarius were significantly less para- 
sitized, with only one parasite per ten individuals. This latter ob- 
servation was also noted in studies of O. impressa (Say) (Hop- 
kins, 1956) and O. dianthophila Wells and Wells (Wells and 
Wells, 1961). At one station A', obsoletus was present in large 
numbers, possibly 12,000/m-, with an equally high concentration 
of O. bisuturalis, 7,000/m-. These figures indicate that at times 
O. bisuturalis, a usually overlooked organism, must play a mod- 
erately significant role in the flow of energy in a tidal flat com- 
munity. In other species, not quantitatively sampled, the occur- 
rence of Odostomia was even greater, in some cases amounting 
to two ectoparasites per host, e.g., Littorina. 

Previous published records of field observations have not re- 
vealed O. bisuturalis in association with any of the seven species 
of moUusks reported in this study. In the laboratory, O. bisutu- 
ralis is known to feed on: Littorina littorea (L.) (Scheltema, 
1965; Robertson, 1967); Bittium altematum (Say) (Scheltema, 
1965); Crucibulum striatum (Say) and Crepidula fornicata (L.) 
(Boss and Merrill, 1965). Previously, the only known natural 
host of O. bisuturalis was the American oyster, Crassostrea vir- 
ginica (Gmelin) (Loosanoff, 1956; Boss and Merrifl, 1965), a 
species not present at Duxbury Beach. 

DISCUSSION 

These observations demonstrate that at least one pyramideflid 
is not host-specific. Further, laboratory studies have shown that 
certain Odostomia may have numerous hosts. Thus, should these 



4 BREVIORA No. 363 

species actually be non-host-specific, as O. bisiituralis seems to 
be, an examination of all environmental factors involved in host- 
specificity and host-preference becomes imperative. 

The great abundance of O. bisiituralis led to the consideration 
of the question of density-dependent factors in feeding behaviour. 
While our observations show the non-specific host-selection of 
O. bisuturalis, they do not reveal any specific information con- 
cerning host-preference. An abnormally large population of O. 
bisuturalis or a diminished preferred food source might force 
many individuals to feed on hosts they would otherwise reject. 

The biological relationship between a motile ectoparasite and 
host-species can be likened to that between a predator and its 
prey. The odostomia-type of predator-prey relationship with re- 
spect to food preference is commonly observed in animals not 
totally dependent on one organism for survival. It has been 
demonstrated that total food abundance, relative abundance of 
food types, spatial distribution of foods and predator satiation 
afl'ect feeding preferences in some animals (Ivlev, 1961). In mol- 
lusks, for example. Wells (1958) found that although the oppor- 
tunistic gastropod Fasciolaria hunter ia (Perry) prefers to eat the 
small oyster drill, Urosalpinx, it will eat oysters if only a minimal 
number of the more desirable gastropods are present. Further, in 
a study of the relationship between time and energy in food pref- 
erences, Emlen (1966: 617) suggested that: 1) ''Animals should 
be more selective in their choice of foods when satiated or when 
food is common, more indiscriminate when starved or when food 
is scarce"; and, 2) "Food preferences appear to change readily 
and appropriately to changes in the environment." 

The particular circumstances in which the ectoparasitic popula- 
tion existed were unusual in that: 1 ) there was a very large popula- 
tion of ectoparasites; and, 2) the preferred natural host for this 
species, Crassostrea virginica, was not present in the local eco- 
system. Thus, our observations corroborate the hypotheses of 
Emlen and indicate that Odostomia bisuturalis may have various 
host-species under natural conditions. 



1970 ECTOPARASITIC ODOSTOMIA 5 

ACKNOWLEDGMENTS 

The manuscript was critically read by Messrs. R. I. Johnson 
and M. K. Jacobson and Dr. R. D. Turner. Mr. W. Baranowski 
brought our attention to the occurrence of great numbers of Odo- 
stomia at the Duxbury site, and Mr. S. Britz measured the speci- 
mens. 



BREVIORA 



No. 363 



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1970 ECTOPARASITIC ODOSTOMIA 7 

REFERENCES CITED 

Ankel, F., and a. M. Christensen. 1963. Non-specificity in host selec- 
tion by Odostomia scalaris MacGillivray. Vidensk. Medd. fra Dansk 
naturh. Foren., 125: 321-325. 

Boss, K., AND A. Merrill. 1965. Degree of host specificity in two species 
of Odostomia (Pyramidellidae: Gastropoda). Proc. Malac. Soc. Lon- 
don, 36: 349-355. 

Dehlinger, R. 1969. Host specificity and the feeding ecology of the 
ectoparasitic family Pyramidellidae. Unpublished manuscript, 55 pp. 

Emlen, J. M. 1966. The role of time and energy in food preference. 
Amer. Nat., 100: 611-617. 

Fretter, v., and a. Graham. 1949. Feeding and reproduction in pyra- 
midellids. Nature, 163: 361-362. 

. 1962. British Prosobranch Molluscs. London, Ray 

Society, 755 pp. 

Hopkins, S. H. 1956. Odostomia impressa parasitizing southern oysters. 
Science, 124: 628-629. 

Ivlev, V. S. 1961. Experimental Ecology of the Feeding of Fishes. New 
Haven, Yale Univ. Press, 302 pp. 

Loosanoff, V. L. 1956. Two obscure oyster enemies in New England 
waters. Science, 123: 1119-1120. 

Robertson, R. 1967. The life history of Odostomia bisiitiualis, and 
Odostomia spermatophores (Gastropoda: Pyramidellidae). Year Book 
Amer. Phil. Soc, 1966: 368-370. 

Robertson, R., and V. Orr. 1961. Review of pyramidellid hosts, with 
notes on an Odostomia parasitic on a chiton. Nautilus, 74: 85-91. 

Scheltema, a. H. 1965. Two gastropod hosts of the pyramidellid gas- 
tropod Odostomia bisiitiiralis. Nautilus, 79: 7-10. 

Wells, H. W. 1958. Predation of pelecypods and gastropods by Fas- 
ciolaria hunteria (Perry). Bull. Mar. Sci. Gulf and Caribbean, 8: 
152-166. 

Wells, H. W., and M. J. Wells. 1961. Three species of Odostomia 
from North Carolina, with description of new species. Nautilus, 74: 
149-157. 



BREVIORA 

MiaseitairM of Comparative Zoology 

Cambridge, Mass. 8 January, 1971 Number 364 

A NEW SCINCID LIZARD FROM BOUGAINVILLE, 
SOLOMON ISLANDS 

Allen E. Greer and Fred Parker^ 



Abstract. The relationships of Sphenomorphus transversus, n. sp., 
from Bougainville, Solomon Islands, are obscure, but in squamation it is 
most similar to inaciilatiis, boiilengcri, forinosensis, Uneopiinctiilatiis. and 
indiciis from eastern Asia; nielanochlorus from New Guinea; and sanctiis 
from Sumatra and Java. S. transversus differs most noticeably from these 
species and from other Bougainville skinks in its dorsal pattern of trans- 
verse dark brown bands on a light olive ground color. 

During investigations in 1960-1963 by Parker on Bougain- 
ville, Solomon Islands, a single individual of a previously unde- 
scribed species of skink was collected. Since one subsequent trip 
(1966) has failed to uncover other specimens of the species, and 
as the possibilities of a second return trip to Bougainville in the 
near future are slim, it seems best to describe the new species from 
the single specimen at hand. 

On the basis of current generic concepts, the species is assigned 
to the genus Sphenomorphus and may be known as 

Sphenomorphus transversus^ new species 

Holotype. Museum of Comparative Zoology 76485; collected 
by a native for Fred Parker at about 2000 feet above sea level in 
an area approximately five miles east of Kunua, northeastern 
Bougainville (Fig. 1), on 9 September 1962. 



1 P. O. Box 52, Daru, Western District, Territory of Papua and New 
Guinea. 

- The species name calls attention to the dark transverse bars on the 
dorsum. 



BREVIORA 



No. 364 



155° E 



56° E 



BUKA I 



30 miles 



■6°S 



•7°S 




6°S-^ 



I55°E 



SHORTLAND 



MONO I (^ 



FAURO 



7°S- 



156° E 



Figure 1. Map of Bougainville showing the location approximately 5 
miles east of Kunua where the type and only known specimen of Spheno- 
morphiis transversus was collected. 



Diagnosis. Similar in squamation to those skinks of the genus 
Sphenomorphus (Table 1 ) that have a single anterior loreal, the 
frontal in contact with 3 or more of the 5 or more supraoculars, 
frontoparietals and interparietal distinct, no nuchals or trans- 
versely enlarged scales in the two vertebral rows (Figs. 2 and 3), 



I97' 



A NEW SOLOMON ISLANDS SKINK 



and the digits and limbs well developed and overlapping when 
adpressed to the body, but differing from other skinks with this 
diagnosis in having the following combination of characters: pre- 
frontals separated medially, 36 rows of smooth scales around mid- 
body, 28-29 smooth subdigital lamellae on the 4th toe, and a 
color pattern of brown transverse bands on a light olive-green 
ground color (Figs. 4 and 5) — a color pattern most similar to 
those of the distantly related Sphenomorphus flavipes, Scincella 
prehensicaiida, and Leiolopisma semoni of New Guinea. 

Description. Body form relatively slender; well-developed pen- 
tadactyl digits and Umbs that overlap when adpressed to the body 
(tip of 4th toe reaches middle of forearm); snout-vent length 68 
mm, tail 92 mm. 




Figure 2. Dorsal view of the head of the holotype of Sphenomorphus 
transversus (MCZ 76485). 



BREVIORA 



No. 364 



Head not depressed, snout somewhat pointed; rostral slightly 
wider than deep, projecting slightly onto dorsal surface of snout 
between nasals; external naris in single nasal; no supranasals; 
single anterior and posterior loreals; frontonasal slightly wider 
than long, forming a short suture with the rostral and a very 
short suture with the frontal; prefrontals large, barely separated at 
their inner angles; frontal 1% times as long as wide, in contact 
with the three anteriormost supraoculars; 5 supraoculars, the 
first smallest, but in no way to be confused with the anterior super- 
ciliaries; lower eyelid scaly; 6th supralabial most directly below 
eye; a complete row of subocular scales separates scales of lower 
eyelid from supralabial series; frontoparietals paired and subequal 
in size with the single interparietal that is sharply pointed pos- 
teriorly; parietals meeting behind interparietal and bordered 
posteriorly by a single large temporal on either side and 5 large 
dorsal scales between the temporals; no symmetrical series of 
nuchals. 

External ear opening vertically elliptic, without auricular lobes; 
tympanum sunk slightly below level of skin; 36 smooth scales 
around midbody, the scales of the two vertebral rows not larger 
than those of the immediately adjacent rows; a pair of enlarged 
preanals; scales of three median subcaudal rows subequal in size. 

Digits rather long and slender; subdigital lamellae smooth and 
undilated throughout length of digit; 28-29 lamellae beneath 4th 
(longest) toe; upper surface of 4th toe covered by one or two 




Figure 3. Lateral view of head of Sphenoworpliiis tnnisversus (holo- 
type). 



1971 A NEW SOLOMON ISLANDS SKINK 5 

single scales at distal end, 3 rows of scales throughout center part 
and 4 rows near base (see Brongersma, 1942). 

Dorsal ground color light olive with a series of complete and 
incomplete transverse dark brown bands from nape to base of 
tail, the brown bands terminating in slightly expanded blotches 
on sides (Fig. 5), an effect especially pronounced at midbody; a 
horizontal brown stripe from anterior loreal through eye to tem- 
poral region; brown blotches on anterior and upper surfaces of 
limbs as well as on upper surface of tail; venter immaculate except 
for a few faint brown spots on throat and underside of tail. 

In life the undersides of the limbs, body, and tail were bright 
yellow. 

Field Notes. The only known specimen of S. transversus was 
taken by a native collector under a decaying log on the steep side 
of a montane river valley covered with tall primary forest. The 
natives did not recognize it as being distinct from S. concinnatus, 
a species common at the type locality of 5. transversus. 

Morphological Comparisons with Other Bougainville Skinks. 
S. transversus is immediately distinguishable from S. concinnatus 
by its more sharply tapered, longer snout; the absence of a dark 
blotch between the ear opening and the forellmb; the smaller ex- 
ternal ear opening; and, the regular transverse barring. 

Only two other Bougainville skinks, S. taylori and S. cranei — 
both very different from S. transversus in squamation — have 
transverse bands on the dorsum. In both these species, however, 
the dorsal pattern consists of very light transverse bands on a dark 
ground color, whereas in S. transversus the transverse bands are 
darker than the ground color. S. transversus also has a more 
noticeably pointed snout than either S. taylori or S. cranei. 

Skull Characters. It is extremely difficult, if not impossible, 
to remove the skull of most skinks without severely damaging the 
skin of the head. For this reason we have not attempted to pre- 
pare a skull from the type and only known specimen of S. trans- 
versus. We have, however, had a palatal view of the skull, and 
the salient features are as follows: there are 9 premaxillary teeth; 
the palatine and pterygoid bones meet along the midhne to form 
a fairly extensive secondary palate; there is no ectopterygoid pro- 
cess; and, there are no pterygoid teeth. Unfortunately, these 
characteristics are not particularly diagnostic, for they would not 
exclude S. transversus from close relationship with any number 



6 BREVIORA No. 364 

of other lygosomines, including those discussed below that are 
most like S. transversiis on the basis of external morphology. 

Comparison with Morphologically Similar Species. In squama- 
tion S. transversus is most similar to those species of Sphenomor- 
phus (Table 1) that have a single anterior loreal, the frontal in 
contact with 3 or more of the 5 or more supraoculars, the fronto- 
parietals and interparietal distinct, no nuchals or transversely en- 
larged scales in the two vertebral rows, and the digits and limbs 
well developed and generally overlapping when adpressed to the 
body. This assemblage, which is almost surely not monophyletic, 
is distributed from southern Asia through the Indo-Australian 
archipelago and Philippines to New Guinea, but not Australia. 

Seven species in this group have the prefrontals separated me- 
dially (in all or some individuals), as is the case in the single 
specimen of S. transversus. Six of these seven species (maculatus, 
boulengeri, jormosensis, lineopimctulatus , and indiciis from 
southern Asia and melanochlorus from New Guinea) have sub- 
stantially fewer subdigital lamellae on the 4th toe (16-22) than 
does transversus (28-29), and the seventh {sanctus from Suma- 
tra and Java) has finely striated body scales to distinguish it from 
the smooth-scaled transversus. Furthermore, none of these seven 
species have a dorsal body pattern consisting of well-defined dark 
crossbars as does transversus. 

This very characteristic dorsal body pattern of dark crossbars 
on a light ground color is most similar to the patterns of the cross- 
banded color morph of Sphenomorphus fiavipes, the females of 
Scincella prehensicauda, and of all Leiolopisma semoni. These 
three species are endemic to neighboring New Guinea and might, 
therefore, seem to be likely relatives of Sphenomorphus trans- 
versus. Current work on scale and palatal characters, however, 
indicates that while fiavipes, prehensicauda and semoni are them- 
selves closely related (in spite of current generic allocations), they 
are only distantly related to SphenomorpJius transversus. 

ACKNOWLEDGEMENTS 

Dr. Ernest E. WiUiams of the Museum of Comparative Zoology 
read the manuscript in several drafts and offered several helpful 
suggestions. Mr. Laszlo Meszoly did the drawings for Figures 2 
and 3, and Mr. Tan T. Riddell took the photographs for Figures 



1971 A NEW SOLOMON ISLANDS SKINK 7 

4 and 5. Part of Greer's work on this paper was done while he 
was a postdoctoral fellow of the National Science Foundation. 
Partial support was provided by National Science Foundation 
grant GB 6944 to Ernest E. Williams. 

LITERATURE CITED 

Brongersma, L. D. 1942. On the arrangement of the scales on the 
dorsal surface of the digits in Lygosoma and allied genera. Zoologische 
Mededeelingen. 24 (1-2): 153-158. 



BREVIORA 



No. 364 





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Figure 4. Dorsal view of the holotype of Splicnomorphiis transvcrsus 
(MCZ 76485) showing the dark transverse bands which give the species 
its name. 



1971 



A NEW SOLOMON ISLANDS SKINK 



11 




Figure 5. Lateral view of Sphenomorphiis transversiis (holotype). 



BREVIORA 

Me seem of Comparative Zoology 

Cambridge, Mass. 15 January, 1971 Number 365 



CHARACTERS AND SYNONYMIES AMONG THE GENERA 

OF ANTS. PART IV. SOME GENERA OF SUBFAMILY 

MYRMICINAE (HYMENOPTERA: FORMICIDAE) 

William L. Brown, Jr.^ 

Abstract. Archaeomyrmex is a new junior synonym of Myrmecina, 
and tribe Archaeomyrmicini accordingly is a synonym of Myrmecinini. 
Dodoiis is a new junior synonym of Pristomyrmex, and the synonymy of 
Hylidris under Pristomyrmex is reaffirmed. Limnomyrmex is a new junior 
synonym of Leptothorax subgenus Nesomyrmex. 

The genera considered in this part all belong to subfamily Myr- 
micinae. My main purpose here is to explain briefly why some 
new synonymy should be proposed. The taxa concerned have all 
been studied during the course of the project "a reclassification of 
the Formicidae," supported by National Science Foundation Grants 
G-23680, GB-2175, and GB-5574. The taxonomic conclusions 
will eventually be embodied in a synopsis and illustrated keys to 
the ant genera of the world. I feel that justification for revisionary 
changes should be published as the need for the changes becomes 
clear. In this way, important findings of the study are made avail- 
able for use by all ant taxonomists without undue delay, and the 
synoptic parts can be freed from the clutter of many detailed 
taxonomic arguments. 

Myrmecina 

Myrmecina Curtis, 1829, Brit. Entom. 6: 226, pi. 265, male. Type 
species by original designation Myrmecina latreillii := Formica graminicola. 

Arclweomyrmex Mann, 1921: 448-451. Type species: Archaeomyrmex 
cacabau, by original designation. NEW SYNONYMY. 

1 Department of Entomolo{!;y, Cornell l'ni\ ersity, Ithaca, New York, 14850. 



2 BREVIORA No. 365 

The unique type of A. cacabau has been searched for in vain in 
the U. S. National Museum and Museum of Comparative Zoology 
ant collections, and must be considered lost. Fortunately, Mann's 
description and figures are reasonably detailed. From them, it is 
clear that the species is essentially a Myrmecina, a fact acknowl- 
edged by Mann when he wrote: "The epinotal and petiolar struc- 
ture are not unlike certain species of Myrmecina." Mann empha- 
sized the ventrolateral carina on each side of the head, probably 
without realizing that this is an invariable character of Myrmecina. 
He also cited the partly smooth, partly costate sculpture of the 
body, especially the trunk, which does set this species off from the 
"average" Myrmecina. But Myrmecina forms with more or less of 
the head and trunk smooth have not been completely unknown, 
and they even occur as phenetic variants in species that are usually 
heavily sculptured in these regions. 

Several Myrmecina species (at least three of them still unde- 
scribed) with predominantly smooth and shining head and trunk 
are in the MCZ collection. Two of the undescribed species are 
from the New Hebrides; in each of these, the posterior pair of 
propodeal teeth is spiniform, but the coarse costate sculpture of 
the lower pleural areas is preserved, as it is in cacabau. Another 
smooth species has come to me from the Philippines. The geo- 
graphical and morphological gaps are thus closed between the 
Fijian and Indo-Australian representatives of what is obviously a 
single stock. A complete examination of the A. cacabau descrip- 
tion fails to reveal any character that will separate it from Myrme- 
cina at generic level. Together with the two New Hebrides species, 
cacabau should be taken to represent no more than a weak species- 
group of Myrmecina. 

Incidentally, an interesting characteristic of some of these species 
is the extreme reduction of antennomere III, just distal to the 
pedicel. The distinction between " 1 1 -segmented" and "12-seg- 
mented" antennae in these forms may prove impossible to maintain 
as a key character. 

Mann's tribe Archaeomyrmecini of course falls as a new 
synonym of Myrmecinini. 

Pristomyrmex 

Pristomyrmex Mayr, 1866: 903. Type species: Pristomyrmex piingens, 
monobasic. 



1971 SOME GENERA OF MYRMICINE ANTS 3 

Hylidris Weber, 1941: 190. Type species: Hylidris myersi, by original 
designation. — 1952: 15-22. Synonymized by Brown, 1953: 9-10. 

Dodous Donisthorpe, 1946: 145; worker, male, larva. Type species: 
Dodous trispinosus, by original designation. NEW SYNONYMY. 

Dodous was based on the single species trispinosus, from Cocotte 
Mountain, Mauritius. Syntypes of this species deposited in the 
British Museum and in the Museum of Comparative Zoology are 
basically Pristomyrmex in form, but they have an extra pair of 
small teeth on the mesonotum, and the head and trunk are finely 
and regularly costulate (= striate). The larva, rather vaguely 
figured in the original description (fig. 4), has the elongate, pro- 
tuberant head characteristic of Myrmecina and Pristomyrmex. 
Donisthorpe also figured the male, which is like known Pristomyr- 
mex males in general habitus. The genitalia as very briefly de- 
scribed may be aberrant, but then the genitalia have not been 
studied at all in most other Pristomyrmex species. 

A second species of Dodous, D. bispinosus, was described from 
Mauritius by Donisthorp)e in 1949. I collected a small sample of 
strays of this species at the type locality, Le Pouce (Mountain) on 
1 April 1969, the last day of a short stay on Mauritius. The speci- 
mens were all foraging workers taken on trees and on the main 
path through the scrubby native forest at about 800 m elevation 
on the "plateau^' near the summit. (A sudden storm prevented my 
finding any nests.) D. bispinosus differs from D. trispinosus in 
lacking the mesonotal teeth (though actually some of my bispinosus 
specimens have low mesonotal tubercles in place of the teeth) and 
in having predominantly smooth and shining sculpture. In fact, 
D. bispinosus is a rather ordinary, if slightly long-legged, Pristo- 
myrmex, and D. trispinosus goes only one step beyond. It seems 
absurd to put these two closely related species in different genera. 
Discovery of the annectant D. bispinosus makes it clear to me that 
Dodous is only the Mauritian complement of the widespread Old 
World genus Pristomyrmex. The concept of Dodous as a separate 
genus is, as far as 1 am concerned, as dead as its namesake. 

I have already (Brown, loc. cit.) placed Weber's Hylidris as a 
synonym of Pristomyrmex. Weber opposed this synonymy, main- 
taining that Hylidris is a distinct genus. But when he described 
Hylidris, Weber took no note of the African species of Pristomyrmex 
described previously by Santschi, Arnold, and Karavaiev, at least 
some of which are senior synonyms of his own Hylidris species and 



4 BREVIORA No. 365 

subspecies (Weber, 1952). Weber has never produced a charac- 
terization of Hylidris that will separate it as a genus from Pristo- 
myrmex, and particularly from the long-synonymized "subgenus" 
Odontomyrmex. \ have collected P. orbiceps in the Ivory Coast, 
and can affirm that colony behavior (lethisimulation), larval form, 
and general adult morphology are fully those of Asian and Aus- 
tralian Pristomyrmex as I have seen them in nature. 

Pristomyrmex is a sharply defined and compact genus, and there 
is no reason that I know of to set the African species apart from it. 
In fact, the African species are as nearly "average" for the genus 
Pristomyrmex as one is likely to find. 

Some other misconceptions expUcit or implied in Weber's dis- 
cussion of 1952 need correction. The petiole of Pristomyrmex has 
a distinct anterior peduncle, though it is short in some species. In 
contrast, the related genus Myrmecina has a sessile petiole of more 
or less prismatic shape. Pristomyrmex and Myrmecina are not 
very closely related to tribe Tetramoriini, though two species have 
been wrongly placed in tetramoriine genera in the past. The larvae, 
for one thing, are very different, and it seems that they may furnish 
the best tribal character for the Myrmecinini if we limit the tribe 
to Pristomyrmex, Myrmecina, Acanthomyrmex, and possibly the 
little-known Perissomyrmex of Guatemala, the larvae of which have 
not yet been found. Tribe Tetramoriini is not "worldwide" in dis- 
tribution, if one ignores obvious introductions by man. The tribe 
has no native species in South or Central America, and only a single 
species of Xiphomyrmex occurs in (Sonoran) North America. 

Leptothorax subgenus Nesomyrmex 

Nesomyrmex Wheeler, 1910, Bull. Amer. Mus. Nat. Hist., 28: 259. 
Type species Nesomyrmex clavipilis, monobasic. 

Leptothorax (Goniothorax) aiict., preoccupied. 

Leptothorax (Caulomyrma) Forel, 1914, Bull. Soc. Vaudoise Sci. Nat., 
50: 233. 

Limnomyrmex Arnold, 1948, Occas. Pap. Nat. Mus. S. Rhodesia, 2(14): 
222. — 1952, Ibid., 2(17): 460, discussion. Type species Limiioiuyrmex 
stramineiis, monobasic. NEW SYNONYMY. 

Soon after its description, the late Dr. Arnold and I engaged in 
correspondence on the question of the distinctness of Limnomyr- 
mex from the subgenus Nesomyrmex of Leptothorax. He stoutly 
maintained that Limnomyrmex was a good genus, and in 1952 {loc. 
cit.) he argued again in print for this stand. Now that I have finally 



1971 SOME GENERA OF MYRMICINE ANTS 5 

seen the unique worker type of L. stramineiis in the Arnold Collec- 
tion at Bulawayo, I can only place this species among the other 
known African Nesomyrmex. I have searched in vain for any 
characters that might set Limuomyrmex apart as a genus. In the 
form of the trunk and both petiolar and postpetiolar nodes, it is 
about "average" for a Nesomyrmex from Africa, and resembles in 
a subdued way some neotropical members of the group. Sculptural 
and a few other differences mark stramineus , but these do not seem 
to be more than species characters. The antennae of stramineus 
are 12-segmented; Nesomyrmex can have either 11 or 12 segments. 
The status of Nesomyrmex as a subgenus of Leptothorax is main- 
tained for the time being, pending the proper study of both taxa. 

REFERENCES 

Brown, W. L.. Jr. 1953. Characters and synonymies among the genera 

of ants. Parti. Breviora No. 11: 1-13. 
DoNisTHORPE, H. St. J. K. 1946. A new genus and species of Formicidae 

(Hym.) from Mauritius. Proc. Roy. Entomol. Soc. London, ser. B, 

15: 145-147. 
Mann, W. M. 1921. The ants of the Fiji Islands. Bull. Mus. Comp. 

Zool., 64: 401-499. 
Mayr, G. 1866. Diagnosen neuer und wenig gekannter Formiciden. 

Verhandl. Zool.-bot. Ges. Wien, 16: 885-908, pi. 20. 
Weber, N. A. 1941. Four new genera of Ethiopian and Neotropical 

Formicidae. Ann. Entomol. Soc. Amer., 34: 183-194. 
. 1952. Studies on African Myrmicinae, I (Hymenoptera, 

Formicidae). Amer. Mus. Novitates 1548: 1-32. 



JBREVIORA 

Mmseuinni of Comparsitive Zoology 

Cambridge. Mass. 15 January, 1971 Number 366 



PULSED SOUNDS OF THE PORPOISE 
LAGENORHYNCHUS AUSTRALIS 

William E. Schevil! and William A. Watkins^ 



Abstract. Pulsed sounds of the porpoise Lagenorhynchns aiistmlis of 
southern Chile were recorded and analyzed. Most were low-frequency 
clicks; some had a 2-kHz bandwidth centered near 1 kHz, and others had 
a 10- or 12-kHz bandwidth with the principal frequency in the lower 5 kHz. 
These porpoises also produced a rapidly pulsed tonal sound. All these 
sounds were very low-level and rarely audible at a distance as great as 20 m. 
We heard none of the whistlelike squeals characteristic of many delphinids. 

From 12 November to II December 1968 the research ship 
HERO of the National Science Foundation (Antarctic Research 
Program) cruised between Valparaiso and Cape Horn, searching 
for cetaceans and pinnipeds, mostly in the sheltered inland water- 
ways of southern Chile. We were concerned with listening for and 
recording the underwater sounds of these animals. 

The species most frequently seen and collected was Lcigeno- 
rhynchus australis (Peale, 1848 ), which has been reported from the 
west coast of Chile south of about S Lat. 40° around Cape Horn 
to the Falkland Islands. We heard them much less often than we 
saw them. 

Methods. The recordings that are analyzed here were made on 
23 November in Canal Messier (at 48° 10' S) and 1, 3, 5, and 6 
December west and south of Navarino Island behind Cape Horn. 
An Atlantic Research LC-34 hydrophone was used to pick up the 
sounds. An impedance-matching pre-amplifier (WHOI) was in- 
serted in the cable 30 cm from the hydrophone. Two cable lengths 



1 Contribution No. 2562 from the Woods Hole Oceanographic Institution. 



2 BREVIORA No. 366 

were used, 125 m from R/V HERO and 30 m from HERO's whale- 
boat. The hydrophone depth varied with local conditions and ex- 
periments, from 2 m to nearly 125 m; it was usually suspended 6-8 
m from a surface float (a rubber balloon) and allowed to drift as 
far from ship or boat as cable-length permitted. 

Tape recordings were made with either a modified Uher 4400 
recorder or a WHOI-built springwound recorder, using a hydro- 
phone amplifier (Watkins, 1963). When the Uher was in use, the 
system-response was limited to a bandwidth, within 4 db, of 40 to 
20,000 Hz; with the WHOI machine, system-response was 20 to 
32,000 Hz (within Vz db from 30 to 30,000 Hz). Playback for 
analysis was on Crown 800 tape recorders. Spectrographic analy- 
ses were made on a Kay Electric model 7029A analyzer and ampli- 
tude analyses on a Tektronix 5 35 A oscilloscope. 

The porpoises were approached as closely and as unobtrusively 
as possible, but even so, often the only sounds heard from the ani- 
mals were within the first 5 seconds of the listening attempts. Un- 
fortunately, because of the disturbance of the water by arrival of 
the boat and the motion of the hydrophone, a longer time than 
this usually was required before local ambient noise could settle 
down enough for faint sounds to be recorded. Usually nothing was 
heard from the porpoises, partly because they were generally taci- 
turn and seemed to produce sounds only occasionally, and partly 
because their sounds were too faint to be audible except on close 
approach, within a few meters of the animals. They appeared to 
be silent when disturbed. 

Sounds. The sounds heard from Lagenorhynchus aiistralis were 
all pulsed. Mostly they were clicks produced in short series or slow 
bursts, but sometimes a rapidly pulsed sound (a buzz) that had a 
tonal quality was heard. The buzz was the only sound heard from 
L. australis at any distance, and it was produced only occasionally; 
consequently most attempts to listen to these porpoises were entirely 
unsuccessful. No squeals (whistles) were heard; this was unex- 
pected since we have heard squeals from other Lagenorhynchus 
(L. albirostris, acutus, obliquidens, and the obscurus of New 
Zealand). 

These sounds of L. australis were low level and generally in- 
audible beyond about 10-20 m. We estimate that the loudest 
chcks were no more than -20 db re 1 dyne/cm- at 1 m, from 
known hydrophone sensitivities and tape saturation levels, and 



1971 PORPOISE SOUNDS 3 

assumed supply voltages and amplifier gains. On only a few occa- 
sions were we convinced that we knew which individual produced 
the sounds that we heard, and therefore our estimates of signal 
strength and of distance from the hydrophone are but guesses. 

The click-sounds were of two types: a broadband click, and a 
relatively restricted-bandwidth click (narrowband) at predomi- 
nantly low frequencies. These two clicks never seemed to be 
mixed. Both types were heard, we thought, from any one individ- 
ual, with no obvious separation between the different kinds of 
clicks, and no gradual transition. Though both types of clicks 
were sometimes heard at slow rates (1 or 2 per sec), the broad- 
band click was usually produced at a more rapid repetition-rate 
(20 to 80 per sec.) than the narrowband click (5 to 25 per sec.). 
The broadband click was shorter and had less energy at low fre- 
quencies than the narrowband click. See the table for a comparison 
of these two clicks. 

The broadband click (Figs. lA and 2) was characterized by a 
sharp onset, a short duration, as well as a more or less continuous 
spectrum to 10 or 12 kHz, occasionally to 16 kHz. Analyses of 
clicks showed a general drop in intensity of 1 to 2 db per 1000 Hz 
above 5 or 6 kHz. This drop was greater than is consistent with 
normal frequency-selective absorption for these distances and fre- 
quencies, so we assume that this attenuation is characteristic of the 
click of L. australis. The duration of the broadband click was 
consistently a little less than 1 msec. Because of the general low 
level of the sounds as well as their usual reduction in intensity at 
higher frequencies, the clicks were easily masked by background 
ambient. 

The narrowband click (Figs. IB and 2) was restricted in fre- 
quency to the lower 2000 Hz and appeared to have its greatest in- 
tensity at or below 1000 Hz. Harmonics did exist, though at greatly 
reduced levels. Analysis at high gain (but still undistorted) showed 
some of the narrowband clicks with harmonic frequencies to 5 or 
6 kHz. The narrowband click, with a duration of 1.5 to 3 msec, 
usually occurred at slower repetition-rates (5 to 25 per sec), and 
consistently had higher intensity at low frequencies than the broad- 
band click. Perhaps because of its lower-frequency emphasis and 
therefore better transmission characteristics, the narrowband click 
was the one most commonly heard. 

The third type of sound, the buzz (Fig. 3) was heard on a few 



4 BREVIORA No. 366 

occasions. This buzz had emphasis at discrete higher frequencies, 
such that both the fundamental and high frequency overtones were 
predominant in the aural impression of the sound. The buzzes 
varied in duration from 0.6 to 1.1 sec. They were composed of a 
pulsed fundamental near 300 Hz (Fig. 4) and strong overtones at 
4 to 5 kHz. Two or three sidebands of the pulse repetition-rate 
(modulation. Fig. IC) may be noted grouped around the 4- to 
5-kHz overtone in spectral analysis (Fig. 3) of these buzzes (see 
Watkins, 1967). The fundamental frequency of the buzz was more 
intense than the overtones, yet at greater distances only the 4- to 
5-kHz tone (with its associated sideband structure) was audible. 
This was probably because of higher background ambient at the 
lower frequencies. The buzz appeared to be produced at a higher 
level than the clicks. 

Discussion. Because of both the pulsed quality of the buzz and 
its restricted frequency, we suppose that this sound was formed by 
rapidly repeated narrowband clicks. Singly, the narrowband clicks 
had few higher frequency components, but in a rapid series the 
overtones were prominent. This is somewhat similar to sounds pro- 
duced by Phocoena phocoena, composed of a rapid repetition of 
narrowband clicks to form a continuous sound with selected higher 
frequency emphases (Schevill, Watkins, and Ray, 1969). We did 
not find the variation in the overtones of the buzz of L. australis 
that we noted for Phocoena, but this may have been due to the 
limited number of the former's buzz sounds that were recorded well 
enough for such detailed analysis. 

Perhaps the buzz was used in communication and it may have 
been associated with stress. This could explain its relatively infre- 
quent occurrence. The only time that the buzz was heard when 
we thought we knew which porpoises were producing it (in Paso 
Micalvi outside of Seno Grandi, Navarino Island, 6 December), a 
group of three animals 15 to 20 m distant suddenly seemed to be 
in a scuffle, darting at and away from each other. This sudden un- 
usual activity coincided with the production of four buzzes, two of 
them concurrently (Figs. 3 and 4), and so we assume that these 
sounds were produced by these porpoises. 

We have no evidence that Lagenorhynchus australis echolocates. 
If the click sounds were used for echolocation as in some other 
species ( Tursiops truncatus, Steno bredanensis, Orcinus orca, 
Phocoena phocoena) , it must have been at relatively close ranges 



1971 PORPOISE SOUNDS 5 

because of the low level of the clicks. We did not hear any "ac- 
celerando" in click series such as is typical of echolocation runs 
during feeding by these other animals; however, we had no sugges- 
tion that the L. aiistralis were feeding when the clicks were heard. 
In fact, the clicks were not consistently associated with apparently 
investigatory behavior by the animals. Porpoises sometimes passed 
within a meter of the hydrophone and even appeared to return and 
examine it without our detecting any sounds. On the other hand, 
clicks were never heard unless a porpoise was close by. 

The two click-types perhaps are equivalent to the two basic 
click-categories noted for Tursiops by Norris, Evans, and Turner 
(1967). They name these clicks by their function, ''discrimination 
clicks" and "orientation clicks." The discrimination click of Tur- 
siops has a reduced bandwidth and emphasis of lower frequencies, 
while the orientation click has a wide bandwidth. In these respects 
they match the sounds heard from L. australis, though no be- 
havioral correlation was possible. 

Although two types of clicks were heard, one with a relatively 
restricted low frequency and other with broadband characteristics, 
it suggests the possibility that only one click type exists in reality 
and the variations noted result from changing orientation by an 
animal possessing a directional sound system. Other cetaceans have 
been shown to have such a directional sound field ( Tursiops, Nor- 
ris, Prescott, Asa-Dorian, and Perkins, 1961; Orcinus, Schevill and 
Watkins, 1966; Steno, Norris and Evans, 1967; and, Platanista, 
Evans in Herald et al., 1969). Our data is insufficient to rule out 
this possibility completely, but the evidence that we have seems to 
argue instead for two distinct click types: 

1 . The click durations of the two types are different. High fre- 
quency emphasis in a low frequency click would not shorten the 
length of the pulse but would simply extend the bandwidth. 

2. The two click-types suddenly interchange with no pause be- 
tween. We have no examples of a gradual shift from one type 
to the other and we have very few individual clicks whose char- 
acteristics are intermediate in form. Some of the subtle varia- 
tions observed in the higher frequency components of successive 
clicks of both types, however, may result from such direction- 
ality, though we did not have opportunity to observe any cor- 
relation of orientation with bandwith. 



6 BREVIORA No. 366 

Because of the difficulties we encountered in hearing the por- 
poises, we were impressed with the low level of their sounds. We 
also were acutely aware that it was not high background that 
obscured their sounds, since the ambient noise levels in this region 
were actually very low. Without carefully and recently calibrated 
equipment, such low sound-levels are difficult (and probably mean- 
ingless) to assess; however, our limitation much of the time ap- 
peared to be the self-noise of the equipment rather than the local 
ambient background. Perhaps the land barriers shielded the inland 
channels from the usual open sea sounds and at the same time 
provided enough shelter so that very little local wind and wave 
noise was generated. In addition, we recognized very little contri- 
bution of sound from other biological sources, and certainly these 
porpoises had but small influence on the local ambient sound. 

ACKNOWLEDGEMENTS 

We thank the Antarctic Research Program of the National 
Science Foundation for support and good help during the cruise 
on board R/V HERO. The acoustic analysis and preparation of 
this report were supported by the Office of Naval Research (Biol- 
ogy branch) under contract Nonr 4446 and Nonr 241.09, and by 
the National Science Foundation grant GA 1475. Experience and 
observation were shared with the other members of the scientific 
party aboard HERO; Kenneth S. Norris as chief scientist and 
George Harvey were particularly involved and helpful. We thank 
Elizabeth T. Bunce and Paul T. McElroy for criticism of the manu- 
script. 

LITERATURE CITED 

Herald, E. S., R. L. Brownell, Jr., F. L. Frye, E. J. Morris, W. E. Evans, 
AND A. B. Scott. 1969. Blind river dolphin: first side-swimming ceta- 
cean. Science. 166 (3911): 1408-1410. 

NoRRis, K. S., AND W. E. Evans. 1967. Directionality of echolocation clicks 
in the rough-tooth porpoise, Steno hredanensis (Lesson). In W. N. 
Tavolga (ed.), Marine Bio-Acoustics, vol. 2. Oxford, Pergamon Press. 
Pp. 305-314. 

Norris, K. S., W. E. Evans, and R. N. Turner. 1967. Echolocation in an 
Atlantic bottlenose porpoise during discrimination. //; R.-G. Busnel 
(ed.), Les Systemes Sonars Animaux, Biologic et Bionique, Jouy-en- 
Josas, France. Pp. 409-437. 



1971 PORPOISE SOUNDS 7 

NoRRis, K. S.. J. H. Prescott, P. V. Asa-Dorian, and P. Perkins. 1961. 
An experimental demonstration of echo-location behavior in the por- 
poise, Tursiops truncatus (Montagu). Biological Bull.. 120 (2): 
163-176. 

SCHEVILL, W. E., AND W. A. Watkins. 1966. Sound structure and direc- 
tionality in Orciniis (killer whale). Zoologica (N. Y.), 51 (2): 71-76. 

ScHEViLL, W. E., W. A. Watkins, and C. Ray. 1969. Click structure in the 
porpoise Phococna phocncna. Jour. Mammalogy. 50 (4): 721-728. 

Watkins, W. A. 1963. Portable underwater recording system. Undersea 
Technology, 4 (9): 23-24. 

Watkins, W. A. 1967. The harmonic interval: fact or artifact in spectral 
analysis of pulse trains. In W. N. Tavolga (ed.). Marine Bio- Acoustics, 
vol. 2. Oxford. Pergamon Press. Pp. 15-42. 



BREVIORA 



No. 366 




B 





/ msec/div. 

Figure 1. Oscillographic pictures of (A) the broadband click, (B) the 
narrowband click, and (C) the pulse modulation of the buzz. Ambient 
noise is superimposed on these sound traces. 



1971 



PORPOISE SOUNDS 



8000- 



Hz 



4000- 



I 




'1 



05 



Seconds 



Figure 2. Spectrographic analysis shows a burst of broadband clicks 
followed by narrowband clicks. Although the latter become much greater 
in amplitude as the animal conies closer, the frequency spectrum remains 
relatively restricted. The bandwidth of the analyzing filter is 300 Hz. This 
figure is the result of a repetitive analysis, with a small horizontal displace- 
ment of the paper between analyses to widen artificially the traces of these 
short-duration sounds for better photographic reproduction. 



Narrowband click 



Broadband click 



Bandwidth 

Principal frequency 

Duration 

Repetition rate 

Intensity (re 1 dyne/cm2) 



2 kHz 

1 kHz or less 

1.5 to 3 msec 

5 to 25 /sec 

— 20 db at principal 
frequency 



10 or 12 kHz 

from less than 1 to 5 kHz 

0.8 to 1 msec 

20 to 80/sec 

— 20db spread over 
bandwidth 



Table of characteristics of the two types of click 
heard from Lagenorhynchiis australis. 



10 



BREVIORA 



No. 366 



7000- 



5000- 



Hz 






2000- 



Seconds 



tw 



i \ 




^ai 



1.5 



Figure 3. Two simultaneous buzzes have empiiasis in the 4- to 5-kHz 
region as well as a strong fundamental at about 300 Hz. The analyzing 
filter bandwidth is 300 Hz. Compare Fig. 4. 



1000- 



Hz 



500- 




 ' ' Seconds 

Figure 4. The fundamental frequencies of the same two buzzes shown 
in Fig. 3 show variation in the region of 300 Hz. The continuous low fre- 
quency band is ship's propulsion noise from the HERO about 5 or 6 miles 
away. The analyzing filter bandwidth is 45 Hz. 



BREVIORA 

Mniseeim of Cojniiparative Zoology 

Cambridge, Mass. 15 January, 1971 Number 367 

MICROMISCHODUS SUGILLATUS, A NEW HEMIODONTID 

CHARACIN FISH FROM BRAZIL, AND ITS RELATIONSHIP 

TO THE CHILODONTIDAE 

Tyson R. Roberts 



Abstract. A new genus and species of Hemiodontidae, designated as 
a new subfamily, Micromischodontinae, is described from the lower Rio 
Negro and Middle Amazon of Brazil. Its osteology is described and 
figured. It appears to be the hemiodontid genus most closely related to 
Chilodontidae. The relationship between the functional and replacement 
teeth of the pharyngeals suggests the probable manner in which the peculiar 
pharyngeal teeth characteristic of Chilodontidae and Anostomidae evolved. 
A brief definition is given of the family Chilodontidae. 

ACKNOWLEDGEMENTS 

Dr. Stanley H. Weitzman, Division of Fishes, U.S. National 
Museum, suspected hemiodontids and chilodontids might be re- 
lated and mentioned this to me two or three years ago. He is now 
working on the relationships of these families and has graciously 
let me examine unpublished illustrations of chilodontid osteology. 
I am indebted to Sr. Heraldo Britski, curator of the fish collections 
of the Museu de Zoologia, Universidade de Sao Paulo, and leader 
of the Expediyao Permanente da Amazonia when the new fish was 
collected, for permitting me to prepare its description. Professor 
George S. Myers, Division of Systematic Biology, Stanford Uni- 
versity. Dr. Weitzman and Sr. Britski reviewed the manuscript. 



2 BREVIORA No. 367 

INTRODUCTION 

The hemiodontid herein described, collected by the Expedi^ao 
Permanente da Amazonia' in 1967, represents a new subfamily. 
While lacking certain morphological peculiarities of the highly 
specialized Chilodontidae, it nevertheless appears to be more 
closely related to them than is any other hemiodontid. In the 
light of its discovery, there can be little doubt that Chilodontidae 
and Hemiodontidae are indeed closely related. Although the 
pharyngeal teeth of this new form are single cusped, the relation- 
ship between functional and replacement teeth on the pharyngeals 
suggests the primitive condition from which the peculiar multi- 
cuspid pharyngeal teeth characteristic of Chilodontidae and 
Anostomidae presumably evolved. Its highly distinctive trophic 
structures indicate an unusual mode of feeding, perhaps similar to 
that of Bivibranchia, considered to have the most specialized 
trophic structures of all characoids. Nevertheless, it represents a 
hne distant from Bivibranchia (and the related but less specialized 
Argonectes) . 

Hemiodontidae are marvelously streamlined, swift-swimming 
fishes mostly six inches to a foot long. They form small groups in 
open water in big rivers and lagos. Hemiodus are known in Brazil 
as "voadores" because of their ability to jump. A group of 
voadores leaping away from predaceous fishes or over a seine net 
to safety is an impressive sight. Spawning presumably takes place 
in open water and the young probably grow up in aggregations 
staying near the bottom in fairly shallow open water. It appears 
to be unrecorded whether hemiodontids form huge schools or 
undertake major spawning migrations. 

Hemiodontids hitherto known readily fall into two subfamilies, 
Hemiodontinae and Bivibranchiinae, adults of which have multi- 
cuspid teeth in the upper jaw and no teeth in the lower jaw. The 
minute, unicuspid teeth and other features of the new fish differ so 
greatly from previously known forms that it represents a new sub- 
family. 



1 The Expedicao Permanente da Amazonia, under the direction of Dr. 
P. E. Vanzolini, is a cooperative effort among the Museu de Zoologia, 
Universidade de Sao Paulo (MZUSP); Instituto Nacional de Pesquisas da 
Amazonia (INPA) in Manaus; and Museu Goeldi in Belem. It is financed 
by the Fundagao de Amparo a Pesquisa of the state of Sao Paulo. Much 
attention has been devoted to fishes since fieldwork began in 1967. The 
fish collections are housed at MZUSP. 



1971 BRAZILIAN CHARACIN FISH 3 

MICROMISCHODONTINAE, new subfamily 

Highly streamlined, fusiform fishes typically hemiodontid in 
habitus and osteology. Teeth pedicellate, with a single strongly 
recurved cusp; tooth crowns black or brownish black, stalks deep 
yellow or yellowish brown. Each dentary and lower pharyngeal 
with two, nearly coextensive rows of 50-60 teeth. Teeth on upper 
pharyngeal arranged in numerous, extremly regular rows (as in 
Anostomidae). Upper jaw with a broad frenum, nonprotractile; 
roof of mouth with fine, linear ridges, without valvelike structures. 
Gill rakers elongate and numerous, with six to eight papillae on 
either side of each gill raker, forming a dense carpetlike hning to 
gill chambers. Lower pharyngeals exceptionally long and slender, 
tooth-bearing for virtually their entire length. Upper limb of 
second gill arch with a fleshy membrane forming a sort of pocket 
anterior to upper pharyngeals. Posterior face of fourth gill arch 
with ordinary gill filaments; face of fifth gill arch smooth; no dorsal 
diverticulum between fourth and fifth arches. Stomach reversed, 
that is, with cardiac portion (entrance of esophagus) posterior 
and pyloric portion anterior in position; pyloric caeca about thirty, 
not well differentiated; length of intestine in preserved specimens 
about equal to standard length, forming a single loop upon leaving 
stomach, then passing straight to vent. Posterior chamber of swim 
bladder about one-half of standard length or six times length of 
anterior chamber, terminating in a fine taper which extends to 
above base of last anal fin ray. Adipose eye-fid thick and very 
strong, extending from immediately behind nostrils well onto gill 
cover, and with a narrow vertical sfit over the pupil (Fig. 1). 

Cranial fontanels as in chilodontids and other hemiodontids, 
anterior fontanel linear and narrow, posterior fontanel slightly 
wider (Fig. 2). Size, shape, and position of jaw bones as in 
Hemiodus; a peculiar fenestra in tooth-bearing portion of dentary 
(a similarly located fenestra present in Hemiodus, absent in fore- 
shortened dentary of chilodontids). Anterior end of ethmoid with 
small lateral knobs. Circumorbital series with simple antorbital, 
supraorbital, and full complement of six infraorbitals; first infra- 
orbital smaller than those succeeding it (enlarged in Chilodon- 
tidae), j^econd through fourth infraorbitals each slightly larger 
than the preceding one. Branchiostegal rays five (five in Hemiodus 
and Argonectes, four in Chilodus and Caenotropus); proximal end 



4 BREVIORA No. 367 

of fourth branchiostegal ray greatly expanded; hyoid bar general- 
ized (apparently highly specialized in Chilodontidae). Gill mem- 
branes free from isthmus, united to each other at a point below 
middle of eye (broadly united to isthmus in chilodontids); isthmus 
scaled anterior to cleithral symphysis (scaleless in chilodontids). 
Three postcleithra; third (lowermost) postcleithrum with a lamel- 
lar, posteriorly directed extension (as in Hemiodus). Weberian 
apparatus and caudal skeleton without unusual modifications. 
Forty vertebrae, including Weberian apparatus. 

IVIICROMISCHODUS, new genus 

Nomendatiiral type-species: M. sugillatus, new species 

Body fusiform and highly streamlined. Secondary sexual di- 
morphism unknown (specimens at hand collected in November 
and December, with unripe gonads). Cranial roof smooth. Sides 
of head largely covered by adipose eye-lids. Nares nontubular, 
close-set and separated only by a flap flush with surface of head. 
Tip of snout extends slightly beyond included lower jaw. With 
mouth fully opened, gape almost vertical and about as large as 
eye diameter. With mouth closed, dorsoposterior edge of maxillary 
slips under first infraorbital bone; maxillary not extending as far 
back as anterior margin of eye, but only to below posterior nostril. 
Toothless portion of lower jaw (posterior to rictal membrane) 
about four or five times longer than tooth-bearing portion. Articu- 
lation of lower jaw below middle of eye; rictal membrane below 
nostril, distinctly in front of anterior orbital rim. Lateral line 
complete, slightly decurved anteriorly, then running just below 
lateral midline of body to last scale row on caudal base. 

Origin of dorsal fin midway between snout tip and base of 
caudal fin. Anal fin small. Caudal fin deeply forked. Dorsal, anal, 
and median caudal fin rays Vv'ith well-developed, overlapping, mem- 
branous lappets or alae (Fig. 1 ). Similar structures occur in many 
fast-swimming lower teleosts, including various other characoids, 
some cyprinoids and clupeoids, and Chanos. 

Known by a single species from the Middle Amazon and lower 
Rio Negro in Brazil. 

Derivation of name. Micromischodus is from the Greek micro, 
small, little; mischos, stalk, petiole, peduncle; and odous (odon), 
odontos, masc, tooth. 



1971 BRAZILIAN CHARACIN FISH 5 

M. SUGILLATUS, new species 
Figure 1 

Note. Standard lengths are used throughout this paper. Un- 
less stated otherwise, proportional measurements are expressed 
as times in standard length. Counts and measurements are given 
for the holotype first, followed in parentheses by the ranges for 
the paratypes. 

Holotype. MZUSP 6773, 152.0 mm, Igarape Tarumazinho, 
15 km NW of Manaus, on the left bank of the Rio Negro, 
Estado do Amazonas, 17-18 November 1967. 

Paratypes. MZUSP 8870, six specimens 125.0-144.6 mm, 
same data as holotype; MZUSP 6691, four specimens 107.3-137.1 
mm, Rio Negro, arredores de Manaus, Estado do Amazonas, 
15-23 November 1967; MCZ 46718, two specimens 118.4 and 
137.1 mm, Rio Canuma, Canuma (near Maues), Estado do 
Amazonas, 28-29 November 1967; MCZ 46719, seven specimens 
79.5-108.9 mm, Igarape do Rio Jamari, Terra Santa, Estado do 
Para, 14 December 1967. 

Proportional measurements. Greatest body depth (at origin of 
dorsal fin) 4.1 (4.0-4.5). Greatest body width (below dorsal 
fin) 5.7 (5.6-6.6). Least depth of caudal peduncle 11.4 (11.3- 
12.4). Distance from snout-tip to dorsal origin 2.01 (1.94-2.08). 
Length of caudal peduncle 7.45 (6.4-7.8). Head 3.4 (3.1-3.4). 
Eye 3.9 (3.4—4.1) in head. Bony interorbital space 3.8 (3.5-4.1) 
in head. Snout 3.5 (3.4-3.8) in head. Width of mouth (measured 
to outer sides of maxillaries) 4.1 (4.1-4.7). 

Fins. Fins, excepting caudal, scaleless. Dorsal fin rays 11 
(11 in all paratypes except one with 10), first two rays simple, 
last ray divided to its base. Proximal two-thirds to three-quarters 
of each ray with well-developed membranous lappets or alae, 
largely overlapping when fin is depressed. Dorsal fin margin 
falcate. Height of dorsal fin 4.7 (4.3-4.8). Base of dorsal fin 9.2 
(8.1-10.3). Anal fin small, about one-third as large as dorsal fin, 
with similar membranous lappets. Anal rays 10 (10), first two 
rays simple, last ray divided to its base. Height of anal fin 8.2 
(7.4-8.3). Anal fin margin falcate. Base of anal fin 12.4 (11.8- 
13.4). Caudal fin deeply forked. Lower caudal lobe slightly 
larger than upper caudal lobe, with its upper margin shghtly con- 
vex (Fig. 1). The lower caudal lobe is similarly modified in other 



BREVIORA 



No. 367 




00 

B 
4) 



c 
a 



B 
B 

q 



CO 

3 



u 
a 

■4-* 

45 



en 

a 



60 

s 

"n 

en 

a 
o 

tn 

s 

o 



u 



3 
oo 



1971 BRAZILIAN CHARACIN FISH 7 

fast-swimming characoids, for example in Hydrocynus goliath 
(Boulenger, 1899, pi. 11). Principal caudal rays 10 -f- 9. Median 
four to six rays with well-developed lappets. Procurrent rays 
moderately numerous (9 + 7 in 125-mm specimen), unspecial- 
ized. Adipose fin small, its base over posterior portion of anal 
fin base. Pectoral and pelvic fins with two or three peculiarly 
thickened and elongated scales forming a sheath for edge of outer- 
most rays. Pectoral fin rays 21 (18-22). Length of pectoral fin 
6.3 (5.3-6.5). Pelvic fin rays 11 (11), outermost ray only un- 
branched. Length of pelvic fin 7.0 (6.1-7.2). 

Scales. Scales cycloid, or with laciniate (but not ctenoid) 
borders. Body completely scaled, 57 (56-64) scales in a lateral 
series; about 21 (16-22) predorsal scales (irregularly aligned); 
11 (11 or 12) scales between lateral line and dorsal origin; 4 (4) 
scales between lateral line and pelvic insertion; 20 (17-22) scales 
between last dorsal ray and adipose fin; 15 (14-16) scales along 
midline between symphysis of cleithra and pelvic base; and 16 
(16-18) scales around caudal peduncle. Prepelvic scales below 
lateral line gradually increasing in size ventralwards; scales on 
abdomen about two or three times larger in diameter than scales 
above lateral line. Caudal fin beyond hypural fan with two or 
three rows of scales. 

Coloration in alcohol. After two years in preservative (fixed in 
formalin while alive and transferred to ethyl alcohol within a few 
months) the specimens are straw colored, darkest above. The 
most notable feature is the solid black or blue-black color on the 
membranes between the distal halves of all of the dorsal fin rays 
(but not on the rays themselves), (The hemiodontid Argonectes 
scapularis and chilodontid Tylobronchiis maculosus have similarly 
marked dorsal fins. ) Pectoral, pelvic, anal, and adipose fins color- 
less; caudal fin dusky, lower lobe of caudal becoming darker (but 
not as dark as dorsal fin) near its tip. A faint longitudinal stripe 
running length of the body but stopping at shoulder, not running 
through eyes or onto caudal fin. Above lateral line fine melano- 
phores lie beneath the scales and in concentrations paralleling 
exposed scale margins. Below lateral line melanophores almost 
entirely absent in some specimens; in other specimens melano- 
phores are virtually absent beneath the scales but are present 
along the scale margins. The reticulated pattern of vertically 
oriented spots thus produced is similar to the pattern present in 



8 BREVIORA No. 367 

all Chilodontidae, except that since the scales are much smaller, 
the spots are small and not as dark. In all specimens body dis- 
tinctly lighter below lateral line than above. Gill cover marked 
by an indistinct dark oval patch caused by a concentration of 
melanophores in the membrane lining inside of gill cover, which 
shows through the opercular bones. 

The trivial name sugillatus (Latin: sugillo, -atus, beaten black 
and blue; sugiUatum, black and blue spot, bruise) refers to the 
coloration on the dorsal fin and opercles. 

Ecological notes. According to Sr. Britski, specimens of M. 
sugillatus were collected by seining along shore in lakes or places 
with slow-flowing, black or crystalline water. A very large number 
of species, predominantly characins, was obtained at these locali- 
ties. The stomach contents of specimens from the Igarape do 
Rio Jamari include an assortment of bottom material, including 
many of what appear to be droppings of small fishes. Very small 
insects are well represented, including larval Diptera and, most 
abundant, a corixid (identified by Dr. John Lawrence) about L5 
mm long. These are about the largest organisms in the stomach 
contents. 

OSTEOLOGY 
Figures 2—15 

Illustrations of the osteology of M. sugillatus are based on a 
125.0-mm paratype from MZUSP 8870. Supplemental observa- 
tions were made on a 102.2-mm paratype from MCZ 46719. The 
nomenclature of bones follows Weitzman (1962) except that 
"vomer" and "intercalar" are used in place of "prevomer" and 
"opisthotic." 

Cranium (Figs. 2-4). Roofing bones of skull smooth and flat- 
tened. Cranial fontanels narrow, complete. Anterior fontanel 
linear and about half as wide as posterior fontanel for almost its 
entire length, but widening immediately in front of epiphyseal bar. 
Ethmoid narrow, with two lateral knobs anteriorly articulating with 
either premaxillary, ventro-lateral laminar projections immediately 
posterior to these knobs, and a median cleft in its posterior half 
(Fig. 2). Supraoccipital crest flat, not extending as far as end of 
cranium. Posttemporal fossae well developed. Dilator groove well 
developed, frontal participating in its formation; dorsal Umit of 



1971 



BRAZILIAN CHARACIN FISH 



antorbjtal 
nasa 



vomer 
ethmoid 



parietal 



epiphyseal bar 
lateral ethmoid 
frontal 



sphenotic 



epiotic 




exoccipital 



supraoccipital 



premaxillary 



infraorbital 6 



Dterotic 



Figure 2. Cranium of Micromischodiis siigillatiis (dorsal view), 
osteological figures based on 125-mm specimen from MZUSP 8870. 



All 



dilator groove marked by a concavity in dorsolateral margin of 
frontal bone; sphenotic spine lamellar, rounded at tip. 

Ethmoid separated from vomer by a cartilaginous septum (in- 
dicated by heavy stippling in Figure 3). Vomer with peculiar 
anterior knoblike processes on either side. Lateral ethmoid rela- 
tively large, with elongate, strutlike process articulating with knob- 
hke process of vomer (Figs. 3 and 4) and a small median projec- 
tion firmly articulated to antero-ventral comer of rhinosphenoid. 
Rhinosphenoid large, sharing strongly interdigitating sutures with 
antero-ventral projection of orbitosphenoid (Fig. 3). Cartilaginous 
septum between dorsal edge of rhinosphenoid and roof of cranium 
and another between ventral margin of rhinosphenoid and para- 
sphenoid (cartilage indicated by heavy stippling in Figure 3). 
Rhinosphenoid and orbitosphenoid not directly contacting para- 
sphenoid. Parasphenoid deeply cleft posteriorly, the thin divisions 
thus formed cleft at their tips (Fig. 4; compare with Weitzman, 
1962, fig. 4 of Brycon on p. 60; and Roberts, 1969, fig. 20 of 
Acestrorhynchus on p. 463). Intercalar well developed. Pterotic 
with strong posteriorly directed spine. 

Jaws and jaw suspension (Figs. 2, 5-7). The size and shape 
of the jaw bones and their relationships to each other are similar 



10 



BREVIORA 



No. 367 



lateral ethmoid ^"^""^^l ^Phenotic pterotjc parietal supraocclpital 



ethmoid 




vomer 



rhinosphenoid 

orbitosphenoid 

pterosphenold parasphenoid Prootic '"<ercalar "basioccipital 

Figure 3. Cranium of Microinischodus sugillatiis (lateral view). 



to those in Hemiodus. PremaxiUary with a slender, medially 
directed symphyseal process, round in cross section and blunt at 
the tip, which approximates but does not articulate or contact its 
opposite fellow. Lateral surface of premaxillary with a shelflike 
projection posterior to which is a groovelike depression into which 
snugly fits anterodorsal corner of maxillary. Dorsal portion of 



parasphenoid 

pterosphenold 
mesopterygoid 
palatine gctopterygoid 



hyomandibular 




epiotic 
basioccipital 



ethmoid 
vomer 



exoccipital 



lateral ethmoid 



frontal 
orbitosphenoid 



intercalar 
pterotic 



sp hen otic 



prootic 



Figure 4. Cranium of Miciomischodus sugillatiis (ventral view). 



1971 



BRAZILIAN CHARACIN FISH 



11 



premaxillary and maxillary firmly embedded in a tough connective 
tissue that binds them to tip of ethmoid although they do not con- 
tact it. Maxillary with dorsoposterior corner expanded and con- 
nected by a broad, strong ligament to palatine (Fig. 2). Maxillary 
bearing a short segment of cephalic sensory canal (Fig. 5). 

Dentary with a slender, median symphyseal process, round in 
cross section, blunt at the tip which approximates and is strongly 
joined by ligaments to its opposite fellow. Tooth-bearing portion 
of dentary elevated; rictal membrane attaches maxillary to lateral 
surface of elevated portion of dentary. Portion of dentary pos- 
terior to gape gradually diminishing in width, about twice as long 
as portion anterior to rictus; articulation with quadrate beneath 

infraorbitals 

supraorbital 



antorbital 

premaxillary 




ope re I e 
subopercle 



maxillary 



interopercle 



preopercle 



quadrate 



angular 



articular 



dentary 



Figure 5. Jaws and facial bones of Micromischodiis siigiUatiis (lateral 
view). 



middle of eye. Elevated portion of dentary with a peculiar fenestra 
below part of the tooth rows (Figs. 5-7); a fenestra identical in 
shape and position occurs in the toothless dentary of Hemiodus 
but is lacking in chilodontids. 

Premaxillary with about 14 minute moveable teeth. Maxillary 
toothless. Dentary with two coextensive rows of minute moveable 
teeth. The 125-mm specimen has about 54 teeth in outer row 
and about 60 (slightly smaller) teeth in inner row, uppermost ten 



12 



BREVIORA 



No. 367 



of which are nonpedicellate; replacement teeth much in evidence 
(Fig. 7). 

The palatine arch presents no unusual features. Metapterygoid- 
quadrate foramen well developed. Hyomandibular well separated 
from mesopterygoid. 

Facial bones (Figs. 5-6). Facial bones present no unusual 
features. Circumorbital series complete. Nasal bone tubular, 
laminar projections minute. Antorbital slender, struthke. Infra- 
orbitals six; infraorbitals 2-4 gradually increasing in size over ones 
preceding them. Infraortibal 1 not enlarged. Infraorbitals 3 and 
4 with tubes from postorbital branch of cephalic sensory canal 
system leading to their posterior margin (Fig. 5). 

Posterior bony margin of gill cover formed largely by sub- 
opercle; subopercle with well-developed, dorsally-projecting spine 
at anteroventral end. Preopercle with a slender tubular extension 
dorsally. Suprapreopercle absent. 

Visceral arches (Figs. 8-10). Hyoid arch without unusual fea- 
tures. Branchiostegal rays five (as in Hemiodus, Argonectes), 
first four articulating with ceratohyal, fifth with epihyal. Proxunal 
end of fourth where it connects with ceratohyal greatly expanded 
(see Fig. 9). 



premaxillary 
maxillary 

palatine 



dentary 
coronomeckelian bone 



opercle 




subopercle 



articular 



Interopercle 



preopercle 



Figure 6. Jaws, jaw suspension, and opercular bones of Micromischodus 
siigillatus (internal view). 



1971 



BRAZILIAN CHARACIN FISH 



13 




Figure 7. Tooth-bearing portion of dentary of Micromiscliodiis 
sugillattis (internal view). 



14 



BREVIORA 



No. 367 



ventral liypohyal 
dorsal hypohyal 




branch lostegal rays 



Figure 8. Hyoid arch, branchiostegal rays, and urohyal of Micro- 
mischodits siigillatiis (dorsal view). 



Pharyngeal teeth (Figs. 9 and 10). Lower phaiyngeals pecu- 
liarly elongate and bearing two rows of teeth for virtually their 
entire length. The recurved crowns of the teeth in anterior row on 
lower pharyngeal project forward; replacement teeth lie anteriorly 
to their bases (Fig. lOA). On the trailing edge of the lower 
pharyngeals is a row of smaller teeth with the recurved crowns 
projecting backwards; replacement teeth lie posterior to their 
bases (Fig. lOB). In 125-mm specimen about 64 teeth in anterior 
row and 60 in posterior row. 

At first glance the anterior and posterior rows of lower pharyn- 
geal teeth each appear to constitute two rows. This is because 



1971 



BRAZILIAN CHARACIN FISH 



15 




basihyal 
basibranchials 



hypobranchials 



ceratobranchials 



epibranchials 

suspensory pharyngeals 



upper pharyngeals 



lower pharyngeal 



Figure 9. Gill arches of Micromischodus sitgillatiis (dorsal view). Left 
side in normal position, right side with uppermost elements pinned out and 
to the side. 



not all of the teeth have assumed the "definitive" functional posi- 
tion; teeth just coming into position are out of line with the rest. 
Since none of the teeth are ankylosed to the bone, the borderline 
between teeth in functional position and replacement teeth is 
indistinct. Evidently some of the replacement teeth are "func- 
tional" before they are in the definitive functional position, and 
even before the functional teeth they are about to replace have 
fallen out. Tooth replacement is much in evidence, and probably 
occurs in waves proceeding the length of the lower pharyngeals. 
In some places a functional tooth may have two replacement teeth 
at its base (see Fig. lOB). These observed characteristics are 



16 



BREVIORA 



No. 367 



highly suggestive of the sort of situation from which the pedicellate 
multicuspid pharyngeal teeth of Chilodontidae and Anostomidae 
presumably evolved. If this view is correct, then successive cusps 
fused below the main cusp to the stalklike base are phylogenetic- 
ally equivalent to successive generations of replacement teeth. 





Figure 10. Lower pharyngeal teeth of Micromischodiis sugillatiis (pos- 
terior view). A, anterior row; B, posterior row. 



The upper pharyngeals bear numerous regularly arranged rows 
of teeth in which the crowns project backwards (in opposition to 
crowns of teeth in anterior row of lower pharyngeal which point 
forwards). The third suspensory pharyngeal bears a small patch 
of similar teeth. Gill rakers edentulous. 

The pharyngeal teeth, although morphologically similar to those 
in the jaws, are more solidly implanted and much larger (except 
for the teeth in the posterior row on lower pharyngeal); still, they 
are considerably smaller than the greatly enlarged and very solidly 
implanted pharyngeal teeth of Chilodontidae and Anostomidae. 
In the 125-mm specimen the teeth in the upper jaw are about 0.2 
mm long; the teeth in the outer row of the lower jaw are 0.4 mm 
long; the teeth on the upper pharyngeal and in the anterior row on 



1971 



BRAZILIAN CHARACIN FISH 



17 



the lower phaiyngeal are 1.0 mm long; and the teeth in the pos- 
terior row on the lower pharyngeal are 0.4 mm long. The highly 
regular arrangement of tooth rows on the upper pharyngeal is 
suggestive of the regular rows on the upper pharyngeals of An- 
ostomidae. The arrangement of teeth in the lower pharyngeals is 
unique. In most characoids, including Hemiodus, the teeth are 
in several irregular rows on an expanded portion of the lower 
pharyngeal near the midline; the distal half of the lower pharyngeal 
is usually toothless. 

Weberian apparatus (Figs. 11 and 12). Weberian apparatus 
showing no unusual features, similar to that of typical Characidae. 
Neural arch pedicle of third vertebra with a dorsally directed pro- 
cess tightly bound into a groovehke fossa in base of neural arch 
complex. Base of neural arch complex extends posteriorly so that 
its posteroventral surface almost contacts entire anterior face of 
neural spine of fourth vertebra. Rib of fifth vertebra with a 
medially directed process ligamentously attached to os suspen- 
sorium. Transverse process of third vertebra, which cradles inter- 
calarium, well developed. Lateral process of os suspensorium very 



neural complex 
claustrum 




neural arch of third vertebra 

transverse process of third vertebra 



supraneural 



neural arch and spine 
of fourth vertebra 



scaphium 



intercalarium 



pleural rib 



lateral process of second/ 

vertebra tripus' 



OS suspensorium 



Figure 11. Weberian apparatus of Micromischodus sugillatus (lateral 
view). 



18 



BREVIORA 



No. 367 



neural complex 



scaphium 



lateral process of centrum 2 




tripus 



rib of fifth vertebra 



OS suspensorium 
centrum 4 

centrum 5 



Figure 12. Weberian apparatus of Micromischodus sugillatiis (ventral 
view). 



large, overlying transformator process of tripus. Neural arch of 
third vertebra extending far anteriorly over second centrum (Fig. 
11). Lateral process of centrum 2 very large. 

Pectoral girdle (Fig. 13). Pectoral girdle without unusual 
specializations. Three postcleithra. Most distinctive feature is 
lamellar projection from proximal part of third postcleithra (simi- 
lar process present in Hemiodus); in other characoids third post- 
cleithrum slender for entire length. 

Pelvic girdle (Fig. 14). Ischiac process well developed; four 
radials; pelvic splint present; rays invariably 11. 

Caudal skeleton (Fig. 15). Caudal skeleton generahzed. Hy- 
purals 5 and 6 fused, rest separate. Two uroneurals. Three 
epurals. Principal caudal rays invariably 10 + 9. Nine upper 
and seven lower procurrent rays in 125-mm specimen. 



' 



197 



BRAZILIAN CHARACIN FISH 



19 



posttemporal 



supracleithrum 



postcleithra 



extrascapular 




coracoid 



Figure 13. Pectoral girdle of Micromischodus sugillatus (internal view). 
Inset: external view of extrascapular and posttemporal. 



20 



BREVIORA 



No. 367 





radials 



ischiac process 



Figure 14. Pelvic girdle of Micromischodus sugillatus (ventral view). 
Enlarged view on right side with radials exposed by removal of outer half 
of each lepidotrich. 



1971 



BRAZILIAN CHARACIN FISH 



21 



upper procurrent rays 



epurals 



uroneural 2 
hypural I 
hypural 2 



uroneural I 
neural spines 




haemal spines 



upper principal rays 



hypural centrum 

hypural 7 

lower principal rays 
lower procurrent rays' 
Figure 15. Caudal skeleton of Micromischodus sugillatiis (lateral view). 



22 BREVIORA No. 367 

DEFINITION OF THE FAMILY CHILODONTIDAE 

A definition of the family Chilodontidae is given here primarly 
for comparison with Micromischodontinae. This definition is not 
the result of thorough researches of all taxa involved; it is an- 
ticipated that studies in progress by Weitzman will gready extend 
knowledge of the group. Trophic structures were emphasized in 
defining Micromischodontinae, as they will also be in the following 
definition. Modification of trophic structures has been the main 
theme in the great adaptive radiation of characoids. Trenchant 
differences in feeding habits and trophic structures characterize 
most genera and higher taxa, and it is natural to emphasize these 
differences in definitions. Some important modifications which do 
not directly involve trophic structures are nevertheless strongly 
linked to modes of feeding, viz., swimming position in Chilo- 
dontidae and Anostomidae. Parenthetically, any attempt to work 
out a phyletic classification of the higher characoid taxa must 
necessarily give major consideration to the evolution of their 
trophic structures. 

Chilodontidae. Characoid fishes reaching about 150 mm in 
standard length which spend much of the time in an oblique head- 
down swimming position. In many regards — including position 
of fins, approximate number of fin rays, and general cranial osteol- 
ogy — they are like Hemiodontidae. They differ from the Hemi- 
odontidae in having the skull, including the lower jaw, and the 
whole body relatively short, and in their trophic modifications. 
Number of scales considerably less than in Hemiodontidae (about 
25-30 vs. 50-125). Pectoral fin with 13-16 rays (18-23 in 
Hemiodontidae). Vertebrae including Weberian apparatus 33 in 
Chilodus, 35 in Tylobronchus (Eigenmann, 1912: 271-273). 

Lower jaw behind rictal membrane greatly foreshortened; first 
infraorbital enlarged; jaw teeth and pharyngeal teeth reduced in 
number. Premaxillary with a single row of conical {Caenotropus, 
Chilodus) or bicuspid {Tylobronchus), stalked teeth; lower jaw 
with a single row of conical, stalked teeth {Chilodus, Tylo- 
bronchus) or no teeth in large adults {Caenotropus). Teeth em- 
bedded in lips and freely moveable, not ankylosed to jaw bone. 
Upper and lower pharyngeals with enlarged teeth with two, three, 
or more cusps ossified to a stout, stalklike base. In Chilodus, 
lower pharyngeal teeth confined to a small, round patch in the 



1971 BRAZILIAN CHARACIN FISH 23 

center of a large, bowllike depression formed by concave dorsal 
surfaces of the greatly expanded (and highly peculiar) lower 
pharyngeal bones. Posterior face of fourth arch and exposed face 
of fifth arch bearing complementary rosettes of what appear to be 
modified gill filaments covered with tiny papillae and with tough 
booklets at their distal ends, evidently adapted to food selection 
(see Gery, 1964, fig. 2 on p. 63). Gill rakers reduced in number; 
bony lamellae of gill rakers reduced or absent in Chilodiis (in- 
variably well developed in Hemiodontidae). Gill membranes 
tightly bound to posteriormost part of isthmus, i.e., immediately 
in front of base of pectoral girdle (free in Hemiodontidae). Hyoid 
bar highly modified. Branchiostegal rays four (verified in Caeno- 
tropiis and Chilodus). Isthmus scaleless. Caudal fin less forked 
and anal fin larger than in Hemiodontidae. Membranous lappets 
on dorsal, anal, and caudal fins reduced. Adipose eyelid reduced. 
Distal half of dorsal fin wholly or partly covered with a black or 
bluish black color, which partly breaks up into spots in Chilodus; 
sides of body with a punctuate color pattern, spots borne on in- 
dividual scales, and usually with a dark, longitudinal stripe on 
the midline extending through the eye onto the middle of the caudal 
fin. 

1 have pointed out (Roberts, 1969: 424, 442) that Chilo- 
dontidae and Anostomidae have similar multicuspid pharyngeal 
teeth, and suggested that perhaps the Chilodontidae should be 
regarded as a subfamily of Anostomidae. In the light of the present 
study, I still feel that the two groups are closely related, but am 
inclined to regard Chilodontidae as of family rank. The chilo- 
dontids are set oflf from Anostomidae by the specialized structure 
of their fourth and fifth gill arches and form a small group of 
clearly related forms. And while it seems clear that the chilo- 
dontids are related to the Anostomidae, the anostomid genus 
closest to them cannot be singled out. Furthermore, the chilo- 
dontids show equally clearly indications of relationship with 
Hemiodontidae — a relationship closer than I previously had 
thought likely. Thus the reasonable solution for now, and one 
which may prove of lasting value, is recognition of three families, 
Hemiodontidae, Chilodontidae, and Anostomidae. It will be noted 
that the Anostomidae form a "well-knit" group of some ten or 
eleven genera. 



24 BREVIORA No. 367 

COMMENTS ON HEMIODONTINAE 
AND BIVIBRANCHIINAE 

The Hemiodontinae comprises Hemiodus (but see Gery, 1963), 
with numerous species differing sharply in color patterns and scale 
counts (see Bohkle, 1955) and two or three closely related genera 
of doubtful distinctness and confusing nomenclatural status (see 
Gery, 1961; 1963). The Bivibranchiinae comprises three quite 
distinct genera, each with but one or two species, Argonectes 
(Bohlke and Myers, 1956), Atomaster (Eigenmann and Myers, 
1927) and Bivibranchia. Briefly, the Bivibranchiinae have a highly 
protractile upper jaw with tricuspid teeth, and highly specialized 
trophic structures in the roof of the mouth and in the pharynx. 
The nature of their pharyngeal teeth has yet to be elucidated. Of 
the three genera, Argonectes is least specialized and approaches in 
some respects the Hemiodontinae, which have relatively nonpro- 
tractile upper jaws with multicuspid teeth of eight or nine cusps, 
and relatively generalized oral and pharyngeal passages. 

In neither of the two subfamiUes do adults have teeth in the 
lower jaw. The dentition of young Hemiodus, however, is very 
different from that of adults. According to Gery (1963: 604), in 
alevins of Hemiodus (tentatively identified as H. unimaculatus) 
up to 17.3 mm in standard length, there are but six to eight teeth 
on the premaxillaries, these teeth having fewer cusps than those 
in adults, and the dentary bears four or six very small conical teeth, 
visible only with strong magnification. We may feel fairly secure 
in supposing (Roberts, 1967) that the earliest dentition in 
Hemiodus consists of small conical teeth in both upper and lower 
jaws. As Hemiodus grow, presumably the upper jaw teeth increase 
in number and are replaced by teeth with successively more cusps, 
whereas the conical teeth in the lower jaw are replaced relatively 
few times, if at all, and drop out altogether at a fairly early stage. 

Menezes and Oliveira e Silva (1949) reported that stomach 
contents of Hemiodus parnaguae from the Rio Parnaiba in Piaui, 
Brazil, contain mud, algae, and remains of higher plants. No in- 
formation is available on food habits of Bivibranchiinae. I suspect 
that Bivibranchia take a mouthful of sand, sort food particles out 
in the gill chambers and then spit the sand out of the mouth. 
Gery (1969: 836) stated that Bivibranchia bury themselves in 
sand "like sand-eels" but gave no further details. Possibly this 
observation involves a feeding activity. 



1971 BRAZILIAN CHARACIN FISH 25 

LITERATURE CITED 

BoHLKE, J. E. 1955. Studies on fishes of the family Characidae. — No. 
lU. Notes on the coloration of the species of Hemiodiis, Pterohemiodiis 
and Aiiisitsia, with the description of a new Hemiodiis from the Rio 
Negro at the Brazil-Colombia border. Acad. Nat. Sci. Philadelphia, 
Notulae Naturae, No. 278: 1-15. 

, AND G. S. Myers. 1956. Studies on fishes of the family 

Characidae. — No. 11. A new genus and species of hemiodontins from 
the Rio Orinoco in Venezuela. Acad. Nat. Sci. Philadelphia, Notulae 
Naturae, No. 286: 1-6. 

BouLENGER, G. A. 1899. Materiaux pour la Faune du Congo. Poissons 
nouveaux du Congo. Ann. Mus. Congo (Tervuren), Zool., ser. 1, 
1 (pts. 1-6): 1-164. 

EiGENMANN, C. H. 1912. The fresh-water fishes of British Guiana. 

Mem. Carnegie Mus., 5: xxii -\- 578 pp. 
, AND G. S. Myers. 1927. A new genus of Brazilian characin 

fishes allied to Bivibranchia. Proc. Nat'l. Acad. Sci. (Washington), 

3(8): 565-566. 

Gery, J. 1961. Pterohemiodiis liielingi sp. nov.. un curieux poisson 
characoide a nageoire dorsale filamenteuse, avec une cle des genres 
d'Hemiodontinae (Ostariophysi-Erythrinidae). Bonner Zoologische 
Beitrage. 314(12): 332-342. 

. 1963. Sur la nomenclature et la systematique du genre 

Hemiodiis Miiller (Pisces, Characoidei). Bull. Mus. Nat'l. Hist. Nat., 
ser. 2, 35(6): 598-605. 

1964. A review of the Chilodinae, with a key to the 



species. Tropical Fish Hobbyist, May, 1964: 5-10, 63-67. 
1969. The fresh-water fishes of South America. In Fitlkau, 



E. J., et alia (editors), Biogeography and Ecology in South America. 
Vol. 2, pp. 828-848. The Hague, Junk. 

Menezes, R. S. and S. L. Oliveira e Silva. 1949. Alimentagao de 
voador, "Hemiodus parnaguae" Eigenmann and Henn, da bacia do Rio 
Parnaiba, Piaui. Rev. Bras. Biol., 9(2): 241-245. 

Roberts, T. R. 1967. Tooth formation and replacement in characoid 
fishes. Stanford Ichth. Bull., 8(4): 251-259. 

1969. Osteology and relationships of characoid fishes, par- 
ticularly the genera Hepsetiis, Salminiis, Hoplias, Ctenoliiciiis, and 
Acestrorhynchus. Proc. California Acad. Sci., ser 4, 36(15): 391-500. 

Weitzman, S. H. 1962. The osteology of Brycon meeki, a generalized 
characid fish, with an osteological definition of the subfamily. Stan- 
ford Ichth. Bull., 8(1): 1-77. 



BREVIORA 



Museium of Compsirative Zoology 

Cambridge, Mass. 29 January, 1971 Number 368 

STRUCTURAL HABITATS OF WEST INDIAN ANOLIS 
LIZARDS I. LOWLAND JAMAICA 

Thomas W. and Amy Schoener^ 



Abstract. This paper reports differences in structural and climatic 
habitat among the commonest Anolis species of three lowland Jamaican 
localities. Three of the species studied, grahami, opalinus, and valencienni, 
occurred at all localities; two other species, sagrei and Uneatopiis, occurred 
at one (Whitehouse) and two (Port Antonio, Mona) localities, respec- 
tively, and thus were complementary. 

With a few exceptions, the ordering of species by height, from highest 
to lowest, was valencienni, grahami, opalinus, and Uneatopiis or sagrei; the 
ordering by diameter, from thickest to thinnest, was opalinus, grahami, 
lineatopus or sagrei, and valencienni; the ordering by insolation, from 
sunniest to shadiest, was sagrei, grahami, valencienni, lineatopus, and 
opalinus; the ordering by size, from largest to smallest, was valencienni, 
lineatopus, grahami, sagrei, and opalinus. Within species, larger individuals 
tended to occur higher and on thicker perches, smaller individuals lower 
and on thinner perches. 

The above orderings result in low interspecific spatial overlap of similarly 
sized individuals in two ways. First, a direct relationship between body size 
and perch diameter within species and an inverse one between species 
ensures that spatially abutting species will overlap most their respective 
individuals least alike in size. Second, a direct relationship within species 
between size and height also, except for valencienni and grahami, results 
in the greatest spatial overlap being between the most dissimilarly sized 
individuals. 

Many statistically significant associations were found between the habitat 
and climatic variables; the most common was a tendency for thin perches 
to be more often occupied in the sun. 



1 Biological Laboratories and Museum of Comparative Zoology, Harvard 
University, Cambridge, Mass. 02138. 



2 BREVIORA No. 368 

This is the first of a series of papers describing in a standard 
way the structural habitat of some West Indian Anolis Hzards. Its 
primary purpose is to document differences between the size and 
sex classes of all the Anolis species found within a particular, 
limited study area. Between-site comparisons will be drawn occa- 
sionally; however, because of the great intersite variation in vege- 
tation structure and its effect on lizard habitat distributions, that 
aspect will be described and analyzed in detail in a larger work 
covering much of the western Caribbean. 

The "structural habitat," a term first invented by Rand (1964) 
for Anolis, refers to the spatial niche of a species population de- 
scribed in terms of characteristics of the vegetation and other 
structures upon which these arboreal animals carry out their activi- 
ties. The two such characteristics that Rand originally used and 
that have subsequently proven most useful in discriminating the 
various species or species-classes are perch height and perch 
diameter (Rand, I.e., 1967a; Rand and Rand, 1966; Schoener, 
1968; Schoener and Gorman, 1968; Laska, 1970), and these will 
be the ones used below. Other possible structural characteristics 
are perch texture, perch color, and the size and nature of the plant 
or other object to which the perch is attached. 

Observations that combine to give an overall picture of the 
spatial dimensions of the niche must be summed over a given 
time period and over a particular set of individuals. The method 
chosen in this and succeeding studies is to lump together "first 
sightings" recorded continuously throughout the day or throughout 
the period of maximum activity from a population of several hun- 
dred animals for each of the the commonest species. Thus, ideally, 
the sites of the major activities — thermoregulation, searching for 
food, capturing and eating prey, and social interaction — are 
weighted when observations are combined according to that frac- 
tion of the day spent by the average individual in the particular 
activity. 

There are several hmitations and qualifications of the structural- 
habitat concept which must be mentioned at the outset. 

First, it does not provide a true picture of the animals' daily 
perch distribution, because inconspicuous animals are more often 
missed. This means that the most visible activities, feeding or fight- 
ing, for example, are disproportionately weighted in the totals. In- 
conspicuousness is perhaps less of a problem for continuous 
observation of single individuals than for "first sightings." 



1971 JAMAICAN ANGLES 3 

Second, weighting activities in proportion to the amount of time 
they take will not necessarily produce the most meaningful measure 
of a species' spatial distribution, either for testing hypotheses of 
optimal individual behavior or of community composition. For 
example, it may be most useful to know the places where prey are 
captured in order to determine how similar species can be and still 
coexist, but this activity consumes a very small amount of time, and 
Andrews (1971) and Trivers (personal communication) have 
both shown that distributions of feeding sites can differ markedly 
from the overall structural habitat. However, taxonomic break- 
down of the prey of the four Bimini Anolis has shown that the 
prey is qualitatively what would be predicted from the overall 
structural habitat (Schoener, 1968). 

Third, consideration of structural habitat alone provides an in- 
complete picture of the total niche of a species. The most impor- 
tant other kind of property characterizing the space in which an 
anole lives is climatic; some measure of this is given below for 
certain situations. A second important way in which animals of 
the same structural habitat may differ is in the prey selected from 
the habitat. 

Fourth, structural habitat as determined by first sightings is a 
static concept: it says nothing about how an animal gets from one 
part of its home range to another, nor indeed about how perches 
of various heights and diameters are actually connected together 
in the habitat. Knowledge of the movements of animals is essen- 
tial for certain kinds of studies, for example, those on foraging 
strategies, and may provide some indication of the type of prey 
captured. This limitation for Jamaican Anolis is important: Trivers 
(personal communication) has shown that valencienni differs 
strikingly from some other Jamaican anoles (e.g., lineatopus) in 
its active but cautious manner of searching for prey. The limitation 
should be kept in mind when valencienni is compared to the other 
species below. 

Despite these disadvantages, the structural habitat has proven a 
useful "summary statistic" in describing Anolis communities. It 
has the great advantage that large populations of animals can be 
sampled quickly, thus permitting several such populations to be 
studied in a season. More balanced and detailed intralocality 
studies of Anolis populations are better for many purposes but 
are impractical for the study of the geographic variation of the 
niche. Hopefully, as greater numbers of these detailed studies 



4 BREVIORA JNO. 368 

become available, it will be possible to set up correspondences — 
e.g., animals which are often found on leaves take large numbers 
of aphids — between the many properties measured in the detailed 
studies and the few properties of the overall structural habitat. 
Then some supposition can be made concerning the geographic 
distribution of many more species characteristics than those ex- 
plicitly given as the "structural habitat." 

FORMAT 

The format for reporting the results in this and succeedmg papers 
will begin with a description of the localities studied, including a 
list of the Anolis lizards seen. This will be followed by a verbal 
summary of the results for each locality, accompanied by tables 
depicting the structural habitat of the lizard classes considered, as 
well as by a table indicating the statistical significance of differ- 
ences in the habitat variables between all possible pairs of the 
lizard classes. Finally, some relation will be made of the results 
to previous studies of the species in question and to studies of the 
habitats of species from other areas. 

METHODS 

Structural habitats were estimated by the "censusing" method 
first developed by Rand (1964). In a transect through the study 
area, each new lizard seen, unless obviously disturbed by the 
observers, is noted as to its perch height, diameter, and (some- 
times) insolation. Rand (1964, 1967a) and Schoener (1968) 
have pointed out the possible errors in this technique, including 
the especially serious one of differential visibility of various por- 
tions of the habitat. Thus lizards, sitting, for instance, on the tops 
of leaves in the canopy, are often likely to escape detection. How- 
ever, the direction of difference between lizard groups within a 
given site should not usually be affected by this kind of error. We 
did most of the observations as a pair, using binoculars, the two of 
us crisscrossing the habitat about 10 to 20 feet apart; this technique 
probably reduced considerably the chance of missing lizards. Study 
areas were often censused several times per day, but as a rule no 
part of the area was censused at intervals closer than one and a 
half hours; observation of lizard behavior in the interval indicates 
that this was ample time for the animals to "recover" from dis- 
turbance. 



1971 JAMAICAN ANGLES 5 

Data were cast into standard tables for easy intergroup compari- 
son of structural habitat (Tables 1-4). For each lizard class for 
which microclimatic information was taken, observations of cli- 
matic categories — sun, shade, and clouds — were lumped into a 
single structural habitat table. Additionally, however, the percent 
occurrence in the three climatic categories were Hsted separately 
for each class (Table 5). 

A powerful new technique of multivariate analysis was used to 
compute the statistical significance of habitat differences among 
the various groups of lizards. The technique utilizes the iterative 
procedure of Deming and Stephan (1940) and was recently ex- 
pounded by Bishop (1969). It is designed to detect associations 
between variables — in our case perch diameter, perch height, lizard 
class, and insolation — of complex contingency tables; thus it can 
handle both nominal and ordinal variables. Because it also simul- 
taneously considers associations between the habitat variables per 
se, this technique should largely eliminate any apparent difference 
in habitat among lizard classes caused entirely by the structure of 
the vegetation. For example, were relatively high perches always 
also relatively thin perches, a lizard class which occupied signifi- 
cantly higher perches, in the statistical sense, would not necessarily 
occupy significantly thinner perches, because of the strong height 
versus diameter interaction. Details of the application of the 
method to our data are given in the appendix (see also Schoener, 
1970). The reader not famihar with these techniques should first 
consult the paper by Fienberg (1970), which is an exposition of 
the method written especially for ecologists. 

THE SPECIES 

There are seven species of Anolis described for Jamaica (Under- 
wood and Williams, 1959). 

Two of the species — sagrei and grahami — can be characterized 
as inhabiting strictly lower and middle elevations. A. grahami is 
very widespread, occurring abundantly throughout the lowlands. 
Ty^icdX grahami (subspecies grahami) are medium-sized {' snout- 
vent length (SVL) = 65.5 mm; 9 SVL = 44.0 mmy green to 



1 Means are of the largest third of all specimens examined (see Schoener, 
1969). 



6 BREVIORA No. 368 

green-blue lizards occurring in all areas but the northeast, where 
they are replaced by grahami aquarum, a somewhat smaller 
(^ SVL = 61.8 mm; 9 SVL = 45.1 mm), bright emerald green 
lizard. A. sagrei, a medium-small (^ SVL = 50.4 mm; 9 SVL = 
40.9 mm) brown species, is restricted in habitat on Jamaica, occur- 
ring only over the western portion of the island and there confined 
to the openest, sunniest areas. It is often associated with rocks. 
Apparently, sagrei has invaded Jamaica from Cuba and is in the 
process of spreading eastward (Underwood and Williams, 1959; 
Williams, 1970). 

Another primarily low and middle elevation species is lineatopus. 
This medium-sized (^ SVL = 62.7 mm; 9 SVL = 43.6 mm) 
lizard is perhaps the most varied in its coloration and pattern: four 
subspecies are recognized, some of which are found in dry open 
areas and others of which are restricted to the darkest forest 
(Underwood and WilUams, 1959). 

Two species have been recorded from the lowlands to c. 4500 
feet. A. opalinus, slightly smaller than sagrei (^ SVL = 49.5 mm; 
9 SVL = 40.5 mm), comes in varying patterns and shades of 
brown and grey. There is scarcely a locality in Jamaica that does 
not have this species, though in the lowlands it is restricted to the 
shadiest areas and in the uplands is found in very open situations 
(Underwood and WilUams, 1959; Rand, 1967; this paper). The 
grey-white, medium-large (^ SVL = 79.4 mm; SVL = 68.5 mm) 9 
valencienni seems not to reach the density that the aforementioned 
species sometimes do but is found throughout Jamaica, including 
some areas above 4000 feet. It appears to be commoner in open 
than in heavily shaded situations, but by no means is absent from 
the latter (see below). 

The above five species are the ones which occurred commonly at 
one or more of the three localities studied, and which are therefore 
included in the comparisons to follow. A sixth species, the "green 
lizard" garmani, was seen at each of the three study sites, but rarely. 
It is the largest of the Jamaican anoles (^ SVL = 110.0 mm; 9 
SVL = 82.5 mm) and occurs throughout the island at all eleva- 
tions (Underwood and Williams, 1959). However, it is most 
abundant relative to other Anolis species at middle elevations 
(e.g., Trivers, MS, and below), though it is also known to be 
common at certain lowland localities, such as the "ironshore" vege- 
tation along the northwest coast. The seventh species, reconditus, 



1971 JAMAICAN ANGLES 7 

is restricted to middle and upland elevations and has only recently 
been discovered (Underwood and Williams, 1959; Lazell, 1966). 

LOCALITIES 

Three lowland localities were selected for study, representing a 
wet, a rather dry, and a mesic area. 

The first, about ten acres in extent, was located east of the town 
of Port Antonio, on Jamaica's northeast coast. Specifically, it ex- 
tended over the northwestern edge of a point of land supporting 
the ruins of an estate locally referred to as the "Folly." The vege- 
tation was quite secondary: planted trees and shrubs, such as Ficus, 
limes, palms, and mango trees intermingled with native vegetation 
such as Tenninalia. This locality had, however, become consider- 
ably overgrown, and there then existed, side-by-side, an area of 
almost continuous canopy and oftentimes sparse understory on the 
one hand, and an area of widely spaced trees and shrubs with 
much low, tangled herbaceous vegetation on the other. Both areas 
were studied and will be discussed separately as "Port Antonio 
Open" and "Port Antonio Closed." 

The locality was worked 30 June-1 1 July 1967. Despite the fact 
that Jamaica was then undergoing one of its most intense droughts, 
rain fell fairly frequently though not protractedly; the area averages 
131 inches of rain per annum (Handbook of Jamaica, 1966). The 
anoline species grahami aquarum, lineatopus lineatopus (or inter- 
mediates betwen lineatopus and ahenobarbus) and, to a lesser 
degree, opalimis and valencienni were abundant in the open area; 
the species opalimis and lineatopus, and to a much lesser degree 
valencienni, were common in the closed area. 

The second study site, about four acres in extent, was located at 
Mona, near Kingston, in tall, open forest near the base of Long 
Mountain. It apparently was marginal to Rand's (1967) "Mona 
bush" study area, but differed in its much greater preponderance 
of grahami. Vegetation in this area consisted of large trees and 
smaller woody shrubs of typical tropical dry forest aspect: thorns, 
flattened canopies and small, numerous leaves. The understory, in 
addition to the shrubs, was mostly grass of about one to two feet 
in height, but certain patches were practically cleared while others 
had a more varied herbaceous vegetation. The latter appeared seri- 
ously affected by the drought. The site in general falls within 
Asprey and Robbins' (1953) "dry limestone scrub forest." 



8 BREVIORA No. 368 

The area was studied 13-18 July 1967. Rainfall was almost non- 
existent during this period. The nearby Hope Gardens record 51 
inches of rain per year (Handbook of Jamaica, 1966), though 
because of the extreme microgeographic variation in climate found 
on the Greater Antilles, this figure may not be the same as that 
for the study site itself. The anoline species grahami grahami, 
lineatopus lineatopus and opal'mus abounded in the area. In addi- 
tion, valencienni was not uncommon. 

The third study area was located about one mile west of White- 
house, near the southwest coast. It consisted of groups of trees 
and shrubs of mesic to xeric aspect, which remained after partial 
conversion into pastureland. The portion of this area closest to the 
coast was planted in limes and pimentos; further upland, patches of 
native trees merged gradually into unbroken forest. In places, con- 
siderable grassy and rocky areas showed effects of heavy grazing. 
The vegetation is labelled by Asprey and Robbins (1953) "culti- 
vated pasture or second growth scrub," bordered by remnants of 
"dry limestone scrub forest," or by forest transitional between that 
and "wet limestone forest." The total area considered encompassed 
about 15 acres, though parts of it were not included in the censuses. 

The area was studied 21-27 July 1967. Weather was regular and 
cychcal during that time, sunny mornings giving way to overcast 
or partly cloudy afternoons, accompanied sometimes by heavy 
downpours. A nearby town (Bluefields) logs 91 inches of rain 
per annum (Handbook of Jamaica, 1966). The form grahami 
grahami occurred throughout the study area. The other two com- 
mon species, sagrei and opalimis, were restricted to open and closed 
areas respectively, and their horizontal ranges, though interdigitat- 
ing, overlapped Uttle at the same time of day. A fourth species, 
valenciemii, was seen rarely. The investigation of the opalimis- 
grahami area has been partly reported in a different context 
(Schoener, 1970) but will be reiterated in entirety below so as 
to standardize its results. 

RESULTS FOR LIZARD STRUCTURAL HABITATS 

In the following discussion, all comparisons, unless stated other- 
wise, are statistically significant (Tables 6-9) as judged by the 
technique described in the appendix. Statements in the text to 
follow, such as lizards of species A "occurred higher" or "were 



1971 JAMAICAN ANGLES 9 

higher" than those of species B, should be interpreted as descrip- 
tive of the modal individual or the bulk of the population rather 
than of all individuals in the species' population. Large lizards 
could always be distinguished as adult males and will generally be 
referred to hereafter simply as "males." Smaller lizards included 
mostly adult or subadult females but also included some subadult 
males; they were all lumped into the class "female-sized lizards" 
because they could not usually be distinguished in the field. When 
sufficiently abundant, the smallest lizards — "juveniles" — are con- 
sidered separately. 

Mona (Tables 1, 6). At Mona, ten classes of lizards in four species 
were considered. 

The highest lizard species observed was valencienni: males occurred 
higher than any other class, and female-sized valencienni were higher than 
all but grahami males. A. grahami was the next highest species: its males 
occurred higher than all classes of lineatopus and opalinns. The males of 
opalinus occurred higher than female-sized grahami and all lineatopus. 
Female-sized grahami were higher than all lineatopus and female-sized 
opalinus. Male lineatopus occurred higher than female-sized opalinus and 
grahami juveniles. Female-sized opalinus occurred higher than grahami 
juveniles and female-sized or juvenile lineatopus. Juveniles of grahami were 
higher than female-sized and juvenile lineatopus. 

A. opalinus as a species was on perches of the greatest diameter; males of 
this species were on significantly thicker perches than all classes but male 
grahami, and only the latter occupied thicker perches than female-sized 
opalinus. Male grahami were also on thicker diameters than any other 
interspecific class. Female-sized opalinus and male lineatopus had about 
the same perch diameters but were on thicker perches than valencienni 
and female-sized or juvenile grahami and lineatopus. Female-sized grahami, 
valencienni, and lineatopus all occurred on thin perches of nonsignificantly 
different diameter. Juveniles of lineatopus and grahami occupied the small- 
est perches, the latter the smallest of all. 

Intraspecifically, in all four species males perched higher than did female- 
sized individuals, and female-sized individuals in grahami and lineatopus 
occurred higher than did juveniles. In all but valencienni, males frequented 
thicker perches than did female-sized individuals, and in grahami and 
lineatopus, female-sized lizards were on thicker perches than juveniles. 

Although climatic observations were not recorded at Mona, our impres- 
sion is that the species tended to separate the way Rand (1967a) has de- 
scribed for a nearby area: grahami and valencienni were in the openest, 
sunniest situations; lineatopus was intermediate; and opalinus was in the 
shadiest areas. Relatively shady areas at Mona are associated with large- 
diametered trees, and the comparatively small opalinus preferred trees 



10 BREVioRA No. 368 

whose diameters were bigger than those for any group but grahami males. 

Port Antonio Open Area (Tables 2, 7). The classes studied in the open 
segment of the Port Antonio site were the same as those observed at Mona. 

In relative height, the lizard classes were arranged in nearly identical 
fashion to those at Mona. Male valencienni were the highest, as before, 
followed by grahami males, which were here significantly higher than female- 
sized valencienni. Probably the greater number of low thin-branched shrubs 
in relation to trees in the open area at Port Antonio is responsible for this 
discrepancy with the Mona area. Next in height were male opaliniis, higher 
than female-sized and juvenile grahami as well as all classes of lineatopus. 
Female-sized grahami and opalinus were distributed over similar heights 
and were higher than any class of lineatopus. Males of lineatopus were 
higher than juvenile grahami, but the latter were higher than female-sized 
or juvenile lineatopus. 

In diameter, there was a major reversal from the pattern at Mona. Adult 
male valencienni, the largest of the four species, occurred on diameters not 
significantly thinner than those of grahami or opalinus males and signifi- 
cantly thicker than those of male lineatopus. Males of opalinus at Port 
Antonio were on thicker diameters than grahami males, and the latter 
showed no significant difference from female-sized opalinus. Female-sized 
opalinus were on thicker perches than female-sized or juvenile grahami, 
lineatopus, or valencienni. Males of lineatopus occurred on larger-diam- 
etered perches than did female-sized and juvenile grahami or female-sized 
valencienni. Female-sized grahami occupied thicker perches than did female- 
sized valencienni or female-sized and juvenile lineatopus. Female-sized 
valencienni occurred on thicker perches than did female-sized lineatopus or 
juveniles of grahami and lineatopus. Finally, female-sized lineatopus were 
on thicker perches than grahami juveniles. 

Within the same species, males of grahami, opalinus, and lineatopus were 
found higher than smaller-sized individuals. In addition, female-sized anoles 
were higher than juveniles in grahami and lineatopus. For each species, 
classes whose individuals were of the largest size were found on thicker 
perches than all classes of smaller individuals. 

Once again, opalinus and grahami segregated by shade and sun, respec- 
tively. And again, opalinus, a small species, occurred on bigger trunks and 
branches than did the larger species grahami or lineatopus. A. opalinus was 
also found close to the ground in shrubby, more tightly packed vegetation, 
where it was able to perch in the shade. In such areas, which were scat- 
tered in patches throughout the study site, grahami ranged higher, being 
found on leaves and more exposed branches. As at Mona, male lineatopus, 
similar in size to male grahami, were more often found on thinner perches. 

Unlike the Mona situation where leaves were mostly small, the Port 
Antonio site contained many broad-leaved herbaceous plants. In such vege- 
tation, particularly on leaves, it was common to see female and juvenile 



1971 JAMAICAN ANGLES U 

grahomi (Table 2). It is possible that aquarum, which is that form of 
grahaini inhabiting the wettest lowland areas (including Port Antonio), is 
both smaller and of a brighter, more leafy green color because of its oppor- 
tunity for occupying the more luxuriant green vegetation resulting from the 
heavy rainfall. 

Port Antonio Closed Area (Tables 3, 8). In this more shaded site, so few 
valencienni were seen that they are all lumped into one category. Repre- 
sentatives of grahami were also very uncommon and are therefore not 
included. In addition, because of the much greater abundance of opalinus, 
female-sized individuals are treated separately from juveniles in that species. 

In height, differences between all possible pairs of lizard classes were 
significant. The order of groups, from highest to lowest, was valencienni, 
opalinus males, lineatopiis males, female-sized opalinus, opalinus juveniles, 
female-sized lineatopus, and lineatopus juveniles. 

In diameter, opalinus males were on thicker perches than any other group. 
Female-sized opalinus, male lineatopus, and valencienni occurred on perches 
not significantly different in diameters, and all were on thicker perches than 
female-sized lineatopus or juveniles of opalinus and lineatopus. Female- 
sized lineatopus occurred on thicker perches than did juveniles of opalinus. 

Intraspecific relations paralleled those for the other two areas: in opalinus 
and lineatopus, the larger the size of the lizard, the higher it occurred, and 
the thicker were its perches. 

Whitehouse (Tables 4, 9). The study site near Whitehouse is identical in 
species composition to those near Mona and Port Antonio except that sagrei 
replaces lineatopus. The only form of lineatopus in the vicinity of the site 
is neckeri, an animal which seeks darker forest than opalinus. As stated 
above, climatic observations were recorded at Whitehouse in addition to 
those on structural habitat. Although reported in part elsewhere (Schoener, 
1970), data treatment here differs in two major respects: the category 
"clouds" was added to those of "sun" and "shade" for the climatic variable, 
and "time" is not considered as an additional variable. 

In this area again, grahami males and valencienni (all classes combined) 
were found at the greatest heights. They were followed by female-sized 
grahami, which occurred higher than any class of sagrei or opalinus. 
Juvenile grahami were found higher than sagrei and male opalinus. Both 
classes of opalinus perched at greater heights than did any class of sagrei. 

Male grahami, male opalinus, and female-sized opalinus did not show 
significant differences in perch diameter, though the first were on the thickest 
perches. Male grahami were found on thicker diameters than male sagrei, 
but the latter did not differ significantly from either class of opalinus. Male 
sagrei occurred on thicker perches than did female-sized grahami, juvenile 
grahami and valencienni. Female-sized sagrei, juvenile sagrei and valen- 
cienni all had greater-diametered perches than did juvenile grahami. In 
addition, sagrei juveniles perched at greater diameters than did the com- 
bined valencienni. 



12 BREVIORA No. 368 

Within the same species, adult males of grahami, sagrei, and opoliniis 
perched higher than female-sized individuals. The latter in sagrei perched 
higher than juveniles, but in grahami the two classes were similar in height. 

Once again, males of the three commonest species occurred on thicker 
perches than did smaller individuals, but the results were not significant for 
opalinus. Juveniles in grahami and sagrei were found on thinner perches 
than the other intraspecific classes. 

Although there was an overall tendency for sagrei and valencienni to be 
found most often in the sun and opalinus most often in the shade or on 
cloudy days, this pattern varied by species class (Table 5). Males of 
opalinus were most consistently found in the shade: they were seen signi- 
ficantly more often during cloudy days or occurred more often on shady 
perches than male and juvenile sagrei, male and female-sized grahami, and 
valencienni. Juveniles of sagrei, in contrast, were very frequently seen in 
the sun: all classes of grahami and male opalinus were seen significantly 
more often in the shade or during cloudy weather than were juvenile sagrei. 
Only two other intraspecific comparisons were significant: female-sized 
grahami were most often seen in the sun or during cloudy days than male 
sagrei, and valencienni were most often seen in the sun or on cloudy days 
than male grahami. Thus there was no invariant tendency for that class 
recorded most often in the shade to be also the one recorded most often 
during cloudy weather. 

Only a few intraspecific differences were significant: male opalinus were 
recorded more frequently in the shade or on cloudy days than smaller 
opalinus; female-sized grahami were more frequently seen in the sun or on 
cloudy days than male grahami, and female-sized sagrei were more fre- 
quently seen in the shade or during cloudy weather than juvenile sagrei. 
Thus there was some inclination for the smaller-sized lizards within a species 
to be on sunnier perches. 

DIFFERENCES BETWEEN HABITAT VARIABLES 

The statistical treatment of the structural-habitat data also de- 
tects significant interactions between the two perch variables, height 
and diameter, and when available, the climatic variable. Thus it 
answers the following kind of question: is there a significant asso- 
ciation between thin perches and high perches for all perches 
combined of the two lizard classes being compared? 

At Mona, for most comparisons among lizard classes, small 
perches occurred at greater heights than did large perches (Table 
6). However, in the three of nine cases in which a significant 
height-diameter interaction was found (male grahami with female- 
sized grahami, male valenciemii, or female-sized valenciemu) , the 



1971 JAMAICAN ANGLES 13 

reverse was true. In the Port Antonio open area, on the other 
hand, where trees were more widely scattered and there was much 
low second growth, all significant associations were of small- 
diametered perches with low heights. Whitehouse resembled the 
Mona area more than Port Antonio in its relation of perch height 
to perch diameter; low perches tended to be of larger diameter. 
This interaction again reflects the vegetation structure: at White- 
house, there were few tall trees and little herbaceous understory — 
most large perches were therefore low, including the fenceposts 
especially preferred by sagrei. The only statistically significant ex- 
ceptions to this pattern were for sagrei juveniles, the most terrestrial 
class of lizards on the site. 

At Whitehouse, it was also possible to look for associations 
between the climatic categories and those of perch height and 
diameter (Table 9). 

There were few significant interactions between perch height and 
insolation, probably because, in the patchy vegetation of the study 
site, the sun penetrated for the most part to vegetation of all 
heights. For intraspecific sagrei comparisons, higher perches 
tended to be relatively shady and lower perches relatively sunny. 
Individuals of sagrei were found more often than those of other 
species in areas away from the shade provided by large trees and 
shrubs: in such areas, most perches are both low and sunny. Lower 
perches in sun than during cloudy weather were found for the com- 
bined data of juvenile grahami and male sagrei. In contrast, the 
lowest perches were found in the shade or sun and the highest on 
cloudy days for female-sized sagrei lumped with grahami males. 
Why these were the only interspecific comparisons showing a sig- 
nificant height-insolation interaction is not apparent. 

There were many more significant associations between perch 
diameter and insolation. All but one were of two sorts: the thinnest 
perches were occupied in the sun and the thickest in either shade or 
on cloudy days. (The exception was for female-sized and juvenile 
grahami: thinnest perches were shadiest, and thickest perches were 
utilized during cloudy weather.) In a previous study which also 
separated observations by time of day, a three-way interaction be- 
tween diameter, insolation, and time was detected at Whitehouse 
(Schoener, 1970). Exterior perches tend to be thinner in all habi- 
tats, but in patchy ones such as that at Whitehouse, tend to be 
sunnier as well — thus the association may simply reflect the phys- 
iognomy of the vegetation. However, Jenssen (1970) found that 



14 BREVIORA No. 368 

individuals of Anolis nebiilosus climb into vegetation during mid- 
day and has attributed this behavior to a warming of the substrate. 
Perhaps a similar thermoregulatory function can explain the lizards' 
avoidance of sunny, large surfaces during most of the day at 
Whitehouse. 

In several of the comparisons for each locality, the statistical 
procedure indicated that there might be significant three-way inter- 
actions between the variables (see appendix). Several are of inter- 
est. Two were interactions between perch diameter, insolation and 
lizard class. These were cases in which a low class, one of sagrei, 
was paired with a higher class, one of either grahami or valencienni. 
In sagrei, thick perches are more likely to be used in the shade on 
sunny days, whereas in the more arboreal forms, thick perches arc 
more likely to be used on cloudy days. Another three-way inter- 
action showed that sagrei males tended to seek out shady perches 
that were most often relatively high, whereas female-sized sagrei 
found their shady perches relatively lower. Both these results 
probably reflect differences in regard to relative availability of sun- 
less perches between the habitats of the classes being compared. 

As inspection of Tables 6-9 shows, there is a considerable num- 
ber of significant interactions involving cHmatic and/or habitat 
variables alone; therefore the extended statistical treatment given 
the data of this paper is well justified. Most of these interactions 
reflect differences in the vegetational structure and its exposure to 
the sun. As mentioned, a few may indicate thermoregulatory be- 
havior on the part of the hzards. However, the use of the climatic 
categories — sun, shade, and clouds — can only give a crude first 
approximation of the climatic preferences of these animals. Finer 
resolution would be gained were temperature, humidity, wind 
speed, and other variables measured at each perch. 

DISCUSSION OF LIZARD STRUCTURAL HABITATS AND 
RELATION TO PREVIOUS STUDIES 

The climatic and structural habitats of the lowland species can 
be summarized as follows. 

1. Climatic. As first pointed out by Rand (1967a) for Kings- 
ton populations, in all localities grahami inhabited relatively open, 
sunny places and opalimis relatively closed, shaded places. At 
Mona and Port Antonio, Uneatopus was intermediate in this regard. 
However, sagrei, its structural habitat counterpart at Whitehouse, 
occurred in sunnier, more exposed places than did grahami. In that 



1971 JAMAICAN ANGLES 15 

locality, opaliniis occurred on lower perches than elsewhere and 
thus occupied in part perches where Uiieatopus would have been 
expected were it present. 

2. Structural. In all four study areas, valencienni as a species 
was seen higher than its congeners (Figs. 1-4). Wherever found, 
grahami was next in height, followed usually quite closely by opa- 
linus. However, at Port Antonio female-sized lizards of grahami 
aquarum were lower than either class of opalinus, reflecting their 
abundance in herbaceous vegetation at that site. Lineatopus and 
sagrei both occurred lowest in their respective sites though sagrei 
appeared relatively more terrestrial. The ranking of species by 
height at Mona was the same as that found by Rand in several 
localities near Kingston. As can be seen from the figures, no par- 
ticular between-species relationship of species-size to height was 
evident. However, within species, smaller lizards always tended to 
occur lower than did larger ones. 

The ordering of species with respect to perch diameter is slightly 
less consistent from locality to locality. At Mona, both male and 
female-sized lizards taken separately showed a perfect inverse rela- 
tion of body size and perch diameter: the largest species, valen- 
cienni, occurred on the thinnest perches, followed by lineatopus, 
then grahami, and finally, the smallest species, opalinus (Fig. 1, 
Table 1) . At Port Antonio Open, the situation was the same ex- 
cept that male valencienni occurred on thicker perches than all but 
male opalinus, and female-sized lineatopus occurred on thinner 
perches than female-sized valencienni (Fig. 2, Table 2). At Port 
Antonio Closed, where only two species were considered in detail, 
opalinus again took thicker perches than did lineatopus for both 
sexes (Fig. 3, Table 3). At Whitehouse, the ordering was essen- 
tially the same as at Mona, except that sagrei replaces lineatopus 
(Fig. 4, Table 4). However, sagrei is smaller than grahami, so 
there is not a perfect inverse relation of species-size and diameter 
at Whitehouse. Taken as a whole, the data are in almost total 
opposition to what would be expected if perch diameters were 
selected by species on the basis of body weight.^ The inverse rela- 
tion is made all the more interesting by the fact that within each 



1 It should be pointed out, however, that garmani, the largest species on 
Jamaica, was very rare and was therefore not considered in the study sites. 
What few data exist on the perch diameter of this species (Rand, 1967a, 
our unpublished data) indicate that garmani do not inhabit thinner perches 
than valencienni but rather are often found on large trees and therefore 
often perch on large branches. 



16 BREVIORA No. 368 

species, all significant associations are of larger individuals with 
larger perches and vice-versa. Clearly some explanation other than 
a purely supportative one must be sought for species-specific differ- 
ences in perch diameter. 

A possible explanation is the following. Given that, within 
species, larger individuals are found on larger perches, an inverse 
relation between perch diameter and species size would be expected 
if species evolved so that that class of a given species overlapping 
in space the most with a class of another species was the one which 
differed the most in size from the latter class. In other words, a 
direct relationship between size and perch diameter within species 
and an inverse one between species is one way of ensuring that 
interspecific spatial overlap is between dissimilarly sized individuals. 
In fact, given the direct, within-species relationship, none of the 
24 possible permutations of the species ordered by diameter results 
in less total difference in the sizes of the most closely overlapping 
interspecific pairs, though a few alternatives are about as good as 
the one discussed. Because anoline lizards of different sizes take 
differently sized foods (Rand, 1967a; Schoener, 1967, 1968; 
Schoener and Gorman, 1968), such staggering of sizes in space 
should alleviate resource competition (Rand, 1967b; Schoener, 
1968). 

Reversal of both the within- and between-species relationships is, 
of course, an alternative way of juxtaposing dissimilarly sized 
classes from different species. Why then does this second arrange- 
ment not occur instead? An answer can perhaps be found if we 
examine the probable course of faunal increase on Jamaica. It is 
highly unlikely that the four species evolved simultaneously and 
sympatrically. Therefore, while in isolation from other anoles, the 
first species to have evolved probably showed a direct within-species 
relationship between body size and perch diameter: not only is a 
direct relationship adaptive over the large range in body sizes 
spanned by the different age classes, but dominant individuals 
in Anolis are usually largest (Rand, 1967b; Trivers, in prep.; 
Schoener, in prep.) and would therefore appropriate the most suit- 
able perches. Furthermore, all solitary species studied in hetero- 
geneous vegetation showed such a direct relationship (Rand and 
Rand, 1966; Schoener, 1967; Schoener and Schoener, in prep.). 
Upon coming together, in order to achieve the second arrangement, 
the species would have to change their species-specific size and/or 



1971 JAMAICAN ANGLES 17 

perch diameters as well as the within-species relationship between 
size and perch diameter. Rather than that, it seems more feasible 
for species to shift their size and/or perch diameters in such a way 
as to preserve the intraspecific relationship and still avoid overlap 
of similarly sized individuals, i.e., in accordance with the existing 
arrangement. The positioning of a relatively large species on 
perches of relatively small diameter could then be facilitated by 
morphological changes in body proportions, such as those in rela- 
tive leg length. Indeed, some proportional differences do seem to 
exist in the Jamaican species: valencienni, the largest species con- 
sidered, has relatively short limbs, particularly in femur. Similar 
changes in proportions would likely be more difficult to build into 
the ontogeny of single species, as would be necessary were the 
second arrangement adhered to. 

Though there is no between-species relationship of perch height 
and size, the within-species tendency for smaller individuals to be 
found relatively low also results in minimal interspecific spatial 
overlap of similarly sized individuals, except for the valencienni- 
grahami combination, in which female-sized valencienni are about 
the same size as male grahami. However, those classes occur on 
quite different perch diameters (Figs. 1-2, Tables 1-4), and Trivers 
(personal communication) has evidence for major differences in 
searching for prey and, possibly, prey taxa between the two species. 
Rand (1967a) noted a tendency for opalinus and lineatopus to 
juxtapose dissimilar sizes according to height, in localities around 
Kingston, but he found the opposite for grahami and lineatopus. 
A further difference between Rand's and our study is that his data 
for small-sized grahami are bimodally clustered by height, one 
mode being below six feet and the other above ten feet. A likely 
reason for the discrepancy is difference in the structure of the avail- 
able vegetation of the respective sites. Rand observed most of his 
grahami on the campus of the University of the West Indies where 
there is little high, shrubby understory surrounding the large trees. 
Thus the distribution of female-sized grahami may have paralleled 
differences in vegetational layers. The three localities we looked 
at were all more overgrown and vegetationally more heterogeneous. 
We also found a greater difference in perch height between male 
and female-sized grahami in all localities than did Rand. Possibly 
at Mona there were many more females on high branches than we 
were able to detect, but this is unlikely to be much of a factor at 



18 BREVIORA No. 368 

either Port Antonio or Whitehouse, where the canopy is lower and 
more broicen. Again, the lack of a viney, bushy understory in the 
"park-like" vegetation where Rand studied most of his grahami is 
probably responsible for the difference. A third possible reason for 
the difference is simply some effect associated with the smaller 
sample size Rand used, either one purely of sampling error, or one 
related to a smaller range of times of day or weather conditions 
than covered in our study. 

ACKNOWLEDGMENTS 

We thank T. A. Jenssen, A. S. Rand, R. L. Trivers, and E. E. 
Williams for critical comments on the manuscript and S. D. Fien- 
berg for statistical advice. We also thank C. B. Lewis and T. Farr of 
the Jamaica Institute and I. Goodbody of the University of the West 
Indies for assistance in the field. Research was supported by NSF 
grants GB 3167 to the Committee on Evolutionary Biology, Har- 
vard University, and NSF grants GB 6944 and B 01 9801 X to E. E. 
Williams. 

APPENDIX I 

Statistical Appendix 

Data of the sort presented above are ideally treated in the form 
of a multiway contingency table, because variables are both ordinal 
(perch height and diameter) and nominal (lizard group, climatic 
category). In the case of nominal variables, there is no problem 
in selecting categories (referred to as "levels"): there are two 
lizard groups and three climatic categories (see above). However, 
for ordinal variables, a continuous set of quantitative data must be 
broken at one or more places in order to form categories. Because 
of the multiphcative increase in the total number of cells in a con- 
tingency table with increasing number of categories for a single 
variable, two categories each were chosen for perch height and 
perch diameter. That is to say, all observations less than or equal 
to some number were cast into one category, and all those greater 
than that number were cast into the other. The point at which the 
data were broken was chosen by computing that number which 
gave the maximum difference in cumulative frequency between the 
two distributions of observations belonging to the hzard groups 
being compared. Hence this procedure was designed to detect 



1971 JAMAICAN ANGLES 19 

maximum differences in height and diameter taken separately be- 
tween the lizard classes, although because of interactions between 
variables, it will not necessarily produce a maximum difference in 
a combined model. The critical values were, of course, usually 
much removed from those required to give maximum interaction 
between the environmental variables themselves (e.g., perch height 
and insolation). The critical value so determined for height or 
diameter was generally different in different comparisons, and 
ranged from one-fourth inch to four inches for diameter and 
eleven inches to ten feet for height. An alternative procedure 
would have been to choose the same intervals for all comparisons, 
but given the great variation in lizard habitat preference, would 
have obscured most differences. What we have in effect done is to 
redefine "high" and "thick" for each comparison. There are sta- 
tistical objections to this procedure, but at present appropriate 
alternative methods of grouping data are not available (Fienberg, 
1970). The points at which the data were broken are fisted here 
(Table 10) for two reasons: 1) Other researchers may wish to 
define "high" and "thick" differently and therefore can better 
compare their method with the one used here; and 2) It is of 
biological interest when comparing habitat distributions to know 
where the point of maximum difference fies, especially in case 
the observations were repeated later in the same or similar areas. 

Once categories were chosen, the procedures diverged for three 
and four variable situations. 

In the four-way case, a contingency model was first set up which 
contained all possible two-factor or pairwise interactions between 
the four variables; in this case there were ( ^ ) = 6 such inter- 
actions. Then an iterative procedure described" elsewhere (Bishop, 
1969; Mosteller, 1968; Fienberg, 1970; Schoener, 1970) was used 
to fit the data to the model, that is, to compute expected values for 
each ceU of the contingency table. Two measures of goodness of 
fit, the standard chi-square and the log-likelihood chi-square (Kull- 
back, 1959) were computed and degrees of freedom determined as 
described by Ku and Kullback (1968) and Fienberg (1970). It 
was then noted whether the model gave a fit satisfactory at the 5 
per cent level. In most cases the two statistics were very similar, 
but where they allowed a different conclusion to be drawn about 
significance, the log-likelihood ratio chi-square was followed. 

Next, each two-way interaction was individually dropped, giving 
six new models. For each of these, the difference between the new 



20 BREVIORA No. 368 

model and the original model was evaluated for statistical signifi- 
cance by testing the difference in their log-likelihood ratio chi- 
squares, according to the partitioning technique expounded in 
Kullback (1959), Ku and KuUback (1968), and Fienberg ( 1970). 
If all new models were significantly diiferent from the old model 
at the 5 per cent level the process was terminated. Otherwise, that 
new model was then chosen (and thereby the corresponding inter- 
action removed) whose log-likelihood ratio chi-square was most 
similar to that of the original model. The procedure was then re- 
peated, five new models each containing four two-way interactions 
being tested against the model containing five two-way interactions. 
Interactions were thus removed, one at a time, until all models 
with a smaller number of interactions were judged significantly 
different from the next most inclusive model, or until no interaction 
remained. 

Because of space limitations, detailed results could not be re- 
ported as they were in a previous paper (Schoener, 1 970) . Instead, 
the results are summarized in Table 10. The six tiers of the table 
correspond to the six possible two-way interactions. For each lizard 
combination, these are given a number from zero to four. A "1" 
denotes that the interaction remained significant in the above sense 
every time it was tested in the removal procedure. A "2" denotes 
that the interaction was significant at least at the termination of the 
procedure. A "3" means that the interaction was significant when 
removed from the most inclusive model (with six interactions) but 
not at termination. A "4" indicates that the interaction was sig- 
nificant sometime during the procedure but not at the beginning or 
end. A "0" indicates that the interaction was never significant. 
Interestingly, in Table 1 most interactions could be labelled either 
"0" or "1", and in the simpler three-variable case, all interactions 
could be so labelled (Tables 7-9). In the discussion of the text, 
any interaction labelled 1-4 is considered significantly non-zero, 
but the tables should be checked for fine distinctions. 

In the case of three-variable tables (perch height, perch diameter, 
and lizard group), there are ( ^ ) =3 two-way interactions. The 
reduction procedure for these was similar to that described for four- 
way tables, but of course is much shorter: only three new models 
need be tested against the most inclusive model on the first round 
instead of six. 

Rarely, a set of models was encountered which never gave a 



1971 JAMAICAN ANGLES 21 

chi-square value denoting a satisfactory fit of the model at the 5 
per cent level, regardless of what interactions were removed. These 
are labelled in the tables. In such cases, differences between models 
were still computed in the usual way and the results listed in the 
tables. In addition, however, a search was programmed for signi- 
ficant three-way interactions, in order to see if an improved fit 
could be obtained. In the case of four variables, there are ( 3 ) = 
4 three-way interactions. The procedure was to test each of four 
models corresponding to the addition of a different three-way inter- 
action to the model with all two-way interactions. For the White- 
house data, there was no tendency for any particular three-way 
interaction to predominate: each produced the best fit at least once. 
Some of these are discussed in the text. In no case was it necessary 
to consider more than one three-way interaction in order to pro- 
duce a satisfactory fit. Once such a fit was obtained, the three 
two-way interactions able to be removed were deleted one at a 
time as before, and differences in chi-square with more inclusive 
models were tested. In most cases, the two-way interactions that 
could be removed without producing a significant difference be- 
tween models were the same as some of those removed in the 
analysis of two-way interaction models only. 

In the case of a model with three variables, there is but a single 
three-way interaction. Fitting this interaction would be a trivial 
exercise resulting in a perfect fit (within the hmits of computational 
accuracy); therefore, three-way interactions could only be con- 
sidered for tables with four variables. 

In several cases it happened that margins (the total number of 
observations in a particular category of a variable or combination 
of such categories) were zero. For these cases, two procedures 
were tried. The first was to correct for the additional degrees of 
freedom lost in such a table according to the method of Bishop 
(unpublished thesis; Fienberg, personal communication). Once this 
was done, the removal procedure could be carried out as befora. 
In no case in the present study was the recalculated number of 
degrees of freedom zero or negative, though if there are too many 
zeros this will happen. A second way to handle zero margins is to 
adjust the table slightly by shifting one (if possible) or more ob- 
servations so that margins are no longer zero. This is best done 
conservatively, that is, so as to reduce the likelihood of achieving 
a significant difference to the variables of interest, in our case those 



22 BREVIORA No. 368 

in structural habitat. For such tables, where there was a choice 
from several cells for selecting the observation to be moved, the 
cell with the most observations was chosen. While far less prefer- 
able than the first method, table adjustment had to be carried out 
for the three-variable case, because the initial 2X2X2 model 
tested has, assuming no zero margins, but one degree of freedom; 
thus no further deletion is possible. Unless otherwise specified, 
values in the tables of significance for four-way comparisons are 
computed by the first method, though in only about 15 per cent of 
tables with zero margins so far examined did conclusions from the 
two methods differ at all. 

APPENDIX II 

Remarks on Other Localities 

Jamaica, like the other Greater Antilles, is large and topographi- 
cally diverse, yet it contains only seven species as compared to 
Puerto Rico's ten, Hispaniola's 24 and Cuba's 24. Jamaica's less 
diverse fauna is in part apparently associated with a great variation 
from locality to locality within Jamaica in regard to what species 
are found in certain segments of the vegetation. Brief visits which 
we made to other Jamaican localities give an inkling of this vari- 
ability. Already shown is that in western Jamaica sagrei replaces 
Uneatopus as the open-area trunk-ground Hzard. In darker, mesic 
forests west of the Whitehouse locality (such as that near Ferris 
Cross), the trunk-ground species is Uneatopus necked, an olive 
green-brown form somewhat smaller than the nominate subspecies. 
A. opalimis is also common in such forests, but inhabits less shady 
places and is more likely to be encountered marginally. A . grahami 
seems entirely absent from these dark forests, but garmani is pres- 
ent. More xeric forests two to five miles east of the Whitehouse 
study area contained no trunk-ground species per se. Instead, 
opalinus occurred often on low perches (though no measurements 
were made), and garmani seemed commoner than at any of our 
study areas. 

Yet other species combinations are possible. In natural beach 
vegetation near Rose Hall on the northwest coast, we saw grahami 
and sagrei commonly. Where this vegetation met the xeric "iron- 
shore" limestone formation, these species were replaced by Uneato- 
pus merope, a rubiginous form well camouflaged on the rust-colored 
limestone, and garmani. In certain moist mid-elevation sites such as 



1971 JAMAICAN ANGLES 23 

can be found about Mandeville, garmani was the common arboreal 
species, and opalinus occurred in quite open, sunny places, includ- 
ing low woodpiles and fenceposts. In these localities we found 
grahami to be practically absent, while lineatopus neckeri was com- 
mon in the blackest part of the forest. E. E. Williams and T. A. 
Jenssen (personal communication) have also observed opalinus in 
exposed situations at Mandeville; Williams, however, ionnd grahami 
moderately common in certain of these situations. In montane 
forest (c. 4000 feet), such as that surrounding Green Hills, we 
frequently observed opalinus in extremely exposed places, including 
along roadsides as at least temporarily a terrestrial lizard. Other 
lizards in the area were valencienni in open situations and garmani 
in somewhat more enclosed places; we also saw several reconditus 
in relatively dark woodland. 

LITERATURE CITED 

Andrews, R. M. 1971. The structural niche and Anolis polylepis. Ecol- 
ogy, in press. 

AsPREY, G. F., AND R. C. RoBBiNs. 1953. The vegetation of Jamaica. Ecol. 
Monogr.. 23: 359-412. 

Bishop, Y. M. M. 1969. Full contingency tables, logits, and split con- 
tingency tables. Biometrics, 25: 383-400. 

Deming, W. E., and F. F. Stephan. 1940. On a least squares adjustment 
of a sampled frequency table when the expected marginal totals are 
known. Ann. Math. Stat., 11: 427-444. 

FiENBERG, S. E. 1970. The analysis of multidimensional contingency tables. 
Ecology, 51: 419-433. 

Jenssen, T. a. 1970. The ethoecology of Anolis nebulosits (Sauria, Iguani- 
dae). J. Herpetology, 4: 1-38. 

Ku, H. H., AND S. KuLLBACK. 1968. Interactions in multidimensional con- 
tingency tables: an information theoretic approach. J. Res. Natl. Bur. 
Standards— Math. Sci., 728: 159-199. 

KuLLBACK, S. 1959. Information Theory and Statistics. New York, Dover 
Publications. 399 pp. 

Laska, a. L. 1970. The structural niche of Anolis scriptiis on Inagua. 
Breviora, 349: 1-6. 

Lazell, J. D. 1966. Studies on Anolis reconditus Underwood and Wil- 
liams. Bull, Inst. Jamaica Science, Ser. 18: 5-15. 

Mosteller, F. 1968. Association and estimation in contingency tables. 
J. Amer. Stat. Assoc, 63: 1-28. 



24 BREVioRA No. 368 

Rand, A. S. 1964. Ecological distribution in anoline lizards of Puerto Rico. 

Ecology, 45: 745-752. 
. 1967a. The ecological distribution of the anoline lizards 

around Kingston, Jamaica. Breviora, 272: 1-18. 
. 1967b. Ecology and social organization in the iguanid lizard 



Anolis lineatopus. Proc. U.S. Natl. Mus., 122: 1-79. 

Rand, A. S., and P. J. Rand. 1966. Field notes on Anolis lineatus in 
Curasao. Stud. Fauna Curasao, 24: 112-117. 

SCHOENER, T. W. 1967. The ecological significance of sexual dimorphism 
in size in the lizard Anolis conspersus. Science, 155: 474-477. 

. 1968. The Anolis lizards of Bimini: resource partitioning in 

a complex fauna. Ecology, 49: 704-726. 

. 1969. Size patterns in West Indian Anolis lizards. I. Size and 



species diversity. Syst. Zool., 18: 386-401. 
. 1970. Nonsynchronous spatial overlap of lizards in patchy 



habitats. Ecology, 51: 408-418. 

Schoener, T. W., and G. C. Gorman. 1968. Some niche differences among 
three species of Lesser Antillean anoles. Ecology, 49: 819-830. 

Underwood, G.. and E. E. Williams. 1959. The anoline lizards of Jamaica. 
Bull. Inst. Jamaica, Science Ser., 9: 1-48. 

Williams, E. E. 1970. The ecology of colonization as seen in the zoo- 
geography of anoline lizards on small islands. Quart. Rev. Biol., 44: 
345-389. 



1971 



JAMAICAN ANGLES 



25 



HIGH 





T 
H 
I 

C 
K 





T 

H 

I 

N 




^Ct] j 



o 



LOW 



© 



Figure 1. Mona. Species-classes are ranked by perch height and perch 
diameter; distances between species-classes are not representative of the 
magnitude of difference. Circles have diameters in proportion to the length 
of the individuals in the designated class. Clear circles are of classes found 
mostly in open, sunny areas; shaded circles are of classes in mostly closed, 
shady situations; intermediate classes are represented by half-shaded circles. 
V = valencienni, G = grahami, O = opalinus, L = lineatopus. 



26 



BREVIORA 



No. 368 



HIGH 




^^P 




T 
H 
I 

C 
K 



■smOH 





H 
I 
N 



^^ 1 




® 



LOW 



Figure 2. Port Antonio Open. Symbols as in Fig. 1. 



1971 



JAMAICAN ANGLES 



27 



HIGH 



T 

H 

I 

C 

K 




^^ ] 



o 



T 
H 
I 
N 



® 



LOW 

Figure 3. Port Antonio Closed. Symbols as in Fig. 1. 



28 



BREVIORA 

HIGH 



No. 368 




H 



K 




^^^B 








i 




T 
H 
I 
N 



LOW 
Figure 4. Whitehouse. Symbols as in Fig. 1. S = sagrei. 



97; 



JAMAICAN ANGLES 



29 



Table 1. Mona. 
Percent observations in various structural habitat categories. 
H = >20'; G = ground; R = rocks; N = sample size. 



Diameter 
Ht.^~~--^in.) 
(feet) 



>5 5-2 1/2 2 1/4-7/8 7/8-1/8 leaves Total 



N = 385 

10.5-20 
5-10 
3-4 3/4 
<3 

Total 

N = 246 

10.5-20 
5-10 
3-4 3/4 
<3 

Total 

N = 31 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 

N = 214 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 



male grahami 


H 


= 2.3 


G 


= 


R = 


3.6 8.1 




6.6 




3.8 





3.6 13.8 




21.4 




9.5 


0.3 


3.6 5.5 




4.6 




3.5 





3.6 2.6 




3.3 




2.5 






12.4 30.0 



35.9 



19.3 



0.3 



female- 


-sized 


grab 


ami 


H 


= G = 


= 0.3 


R 


0.7 


2.7 






2.9 




2.6 







0.3 


3.4 






14.9 




28.2 


1.0 




0.3 


2.7 






6.0 




11.5 







2.7 


4.1 






7.2 




8.4 








22.1 
48.9 
16.2 
10.7 

= 

8.9 
47.9 
20.5 
22.4 



4.1 



13.0 



30.9 



50.6 



1.0 



juvenile £r 


ah 


ami 


H = 





G = 


R = 3.2 
































25.8 












4.8 




37.1 


3.2 









6.5 




19.4 







25.8 
45.1 
25.9 









11.3 


male 


opalinus 


H = 


1.9 


4.2 


2.3 


4.2 


21.0 


21.3 


2.3 


7.0 


6.3 


1.9 


5.6 


3.3 


10.3 


37.8 


33.2 



82.3 

; = 

1.4 

12.4 

3.5 

0.5 

17.8 



3.2 
R = 


0.5 


0.5 



9.8 

59.4 
19.1 
11.3 



30 



BREVIORA 



No. 368 



Table 1. (cont'd) 



-~-~...,^^ Diameter 
Ht>-~~^in.) 
(feet)^---^ 


>5 


5-2 1/2 


2 1/4-7/8 


7/8-1/8 


leaves 


Total 


N = 235 


female-sized 


opalinus H 


= 


G 


= 0.9 


^ = 


10.5-20 


0.4 


2.1 


1.3 


0.9 







4,7 


5-10 


2.6 


10.2 


18.1 


14.3 







45.2 


3-4 3/4 


1.7 


4.7 


10.9 


7.5 







24.8 


<3 


3.4 


8.1 


8.3 


4.9 







24.7 


Total 


8.1 


25.1 


38.6 


27.6 









N = 15 


juvenile opalinus H = 


G = 





R = 




10.5-20 






















5-10 











22.2 







22.2 


3-4 3/4 











11.1 







11.1 


<3 





11.1 


22.2 


33.3 







66.6 


Total 





11.1 


22.2 


66.6 









N - 838 


male 


lineatop 


us H = 0.2 


G = 


0. 


8 R = ( 


) 


10.5-20 


0.4 


1.1 


1.8 


0.1 







3.4 


5-10 


2.6 


13.4 


22.6 


13.0 







51.6 


3-4 3/4 


2.1 


7.2 


14.1 


9.5 




0.1 


33.0 


<3 


1.7 


2.5 


3.6 


3.0 







10.8 


Total 


6.8 


24.2 


42.1 


25.6 




0.1 




K = 436 


femal 


e-sized 


lineatopus 


H = 




G = 4.4 


R = 


10.5-20 






















5-10 


0.5 


1.4 


6.0 


3.9 




0.2 


12.0 


3-4 3/4 


0.5 


4.6 


8.4 


18.9 







32.4 


<3 


1.4 


8.3 


16.3 


24.8 




0.7 


51.5 


Total 


2.4 


14.3 


30.7 


47.6 




0.9 





1971 



JAMAICAN ANGLES 



31 



Table 1. (cont'd) 



Diameter 
Ht. -^in.) 
(feet) 

N = 24 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 

N = 15 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 
K = 16 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 

N = 3 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 



>5 5-2 1/2 2 1/4-7/8 7/8-1/8 leaves Total 



juvenile lineatopus H=0 G=12.5 R=0 







4.2 

8.3 






2.1 






8.8 
56.3 



12.5 

male valencienni 
6.7 
6.7 





2.1 



64.6 



H = 6.7 G = 
6.7 13.3 
6.7 33.3 
13.3 
6.7 



66.6 



6.3 



25.1 



12.6 



juvenile valencienni 







50.1 

= G 

33.3 





66.7 

100.0 






8.3 







12.5 

75.0 



8.3 



26.7 

46.7 

13.3 

6.7 



female- 


-sized 


val 


encienni 


H = 6 


3 


G = 





6.3 




6.3 


12.5 










12.5 




6.3 


6.3 







6.3 


6.3 







12.5 


















18.8 








25.1 
25.1 
25.1 
18.8 


33.3 




66.7 



32 



BREVIORA 



No. 368 



Table 2. Port Antonio Open. 
Percent observations in various structural habitat categories. 
H = >20'; G = ground; R = rocks; N = sample size. 
Diameter 



Ht>^~..,,.^(in.) 
















(feet)^^^-,^ 


>5 


5-2 1/2 


2 1/4-7/8 


7/8-1/8 


leaves 


Total 


N = 146 


male 


grahami 


H = 4.1 


G 


= 1.4 


R = 




10.5-20 


2.7 


6.9 


2.7 










12.3 


5-10 


5.5 


7.5 


12.3 




11.0 





36.3 


3-4 3/4 


5.5 


3.4 


1.7 




9.9 


0.7 


21.2 


<3 


4.8 


2.1 


6.8 




8.9 


2.1 


24.6 


Total 


18.5 


19.9 


23.6 




29.8 


2.7 




N = 163 


female-sized < 


grahami 


H 


= 0.6 


G = 2.5 


R = 


10.5-20 


0.6 


0.6 


0.6 










1.8 


5-10 


1.2 


2.5 


7.7 




5.2 





16.6 


3-4 3/4 


1.2 





2.8 




10.7 


1.8 


16.6 


<3 


3.7 


2.5 


4.6 




34.7 


16.6 


62.0 


Total 


6.8 


5.5 


15.6 




50.6 


18.4 




N = 75 


juvenile grab 


ami H = 





G = 


R = 




10.5-20 






















5-10 






















3-4 3/4 













10.7 





10.7 


<3 








1.3 




57.3 


30.7 


89.4 


Total 








1.3 




68.0 


30.7 




N = 17S 


male 


opalinus 


H = 1.1 




G = 


R = 




10.5-20 


0.6 


1.7 


10.8 




1.7 





14.8 


5-10 


5.7 


15.9 


12,8 




4.3 





38.6 


3-4 3/4 


6,3 


11.4 


5.4 




6.0 





29.0 


<3 


4.6 


7.4 


0.6 




3.4 


0.6 


16.5 


Total 


17,1 


36.4 


29.6 




15.3 


0.6 





1971 



JAMAICAN ANGLES 



33 



Table 2. (cont'd) . 



-...,,^^ Diameter 














HtT~~-^-^4in . ) 














(feet) ^^-^-^^ 


>5 


5-2 1/2 2 


1/4-7/8 


7/8-1/8 


leaves 


Total 


N = 136 


female 


-sized opa 


linus H 


= G = 


= R = 





10.5-20 





1.5 











1.5 


5-10 


3.7 


5.2 


14.3 


4.8 


0.7 


28.7 


3-4 3/4 


3.7 


2.9 


5.5 


7.0 


0.7 


19.9 


<3 


2.9 


6.6 


11.0 


27.9 


1.5 


50.0 


Total 


10.3 


16.2 


30.9 


39.7 


3.0 




N = 21 


juveni 


le opalinus H = 


G = 


R = 




10.5-20 




















5-10 








4.8 


4.8 





9.5 


3-4 3/4 











14.3 





14.3 


<3 








9.5 


66.7 





76.2 


Total 








14.3 


85.7 







N = 183 


male 1 


ineatopus 


H = 


G = 3.3 


R = 




10.5-20 




















5-10 





1.1 


1.6 


3.8 





6.6 


3-4 3/4 


2.2 


6.6 


5.2 


13.4 


0.6 


27.9 


<3 


3.8 


7.7 


12.0 


37.7 


1.1 


62.3 


Total 


6.0 


15.3 


18.9 


54.9 


1.6 




N = 110 


female 


-sized lineatopus 


H = 


G = 11.8 


R = 


10.5-20 




















5-10 




















3-4 3/4 








0.5 


5.0 


0.9 


6.4 


<3 





0.9 


9.1 


63.6 


8.2 


81.8 


Total 





C.9 


9.5 


68.6 


9.1 





34 



BREVIORA 



No. 368 



Table 2. (cont'd) 



Htr-~-~-^n.) 
(feet) ^~~--.>.^ 


>5 


5-2 1/2 2 


1/4-7/8 


7/8-1/8 


leaves 


Total 


N = 23 


juveni 


le lineatopus 


H 


= G = 


26.1 


R 


= 


10.5-20 
























5-10 
























3-4 3/4 
























<3 













56.5 


17.4 




73.9 


Total 













56.5 


17.4 






N = 25 


male valencienni 


H = 


4. 


G = 


R = 







10.5-20 


8.0 


12.0 


16.0 












36.0 


5-10 


8.0 


12.0 


12.0 




8.0 







40.0 


3-4 3/4 


4.0 


4.0 















8.0 


<3 








4.0 




8.0 







12.0 


Total 


20.0 


28.0 


32.0 




16.0 









N = 36 


female 


-sized valencienni 


H = 2.8 


G = 





R = C 


10.5-20 


2.8 


















2.8 


5-10 


2.8 


2.8 


8.3 




19.5 







33.4 


3-4 3/4 


2.8 


8.3 







11.1 


2.8 




25.0 


<3 


2.8 










33.3 





— 


36.1 


Total 


11.1 


11.1 


8.3 




63.9 


2.8 




N = 3 


juveni 


le valencienni 


H 


= G = 


R 


= 





10.5-20 
























5-10 













33.3 







33.3 


3-4 3/4 
























<3 













66.7 





— 


66.7 


Total 













100.0 








1971 



JAMAICAN ANGLES 



35 



Table 3. Port Antonio Closed. 
Percent observations in various structural ha±>itat categories. 
H = >20'; G = ground; R = rocks; N = sample size. 
Diameter 




N = 185 


male 


opalinus 


H = 1.6 


G = 0. 


5 


R = 




10.5-20 


6.5 


1.6 


1.6 


2.2 







11.9 


5-10 


7.0 


9.7 


22.2 


9.7 







48.6 


3-4 3/4 


5.9 


1.6 


8.6 


2.7 




1.1 


19.9 


<3 


1.6 


2.7 


9.2 


3.2 




0.5 


17.2 


Total 


21.1 


15.7 


41.6 


17.8 




1.6 




N = 206 


fema] 


.e-sized 


opalinus 


H = 1.0 


G = 


2.4 


R = 


10.5-20 


0.5 


0.5 


0.7 


1.2 







2.9 


5-10 


8.3 


3.4 


9.5 


15.8 







37.0 


3-4 3/4 


5.3 


1.5 


5.8 


6.8 




0.5 


19.9 


<3 


6.3 


3.9 


9.5 


15.8 




1.5 


37.0 


Total 


20.4 


9.2 


25.5 


39.6 




1.9 




N = 79 


juvenile opal 


inus H = 


G = 





R = 




10.5-20 






















5-10 





1.3 


1.3 


19.0 







21.5 


3-4 3/4 











17.7 







17.7 


<3 








9.5 


50.0 




1.3 


60.8 


Total 





1.3 


10.8 


86.7 




1.3 




N = 122 


male 


lineatopus H = 


G = 


R 


= 




10.5-20 






















5-10 


4.1 


3.3 


15.6 


14.8 







37.7 


3-4 3/4 


5.7 


3.3 


10.2 


18.4 




0.8 


38.5 


<3 


4.1 


3.3 


9.0 


7.4 







23.8 



Total 



13.9 



9.9 



34.8 



40.6 



0.8 



36 



BREVIORA 



No. 368 



Table 3 . (concl'd) . 



"--■-^^Diameter 
(feet) ^^^^ 


>5 


5-2 1/2 


2 1/4-7/8 


7/8-1/8 


lee 


ives 
3.6 


Total 


N = 112 


female 


-sized lineatopus 


H = 0" 


G = 


R = 


10.5-20 


























5-10 





0.9 


0.9 




8.9 









10.7 


3-4 3/4 





0.9 


4.9 




21.0 


0. 


9 




27.7 


<3 


2.7 


1.8 


16.5 




30.8 


6. 


3 




58.0 


Total 


2.7 


3.6 


22,3 




60.7 


7 


2 






N = 32 


juveni 


le lineatopus 


H = 


G = 


3.1 




R 


= 


10.5-20 


























5-10 













6.3 









6.3 


3-4 3/4 













6.3 









6.3 


<3 





3.1 


9.4 




53.1 


18 


8 




84.4 


Total 





3.1 


9.4 




65.7 


18 


8 






N = 13 


valencienni 


H = 


G = 


R = 











10.5-20 


7.7 


7.7 


15.4 




7.7 









38.5 


5-10 








15.4 




15.4 









30.8 


3-4 3/4 


15.4 


7.7 







7.7 









30.8 


<3 


























Total 


23.1 


15.4 


30.8 




30.8 












197; 



JAMAICAN ANGLES 



37 



Table 4. whitehouse. 
Percent observations in various structural habitat categories. 
H = 20'; G ■= ground; R = rocks; N = sample size. 
Diameter 

>5 5-2 1/2 2 1/4-7/8 7/8-1/8 leaves Total 



Ht.^'^-.^dn.) 
(feet) 



N = 219 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 

N = 284 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 

N = 54 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 

N = 88 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 



male 


g 


rahami 


H 


= 1.4 


G 


= 0.5 


R = 


1.8 




1.8 




2.3 




1.4 





2.7 




9.6 




21.5 




9.1 


2.3 


0.5 




7.3 




10.1 




4.1 


0.5 


1.8 




10.1 




7.1 




4.3 






6.8 28.8 



41.0 



18.9 



2.8 



fema] 


.e- 


-sized 


2£ 


ahami 


H 


= 


G = 2.5 


R 












0.4 







7 







0.7 




2.8 




14.1 




21 


8 


4.6 




1.8 




1.8 




5.8 




7 


9 


2.5 




1.4 




9.9 




12.3 




7 


7 


1.1 





7.3 
45.2 
22.5 
28.3 

= 0.4 

1.1 
44.0 
19.8 
32.4 



2.9 14.5 



32.6 



38.1 



8.2 



juvenile gr 


ahami 


H = 





G = 


R = 























3.7 




38.9 





1.9 




1.9 




31.5 










6.5 




13.9 


1.9 




42.6 
35.3 
22.3 



1.9 



12.1 



J4.3 



1.9 



male 


opalinus 


H = 





G = 


= 


R 


= 



























1.1 


6.8 


18 


2 




4.6 









2.3 


13.6 


15 


9 




1.1 









1.1 


20.5 


9 


1 




4.6 




1. 


1 




30.7 
32.9 
36.4 



4.5 40.9 



43.2 



10.3 



1.1 



38 



BREVIORA 



No. 368 



Table 4. (cont'd) . 



^"^^Diameter 
















Ht7""^^^in.) 
















(feet)^<v^ 


>5 


5-2 1/2 


2 1/4-7/8 


7/8-1/8 


leaves 


Total 


N = 72 


female 


-sized 


opalinus H 


= 


G 


= 2.8 


R = 


10.5-20 






















5-10 





5.6 


7.0 


1.4 







14.0 


3-4 3/4 


2.8 


4.2 


16.7 


1.4 







25.1 


<3 


2.8 


31.9 


19.5 


4.2 







58.4 


Total 


5.6 


41.7 


43.2 


7.0 









N = 10 


juveni 


le opal 


inus H = 


G = 





R = 




10.5-20 






















5-10 








10.0 


20.0 







30.0 


3-4 3/4 





10.0 


10.0 


20.0 







40.0 


<3 





10.0 


10.0 


10.0 







30.0 


Total 





20.0 


30.0 


50. D 









N = 263 


male sagrei 


H = G = 


6.5 


R 


= 2.7 




10.5-20 






















5-10 





0.8 


1.5 










2.3 


3-4 3/4 





6.5 


8.4 


2.3 







17.2 


<3 


2.3 


30.0 


27.8 


11.4 







71.5 


Total 


2.3 


37.3 


37.7 


13.7 









N = 393 


female 


-sized sagrei H = 


G 


= 


13.2 R 


= 4.8 


10.5-20 






















5-10 








0.8 


0.3 







1.1 


3-4 3/4 





1.6 


1.3 


0.3 







3.2 


<3 


2.5 


31.8 


22.5 


21.0 







77.8 


Total 


2.5 


33.4 


24.6 


21.6 










1971 



JAMAICAN ANGLES 



39 



Table 4. (concl'd) . 



Diameter 
(feet) 



N = 251 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 

N = 7 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 

N = 8 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 

N = 7 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 



>5 5-2 1/2 2 1/4-7/8 7/8-1/8 leaves Total 



juveni 


le sag 


rei 


H 


= 





G = 31 


9 


R 


= 4 






































8 




1.6 












0.8 







4 




2.0 









2.0 


17.8 




12 


6 




25.6 




0. 


4 



29.2 



14.3 42.9 42.9 
female-sized valencienni H = 
















37.5 






25.0 


37.5 



37.5 



62.5 



0.4 



G = 














2.4 
3.2 

58.4 



ma] 


Le 


va 


lencienni 


H = 





G = 


R = 




























14 


3 







28.6 




42.9 

















14.3 




































juvenile valencienni 


H 


= 


G = 


= 


R = 























42.9 




14 


3 















28 


6 










14.3 

















85.8 
14.3 


R = 


25.0 
37.5 
37.5 




57.2 
28.6 
14.3 



57.2 



42.9 



40 



BREVIORA 



No. 368 



Table 5. Percent observations for Whitehouse 
species in climatic categories. 





Sun 


Shade 


Clouds 


male sagrei 


17.4 


74.4 


8.3 


female-sized sagrei 


15.9 


73.8 


10.2 


juvenile sagrei 


33.8 


58.8 


7.4 


male grahami 


12.4 


74.6 


12.9 


female-sized grahami 


20.5 


61.4 


18.1 


iuvenile grahami 


15.7 


66.7 


17.6 


male opalinus 


3.5 


72.1 


24.4 


small opalinus 


14.5 


66.3 


19.3 


valencienni 


36.4 


50.0 


13.6 



1971 



JAMAICAN ANGLES 



41 



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42 



BREVIORA 



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1971 



JAMAICAN ANGLES 



43 



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44 



BREVIORA 



No. 368 



TuuaxouaxEA 

XI GUIS 



p TUuaxouaxBA 

snuTXBdo XTSUJS 

p snuTx^do 

aXTuaAnC 
sndo:;BauTx 



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pazTS 

-aXBuiaj 



p sndot^Bauxx 



u 
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n) 



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1971 



JAMAICAN ANGLES 



45 



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46 



BREVIORA 



No. 368 



juuaTouaxBA 



sridoieauf X 



sndo:^BauTX 

pazTs 

-a-[Bura3 



p snSo^BaTrfx 



aiTuaAnC 
^ * pj- 

snuTXBclo 



snuTXBdo 

pazTs 

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p snujx'sdo 



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1971 



JAMAICAN ANGLES 



47 



w 

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p snuixBdo 



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48 



BREVIORA 



No. 368 



TUUaTOUa-[BA 

snuTxedo 

XIEUIS 

p snuTXBdo 



ajjuaAnC 
TureqeaB 



TuiiqBxB 
pszTS-ajBuraj 



p Ttiiei{9j5 



aXJuaAn£ 



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pazTS 

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p TaoEBs 



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o o o o 



5 5 

t-i o o m o 



o o o o 



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O HO iHOOOO 



10 

E 



I 



1971 



JAMAICAN ANGLES 



49 



JUU3JOUaXBA 



snuTxedo XT'^uis 



p snuTXBdo 



9X_TuaAn£ 
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"fureqioB 

pazTS 

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p TureiiBa6 



aXJu3An£ 
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-aXBuraj 
p xaxEiis 




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50 



BREVIORA 



No. 368 



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paz^s-axBuraj 



p TUUsyouaxBA 



snuTxedo 

XXBUIS 



p snujx^do 



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sndoieauTx 



Id 
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p sndo^BauTx 



aXJua/vnC 
puBqexB 



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pazTs 

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1971 



JAMAICAN ANGLES 



51 



TUU3JOUaXBA 



_aXiuaAn£ 
sndoieauTX 



sndo:;B3UTX 
pazTS 



TJ p sndo^BSUTT 
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pazTs 

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p snujXBdo 







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52 



BREVIORA 



No. 368 



TuuaxouaxBA 
XT^uis 



p IUU3TOUaiBA 



snuT-[Bdo XT^u^s 



c 

s- 

o 

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c 
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■p 
u 
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p snuTXBdo 



9XTU3AnC 



sndo:iBauTX 



sndo:iB3UTX 

pazTs 

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p sndo:iBauTX 



ajQUBAnC 



Tureqeab 



pazTS 
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p 


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1971 



JAMAICAN ANGLES 



53 



0) 

n 

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TuuaTouaxBA 



snuTXBdo 
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p snujx^do 



aXTU9AnC 



Tureq¥j5 



TureiiBab 

PSZTS 

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p TureqBj5 



ariuaAnC 
^-1 



TaxbBS 



xaa&Bs 

pazTS 

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p TajBBS 




fo 



vo 



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BREVIORA 



Mitasemiinii of Comparative Zoology 

Cambridge, Mass. 29 January, 1971 Number 369 

LITHOPHAGA ARISTATA IN THE SHELL-PLATES OF 
CHITONS (MOLLUSCA) 

Robert C. Bullock 

and 
Kenneth J. Boss 



Abstract. The occurrence of the mytilid bivalve Lithophaga aristata as 
a borer into the shell-plates of polyplacophorans is unreported. Our investi- 
gation revealed this lithophage in the Panamic Chiton stokesii and, less 
commonly, in the West Indian C. tiiheniihitiis. A review of other organ- 
isms known to associate with chitons is provided, although none is appar- 
ently deleterious to the host-species as in the case of Lithophaga. Damage 
to the chiton by L. aristata appears to consist predominantly of the weaken- 
ing of the shell-plates and not the destruction of the aesthetes of the 
nervous system. 

INTRODUCTION 

Although several symbiotic organisms are known to live in 
association with chitons, the boring of the mytilid bivalve Litho- 
phaga into the shell-plates of polyplacophorans appears to be 
unreported in the literature. During a dissection of a specimen of 
Chiton stokesii Broderip, 1832, several Lithophaga {Myojorceps) 
aristata (Dillwyn, 1817) were discovered in the shell-plates. A 
survey was undertaken to assess the occurrence, and to determine 
the nature, of the infestation of Lithophaga in C. stokesii and 
other species of chitons from various localities. In addition, the 
known symbionts of chitons were reviewed. The results, presented 
in this paper, indicate that the presence of Lithophaga in the shell- 
plates of chitons is unusual and represents the most detrimental 
polyplacophoran symbiont known. We have observed L. aristata 
boring in the shell-plates of the Panamic Chiton stokesii and the 
Caribbean Chiton tuberculatiis Linnaeus, 1758. 



BREVIORA No. 369 



ACKNOWLEDGMENTS 



The manuscript has been critically read by our colleagues in 
the Museum of Comparative Zoology, Messrs. R. I. Johnson and 
M. K. Jacobson, and Dr. Peter W. Glynn of the Smithsonian 
Tropical Research Institute. The X-ray apparatus was made avail- 
able by the Museum of Comparative Zoology through a Milton 
Fund grant to Drs. R. D. Turner and S. J. Gould. Funds enabhng 
the senior author to collect Panamanian Polyplacophora were 
provided by a National Science Foundation grant, GB 8620, issued 
to the Committee on Evolutionary Biology, Dr. R. Rollins prin- 
cipal investigator. 

METHODS AND MATERIALS 

Numerous specimens of Chiton stokesii, collected at various 
localities in the Gulf of Panama by the senior author during July 
and August 1969, were examined by radiographic techniques for 
the presence of Lithophaga. A survey was made of the large col- 
lection of Polyplacophora in the Museum of Comparative Zoology, 
Harvard University, in an effort to locate other species host- 
ing Lithophaga, and X-rays of suspected host-individuals were 
made. All radiographs were checked for the number of lithophages 
present, their spatial distribution, and orientation. Borers were 
extracted at random to check their identity and all proved to be 
L. aristata. 

POLYPLACOPHORAN SYMBIONTS 

Few records are to be found in the literature concerning sym- 
bionts of polyplacophorans, but organisms representing several 
phyla are associated with chitons. Cryptochiton stelleri (Midden- 
dorff, 1846) is known to harbor two commensals: a crustacean, 
Opisthopus transversus (Rathbun, 1893) and an annelid, Arctonoe 
vittata (Grube, 1855) (MacGinitie and MacGinitie, 1968; Web- 
ster, 1968). 

Glynn (1968) and Menzies and Glynn (1968) summarized 
present knowledge of the symbionts of the mantle cavity on the 
West Indian chitonids, Acanthopleura granulata (Gmelin, 1791) 
and Chiton tuberculatus Linnaeus, 1758. Included were: the 
isopods, Dynamenella perforata (Moore, 1901) with A. granulata 
and C. tuberculatus; Exosphaeroma alba Menzies and Glynn, 



1971 LITHOPHAGA IN CHITONS 3 

1968, Exosphaeroma cremilatum (Richardson, 1902), Dynamen- 
opsis dianae Menzies, 1962 with C tuberciilatus; Exosphaeroma 
alba var. chromata Menzies and Glynn, 1968 with C. mannoratus 
Gmelin, 1791; and the foraniiniferan, AcerviiUna inhaerens 
Schulze, 1854 and the amphipod, Parhyale hawaiensis (Dana, 
1853) both with C. tuberciilatus; the harpacticoids, Harpacticus 
sp. and Heterolaophonte sp. with A. ^ranulata and C tuberciilatus; 
and the coUembolan, Actaletes ueptiini Giard, 1889 with A. 
gramilata. 

The mite Halixodes chitonis (Brucker, 1897) has been found 
attached to the gills of the Neozelanic Cryptoconchus porosus 
(Burrow, 1815) (Brucker, 1897; Brucker and Trouessart, 1900). 
Helfman (1968) observed the ctenostomatous ectoproct Farella 
elongata (van Beneden, 1845) in the ventral girdle tissue border- 
ing the pallia! groove. Arey and Crozier (1919) reported the 
following symbionts on the shell-plates of C. tuberciilatus: the 
barnacle, Tetraclita; the polychaetes, Spirorbis and Serpula; and 
algae, including the "Enteromorphas." They mentioned that the 
algae afforded protection for various young moUusks, nematodes, 
archiannelids, and protozoans. None of these symbionts has been 
shown to be harmful to the host. 

After conducting extensive studies on Chiton tuberciilatus , Arey 
and Crozier (1919: 171-172) remarked: "The general impres- 
sion derived from the consideration of destructive agents in relation 
to Chiton is that these mollusks are very efficiently protected. The 
length of life which they seem to attain, the variety of habitats 
which they frequent, and the character of their sensory responses, 
which determine certain features of their life in their habitats, 
afford important evidence to this effect." 

While the above statement is generally true for C. tuberciilatus, 
the Panamic C. stokesii appears far more vulnerable to attack by 
destructive agents than C. tuberciilatus. We observed large indi- 
viduals of C. stokesii from different localities that were not only 
greatly eroded, but heavily fouled with calcareous algae, bryozoans, 
and polychaete tubes. Most of the latter were heavily infested with 
Lithophaga aristata, some of which had grown large enough to fall 
out of their burrows, leaving greatly weakened shell-plates. The 
cases of C. tuberciilatus from Trinidad (MCZ 31955) and Isla 
Margarita (MCZ 273763), in which we found examples harboring 
L. aristata, appear to be rare. Our examination of numerous other 



4 BREVIORA No. 369 

samples of C. tuberculatus produced no additional Lithophaga. 
It is probable that differences in shell-structure account for the 
greater penetrability and susceptibility for fouling and boring in 
C stokesii. 

RESULTS AND DISCUSSION 

The mytilid bivalve Lithophaga {Myojorceps) aristata (Dillwyn, 
1817) (Figs. 7 and 8) bores into calcareous substrates, including 
the shells of large bivalves (e.g., Spondyhis, Chama, Ostrea) and 
gastropods (e.g., Haliotis, Patella, Strombus, and Pleuroploca) . 
The species occurs in warm temperate to tropical waters in the 
eastern Pacific, western Atlantic, and eastern Atlantic regions and 
is usually found in shallow water, although Soot-Ryen (1955) 
reported a living specimen taken from 165 fathoms (Turner and 
Boss, 1962). 

In both C. stokesii and C. tuberculatus, Lithophaga aristata 
was present only in large specimens. This relationship coincides 
with the findings of Arey and Crozier (1919) and Crozier and 
Arey (1920) who observed the presence of barnacles, polychaetes, 
and algae only on larger C. tuberculatus. The erosion of the shell- 
plates, which is brought about by physical agents of the environ- 
ment and by organisms which live on the chiton's shell, appears 
to be a prerequisite for the boring of Lithophaga. During settle- 
ment the pediveligers of L. aristata evidently reject the uneroded 
areas of the polyplacophoran shell and metamorphosis occurs on 
the eroded substrate. We noted that most lithophages began 
boring at the posterior edge of the intermediate valves, which was 
normally eroded in large individuals. Large C. stokesii showing 
little or no erosion had few, if any, L. aristata; the valves of those 
chitons that were considerably eroded revealed Lithophaga boring 
in them at various places, not just at the posterior edge. Chiton 
viridis Spengler, 1797, a Caribbean species that normally lives 
below the low-water mark, is rarely eroded and no Lithophaga were 
found in the shell-plates of this species. 

After initial penetration of the shell, most L. aristata bored hori- 
zontally. In several instances we observed the burrows of Litho- 
phaga extending into a second valve. In one example from Culebra 
Island, Canal Zone, which harbored over 40 L. aristata (Fig. 1 ), 



1971 LITHOPHAGA IN CHITONS 5 

two individual lithophages had bored vertically from one valve to 
the next, penetrating the intervening musculature (Fig. 4). One 
such burrow passed from valve III into the insertion plate of valve 
IV (Fig. 1). All cases of vertical burrows apparently occurred in 
overcrowded conditions. 

Most burrows of intermediate valves were roughly parallel with 
the antero-posterior axis of the chiton with the siphons of the 
Litlu)pluii>a pointed posteriorly, although they deviated somewhat 
by orienting themselves along an axis extending from the zone of 
erosion toward the nearest growth zone. The reason for this is 
obvious. Should a lithophage burrow perpendicularly to the antero- 
posterior axis and only in the region of the mucro, it would risk 
having its surrounding substrate eroded away. By burrowing from 
the zone of erosion toward a growth zone, the lithophage is assured 
of an increasing substrate in which to bore. This explanation clar- 
ifies the otherwise haphazard orientation of the burrows in the 
posterior valve, where the oldest shell material is near the center, 
not at the posterior edge (Fig. 2). 

As the lithophage increases in size, it faces problems caused 
by the restricted space in which it can grow. Although some 
Lithophaga enlarge their burrows dorsally, most penetrate ventrally 
and eventually reach the mantle of the chiton. When the latter 
situation occurs, the chiton secretes a thin calcareous shield in an 
effort to contain the intrusion of the lithophage. Sometimes more 
than half of the ventral portion of the lithophage is situated below 
the ventral shell-plate surface. In spite of the efforts of the Lith- 
ophaga to increase in size and the chiton's effort to contain it, the 
lithophage soon reaches a point where further growth is impossible. 
Whether this represents a truly stenomorphic condition or not is 
uncertain, because we do not know if the L. aristata we observed 
ever reached sexual maturity. Lithophaga aristata is known to 
attain a length of 52 mm (Turner and Boss, 1962); the largest 
specimen extracted from a C. stokesii was 9.0 mm, while the aver- 
age length was about 7.0 mm. 

There is evidence that at least a few L. aristata outgrow their 
restricted polyplacophoran substrate (Fig. 6). Some of the largest 
burrows that we examined were exposed along their entire dorsal 
surface, indicating that the lithophages may have fallen from their 



6 BREVIORA No. 369 

burrows. It is probable that specimens that outgrow the chiton 
perish in the external environment.^ 

The effect of numerous Lithophaga in the shell-plates must be 
detrimental to Polyplacophora. In addition to damaging the spe- 
cialized portion of the nervous system that makes up the aesthetes 
in the tegmentum, Lithophaga weakens the valves and, at times, 
probably affects the maneuverability of the chiton. The seriousness 
of damage to a large amount of the tegmental nervous tissue is 
open to question and may depend upon the species involved. Aes- 
thetes are photosensitive, being activated both by light of constant 
intensity and by a decrease of light intensity (Arey and Crozier, 
1919). Studies on the growth and behaviour of Chiton tubercu- 
latus indicated that normal erosion of shell-plates and concomitant 
loss of tegmental aesthete photosensitivity produced at least a 
partial inversion in its phototropic response. While young C. tiiber- 
ciilatiis are photonegative, older individuals may be irresponsive or 
photopositive (Arey and Crozier, 1919; Crozier and Arey, 1920), 
although Glynn (personal communication) found older C. tubercu- 
latus from Puerto Rico also to be photonegative. It appears, then, 
that Lithophaga mainly affects the durability of the shell, rendering 
the chiton more susceptible to predation. 

REFERENCES CITED 

Arey, L. B., and W. J. Crozier. 1919. The sensory responses of Chiton. 

J. Exper. Zoo!., 29: 157-260. 
Brucker, a. 1897. Sur un noiivel Acarien marin. C. R. See. Biol., 49: 

632-633. 
Brucker. A., and E. Trouessart. 1900. Seconde note sur un Acarien 

marin (Halacaride), parasite de VAcanthocliiton porosiis. C. R. Soc. 

Biol.. 52: 107 109. 
Crozier. W. J., and L. B. Arey. 1920. On the ethology of Cliiton tiiber- 

ctilatiis. Proc. Natl. Acad. Sci.. 5: 496-498. 



1 Although Hodgkin (1962) maintained L. pitimiila kelseyi Hertlein and 
Strong, 1946 outside their burrows for over one year under laboratory con- 
ditions. Otter (1937) was unsuccessful in his attempts to rear L. cumingi- 
ana (Reeve, 1857) and L. teres (Philippi. 1846) that had been removed 
from their burrows. It is doubtful if Lilliophaga could survive out of its 
burrow under exposed conditions. 



1971 LITHOPHAGA IN CHITONS 7 

Glynn, P. W. 1968. Ecological studies on the associations of chitons in 

Puerto Rico, with special reference to sphaeromid isopods. Bull. Mar. 

Sci., 18: 572-626. 
Helfman, E. S. 1968. A ctenostomatous ectoproct epizoic on the chiton 

Ischnochiton mertensii. Veliger, 10: 290-291. 
Hodgkin, N. M. 1962. Limestone boring by the mytilid Lithophaga. 

Veliger, 4: 123-129, 3 pis. 
MacGinitie, G. E., and N. MacGinitie. 1968. Notes on Cryptochiton 

stelleri (Middendorff, 1846). Veliger, 11: 59-61, pi. 6. 

Menzies, R. J., AND P. W. Glynn. 1968. The common marine isopod 
Crustacea of Puerto Rico. A handbook for marine biologists. Studies 
Fauna Curasao, 27: 1-133. 

Otter, G. W. 1937. Rock-destroying organisms in relation to coral reefs. 

British Mus. (Nat. Hist.) Great Barrier Expedition 1928-29, Sci. 

Repts., 1: 323-352, 6 pis. 
Soot-Ryen, T. 1955. A report on the family Mytilidae (Pelecypoda). 

Allan Hancock Pacific Expeditions. 20: 1-154, 10 pis. 
Turner, R. D., and K. J. Boss. 1962. The genus Lithophaga in the 

western Atlantic. Johnsonia, 4: 81-116, pis. 57-75. 

Webster, S. K. 1968. An investigation of the commensals of Crypto- 
chiton stelleri (Middendorff, 1846) in the Monterey Peninsula area, 
California. Veliger. 11: 121-125. 



BREVIORA 



No. 369 




1971 LITHOPHAGA IN CHITONS 



Figure 1. Radiograph of disarticulated shell-plates from a specimen 
of Chiton stokesii from Culebra Island. Panama Bay, Canal Zone 
(MCZ 277122), showing a high degree of infestation by Lithopliaga aris- 
tata (0.84 x ). 

Figure 2. Enlargement of posterior valve of Fig. 1 (3.2 X ). 

Figure 3. Typical siphonal opening of L. aristata burrow in an uneroded 
portion of a C. stokesii shell-plate (12 X )• 

Figure 4. Intervening shell-plate musculature located between valves IV 
and V in Fig. 1, showing damage resulting from penetration of Lithophaga 
(9.2 X). 

Figure 5. Example of L. aristata (MCZ 277123) in shell-plate cross 
section of C. stokesii from Punta Mala, Panama (3.9 x )• 



10 



BREVIORA 



No. 369 




Figure 6. Exposed burrow of Lithophaga aristata in Chiton stokesii from 
Panama City, Panama (MCZ 78821) (4.2 x ). 

Figures 7-8. L. aristata extracted from burrow illustrated in Fig. 5 
(MCZ 277123) (6.5 x ). 



BREVIORA 

Miaseuni of Comparative Zoology 

Cambridge, Mass. 31 March, 1971 Number 370 

ECOLOGICAL OBSERVATIONS ON A LITTLE KNOWN 
SOUTH AMERICAN ANOLE: TROPIDODACTYLUS ONCA 

James P. Collins^ 

Abstract. The little known anole Tropidodactylus onca on the island 
of Margarita is typically restricted to belts of low xerophytic vegetation 
adjacent to the open sandy area of natural beaches. Most animals are 
found on the ground or in low bushes and occur up to a height of 30.0 
cm. They are poor climbers and will occasionally escape into holes made 
by ghost crabs. 

INTRODUCTION 

A brief visit (from July 8 to July 21, 1968) to the Fundacion 
La Salle on Margarita Island, Venezuela, afforded me an oppor- 
timity to collect and observe a little known anole, Tropidodactylus 
onca. Margarita is a continental island approximately twenty-one 
miles off the district of Sucre on the northern coast of Venezuela. 
It is approximately two hundred air miles northeast of Caracas. 

Tropidodactylus onca is a speciaUzed derivative of Anolis but 
with keeled scales underneath the digits instead of the expanded 
digital pads with adhesive lamellae so characteristic of the latter 
primarily arboreal genus. The difference in morphology should 
be reflected in ecology, but there have been no detailed reports 
on the habits, habitat, or even color in Ufe of T. onca. This 
paper attempts to remedy this gap in information. 

Description and color in life. Tropidodactylus onca is a rela- 
tively large anole. The largest of the specimens collected is 75 
mm snout- vent length. The tail is round with no dorsal crest 
and is approximately equal to the snout-vent length of the animal. 

The most distinctive specialization of the anoles in general, 
the dewlap, is extremely well developed in this genus. It has a 
bright yellow ground color in which individual red scales are 
embedded. 

1 Museum of Zoology, University of Michigan, Ann Arbor. Mich. 



BREVIORA 



No. 370 



The dorsal color of the lizard varies from a very light ashy- 
gray to a dark gray-brown with a disruptive pattern of black 
and white longitudinal markings. These vary from barely visible 
to very prominent. The ventral surface of the lizard is white. 
The species is not sexually dichromatic and is very difficult to 
sex externally. The cryptic coloration of the species is perfect. 
In the field the animals are indistinguishable from their sur- 
roundings. In fact, an animal can usually be located only when 
the collector inadvertently frightens it into movement. 

Habits and habitat. Tropidodactylus onca is a beach anole. 
Its distribution is typically restricted to the belt of low xerophy- 
tic vegetation adjacent to the open sandy area of a natural beach. 
The exact width of this belt and its continuity varies according 
to the geological and ecological factors of the particular locality. 
The animal was never observed in the open sandy areas devoid 
of vegetation, and penetrates only slightly into the more land- 
ward areas where the vegetation is higher than 0.75 to 1.00 m. 



20 

"T" 



10 



64" 



50 



10 



50'- 



40 




LOS FRAILES 

El Aguo 
Punta Montadaro 



Playa Guacuco 



ISLA CUBAGUA 



ISLA COCHE 




PENINSULA DE ARAYA 




(0' 



SO 



Figure 1. Margarita Island. Localities at which Tropidodactylus onca 
was observed or collected are shown as solid circles. 



1971 TROPIDODACTYLUS ONCA 3 

All the specimens, with the exception of one taken at a height 
of 1.25 m, were collected on the ground or up to 30.0 cm high 
on low bushes, vines, etc. 

Observation and collecting was restricted to six localities (Fig. 
1), all on the eastern half of the island. Roze (1964), however, 
has reported the lizard from the western half (Macanao). Of the 
six localities in which the species was observed, five are on the 
coast. The exception, El Aguila, is a town approximately 2.5 
km from Punta de Piedras. Possible reasons for the animal's 
appearance here will be discussed later. Outside of this single 
exception, no specimens were ever observed in noncoastal por- 
tions of the island and all were collected at sea level. 

The vegetation of the zone in which Tropidodactylus is found 
consists of only low ground growth. The sand-shrub communities 
of the five coastal localities in which Tropidodactylus is found 
each contain at least two and as many as four of the following 
species of plant: Sesuvium portidacastrum, Philoxerus vermicu- 
laris, Bat is maritima, Sporobolus (virginicus?), Ipomoea (pescap- 
rae?), and Mallotonia gnaphalodes. Howard (1950) lists these 
six species as pan-Caribbean in distribution. These are found in 
association with less abundant and restricted species, the exact 
taxa varying from locality to locality. The landward edge of this 
coastal community typically contains representatives of the genera 
Opuntia, Melocactus, Lemairocereus, Philoxocereus, and Proso- 
phis. Tropidodactylus penetrates slightly into this zone. 

The majority of the animals collected were taken in large 
patches of Ipomoea found at two of the localities investigated (El 
Agua and Playa Guacuco). The reptile was found both on the 
plants and in the open space between them. If the patch was 
dense enough, the animals were typically found with their head 
on top of the leaves and their trunk and tail among the tangled 
vines. Some were also found on an occasional outcropping of 
rock or log. When frightened, the animal would either duck into 
the mat of vegetation (if dense enough) or scamper across the 
open sand until it reached a vine or series of vines which it would 
then proceed to run clumsily over. Being nonwoody, the plants 
do not give much support and the animal could easily be taken. 
In the area just north of Punta Montadero where Mallotonia, a 
woody-stem plant, is dominant, the animal's behavior was very 
different. Here, when first sighted, the lizard was always on the 



BREVIORA 



No. 370 




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1971 TROPIDODACTYLUS ONCA 5 

ground. When pursued, the majority of animals observed would 
merely run among the ground cover. A few specimens, however, 
were observed to climb the Mallotonia, some to a height of 30.0 
cm. Their climbing was clumsy and ineffective. The toe structure 
of this genus is not well adapted for tree climbing. Unlike most 
anoles, T. onca is not arboreal. 

Another means of retreat should also be pointed out. At times, 
a specimen, being pursued, would run into a large hole in the 
sand opening into a tunnel. Ruthven (1922) also reports this 
species as escaping into holes. It should be noted, however, that 
these holes are resting places made by ghost crabs (Ocypode) and 
are not dug by Tropidodactylus. It should also be noted that this 
was a rather infrequent means of escape, used by the lizard only 
when almost completely exhausted. 

At each of the six localities, T. onca is found sympatric with 
Cnemidophorus lemniscatus lemniscatus. In those localities (El 
Agua and Punta los Cocos) where the landward border of the 
coastal area is occupied by a semi-desertic community, the terri- 
tory of Tropidodactylus partially overlaps that of Tropidurus tor- 
quatus hispidus. The Tropidodactylus penetrate this zone for only 
a very small distance. In some areas, two other organisms also 
found sympatric with Tropidodactylus are the gecko Gonatodes 
vitatus vitatus and the microteiid Gymnopthalmus laevicauda. 

Roze (1964) has the following note concerning the diet of 
Tropidodactylus: "The stomach contents examined in various 
specimens of this species revealed the remains of grasshoppers 
(Grillidae), Coleoptera, spiders, and various species of Diptera, as 
well as the remains of other unidentifiable arthropods." Tropido- 
dactylus then, hke most anoles, is insectivorous. Similarly, like 
most anoles, the animal is diurnal in its activity. All but one of 
the twenty-five specimens were captured during the day. The 
single exception was collected alongside the road near the town 
El Aguila approximately 2.5 km from Punta de Piedras. It was 
on a branch of a low bush, Jatropha gossypiifolia, in the cleared 
margin alongside the road. The animal was in typical anole 
sleeping posture, snout toward the main stem, but with its eyes 
open. Just prior to being seized, the animal moved its head but 
did not attempt to flee. This single exception to the otherwise 
complete coastal distribution of the animals on the island most 
probably migrated to this inland area along the corridor of low 
vegetation bordering either side of the roadway. This habitat is 
ecologically similar to that of the coastal zone. 



6 BREVIORA No. 370 

ACKNOWLEDGMENTS 

I am grateful to Dr. Janis Roze and Dr. Ernest E. Williams for 
critically reading the manuscript and for their valuable sugges- 
tions. This study was carried out at the Fundacion La Salle, Mar- 
garita Island, Venezuela; I thank Hermano Gines for making the 
facilities there available to me. Field expenses were partially met 
by NSF-GY-4183, administered by Manhattan College, and NSF- 
GB-6944 to Ernest E. Williams. 

REFERENCES 

Howard, R. A. 1950. Vegetation of the Bimini island group. Ecol. Mono. 
20: 317-349. 

Roze, J. A. 1964. La herpetologia de la Isia de Margarita, Venezuela. 
Mem. Soc. Cien. Nat. La Salle, 24 (69): 209-241. 

RuTHVEN, A. G. 1922. The amphibians and reptiles of the Sierra Nevada 
de Santa Marta, Colombia. Miscellaneous PubUcation No. 8, Museum 
of Zoology, University of Michigan. 



BREVIORA 

Miaseiuioi of Comparative Zoology 

Cambridge, Mass. 31 March, 1971 Number 371 



A NEW SPECIES OF BROMELIAD-INHABITING GALLIWASP 
(SAURIA: ANGUIDAE) FROM JAMAICA 

Albert Schwartz^ 

Abstract. A new species of anguid lizard, Diploglossus fowleri, is 
described from two specimens collected from bromeliads at the northern 
edge of Jamaica's Cockpit Country. The affinities of the new species are 
with D. hewardi and D. diiqiiesneyi; both D. fowleri and D. duquesneyi 
appear to be geographic or ecological isolates of the widespread D. hewardi. 

The Antillean islands of Jamaica and Hispaniola have excep- 
tionally large numbers of species of the anguid lizard genus 
Diploglossus Wiegmann. The latter island has six extant species, 
whereas Jamaica likewise had six species of which one {occiduus 
Shaw) is presently considered extinct. Cousens (1956) summar- 
ized the then-known Jamaican galliwasps and regarded cnisculus 
Carman, harbour i Grant, hewardi Gray, and duquesneyi Grant 
as valid species. Since that time, D. microblepharis Underwood 
has been named from a single specimen from the northeastern 
Jamaican coast. Cousens (1956), followmg Grant (1940b), sep- 
arated the four forms then recognized into two major groups: 
one group {crusculus, barbouri) with short legs and the other 
{hewardi, duquesneyi) with long legs. Schwartz (1970), in dis- 
cussing D. occiduus, suggested that the species crusculus-hewardi- 
barbouri-occiduus might represent a phylogenetic series, despite 
the interposition in this sequence of both long- and short-limbed 
species. D. microblepharis stands alone; its relationships are with 
the Puerto Rican D. pleei Dumeril and Bibron and the Cuban D. 
delasagra Cocteau. 

In the summer of 1961, while cutting bromeliads in the decid- 
uous forest at the northern edge of Jamaica's Cockpit Country, 

1 Miami-Dade Junior College, Miami, Florida 33167 



2 BREVIORA No. 371 

the extensive karst region in northwestern Jamaica, we secured a 
single immature galUwasp. Despite the peculiar habitat (no Antil- 
lean Diploglossus had ever been recorded from bromehads) the 
Hzard bore resemblances to D. hewardi, and it was so considered 
in the field. Not until 1969, when the paper dealing with D. 
occiduus (Schwartz, 1970) was in preparation, was the lizard 
re-examined in a routine study of D. hewardi for comparative 
purposes. At that time, the difference in scutellation between D. 
hewardi and the 1961 juvenile specimen quickly became appar- 
ent. Further examination of the specimen indicated that, although 
it resembled D. hewardi in general (being a long-limbed form), 
it differed chromatically and in pattern from that species. But, 
since it was immature, no further course of action was planned. 

It was thus with great pleasure that I accepted the invitation 
of Dr. Thomas H. Patton of the Florida State Museum to visit 
Jamaica and stay at Worthy Park Estate during August 1970. 
Although it was hardly likely that, even with persistent bromeliad 
cutting, we would encounter another specimen of the arboreal 
galliwasp, plans were made to revisit the site of capture of the 
first individual (Windsor, Trelawny Parish). Thanks to the efforts 
of my assistants and native help, we were successful in securing 
another and adult specimen of the same form. Study of both indi- 
viduals convinces me that they represent a new species, related to 
D. hewardi, which has apparently taken to a bromeliad-inhabiting 
niche — a niche that is virtually unoccupied by Antillean reptiles. 

In the summer of 1961, I had the capable assistance of Ronald 
F. Klinikowski and David C. Leber. Our activities were facilitated 
by C. Bernard Lewis of the Institute of Jamaica. The 1970 trip 
was made both pleasant and profitable by the presence of Dale E. 
Becker, Michael T. Felix, and Danny C. Fowler, whose energy 
expenditures in bromeliad cutting were noteworthy. In addition, 
I have examined specimens collected by Richard Thomas in 1967, 
and by Robert Brenner and Paul Moravec in the same year. All 
specimens are in the Albert Schwartz Field Series (ASFS) with 
the exception of the holotype of the new taxon and two speci- 
mens of D. duqiiesneyi, which are in the Museum of Comparative 
Zoology (MCZ) at Harvard University. All measurements are in 
millimeters and color designations are from Maerz and Paul 
(1950). I am especially grateful to Dr. Patton for making the 
Worthy Park facilities available to us, and to Dr. Ernest E. Wil- 
liams for the loan of the holotype of D. duquesneyi. 



1971 BROMELIAD GALLIWASP 3 

In honor of Danny C. Fowler, whose endeavors on my behalf 
can only be recognized in a token fashion by associating his name 
patronymically with the species, I propose that this bromeliad- 
inhabiting galliwasp be called 

Diploglossus fowleri, new species 

Holotype. MCZ 125601, a female, from Windsor, elevation 
about 500 feet (153 meters), Trelawny Parish, Jamaica, taken 
15 August 1970 by Danny C. Fowler. Original number ASFS 
V19902. 

Paratype. ASFS 14421, same data as holotype, 12 July 1961, 
D. C. Leber. 

Diagnosis. An apparently moderately sized (only known adult 
105 mm snout-vent length), long-limbed, bromeliad-dwelling gal- 
liwasp distinguished from all other Jamaican species by a com- 
bination of: 1) low number (101-103) of ventral scales between 
mental and vent, 2) low number (41-43) of scales around body 
at midbody, 3) angular subocular scale modally between supra- 
labials 6 and 7, 4) enlarged postmental scale contacting 5 infra- 
labial scales, 5) fourth toe lamellae 18-21, 6) ratio of head 
width to head length high (80.0), 7) auricular opening small, 
8) dorsal trunk and dorsal caudal scales keeled and striate, 9) 
ventral scales smooth, 10) dorsal pattern of tans and browns 
arranged in a distinct chevronate pattern, and 11) with dark 
markings on the head shields. 

Distribution. Known only from the type locality. 

Description of holotype. An (apparently) adult female with a 
snout- vent length of 105 mm and tail (almost entirely regener- 
ated) 75 mm; ventral scales between mental and vent 103, 41 
scales around body at midbody; fourth toe lamellae 21, angular 
subocular between supralabials 6 and 7 on one side, between 7 
and 8 on the other; head length 18.5, head width 14.8; ratio of 
head width to head length 80.0; median enlarged postmental 
(= first unpaired chin shield) small and contacting 5 infralabials. 
In life, dorsal pattern consisting of a series of about 16 or 17 
wood brown chevrons, their apices pointing posteriorly, from the 
neck to the sacrum, on a tan ground; sides with somewhat lighter 
brown continuations of these chevrons both on the neck and 
between the limbs, the lateral continuations forming a series of 
more or less vertical brown bars which extend ventrad to about 
the level of the limb insertions; a few scattered paler tan dots or 



4 BREVIORA No. 371 

flecks in two vague lateral horizontal rows, associated with the 
lateral brown vertical bars; head tan, with more or less symmet- 
rical wood brown markings (a pair on the snout, an unpaired 
median blotch in the preorbital region, a median unpaired blotch 
on the posterior portion of the frontal, and the interparietal- 
parietal region with the scales dark edged); a black preorbital line 
on the lores; temples longitudinally streaked with very dark wood 
brown; a series of three brown lines on the supralabials, one below 
the eye, the two others extending vertically across the supralabials 
in the loreal region, all continuous ventrally across the infralabials; 
a series of three very dark brown to black nuchal blotches, the 
posteriormost the largest and located above the insertion of the 
forelimb; Umbs mottled brown and black dorsally, the forelimbs 
additionally with some intermixed tan areas and consequently 
appearing more mottled or marbled than the hindlimbs; underside 
pale orange, with discrete brown longitudinal streaks (four scales 
in length) or flecks on throat, and deep orange streaks on venter; 
underside of limbs and tail (unregenerated portion) pale orange; 
iris brown with orange pupillary ring. 

Variation. The paratype is a juvenile lizard with a snout- vent 
length of 66 mm. Scale counts are: 101 scales between mental 
and vent, 43 scales at midbody, angular subocular between supra- 
labials 6 and 7 on one side, between 8 and 9 on the other, fourth 
toe lameUae 18; head length 12.7, head width 9.3 (ratio 73.2). 
In hfe, the paratype was tan (PI. 14G6) dorsally with about 18 
dorsal chevrons between the neck and the sacrum; the sides were 
paler tan (PL 13D3). The snout was olive, with the jowls and 
the base of the tail slightly reddish. The Hmbs were tan, spotted 
with dark brown to black. The venter was translucent gray, 
marbled with brown on the throat, and marked with reddish on 
the trunk and underside of the hindlimbs and tail. The facial 
markings, described for the holotype, were equally as prominent 
in the juvenile paratype. The dorsal chevronate pattern was dark 
brown to black, and on the sides the chevrons were continuous 
with weakly defined lateral vertical brown bars, each of which 
was followed by a creamy bar. Three nuchal-supra-axillary 
blotches were black, and the frontal head shield had a dark ante- 
rior margin with some additional dark sulTusions on the dorsal 
surface of the head. The postmental scale in the paratype is very 
small, but it contacts 7 infralabials; the contact on the right side 



1971 BROMELIAD GALLIWASP 5 

between the postmental and the third infralabiai is slight, but 
the contact on the left side is slightly more broad. 

Comparisons. D. fowleri needs comparison only with the three 
long-limbed Jamaican species (occiduus, hewardi, duquesneyi) . 
The new species differs from the short-limbed cnisculus and 
barboiiri in having much larger Umbs and from microblepharis 
in having the frontal longer than broad (in microblepharis, the 
frontal is broader than long). Counts of ventral scales (101-103) 
in fowleri overlap (of the other species) only the counts of crus- 
culus (97-122, data from Grant, 1940b); all other Jamaican 
species combined have ventral counts ranging from 107 to 150, 
with the low count of 107 in the giant occiduus, the high count 
of 150 in barbouri. In midbody scales, fowleri (41-43) overlaps 
only cruscuhis (36-49) and microblepharis (43). Combined 
midbody counts for all other Jamaican species (with the excep- 
tion of cruscuhis and microblepharis) vary between 47 {bar- 
bouri) and 59 {hewardi). In having the angular subocular 
between supralabials 6 and 7, fowleri resembles barbouri and 
cruscuhis but differs from hewardi and duquesneyi (7 and 8), 
microblepharis (5 and 6), and occiduus (8 and 9). 

In fowleri, the dorsal scales are striate and keeled; this condition 
occurs in all other Jamaican galliwasps with the exception of 
occiduus (dorsals striate but not keeled). In having smooth 
ventrals, fowleri resembles barbouri, hewardi, occiduus, and 
microblepharis. The ventral scales are striate in crusciilus and 
duquesneyi. Note, however, that hewardi may have weakly striate 
ventrals, and duquesneyi may have smooth ventrals. Finally, the 
striate and keeled dorsal caudal scales of fowleri are Hke those of 
cruscuhis and duquesneyi; all other Jamaican species have smooth 
{hewardi, occiduus) or keeled {microblepharis) superior caudals. 
From the above summary, it is obvious that fowleri combines 
features of scuteUation of several Jamaican species in new and 
different ways, and that the new species differs in combination of 
these characteristics from all other Jamaican species. 

Presumably, as will be noted below, D. fowleri is a local deriva- 
tive of the widespread D. hewardi. The fact that the juvenile 
fowleri was, in the field, considered as hewardi suggests the simi- 
larities between the two species. However, in addition to the 
structural differences noted in the above paragraph, the two spe- 
cies differ strikingly in coloration in life and perhaps less so in 



6 BREVIORA No. 371 

dorsal pattern. More importantly, the size of the auricular open- 
ing in fowleri is much the smaller; comparison of the opening in 
the fowleri holotype and a similarly sized hewardi (ASFS 14892; 
female with snout- vent length of 109 mm) reveals, even upon 
casual inspection, that the auricular opening of fowleri is slightly 
more than half the size of that of the hewardi. In addition, the 
two species differ in that fowleri has larger ventral scales (101- 
103 between mental and vent in fowleri, 113-135 in hewardi), 
and fewer scales at midbody (41-43 versus 49-59 in hewardi). 
The enlarged postmental contacts 7 infralabials in all hewardi ex- 
amined, whereas at least in the fowleri holotype this scale con- 
tacts only 5 infralabials (weak contact with 7 infralabials in the 
paratype). In fowleri, the angular subocular modally hes between 
supralabials 7 and 8, whereas in hewardi it lies between suprala- 
bials 6 and 7. D. fowleri exceeds D. hewardi in number of fourth 
toe lamellae (15-19 in 22 hewardi, 18 and 21 in two fowleri). 
Finally, the head width/head length ratio in adult female hewardi 
varies between 70.7 and 74.1, whereas in the fowleri holotype, 
this ratio is 80.0. There are no comparably sized juvenile hewardi 
for comparison of this ratio in the paratype of fowleri, but the 
ratio (73.2) in this specimen lies near the upper extreme of ratios 
in hewardi with shorter snout-vent lengths (45-52 mm; ratios 
66.4 to 73.8). 

The dorsal coloration of hewardi has been repeatedly recorded 
as greenish brown to greenish tan, but some individuals have the 
dorsum very dark brown (almost black) to metallic tan. The 
head regularly is unmarked dorsally, and vertical subocular and 
loreal lines are absent. The dorsal pattern consists of a trans- 
verse series of confused bars or bar fragments; these pattern ele- 
ments are usually so broken that no meaningful count can be 
taken. There is a strong tendency for the hewardi dorsal pattern 
elements to consist of bars, rather than chevrons as in fowleri. 
Perhaps the most distinctive pattern feature of hewardi, in con- 
trast to fowleri, is that of the throat. In hewardi, the throat has 
a broad dark reticulum, the pattern extending as far posterior 
as the forelimb insertions. This pattern is expressed even in the 
smallest juveniles and becomes more intense with increasing size. 
No hewardi has the discrete brown throat lines and flecks of 
fowleri. In addition, the ground color of the throat in hewardi 
is often blue to purplish, not pale orange as in fowleri. The deep 
orange belly markings of fowleri are absent in hewardi; some 



1971 BROMELIAD GALLIWASP 7 

hewardi have belly markings that are not discrete as in fowled 
and are gray in life. 

Comparisons in detail with D. occiduus are hardly necessary. 
In addition to the scutellogical differences noted above, the huge 
size of occiduus (to 305 mm snout-vent length) and its presumed 
terrestrial habits, coupled with its general bulk, immediately dis- 
tinguish it from fowled. 

The only other long-limbed Jamaican galliwasp is D. duques- 
neyi. Scutellogical differences have already been noted between 
this species and fowled. I have examined the holotype (MCZ 
45194) and one other specimen (MCZ 45181) of duquesneyi. 
The species was casually defined by Grant (1940a: 6) on the 
basis of one juvenile specimen, and Cousens (1956) gave addi- 
tional pigmental and pattern differences between two specimens 
of duquesneyi, and hewardi. I have examined the two extant 
duquesneyi and both are damaged about the body so that accurate 
scale counts are difficult. Ventral scales between the mental and 
vent are about 116 and 122, midbody scales are about 48 and 
49, and fourth toe lamellae are 19 and 23. The angular subocular 
lies between supralabials 7 and 8 on both sides of both specimens. 
D. hewardi and D. duquesneyi are comparable in dorsal pattern: 
the transverse markings in both are distinctly straighter and more 
barlike than the chevronate pattern in fowleri. In addition, com- 
parison of equally sized hewardi and duquesneyi shows that du- 
quesneyi (like fowleri) has a larger auricular opening than 
hewardi. 

D. fowleri differs from D. duquesneyi in that the former has 
fewer ventrals between mental and vent (101-103 versus 116- 
122), fewer midbody scales (41-43 versus 48-49), the angular 
subocular between supralabials 6 and 7 rather than between 7 
and 8, and smooth rather than striate ventrals (although the holo- 
type of duquesneyi has smooth ventrals). Two pattern elements 
differentiate duquesneyi from fowleri: the former has the tail (at 
least in juveniles) banded alternately black and sky blue (Grant, 
1940b: 106), a feature unknown in any other Antillean galliwasp, 
and duquesneyi has an immaculate throat and venter (color un- 
known), a feature that separates duquesneyi from both fowleri 
and hewardi. D. duquesneyi also lacks the prominent facial mark- 
ings of D. fowleri. Finally, the head width/head length ratio (X 
100) in duquesneyi is much less than this ratio in both fowleri 



8 BREVIORA No. 371 

and hewardi. In an apparently subadult female duquesneyi with 
a snout-vent length of 96, the HW/HL ratio is 69.8, below that 
of similarly sized female hewardi (ratios 70.7-13.1) and much 
below that of the slightly larger female holotype of jowleri (80.0). 
The HW/HL ratio in the juvenile holotype of duquesneyi (snout- 
vent length about 65) is 66.4, whereas this ratio in the jowleri 
paratype (snout-vent length 66) is 73.2; the HW/HL ratio in 
the duquesneyi holotype falls at the lower extreme of this ratio 
in smaller hewardi (ratio 66.2 to 67.3 in hewardi juveniles with 
snout-vent lengths of 49 to 52). 

Interestingly, Richard Thomas noted that a D. hewardi from 
Darliston, Westmoreland Parish, in western Jamaica, (and far 
removed from the known range of D. duquesneyi, which has been 
taken only on Portland Point, Clarendon Parish, in south-central 
Jamaica) with a snout-vent length of 48 mm, had pale blue distal 
tail bands alternating with brown bands. There seems little doubt 
that hewardi, duquesneyi, and jowleri are closely related, and 
that duquesneyi and presumably jowleri are peripheral geographic 
satellite species derived from parent hewardi in special situations. 

Remarks. The two specimens of D. jowleri were collected 
under the following circumstances. Both specimens were taken 
from bromeliads along the edge of the steep trail from Windsor 
Great House to Windsor Cave and thence up the escarpment of 
the Cockpit Country. In the case of the holotype, a Jamaican had 
been hired to cut arboreal bromeliads and had climbed a tall 
tree of moderate girth (0.5 meters) just below the path in decidu- 
ous forest. He had cut all but the last one or two bromeliads when 
the galliwasp rapidly descended the trunk of the tree and paused 
in confusion on a leaf about six feet above the ground. There is 
no doubt that the animal had been disturbed from its diurnal 
retreat by the chopping of adjacent bromeliads and had decided 
to abandon its place of retirement. The small paratype was taken 
from the moist center of a bromehad that had been growing 2.5 
meters above the ground. When the bromeliad was cut and thrown 
onto the narrow path, the lizard was found inside the whorls of 
leaves. In both cases, the adjacent area was well forested. The 
elevation along the path is about 500 feet (153 meters). 

The Jamaican Cockpit Country is a karst region in north- 
western Jamaica. Its extent is about 20 miles (32 kilometers) 
east-west and about 10 miles (16 kilometers) north-south; the 
region centers in Trelawny Parish but extends for short distances 



1971 BROMELIAD GALLIWASP 9 

into St. James Parish on the west and St. Elizabeth and Man- 
chester parishes to the south. No roads penetrate it, but a series 
of peripheral roads allows some ingress into the region. An excep- 
tion is a relatively newly constructed road north of Quick Step 
on the southern border of the Cockpit, where penetration of about 
five miles (8 kilometers) is possible into virtually virgin territory. 

In search of Sphaerodactylus and hylid and leptodactylid frogs, 
we cut both terrestrial and arboreal bromeliads in several regions 
associated with the Cockpit periphery and elsewhere: between 
Spring Vale and Mulgrave (St. James and St. Elizabeth parishes), 
between Stonehenge and Burnt Hill (Trelawny Parish); south 
of Moneague on Mt. Diablo and west of Lluidas Vale (St. Cath- 
erine Parish), in the Dolphin Head region between Askenish and 
Town Head (Hanover and Westmoreland parishes), between 
Plum Park and Garlands (St. James Parish), and between Raheen 
and north of Quick Step (Trelawny Parish). In no case did we 
secure D. fowleri, although a single D. cnisculus was secured from 
a terrestrial bromehad north of Cave in Westmoreland Parish. 
The possibiUty remains that D. fowleri is not an obligate inhab- 
itant of bromeliads, and that it is a terrestrial galliwasp that, in 
the pitted, pocked, and rock-strewn Cockpit Country, finds diur- 
nal sanctuary in terrestrial situations from which it would be a 
lucky collector indeed who would secure it. On the other hand, 
there is no evidence to controvert the apparent fact that D. fowled 
is indeed a bromeliad dweller and that it occurs in no other situ- 
ation. If such is the case, it must be either extremely uncommon, 
remarkably elusive, or ecologically or altitudinally restricted in 
some presently unknown fashion. Along these lines, see Under- 
wood's (1959: 1) comments on his inability to secure a second 
specimen of D. microblepharis. The fact that the area where the 
microblepJiaris was secured backs upon limestone hills suggests, 
as Underwood stated, that it may have wandered from its usual 
habitat into a situation where it was fortuitously secured with 
relative ease. 

Diploglossiis fowleri is not known to be sympatric with any 
other species of galhwasp. However, D. hewardi has been taken 
1.5 miles NW of Windsor, and D. cruscidiis has been secured 3.0 
miles N W of Windsor — both in terrestrial situations. In addi- 
tion, D. barbouri has been collected along the eastern margin of 
the Cockpit Country between Stonehenge and Burnt Hill. The 



10 BREVIORA No. 371 

lack of precisely sympatric records between fowleri and any of 
these three species is not surprising, since, as pointed out above, 
collecting galliwasps within the Cockpit Country itself is a difficult 
and well-nigh impossible task except in especially favorable local- 
ities. If fowleri is truly bromeliadophilous, then it may in places 
be syntopic with D. crusculus, but such syntopy remains to be 
encountered. 

As presently understood, then, D. fowleri is a bromehad- 
inhabiting galliwasp that is presumably limited to the Cockpit 
Country area and possibly to lower elevations in that region. It 
is rather surprising that the bromeliad niche has been so neglected 
by Antillean reptiles, in contrast to Antillean amphibians. Cer- 
tainly Jamaica has the highest share of bromeUadicoles, both 
amphibians and reptiles; in addition to D. fowleri, Hyla brunnea, 
H. wilderi, H. marianae, and Eleutherodactylus jamaicensis are 
obligate bromeliad dwellers, and several other frogs {E. grabhami, 
E. cundalli, E. pantoni) are encountered with regularity in terres- 
trial bromeliads. Among reptiles, Sphaerodactylus oxyrhinus 
appears to be confined to this situation, and a new species of 
Sphaerodactylus, to be described by Richard Thomas, likewise is 
thus limited in habitat. S. argiis, D. crusculus, and Tropidophis 
haetianus are encountered in bromefiads upon occasion. This list 
of both obligate and facultative bromeliadicoles far exceeds that 
from any other Antillean island. On the other hand, no one has 
systematically cut arboreal and terrestrial bromefiads elsewhere 
than on Jamaica. It seems likely that this is a niche that will 
well repay investigation on other Antillean islands. 

LITERATURE CITED 

CousENs, Peggy N. 1956. Notes on the Jamaican and Cayman Island 

lizards of the genus Celestiis. Breviora, No. 56: 1-6. 
Grant, Chapman. 1940a. Notes on the reptiles and amphibians of Jamaica, 

with diagnoses of new species and subspecies. Jamaica To-day. London 

and Aylesbury, Hazell, Watson, and Viney, Ltd. Chapter 15: 151-157. 
1940b. II. The Reptiles. In Lynn, W. G., and C. Grant, 

The herpetology of Jamaica. Bull. Inst. Jamaica, Sci. Ser., 1: 1-148. 
Maerz, a., and M. Rea Paul. 1950. A Dictionary of Color. New York, 

McGraw-Hill Book Co., pp. i-vii, 1-23, 137-208, 56 pis. 
Schwartz, Albert. 1970. A new species of large Diploglossus (Sauria: 

Anguidae) from Hispaniola. Proc. Biol. Soc. Washington, 82(60): 

777-788. 
Underwood, Garth. 1959. A new Jamaican galliwasp (Sauria, Anguidae). 

Breviora, No. 102: 1-13. 



BREVIORA 

Mmsemim of Contiparative Zoology 

Cambridge, Mass. 31 March, 1971 Number 372 



THE PALEONTOLOGY AND EVOLUTION OF CERION II: 

AGE AND FAUNA OF INDIAN SHELL MIDDENS 

ON CURACAO AND ARUBA 

Stephen Jay Gould 

Abstract. Cerion iiva has been found in great abundance in three Meso- 
Indian (preceramic) shell middens on Curasao. Shells from all three sites 
yield radiocarbon ages of about 4000 years B.P. Different groups of Meso- 
Indians from Venezuela reached Curasao and the nearby island of Cubagua 
at about the same time. A Neo-Indian (ceramic) midden on Aruba is ap- 
proximately 1500 radiocarbon years old. Lists of the molluscan fauna from 
all sites contain only intertidal and shallow water species. Collecting areas 
can be specified by noting differences among sites in the presence of species 
from various environments (rocky intertidal, mangrove, shallow grassy and 
shallow rocky). 

In the shell middens, Cerion presents two outstanding features: 1) almost 
all shells have had the apical whorls removed artificially and, 2) shells are 
larger than any living today. The apical whorls were removed by striking; 
flint tools found at the sites accomplish this task easily. This was done to 
release the internal vacuum and allow the animal to be sucked out through 
the normal aperture. Larger shells might indicate, since modern Cerion is 
so phenotypically variable, that the climate of Curasao 4000 years ago was 
more moist (and therefore more hospitable) than today. But there is no 
independent evidence for more rainfall at that time. If the effect is mainly 
genetic, these shells might come from relict populations, adapted to the 
pluvials of the previous glaciation. Cerion iiva has been found in a shell 
midden in Venezuela; this establishes the reciprocity of trade between main- 
land and offshore islands. 

INTRODUCTION 

Only a few mollusks have won entry into the Papiamento lan- 
guage of the Dutch Leeward Islands. These are mostly edible 
species — kiwci (Cittarium pica), karko (Strombus gigas), and 
tcipa koncha ("cover shell" — a general name for chitons). Yet 



2 BREVIORA No. 372 

Cerion uva, the ubiquitous pulmonale of these islands, stands out 
for the plethora of names attached to it, names that distinguish 
small from large and beach from bush. Nevertheless, Cerion plays 
almost no role in the economy of these islands today — though 
one of its names, kokoUshi kalakuna (turkey shell), reflects the 
fact that it is sometimes fed to turkeys as a source of lime. It 
is never eaten, save as an aphrodisiac by some older residents 
who believe that sea shells preserve sexual potency (and do not 
realize that this halophilic pulmonale, which lives just landward 
of Tectariits muricatus, does not come from the sea). But to 
another people, the original Indian inhabitants of Curasao, Cerion 
uva was a major source of food, for the oldest middens of the 
island are crammed with their shells. 

Of the many sheU sites that have been studied (Van Heekeren, 
1960: 103-109, for review of archaeological work and Van Heek- 
eren, 1963), Cerion is known only from the older, preceramic 
middens of Curasao. Whenever it occurs, it presents two peculi- 
arities: sheUs are far larger than the largest living C. uva, and 
most all have had the apical whorls removed artificially. 

Thanks to the kindness of Father Paul Brenneker and Mr. 
Elis JuUana, local collectors, folklorists, and historians (and my 
informants for the opening paragraph), and Dr. F. Creutzberg, 
Director of the Biological Station at Piscadera Baai, Curasao, 
I had the opportunity to study the sheU sites during the summer 
of 1968. In this paper, I shall review the archaeological setting of 
these islands, report on radiocarbon dating of the shell sites, tabu- 
late the fauna of each and present environmental interpretations, 
and discuss the occurrences of Cerion with special reference to 
the peculiarities mentioned above. 

CARIBBEAN PREHISTORY AND DESCRIPTION OF SITES 

The Dutch Leeward Islands are tied, geographically, to Vene- 
zuela. Aruba, only 27 km from the mainland, lies on the coastal 
shelf, in easily navigable waters. Curacao and Bonaire are more 
distant (64 and 87 km respectively), and the passage is deeper 
(up to 1500 m) and more treacherous (Van Heekeren, 1960: 
103). The early colonization of these islands must be discussed 
in the context of Venezuelan archaeology (Cruxent and Rouse, 
1958-59, 1969; Rouse and Cruxent, 1963; Rouse, 1960, 
1964, 1966). 



1971 CERION FROM INDIAN SHELL-HEAPS 3 

The Pre-Columbian inhabitants of Venezuela and the Carib- 
bean are designated Paleo-, Meso-, or Neo-Indians on the basis 
of technology and inferred economy. Although the three stages 
do express a chronological progression, none of their artifacts 
function as "index fossils" in establishing contemporaneity 
throughout the Caribbean, for the traits of a new stage are 
attained at different times by different peoples. There were, for 
example, still some preceramic Meso-Indians on Haiti and Western 
Cuba when Columbus arrived (Rouse, 1966). 

The original inhabitants of the New World were Paleo-Indians, 
"hunters of mammoths and other large land mammals" (Rouse, 
1966: 125). Their stone tools have been found in Venezuela and 
designated as markers of the Joboid Series. They date, approxi- 
mately, from 17,000-7,000 B.P. The oldest radiocarbon date 
for Joboid charcoal is 16,870 years B.P. (Rouse and Cruxent, 
1963). In earlier works, Cruxent and Rouse held that Paleo- 
Indians were not sea-farers, but Paleo-Indian sites have recently 
been found at Mordan in the Dominican Republic and dated to 
at least 4560 radiocarbon years B.P. They beheve, moreover, 
that the Mordan site is predated by another at Casimira that may 
be as much as 7,000 years old (Cruxent and Rouse, 1969). 
Although the mainland source of these first Hispaniolans is not 
known, these finds indicate that some Paleo-Indians crossed con- 
siderable stretches of ocean, probably on rafts and by accident 
(Cruxent and Rouse, 1969). 

Much scholarly agitation of late has been directed to the issue 
of whether or not Paleo-Indians were responsible for the extermi- 
nation of large land mammals (Martin and Wright, 1967). In 
any event, their demise drew our pre-agricultural people to the 
sea and inaugurated MesoTndian culture, characterized by "rela- 
tively few stone tools. Projectile points are made of bone rather 
than stone and shell artifacts are common, reflecting the mari- 
time orientation" (Rouse, 1966: 126). Meso-Indian artifacts in 
Caribbean Venezuela belong to the Manicuaroid Series and date, 
approximately, from 7,000 to 3,000 years B.P. The oldest radio- 
carbon date for mainland Venezuelan Meso-Indians is 5750 B.P. 
(Rouse and Cruxent, 1963). There is an extensive Meso-Indian 
site on Cubagua, another of Venezuela's offshore islands. Char- 
coal from the base of this deposit dates at 4275 radiocarbon 
years B.P. 



4 BREVIORA No. 372 

The subsequent Neo-Indian culture is "marked by pottery 
making and fully developed agriculture" (Rouse, 1966: 126). 
The invention of pottery was the crucial archaeological event that 
inaugurated the Neo-Indian period; therefore MesoTndian and 
earlier sites are often designated simply as "preceramic." Agri- 
culture, with manioc as a staple crop, and pottery were developed 
in the Orinoco Valley during the 2nd millennium B.C. During 
the 1st millennium B.C., some Neo-Indians moved out to the 
coast and became sea-farers. Displacing Meso-Indians as they 
went, they migrated to the coastal islands, up the Lesser Antilles 
and reached the Greater Antilles ca. 250 A.D. and the Bahamas 
ca. 1000 A.D. This displacement was still occurring when Colum- 
bus reached the New World (Cruxent and Rouse, 1969). 

The Cerion sites of Curasao are all Meso-Indian in nature. I 
studied the following three sites: 

1. Rooi Rincon — North coast, west of Hato Airfield; in soil 
at the base of a small cave in a raised Pleistocene reef that also 
houses the larger cavern of Hato and several others; approximately 
40 m above present sea level and 1 km from the coast. This well- 
known site was excavated by Cruxent in 1965 (Tamers, 1967) 
and by Van Heekeren in 1960 (Van Heekeren, 1963). Crudely 
chipped stone tools and flint flakes are common but, after dig- 
ging for 14 days. Van Heekeren found only one other artifact, a 
shell disc bead (Van Heekeren, 1963: 5). The naturally broken 
columellar tips of Strombus gigas are similar in form to some of 
the fashioned shell gouges common in the Manicuaroid deposits 
of Cubagua (Cruxent and Rouse, 1958-59); they may have been 
used for digging meat out of sheUs. Many other natural objects 
could have been used as tools. Particularly suspect are the 
smoothly eroded and fairly pointed branches of the stag horn 
coral, Acropora cervicornis, that are fairly common at this site 
and at Kintjan (site 2). These, obviously, have no nutritional 
value and must have been carried to the site for some other pur- 
pose. Other objects, land crab claws for example, might have 
been used for digging meat from shells after their own contents 
had been consumed. I found a few bits of charcoal: some of 
the shells are strongly scorched. Cruxent says of this deposit: 
"A Meso-Indian complex of collectors with industry of stone 
chips. Classified as a marginal development of El Jobo. No 
archaeologic station of this type presently known in Venezuela" 
{in Tamers. 1967: 244). 



971 



CERION FROM INDIAN SHELL-HEAPS 



2. Kintjiin — Near south coast, east ^ Willemstad. The area, 
a hillslope, is being cleared for construction and shells are loose 
at the surface; their presence in a small area indicates original 
concentration in a coherent deposit. Flint chips and crude stone 
tools are, as at Rooi Rincon, common at this site. 

3. Tafelberg — Near south coast, just east of the Tafelberg 
Santa Barbara. Only a few shells could be collected from the 
recently blasted rubble of these phosphate workings. Mr. Harry 
Evers, engineer at the Tafelberg phosphate workings, informs me 
that, prior to the blasting, the shell heap was a coherent deposit 
with two layers, marine shells at the base and decapitated Cerion 
at the top. I found no artifacts at this much disturbed site. 

Dr. P. Wagenaar Hummelinck, pre-eminent natural historian of 
these islands, has told me (personal communication, 1970) of 
one additional Cerion locality at Hato Cave; I have not seen this 
site. He also states that he knows of no other Cerion site on any 
of the three islands. 

For comparison, I add to the Cerion sites of Curacao one 
later, Neo-Indian deposit from Aruba: 





t:.t V- 




^pt>^^ 



Figure 1. Artifacts from Ceru Canashito, Aruba. 

la) left: rock drawing, presumably depicting a pregnant woman, 
lb) right: shell disc made from Melongena melongena. Actual 
height: 43 mm. 



6 BREVIORA No. 372 

4. Ceru Canashito — North slope of this Hmestone terrace. 
I chose this among the many Neo-Indian sites of Aruba for two 
of its outstanding features. Good skeletal material has been col- 
lected from the caves near its summit (Tacoma, 1959), and these 
caves contain some of the best of the celebrated and mysterious 
rock paintings of these islands (Hummelinck, 1953, 1957). One 
of these, probably depicting a pregnant woman, is reproduced as 
Figure la. (There is, of course, no reason to assume that the 
rock drawings are contemporaneous with the shells; Van Heek- 
eren (1960), in fact, suspects that they were fashioned by Meso- 
Indians and venerated by later inhabitants.) Shells occur at all 
levels of the slope, but are concentrated by gravity at the base 
in an inhomogeneous deposit. Sherds of a coarse, unornamented, 
grit-tempered pottery are common. Shell artifacts include the 
columellar points of Strombus gigas and the unperforated shell 
disc, made from the outer whorl of Melongena melongena, shown 
in Figure lb. Such unperforated shell discs are common on the 
islands; their function is unknown (Van Heekeren, 1960: 112). 

AGE OF THE SHELL MIDDENS 

Tamers (1967) reported the first radiocarbon dates from 
archaeological sites in the Dutch Leeward Islands; all samples 
were charcoal and all were supplied by Cruxent. Included are 
five dates for the Rooi Rincon shell midden, two from a pit previ- 
ously excavated by Van Heekeren and three from two new pits. 
The dates range from 3900 ± 50 to 4490 ± 60 with a mean of 
4194 radiocarbon years (see Stuiver and Suess, 1966 on the 
relationship between radiocarbon and calendar years). These 
are the only dates previously calculated for preceramic sites on 
these islands. 

Radiocarbon ages were determined for 1 1 shell samples by 
Geochron Laboratories, Inc., Cambridge, Massachusetts (Chama 
macerophylla and Cittarium pica from each of the five sites and 
Anadara notob'iUs from Ceru Canashito) . "The shells were cleaned 
of foreign material and were thoroughly leached with dilute HCl 
in an ultrasonic cleaner to remove the surficial layer of carbonate 
and expose fresh material. The cleaned shells were then hydro- 
lyzed to recover CO., for the analysis" (personal communication 
from H. W. Krueger of Geochron). Dates are based on a half- 
life of 5570 years and referenced to 1950 A.D. 



1971 CERION FROM INDIAN SHELL-HEAPS 7 

Dates based on shells are not as reliable as those determined 
for pure carbon (charcoal), for CaCO,, is often altered by per- 
colating, acidic groundwaters. I was anxious to determine the 
correspondence between shell and charcoal dates for Rooi Rincon; 
I found no charcoal at any of the other sites. All dates are shown 
in Table 1. 

The correspondence at Rooi Rincon is satisfactory, and all pre- 
ceramic sites of Curacao are about 4000 radiocarbon years old. 
This date is particularly interesting since it corresponds so well 
with the base of the great Meso-Indian site at Punta Gorda, 
Cubagua Island (p. 21). The artifacts of this Cubagua complex 
of the Manicuaroid series differ greatly from those of Rooi Rin- 
con (Cruxent and Rouse, 1958-59) and we must assume that 
different groups of Meso-Indians from Venezuela colonized the 
coastal islands at about the same time. 

The great spread of dates for the Neo-Indian site of Ceru Cana- 
shito can be explained in two ways. It is a very inhomogeneous 
deposit of shells artificially concentrated at the base of a slope 
and may represent a long span of habitation. Alternately, the Cit- 
tarium date could be spuriously young. Cittarium has been and 
remains a staple food of the islands. The kiwa is sold at all native 
market places; shells are carried and discarded all over the island. 
If this date has been falsified by the inclusion of a fairly modem 
shell, then the Canashito midden may represent a more coherent 
deposit, about 1500 radiocarbon years old. 

FAUNA OF THE SHELL MIDDENS 

In presenting these faunal lists, I have excluded the micro- 
molluscs that could have played no role in the economy of the 
Indians (though Tnmcatella and other rissoids are reasonably 
common as accidental transports). In each site, there are a few 
species that clearly dominate; these are merely listed as common. 
Numbers of specimens are given for other species. I have used 
Warmke and Abbott (1961) and Coomans (1958) as guides to 
identification; order of listing and family allocations follow the 
former source. 

1. Rooi Rincon 
AMPHINEURA 

A cant ho pleura graniilata — common 



8 BREVIORA No. 372 

GASTROPODA PROSOBRANCHIA 
Trochidae 

Cittarium pica — common 

TURBINIDAE 

Astraea tecta — 1 
Astraea tuber — 1 
Neritidae 

Merita peloronta — 11 
Nerita versicolor — 6 
Nerita tesselata — 4 

LiTTORINIDAE 

N odilittorina tuberculata — 4 

Echinus nodulosus — 1 

Tectarius muricatus — 1 
Vermetidae 

Petaloconchus mcgintyi — 3 
Strombidae 

Strombus gigas — 4 apices and 3 columellas 

MURICIDAE 

Murex brevifrons — 8 
Magilidae 

Coralliophila abbreviata — 2 

Coralliophila caribbea — I 
Fasciolariidae 

Leucozonia nassa — 1 
Xancidae 

Vasum capitellum — 1 

GASTROPODA PULMONATA 
Cerionidae 

Cerion uva — common; 18 of 129 specimens have in- 
tact apices 

BIVALVIA 
Arcidae 

Area zebra — 12 valves 

Area imbricata — 4 

Anadara notabilis — 4 
Mytilidae 

Brachidontes exustus — 2 
Pteriidae 

Pinctada radiata — 1 3 



1971 cerion from indian shell-heaps 9 

Pectinidae 

Pecten ziczac — 2 

LiMIDAE 

Lima scabra — 10 

OSTREIDAE 

Ostrea jrons — 1 2 
Crassostrea rhizophorae — 9 . 
Chamidae 

Chama macerophylla — common 
Pseudochama radians — 2 

Nonmolluscan remains: a few branches of stag-horn coral 
{Acropora cervicornis) , land crab claws (common), a few barna- 
cles, fish bones and a small fragment of an echinoderm test. 

Not all these animals were eaten. Many, especially among the 
snails, are small and rare at the site (turbinids, magilids, fasci- 
olariids, and xancids); others (Petaloconchus and barnacles) 
cement to other shells and surely won a free ride on their edible 
hosts (probably Chama). 

The main food sources were the land snail Cerion, land crabs, 
intertidal chitons, the intertidal and just subtidal snail Cittarium 
and the shallow water clam, Chama; all are very abundant and 
easily gathered. Less common but still important as food sources 
are the conch Strombus gigas, Nerita peloronta, and Murex brev- 
ifrons among the snails (the last two artificially broken in char- 
acteristic ways — Figs. 2 and 3 ) and arcids, oysters, and limids 
among the clams. 

The shells provide an excellent picture of the environment from 
which they were gathered. All the major intertidal rock-clingers 
are represented (all three common West Indian Nerita, chitons, 
and the famous homeomorphic series Nodilittorina-Echinus- 
Tectarius). These species inhabit rocky shores in areas of active 
surf. All other species can be found in less than 10 feet of water 
on a varied bottom containing reefy and rocky areas (Chama, 
Area, Lima) and stretches of sand and grass (Anadara, Strom- 
bus). There may have been a lagoon with mangroves nearby, 
for many important elements of the mangrove-root community 
are present (Murex brevijrons, Ostrea jrons, Crassostrea rhizo- 
phorae, and Brachidontes exustus). 

Van Heekeren (1963) stated, correctly no doubt, that the 
shells were collected on the nearby north coast (Fig. 4b). Since 



10 



BREVIORA 



No. 372 




Figure 2. Miire.x brevifroiis shells from Kintjan (left) and Rooi Rincon 
(right). Note characteristic breakage pattern in both. This can be achieved 
by placing the shell face down upon its aperture and striking the apex. 
Actual height of Kintjan specimen: 54 mm. 




Figure 3. Neritids from Rooi Rincon broken in characteristic fashion. 
Left: apertural portion from rear; Right: apertural portion from front. 
Such a break is made by placing the shell face down upon its aperture and 
striking the body whorl with a blunt object. This is also the natural break- 
age pattern in most cases. Right-hand fragment is 18 mm high. 



1971 CERION FROM INDIAN SHELL-HEAPS 11 

the unremitting trade winds blow against this coast (producing 
a strong surf most unconducive to shell gathering), Van Heekeren 
suggested that sea level at this earlier time was 6-7 m higher 
than today. This would submerge the extensive raised reef that 
forms the lower terrace all around Curacao and produce a broad 
area of calmer, shallow water. (And from the supposed extent 
of this change in level, he postulated a great age for the deposit 
and classified it, tentatively, as Paleo-Indian.) This hypothesis 
of a major shift in sea level is unnecessary for two reasons: 1) 
With an age of 4000 radiocarbon years, any eustatic fall in 
level is ruled out; if anything, mean sea level then was a bit 
lower than today (Redfield, 1967; Milhman and Emery, 1968). 
This leaves tectonic uplift. Curacao has, indeed, been uplifted 
during the Pleistocene (the oldest terrace, atop the Tafelberg, 
lies at 140-200 m, but 7 m in 4000 years is not likely). 2) The 
trade winds do produce a strong surf along the north coast. But 
Rooi Rincon lies on that part of the coast that runs due east- 
west; here the winds run along the coast and the waters are fairly 
calm. Modern Cerion populations illustrate the climatic results 
of changes in coastal direction. Cerion lives atop the first terrace 
all along the coast. In areas continually buflfetted by the strong 
dry wind, they aestivate for much of their lives and remain small 
as adults; they grow bigger in calmer areas. A graph of Cerion 
size vs. distance from Westpunt (Fig. 4a) is a good map of coastal 
direction (Fig. 4b). Cerion is small where the coast runs north- 
south and large where it runs east-west. They reach their greatest 
size at Rooi Rincon. Thus, Rooi Rincon lies in the only area of 
Curasao that provides good conditions for shell gathering on the 
north coast. 

2. Kintjan 

GASTROPODA PROSOBRANCHIA 
Trochidae 

Cittarium pica — common 
Strom BiDAE 

Strombus gigas — common 
Cymatiidae 

Charonia variegata — 1 

MURICIDAE 

Murex brevijrons — 3 (broken as at Rooi Rincon, 

Fig. 2) 



12 



BREVIORA 



No. 372 



Melongenidae 

Melongena melongena — 2 

GASTROPODA PULMONATA 
Cerionidae 

Cerion uva — common, 7 of 347 specimens have in- 
tact apices 

BIVALVIA 

Arcidae 

Area imbricata — 13 
Barbatia cancellaria — 3 



Anadara notabilis - 
Pteriidae 

Pinctada radiata — - 
Pectinidae 

Pecten ziczac — 7 
Limidae 

Lima scabra — 6 



common 




Figure 4. Correlation of coastal direction and shell size. 

4a) left: map of Cura^,ao. 1. Rooi Rincon at point where coast 
runs east-west. 2. Kintjan. 3. Tafeiberg. 4. Schottegat (where shells at 
Kintjan were collected). 



1971 



CERION FROM INDIAN SHELL-HEAPS 



13 



OSTREIDAE 

Ostrea frons — 7 
Crassostrea rhizophorae — 6 
Chamidae 

Chama macerophylla — common 

NonmoUuscan remains: branches of stag-horn coral (Acropora 
cervicornis), barnacles, and fish bones. 

The shallow water fauna of Kintjan is very similar to that of 
Rooi Rincon, both in species composition and order of dominance 
{Chama and Cittarium followed by S trombus, arcids, oysters, and 
limids). Since shells are not so common at Kintjan, several spe- 
cies, rare and unimportant at Rooi Rincon, are not found here. 




10 20 30 

Distance from Westpunt (miles) 

4b) right: Mean shell heights (20 adults per sample) for local 
populations living in similar microhabitats directly on the first terrace along 
the east coast of Curasao. Shells are largest where trade winds do not hit 
coast directly. 



14 BREVIORA No. 372 

I found no land crabs at Kintjan, but Cerion uva is even more 
common here than at Rooi Rincon. There is, however, one out- 
standing difference between the two sites: there are no intertidal 
rock-dwellers at Kintjan (neritids, littorinids, or chitons), while 
all the common forms are found at Rooi Rincon. This difference 
permits us to specify the collecting area for Kintjan shells. 

The entire periphery of Curasao is framed by an uplifted Pleis- 
tocene reef; intertidal forms are common all around the coast. 
But the central areas are underlain by volcanic rocks that erode 
more easily than the coastal limestone. During the last glacial 
period, when sea levels were lower, extensive drainage systems 
were developed on the volcanic terrain; these breached the harder 
limestone rim in only a few places. These valley systems were 
drowned when sea level rose and produced the outstanding pro- 
tected harbors that characterize all three islands: narrow inlets 
with expansive inland waters. Willemstad, the capital of Curacao, 
is built on both sides of the largest harbor, the Schottegat. The 
inland shores of the Schottegat are volcanic; in the absence of 
strong surf and a rocky coast, the rock-dwelling intertidal forms 
do not inhabit these shores. I conclude that the Kintjan shells 
were collected in the Schottegat (Fig. 4b); the extensive, calm, 
shallow waters provided an excellent site for gathering. 

3. Tafelberg 

GASTROPODA PROSOBRANCHIA 
Trochidae 

Cittarinm pica — several fragments 

LiTTORINIDAE 

Tectarius muricatus 

GASTROPODA PULMONATA 
Cerionidae 

Cerion uva — common, 5 of 1 1 1 have intact apices 

BIVALVIA 
Arcidae 

Area imbricata — 1 
Chamidae 

Chama maeerophylla — common 
The site has been thoroughly disturbed by blasting. 



1971 CERION FROM INDIAN SHELL-HEAPS 15 

4. Ceru Canashito 
AMPHINEURA 

Acanthopleiira granulata — 4 plates 

GASTROPODA 
Trochidae 

Cittarium pica — 8 
Turbinidae 

Astraea tecta — 1 
Neritidae 

Nerita tessellata — 3 
Littorinidae 

Tectarius miiricatiis — 5 

MODULIDAE 

Modulus modulus — 1 
Cerithiidae 

Cerithium algicola — 1 

Cerithium Utteratum — 1 
Strombidae 

Strombus gigas — common 
Muricidae 

Murex pomum — 7 

Murex brevijrons — 1 

Thais deltoidea — 1 
Melongenidae 

Melongena melongena — common 
Xancidae 

Vasum muricatum — common 

BIVALVIA 
Arcidae 

A nadara notabilis — common 
Pteriidae 

Pinctada radiata — 1 

LUCINIDAE 

Codakia orbicularis — common 
Chamidae 

Cliama macerophylla — common 
Pseudochama radians — 1 



16 BREVIORA No. 372 

Intertidal rock-dwellers are found here, but the series is not 
nearly so complete as at Rooi Rincon (only one Nerita, Tectarius, 
but neither Echinus nor Nodilittorina). Among shallow water 
forms, there are two major differences between Canashito and 
both Rooi Rincon and Kintjan. The Curasao sites contained a 
suite of mangrove-dwellers that are completely absent here (Cana- 
shito yielded one Murex brevijrons, a common mangrove form, 
but Murex pomum, an open water species absent from both Cura- 
sao sites, is the common Murex here). In addition, Canashito 
contains a suite of shells {Modulus, the two Cerithium species 
and, especially, the common Codakia orbicularis) that inhabit 
grass and algal beds; none of these occur in the Curasao deposits. 
The shells were probably collected in calm waters off the leeward 
south coast, near the site of the present airport. 

CERION UVA IN THE PRECERAMIC MIDDENS 
OF CURACAO 

In all three preceramic middens of Curagao, the most common 
moUuscan shell is that of the land snail Cerion uva. These shells 
present two outstanding features: more than 80 percent in each 
locality have lost their apical whorls and shells are larger and 
more variable than modern specimens. 

1. Removal of the apical whorls. By reason and experiment, 
one of a list of possible proposals can be identified as the cause 
of removal. I list the suggestions made to me by many friends 
and colleagues. 

A) Natural removal 

B) Artificial removal 

i) by biting 
ii) by rubbing 

iii) by crushing (striking with the shell held up- 
right) 
iv) by slicing (striking with the shell placed on 
its side). 
Although the apical whorls form the weakest part of the shell, 
I do not believe that they could have been lost naturally by so 
many specimens. I have extensive collections of much older fos- 
sils from fissure-fills on Aruba. These tumbled, often down sev- 
eral meters, into the fissures, suffered strong compaction, under- 
went tectonic uplift and still retain, in almost all cases, the apical 



971 



CERION FROM INDIAN SHELL-HEAPS 



17 



whorls. I have never seen a natural accumulation, cither recent 
or fossil, in which many specimens are missing their apical whorls. 

After suffering one dental misfortune, I am quite sure that the 
tops cannot be bitten off. Apices can be removed by rubbing 
either against limestone or volcanic rock, but the process is 
much too laborious and time-consuming. I am convinced that 
the tops were removed by striking. They were not crushed by 
striking the top of the shell while holding the bottom against a 
substrate (and keeping the shell vertical), for this process invari- 
ably breaks the lower lip of the aperture before crushing the top. 
If, however, the shell is placed on its side, horizontally against 
the substrate, the top can easily be removed by striking with a 
sharp instrument. In fact, the flint chips and stone tools of Rooi 
Rincon and Kintjan, are excellent devices for this purpose. With 
a bit of practice, the apices can be removed with a single blow. 

This leaves open the question of why the apices were removed. 
1 can imagine three interpretations: 

A) Removal is unrelated to eating; the shells were used for 
an ornamental or other purpose. 

B) When the top is removed, the animal can be sucked out 
through the apical hole thus produced. 

C) Removal of the top aids, somehow, in sucking the animal 
out through its normal aperture. 

I cannot imagine what nongastronomical purpose so many 
thousand decapitated shells could have served. Moreover, the 
following demonstration that decapitation is an aid to removal 
of the animal argues strongly against A. 




Figure 5. X-ray photographs of decapitated Ccrion uva from Kintjan 
(left 2 specimens) and Rooi Rincon (right 2). Since internal whorl parti- 
tions are intact, animal was not removed through apical hole. Specimen on 
left is 32.8 mm high. 



18 BREVIORA No. 372 

If the animal were sucked out through the top, some of the 
internal whorl partitions would have to be broken, for the large 
foot could not fit in the small whorls left near the top of the shell. 
X-ray photographs of decapitated shells (Fig. 5) show clearly 
that the whorl partitions are never disturbed. The animal could 
not have been extracted through the apical hole. 

If you take an intact shell with its animal inside and suck as 
hard as possible at the aperture, the animal cannot be extracted. 
But, when the apex is removed, a single hard suck upon the aper- 
ture will extract either the large foot of the animal or the entire 
body itself. Removal of the top breaks the vacuum inside the shell 
and facilitates the extraction of its contents. The entire process 
is really quite efficient: one strike, one suck, and the animal is 
removed. Several can be eaten in a minute (though I recommend 
Cerion only to the starving). 

Somehow, I find it satisfying to think that the Meso-Indians of 
Curacao discovered an important physical principle for such a 
practical procedure. This idea, so obvious to all of us who were 
raised in the pre pop-top age of the beer can industry, is by no 
means a self-evident principle. 

2. Variation and jorm of Cerion uva. Any sample from a shell 
midden is, of course, strongly biased from a biometrical point of 
view. The probable bias, in these cases, is twofold: the selection 
of large individuals (for Cerion is not a large snail and much 
work must be expended for little nutrition), and the amalgama- 
tion of shells from several local populations. 

Much has been made in the literature of the extreme intraspe- 
cific variability of land snail shells. This indeed is true, but it is 
usually of a particular kind (and this is rarely emphasized). The 
variation is interpopulational, i.e., the shells of any local popu- 
lation are not unusually variable, but differences among the means 
of local populations are often extreme. Thus, it is likely that our 
two biases will afi'ect the mean of a midden sample in opposite 
ways: the selection of large shells will augment the mean, but 
the amalgamation of large individuals from several local popula- 
tions will produce a midden mean smaller than the true mean of 
a local population with large shells. 

The rise in variability from amalgamation of local populations 
can be gauged by comparing coefficients of variation (C.V.) 
(Simpson, Roe, and Lewontin, 1960: 89-95) of midden samples 



1971 



CERION FROM INDIAN SHELL-HEAPS 



19 



and modern local populations for the same character. Table 2 
presents C.V/s for shell height of the three midden samples and 
a mean value for 69 modern local populations (Gould, unpub- 
lished data for monograph in preparation; N = 20 for all samples, 
midden and modern; values for midden shells are estimates for 
actual height with decapitated apical whorls restored; all shells 
are adults with completed growth ) . All midden means are above 
the modern grand mean. Rooi Rincon and Tafelberg are within 
the span of modern C.V.'s (4.03 to 10.18), but, at 15.45, shells 
from Kintjan are far more variable than those of any modern 
local population. 

The striking feature of midden samples is the large size of some 
of their shells. Fortunately, Cerion iiva is among the world's best 
known land snails from a biometrical point of view. Three major 
studies have been done in this century: by Baker in the earlv 
1920's (Baker, 1924), by Hummelinck in the late 1930's (Hum'- 
mehnck, 1940) and by myself during the past two years. Table 
2 compares the heights of shells in midden and modern samples. 
Each modern study has uncovered a local population with greater 
mean height than the smallest midden sample, and one of Hum- 
melinck's local populations exceeds the largest midden sample in 
mean height. Still, of course, the midden means are all well above 









T^'*' 





Figure 6. Comparison of largest shell heap (left, from Kintjan, 34.3 mm 
high) Cerion and largest modern shell. Difference is much more striking in 
actual shells in which areal artifact of two dimensional representation is 
lost and judgment of size is made more properly by volume. 



20 BREVIORA No. 372 

the grand mean of means for each modern study. However, as 
mentioned previously, the midden means are almost surely lower 
than the true means of local populations with large shells living at 
that time. A more appropriate comparison might be made using 
maximal size. 

Among almost 12,000 modern snails from 248 local popula- 
tions over 50 years, no snail greater than 30 mm in height has 
ever been found. (In only one of Hummelinck's local populations 
did any individuals exceed 29 mm; neither Baker nor Gould found 
any taller than 28.5 mm.) Yet snails exceeding 30 mm in height 
are very common in two of the three midden samples and, at 34.3 
mm, the largest snail from Kintjan dwarfs my modern "giant" 
(Fig. 6). 

Two separate factors can make a snail tall, and both operated 
to produce the large midden shells. First, a snail can increase in 
height simply by adding more whorls. Each of the decapitated 
shells of Figure 5 shows 1 1 whorls below the break; the complete 
shell would have had one or two more postprotoconch whorls. 
Modern shells with more than IOV2 postprotoconch whorls are a 
great rarity (Baker and Hummelinck included protoconch whorls 
in their count, hence their larger figures). Secondly, a tall snail 
may have as many whorls as a smaller one, but simply have larger 
whorls. Protoconch size is a good measure of general whorl size 
(Gould, 1969). Only Rooi Rincon has enough complete shells 
to permit the calculation of mean protoconch width. At 1.67 mm, 
mean protoconch width for Rooi Rincon is at the top of the range 
of modem mean widths (1.41-1.69 mm for 69 samples, N ^ 20 
for each sample ) . The midden shells grew more whorls than any 
modern sample and had larger whorls than most. 

Why were the midden snails larger than modern snails? All 
three modern studies have demonstrated the extreme phenotypic 
plasticity of Cerion iiva. Shell size of adults is a direct function of 
microenvironment; snails are large when habitats are moist, calm, 
and well vegetated. Curasao today is an arid island. It receives 
only 17-22 inches of rain per year, most in brief downpours. It 
is hard to imagine a less hospitable area in the West Indies for 
pre-agricultural Meso-lndians. I do not know what they could 
have found, in this cactus-covered land, to supplement a diet of 
sea food. It is therefore tempting to think that the large midden 
shells indicate a wetter climate that might have supplied to Meso- 
lndians some of the tropical fruits that adorn most West Indian 



1971 CERION FROM INDIAN SHELL-HEAPS 21 

islands. Unfortunately, there is no other evidence for greater rain- 
fall 4000 years ago. If Curasao were much larger or higher than 
it is today, continental effects might lead to increased rainfall. 
But the eustatic rise of sea level has not been more than 10 feet 
during the past 4000 years (Redfield, 1967; Milliman and Emery, 
1968) and the direction of tectonic movement has been upward 
(Weyl, 1966). Rouse and Cruxent (1936: 38) believe that tem- 
peratures and rainfall have not varied appreciably during the past 
5000 years in Venezuela and surrounding areas. 

If large size is not an immediate phenotypic response to local 
conditions more favorable than today's, then I suspect that the 
midden snails were programmed to be large, i.e., that the effect 
is mainly genetic. In this case they probably represent the relict 
populations of snails that had been genetically adapted to more 
favorable conditions during pluvial cycles of the previous glacial 
period. In any event, they served the Meso-Indians well; it would 
be hard to make a meal of modern Cerion. 

There is an interesting postscript to the relationship of Cerion 
with Meso-Indians. There is considerable evidence for trade 
between the mainland and coastal islands, but it is all unidirec- 
tional. Rouse and Cruxent (1963: 45) found trade pottery from 
Venezuela in the Punta Gorda complex of the Manicuaroid Series 
on Cubagua. Du Ry (1960: 85) discovered that the oldest pot- 
tery of Aruba is finer in texture than later examples. He assumes 
that this first pottery was imported from northeastern Venezuela 
and that the later work is indigenous. In a nearly-forgotten work, 
Berry (1934) found Cerion iiva in an Indian shell heap near Lake 
Valencia, Venezuela. Berry was not convinced that these shells 
were imported from the Dutch Leeward Islands. But his argu- 
ment that Cerion might have once inhabited the shores of Lake 
Valencia can be discounted because this halophile would not sur- 
vive so far inland. I also doubt that Cerion inhabited the coast of 
Venezuela, for it has never been recorded from shell heaps there. 
Since there is no evidence that Cerion uva ever lived elsewhere 
than the Dutch West Indies, I conclude that the Valencia speci- 
mens establish the reciprocity of transport between Venezuela 
and the islands. 



22 BREVIORA No. 372 

ACKNOWLEDGEMENTS 

I thank Father Paul Brenneker and Mr. Ehs Juhana, local folk- 
lorists and archaeologists, who collected with me at Rooi Rincon; 
Dr. F. Creutzberg, Director of CARMABI, who showed me the 
Kintjan site, and Mr. Harry Evers, who allowed me to collect at 
the Tafelberg midden. This work was supported, in part, by 
N.S.F. Grant No. GB-12553. 



1971 CERION FROM INDIAN SHELL-HEAPS 23 



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1971 CERION FROM INDIAN SHELL-HEAPS 25 

LITERATURE CITED 

Baker, H. B. 1924. Land and freshwater molluscs of the Dutch Leeward 
Islands. Occas. Pap. Mus. Zool. Univ. Mich., No. 152. 158 pp. 

Berry, C. T. 1934. Pleistocene remains found near Lake Tacarigua, Vene- 
zuela. J. Washington Acad. Sci., 24: 387-395. 

CoOMANS, H. E. 1958. A survey of the littoral Gastropoda of the Nether- 
lands Antilles and other Caribbean Islands. Stud. Fauna Curasao, 
8: 42-111. 

Cruxent, J. M., AND L Rouse. 1958-59. An Archaeological Chronology of 
Venezuela. Social Sci. Monogr. VI, vols. I, 277 pp. and 11, 223 pp. 
Pan American Union, Washington, D.C. 

1969. Early man in the West Indies. Sci. Am. 421: 42-52. 

Du Ry, C. J. 1960. Notes on the pottery of Aruba, Curasao, and Bonaire. 
Stud. Archaeol. Netherlands Antilles, I: 81-102. 

Gould, S. J. 1969. An evolutionary microcosm: Pleistocene and Recent 
history of the land snail P. (Poecilozonites) in Bermuda. Bull. Mus. 
Comp. Zool., 138: 407-532. 

Heekeren, H. R., VAN. 1960. A survey of the non-ceramic artifacts of 
Aruba, Curacao, and Bonaire. Stud. Archaeol. Netherland Antilles, II: 
103-120. 

1963. Prehistorical research on the islands of Curagao, Aruba, 

and Bonaire m I960. Stud. Archaeol. Netherlands Antilles, III: 1-24. 

Hummelinck, p. W. 1940. Mollusks of the genera Cerion and Tiidoni. 

Stud. Fauna Curasao, Aruba, Bonaire, and the Venezuelan Islands, 2: 

43-82. 
1953. Rotstekeningen van Curasao, Aruba en Bonaire. 

(Linear rock designs of Curasao. Aruba, and Bonaire). West-Indische 

Gids, 34: 173-209. 
1957. Rotstekeningen van Cursn^diO, Aruba en Bonaire. West- 



Indische Gids, 37: 93-126. 

Martin, P. S., and H. E. Wright, Jr. (eds.). 1967. Pleistocene Extinctions: 
the Search for a Cause. New Haven, Yale Univ. Press. 453 pp. 

Milliman, J. D., and K. O. Emery. 1968. Sea levels during the past 35,000 
years. Science, 162: 1121-1123. 

Redfield. a. C. 1967. Postglacial change in sea level in the western North 
Atlantic Ocean. Science, 157: 687-691. 

Rouse, I. 1960. The entry of man into the West Indies. Yale Univ. Publ. 

Anthrop., No. 61. 26 pp. 

1964. Prehistory of the West Indies. Science, 144: 499-513. 

1966. Paleo- and Meso-Indians of the Caribbean area. Qua- 

ternaria, 8: 125-132. 



26 BREVIORA No. 372 

Rouse, I., and J. M. Cruxent. 1963. Venezuelan Archaeology. New 

Haven, Yale Univ. Press. 179 pp. 
Simpson, G. G., A. Roe, and R. C. Lewontin. 1960. Quantitative Zoology. 

New York, Harcourt, Brace and Co. 440 pp. 
Stuiver, M., and H. E. Suess. 1966. On the relationship between radio- 
carbon dates and true sample ages. Radiocarbon 8: 534-540. 
Tacoma, J. 1959. Indian skeletal remains from Aruba. Stud. Phys. Anthrop. 

Netherlands Antilles, II: 95-112. 
Tamers, M. A. 1967. Instituto Venezolano de Investigaciones Cientificas. 

Natural radiocarbon measurements 111. Radiocarbon, 9: 237-245. 
Warmke, G. L., and R. T. Abbott. 1961. Caribbean Seashells. Livingston 

Co. 346 pp. 
Weyl, R. 1966. Geologic der Antillen. Berlin, Gebriider Borntraeger. 

410 pp. 



BREVIORA 

Mnasemim of Comiparative Zoology 

Cambridge, Mass. 31 March, 1971 Number 373 



THE CHANARES (ARGENTINA) TRIASSIC 
REPTILE FAUNA. 

VIII. A FRAGMENTARY SKULL OF A LARGE THECODONT, 
LUPEROSUCHUS FR ACTUS 

Alfred Sherwood Romer 

Abstract. Incomplete remains of a large skull, not improbably repre- 
S2nting a raiiisuchid thecodont from the early Middle Triassic of Argentina, 
are described as Luperosiichiis fractns, gen. et sp. nov. Large dermal scutes, 
found isolated, may pertain to this form. 

INTRODUCTION 

A moderate number of specimens assignable to the reptilian 
order Thecodontia are present in our Chaiiares collections. Apart 
from materials that are difficult of interpretation or assignment, 
there are definitely present: ( 1 ) a small and primitive member 
of the Ornithosuchidae; (2, 3) two long-snouted forms, with gen- 
eral proportions resembling crocodilians, but without any positive 
indications of affinities with that group; (4) a small form with a 
very lightly built skull, of which the limbs are unknown; (5, 6) 
two forms known from very slender hind limbs of unusual con- 
struction; and (7) a large animal, probably a rauisuchid. repre- 
sented only by a partial skull. In addition there are various 
isolated materials, pseudosuchian in nature. In the present short 
paper 1 shall describe only the last specimen listed, leaving the 
others for later description. 

Since our collections were made, Sr. Bonaparte of Tucuman 
has made several visits to the Chaiiares region, and found, inter 
alia, a fair amount of thecodont material. He invited me to make 
use of this in my work on thecodonts, and in June 1970 I spent 
a week in Tucuman studying this material. I found no identifiable 
forms not already present in the Harvard-La Plata collections, 



BREVIORA 



No. 373 



but in a number of regards his materials supplemented ours and 
substantiated our conclusions. I am deeply grateful to Sr. Bona- 
parte and the authorities of the Instituto Lillo for placing this 
material at my disposal. 



LuPEROsucHUS FRACTUS gen. et sp. nov. 

Combined generic and specific diagnosis. A large thecodont, 
with an estimated skull length of about 60 cm, probably pertain- 
able to the family Rauisuchidae. A shtlike opening apparently 
present posterior to the nares between premaxilla and maxilla; 
antorbital opening large; apparently no parietal foramen; lateral 
temporal opening with vertical posterior border; archosaur type 
of otic notch partially developed. 

Holotype of the species. La Plata Museum 1964-X1-14-9, an 
incomplete skull, consisting of most of the dermal roof and part 
of the left side of the "face" collected from the Chanares Forma- 
tion in La Rioja Province, Argentina, north of the north fork of 
the Chanares River, about 5 km NE of the point where this river 
emerges into the Piano de Talampaya. 

The generic and specific names refer to the fragmentary and 
perplexing nature of the type material. 

I am indebted to National Science Foundation Grant GB-2454 
for aid in the collecting of the material and to further grants for 
its preparation and for publication costs. 




Figure 1. Side view of the fragmentary type skull of Liiperosiicluis frac- 
tus. as preserved. X 1/6. 



197 



LUPEROSUCHUS SKULL 



Description. This form is represented by a single fragmentary 
specimen that includes most of the dorsal surface of a skull and 
part of the dermal bones of the left side of the skull (Figs. 1,2). 
The condition of the material is none too good, and sutures are 
generally difficult to determine. The specimen was found close 
beside the skeleton of a dicynodont. Near it were found a con- 
siderable number of weathered scraps of bone; whether they 
belong to the specimen here described or to the dicynodont 
is uncertain. 

The animal was a large one; the portions of the skull preserved 
measure 54.5 cm in length and if the missing anterior and posterior 
regions be restored, the length in life would have been about 60 
cm. In general, the reptiles present in the Chanares Formation 
are of modest size; apart from this Liiperosuchus specimen, the 
dicynodonts are the only large animals known. 

As mentioned, most of the skull roof is preserved; the cranium 
was obviously long and slender, as in many early archosaurs. 
Posteriorly, the parietals are incomplete, and their posterior exten- 
sions, which presumably formed the median boundaries of the 
superior temporal fenestrae, are missing. There was no parietal 
foramen in the portion of the bone preserved (although it may 
possibly have been present in the missing posterior portion). A 
median longitudinal suture can be made out for almost the entire 
length of the roof as preserved. Other sutures are obscured by 
poor preservation and bone fusion in this seemingly mature skull. 




Figure 2. Dorsal view of the skull, restored. Parts present in stipple. 
Abbreviations: /. frontal; /. jugal; /. lacrimal; m, maxilla; /;. nasal; p, pari- 
etal; pj, postfrontal; pm. premaxilla; po, postorbital; prj. prefrontal; qj. 
quadratojugal; sq, squamosal. X 1/6. 



4 BREVIORA No. 373 

I have restored the probable sutural pattern, but it should be 
emphasized that uncertainties exist. 

The area of the posterior part of the frontals and the median 
portion of the parietals is depressed, and bounded on either side 
by prominent ridges running back along the lateral margins of 
the frontals and continuing backward along the parietals. Postor- 
bitals are present along the back portion of the supraorbital rims 
and extend backward and medially to meet the parietals along 
the anterior border of the superior temporal fenestrae. As far as 
can be determined, there were large postfrontals, forming part 
of the upper margins of the orbits and extending back between 
frontals and postorbitals to gain contact with the parietals. The 
frontals are broad posteriorly; anteriorly they become reduced in 
width between the prefrontals. It is possible that the frontals 
entered the orbital margins briefly, but imperfections of the speci- 
men render this uncertain, and they may have been excluded by 
a narrow contact between postfrontals and prefrontals. The latter 
elements appear to be relatively narrow, projecting somewhat 
outward over the anterodorsal corner of the orbits and extending 
a modest distance forward on either side on the dorsal surface. 
Anteriorly, about opposite the front margin of the antorbital vacu- 
ity, the nasals, as seen in side view, rise upward markedly above 
the general line of the skull roof on their forward course. I was 
at first inclined to believe this appearance was due to post-mortem 
distortion; however, inspection indicates that this "roman nosed" 
elTect is a real structural feature; the conjoined nasals form a 
sharp ridge below which the two bones are apposed for some dis- 
tance and then slant outward toward either side ventrally. It 
seems obvious that the nasals are incomplete anteriorly. Ventrally 
the point of separation of the nasal from the posterior extension 
of the premaxilla below it indicates the probable position of the 
posterior angle of the naris. Most of the premaxilla is missing. 
A small fragment of bone attached to the anterior end of the 
maxilla presumably represents the most posteroventral position 
of the bone. More dorsally a band of bone with well-defined 
margins extends dorsoposteriorly between maxilla and nasal, indi- 
cating a posterior extension of the premaxilla that excludes the 
maxilla from the narial margin, as in certain other thecodonts 
(and ornithischians). The whole aspect of the anterior portion 
of the skull, as far as preserved, strongly suggests the presence 



1971 LUPEROSUCHUS SKULL 5 

of an expanded narial area, and in Figure 3 I have restored the 
narial region on this supposition. 

A large portion of the maxilla is present. A ventroanterior area, 
much thickened, represents the ventral margin adjacent to the 
premaxilla. This region is excavated internally and, although 
preservation is imperfect, represents the area of insertion of a 
series of large, probably subthecodont, anterior maxillary teeth. 
Above this region the anterior margin of the maxilla slants upward 
and backward parallel to the posterodorsal extension of the pre- 
maxilla. In the specimen as preserved the two bones are separated 
here by a long if narrow slit. For much of this distance the facing 
margins of both bones are broadened so that they can readily be 
apposed to one another; hence, when I first attempted a restora- 
tion of the skull, I placed these margins in firm apposition. But 
in contrast to the close union of all other portions of the skull, 
in the specimen as preserved, there was here a very distinct separa- 
tion, suggesting that a slitlike opening was present in life. Dr. 
W. D. Sill, who is currently studying Saurosuchiis, a seemingly 
related form from the Ischigualasto Formation, informs me that 
such an opening was definitely present in that genus, and I have 
therefore indicated such an opening in the restoration in Figure 
3. I have no worthwhile suggestion as to the possible function 
of this slit. 

Back of the nasal region, dorsal and lateral surfaces are sharply 
separated for most of the skull length and, even allowing for 
possible crushing, it seems certain that the side walls descended 
nearly vertically from the lateral dorsal ridges. A short length 
of maxilla is preserved ventrally; above, there is a broad plate of 
bone apparently formed by the maxilla, extending back above the 
antorbital fenestra. The margins of this fenestra are, for the 
most part, clearly outlined; it was an opening of considerable size. 
In many advanced thecodonts the fenestra is centrally situated in 
a depressed area of the cheek; in this specimen the anterior rim 
of this depression is clearly incised in the maxilla. The suture 
between prefrontal and lacrimal is not clear, but the latter bone 
apparently includes the posterior part of the upper margin of the 
antorbital fenestra as well as the preserved portion of a stout bar 
of bone that separates orbit and antorbital fenestra. Behind the 
orbit, the bar of bone between orbit and lateral temporal fenestra 
is completely preserved, and there are indications of a suture well 



BREVIORA 



No. 373 



down this bar, between postorbital and jugal. A fraction of the 
latter bone is present, defining the lower margin of the orbit, a 
section of the cheek rim, and a small area of the anteroventral 
margin of the lateral temporal fenestra. Above this fenestra a 
stout bar of bone is present, presumably formed anteriorly by 
the postorbital, posteriorly by the squamosal (the suture between 
the two is not clear). An incomplete flange of the latter bone 
extends directly downward as part of the posterior border of the 
lateral fenestra. The squamosal extended backward beyond the 
level of this descending flange, although this extension is broken 
off in the specimen. The vertical descent of the squamosal flange 
indicates that the posterior border of the fenestra had not acquired 
the V-shaped contour seen in various more advanced thecodonts; 
on the other hand, the posterior prong of the squamosal suggests 
the initiation of a typical archosaur type of otic notch. 

In Figure 3 I have freely restored the skull in side view to give 
a suggestion of its probable appearance in life. Despite the incom- 
plete nature of the evidence I do not think that there can be too 
great a departure from life conditions in most regards. Most 
doubtful, because of lack of material, is the suspensorial region. 

Systematic position. As to relationships of Luperosuchiis, an 
early Middle Triassic form, one tends to think first of the larger 
erythrosuchid members of the Proterosuchia — a group most 
recently discussed by Reig (1970), and by Charig and Reig 
(1970). Primitive, for example, is the apparent presence of a 
large postfrontal. Liiperosuchus, however, is more advanced than 




Figure 3. Side view of the skull, restored. Abbreviations as in Fig. 
2. X 1/6. 



1971 



LUPEROSUCHUS SKULL 



proterosuchians in various regards, such as the large size and 
incised nature of the antorbital fenestra, probable absence of a 
parietal foramen, and the apparent beginning of the pseudosuchian 
development of an otic notch. More reasonable is assignment to 
the Rauisuchidae (or Prestosuchidae), a family of large but rela- 
tively primitive Middle Triassic thecodonts, first seriously studied 
by Reig (1961). Included here may be such forms as Ticinosii- 
chiis from the European Anisian (Krebs, 1965), Fenhosuchus 
and, doubtfully, Shansisiichus from China (Young, 1964), Stcigo- 
nosuchus (Huene, 1938), and Mandasuchus from the Manda 
beds of East Africa. The presence of rauisuchids in the Middle 
Triassic of South America is well attested by the presence of 
Rauisiichiis and Prestosuclms from the Santa Maria of Brasil and 
Saiirosuchus of the Middle Triassic Ischigualasto Formation of 
Argentina. 

The material of Liiperosuchus is too fragmentary to warrant 
any extended discussion of rauisuchid relationships. Are they, as 
Reig believes (1970, fig. 10), a side branch from a somewhat 
advanced pseudosuchian stock, or could they have progressed in 
parallel fashion from the proterosuchian base of the Thecodontia? 
Are they a sterile group, without descendants, or could they be 
related to the ancestry of certain of the later saurischians, the 
Prosauropoda (Palaeopoda) or, more especially, ancestral Sauro- 
poda? It is possible that Dr. SilFs current studies of Saurosuchus 
will shed light on rauisuchid relationships. 

Dermal scutes. In two instances we found in the Chanares 
region large scutes not definitely associated with other identifiable 
skeletal remains (Fig. 4). They are too large to be attributed to 
any of the other (and much smaller) thecodonts present in our 





1 2 CM 

J I 



Figure 4. Two dermal scutes, possibly referable to Luperosuchus. 



8 BREVIORA No. 373 

collections (and they are not, of course, attributable to the synap- 
sids, which make up the remainder of the materials collected). 
Of known forms from the Chanares, Luperosuchus is the only 
one to which they could have belonged and, since comparable 
scutes are known in other rauisuchids, we may provisionally assign 
them to the present genus. None of the scutes is perfectly pre- 
served. One type, rectangular in shape, has a thickened, saw- 
toothed border along one edge, indicative of an interdigitating 
connection with another element. Such scutes are presumably 
paramedian paired scutes, found in various other thecodonts. 
Subcircular scutes, also present, may be more lateral elements or 
median caudal ones. 

REFERENCES CITED 

Charig, a. J., AND O. A. Reig. 1970. The classification of the Protero- 

siichia. Biol. Jour. Linn. Soc, 2(2): 125-171. 
HuENE, F. VON. 1938. Ein grosser Stagonolepide aus der jiingeren Trias 

Ostafrikas. Neues Jahrb. Min. Geol. Pa!., Beii.-Bd., 80: 264-278. 

Krebs, B. 1965. Ticinosuchiis ferox nov. gen. nov. sp. Ein neuer Pseudo- 

suchier aus der Trias des Monte San Giorgio. Schweiz. Palaont. Ab- 

handl., 81: 1-140. 
Reig, O. A. 1961. Acerca de la Posicion Sistematica de la Familia 

Rauisuchidae y del Genero Saiirosiichiis (Reptilia, Thecodontia). 

Publ. Mus. Munic. Cienc. Nat. Tradic. Mar del Plata, 1(3): 73-114. 
1970. The Proterosuchia and the early evolution of the 

archosaurs; an essay about the origin of a major taxon. Bull. Mus. 

Comp. Zool., 139(5): 229-292. 
Young, C. C. 1964. The pseudosuchians in China. Palaeont. Sinica, new 

sen C, No. 19: 107-205. 



BREVIORA 

Mmseiuijni of Comparative Zoology 

Cambridge, Mass. 15 June, 1971 Number 374 



THE FISHES OF THE MALAYSIAN FAMILY 
PHALLOSTETHIDAE (ATHERINIFORMES) 

Tyson R. Roberts^ 

Abstract. The tiny fishes of the family Phallostethidae, from Malaya 
and Thailand, develop a large penis and differ radically in structure of the 
bilaterally asymmetrical priapium from the somewhat larger fishes of the 
more widely distributed Neostethidae, the only other family in the sub- 
order Phallostethoidea. A morphological characterization of the Phallo- 
stethidae is given and its features compared to those of Neostethidae. 
There are three species: Phallostethus diinckeri Regan (1913), known 
only from the type specimens collected in the mouth of the Muar River 
in Johore, Malaya; Phenacostethus smithi Myers (1928), known from the 
types and many other specimens collected in the khlongs of Bangkok and 
reported in this paper from Chantaburi Province in southeast Thailand; 
and Phenacostethus posthon, new species, from the Indian Ocean coast of 
peninsular Thailand. Ph. posthon and Ph. smithi differ considerably in 
morphology of the priapium and penis. Furthermore, the asymmetrical 
priapium in Ph. posthon is invariably sinistral. In all other phallostethoids, 
so far as known, it may be either sinistral or dextral; in Ph. smithi the ratio 
of sinistral and dextral males is near equality (Hubbs and Hubbs, 1945). 

The ecology of phallostethids is described for the first time, excepting 
some brief remarks by H. M. Smith (1927; 1945), who seems to have 
confused Phenacostethus in the field with neostethids and perhaps with 
Oryzias. An hypothesis is offered that the selective advantage of internal 
fertilization in Phallostethoidea (an oviparous group) lies in permitting 
temporal separation of mating and spawning activities, corresponding, re- 
spectively, with periods of low water and high water in habitats subject 
to strong tidal fluctuations. Two trends in the reproductive biology of 
atheriniform fishes that might be conducive to the evolution of internal 
fertilization are: 1) towards eggs in which either embryonic development 
is slowed down or temporarily arrested, or hatching of embryos is deferred; 
and 2) away from expelling all ovulated eggs at once and towards expel- 
ling them in small batches or even singly. 



1 Museum of Comparative Zoology, Harvard University, Cambridge, 
Massachusetts 02138. 



2 BREVIORA No. 374 

ACKNOWLEDGMENTS 

My studies in Thailand were carried out under the sponsorship 
of the Thai National Research Council. The College of Fisheries 
of Kasetsart University acted as my host, providing laboratory 
space, library facilities, and access to fish collections, including 
specimens of Phenacostethus smithi collected by H. M. Smith. I 
wish to thank the following people for their substantial aid, par- 
ticularly in the aspects of my fieldwork concerning phallostethoids: 
Dean Jinda Thiemeedh, Mr. Prajit Wongrat, and Mrs. Supap 
Monkolprasit of the College of Fisheries; Miss Prachuab Suk- 
charean and Mr. Sopon Chantarat of the Marine Fisheries Station 
of Songkhla; and Dr. Vagn Hansen, Director of the Phuket Marine 
Biological Center. Mrs. Monkolprasit was extremely helpful, par- 
ticularly in arranging my trips. Dean Thiemeedh kindly en- 
couraged my work and arranged transportation to Chantaburi 
Province, where, with Mr. Wongrat's help, not only Ph. smithi, 
but also large series of the neostethids Neostethus siamensis 
(hitherto known only from a single female) and Ceratostethus 
bicornis (previously unrecorded from Thailand) were obtained. 
Mr. Wongrat also helped find Phenacostethus near Bangkok. 
Miss Sukcharean arranged my travels from Songkhla to Satul; Mr. 
Chantarat accompanied me on this trip and helped collect the 
first specimens of Phenacostethus posthon. Dr. Hansen arranged 
my fieldwork in Pungah. 

For translations of the papers by Aurich and Woltereck I am 
obliged to Miss Deborah White and Dr. Elizabeth Deichmann. 
Prof. George S. Myers read the paper in manuscript. 

INTRODUCTION 

This account of the family Phallostethidae is the first paper 
dealing with the fresh- and brackish-water fishes collected by me 
in Thailand from April 15 to July 14, 1970, and deposited in the 
fish collection of the Museum of Comparative Zoology. Collecting 
phallostethoid fishes was one of the main objectives of my field- 
work in Thailand. In addition to Phenacostethus smithi Myers 
(1928) and the new phallostethid described in this paper, large 
series of the neostethids Neostethus siamensis Myers (1937) 
and Ceratostethus bicornis (Regan, 1916) were obtained. These 
represent the first specimens of Ceratostethus recorded from Thai- 
land, and the only specimens of Neostethus siamensis other than 



1971 PHALLOSTETHIDAE 3 

the female holotype. (/V. siamensis is close to, and perhaps spe- 
cifically identical with, N. lankesteri Regan (1916), the type 
locality of which is the mouth of the Muar River, Johore, and 
Singapore.) The osteology and functional anatomy of Cerato- 
stethus will be considered in another paper. 

The Phallostethoidea are small, highly specialized fresh- or 
brackish-water fishes in which males have a remarkable sub- 
cephalic copulatory organ, the priapium. The skeleton and mus- 
culature of this complicated bilaterally asymmetrical organ, which 
functions both in clasping and intromission, are derived mainly 
from the pelvic fins and girdle. Minor contributions come from 
the first pair of ribs and anteroventral part of the pectoral girdle. 
In females the pelvic fins are absent or vestigial. Aurich (1937) 
divided the Phallostethoidea into two "Familien," but gave these 
divisions names in subfamily form, Phallostethinae and Neo- 
stethinae. Berg (1940: 465-466) recognized them as families, 
Phallostethidae and Neostethidae, as did Rosen (1964: 261) 
and Greenwood et al. (1966: 398). Neostethidae, comprising 
eight genera and about 15 species, have been recorded from 
Thailand, Malaya, Sumatra, Borneo, and the Philippine Islands. 
Six of the genera — Gulaphallus Herre (1925), Mirophallus 
Herre (1926), Plectrostethiis Myers (1935), Solenophallus Au- 
rich (1937), Ctenophallus Herre (1939), and Manacopus Herre 
(1940) — are known only from the Philippines. 

The Phallostethidae, even more specialized (and rarer in mu- 
seum collections) than Neostethidae, comprise three species from 
the Malay Peninsula and adjacent parts of Thailand. Phallostethus 
dunckeri Regan (1913), the first phallostethoid to be described, 
is known only from the type specimens Duncker collected previous 
to 1904 at the mouth of the Muar River, about 20 miles south 
of Malacca, Johore Province, Malaya (Duncker, 1904: 171). 
Phenacostethus smithi, hitherto known only from several large 
series collected by H. M. Smith from khlongs in Bangkok, was 
obtained by me at Bangkhen (a suburb of Bangkok) and at 
Chantaburi, near the southeast corner of Thailand (near Cam- 
bodia). The third species, described in this paper, is from the 
Indian Ocean coast of Thailand. All localities where phallostethids 
have been collected are shown in Figure 1. The present paper 
presents characterizations of the family Phallostethidae and of 
the phallostethid species, a description of the new species just 
mentioned, and observations on the ecology of Phallostethidae. 



BREVIORA 



No. 374 



ir 



10" 



5*- 




- 10" 



15* 



5* 



100* 



lOS* 



Figure 1. All localities where Phallostethidae have been collected. 1. 
Mouth of Muar River at Bandar Maharani (type locality of Phallostethus 
dimckeri Regan, 1913); 2. Bangkok (type locality of Phenacostethiis smithi 
Myers, 1928); 3. Bangkhen, a suburb of Bangkok (Ph. smithi); 4. Chanta- 
buri City {Ph. smithi); 5. Khlong La Ngoo, 48 km NW of Satul Town, 
6° 52' 30" N, 99° 48' 10" E (type locality of Phenacostethiis posthon n. 
sp.); 6. Khlong Kla Sohm, 15 km S of Pungah Town, on Pakasem Road 
from Pungah going towards Phuket Island (type locality of Ph. posthon 
n. sp.) 



Definition of the suborder Phallostethoidea and discussion of 
phyletic trends in the Phallostethoidea will be presented in a 
forthcoming paper on Ceratostethus. 

Ph. smithi provides an Asian example of the phenomenon (of 
which Africa and South America provide numerous examples) 



1971 PHALLOSTETHIDAE 5 

that the smallest fishes amidst the richest tropical freshwater 
faunas are representatives not of the dominant fish groups present, 
but of groups with a marginal distribution pattern. The ecology 
of such minute fishes, when known, usually proves to be highly 
specialized. 

Rosen (1964) united the exocoetoids, scomberesocoids, adri- 
anichthyoids, cyprinodontoids, atherinoids and phallostethoids in 
a new order, the Atheriniformes. Atherinoids and cyprinodont- 
oids were widely separated in earlier classifications, the artificial- 
ity of which has become increasingly apparent. Such similarities 
as were noted between atherinoids and cyprinodontoids had 
usually been attributed to convergence. Having personally investi- 
gated the osteology of phallostethoids (which evidently are re- 
lated to atherinoids), atherinoids, and cyprinodontoids, and 
reviewed much of the literature on osteology and reproductive 
biology of these groups, I am inclined to believe that they may 
be related. Some of the similarities in reproductive biology were 
first brought to my attention in a talk given by Neal R. Foster 
at the 1968 meetings of the American Society of Ichthyologists 
and Herpetologists. 

Note on the figures. Figures 2-5, prepared with the aid of a 
Wild microscope and camera lucida, are based on formalin speci- 
mens. Formalin specimens of Phallostethidae are more nearly 
normal in appearance than alcoholic specimens, since the latter 
invariably undergo at least some shrinkage. In specimens that 
have been transferred from the original formalin fixative to 60 
per cent ethyl alcohol for permanent storage, teeth protrude more 
from the gums, scales stand out more clearly, the membranous 
dome atop the head has disappeared, and the caudal peduncle is 
decidedly narrower. 

CHARACTERIZATION OF THE FAMILY PHALLOSTETHIDAE 

The following characterization of the Phallostethidae is based 
on my observations of Ph. sinithi and Ph. posthon, including study 
of alizarin preparations, and on accounts of Ph. smithi by Myers 
(1928), Bailey (1936), and TeWinkel (1939), and of Phallo- 
stethus dunckeri by Regan (1913; 1916). 

1 . Slender elongate phallostethoids, very delicate, largely trans- 
lucent, with deciduous scales; externally visible concentrations of 
melanophores restricted to the top of the braincase, middle of the 



6 BREVIORA No. 374 

dorsum, midlateral intermuscular septum, priapium, and bases and 
edges of fin rays; maximum standard length about 23 or 24 mm. 

2. Dorsum of head with a translucent, membranous dome. 

3. Mature individuals of both sexes with a bright orange-yellow 
bar on caudal peduncle. 

4. Branchiostegal rays 4. 

5. Main "externalized" clasping bone in the priapium is the 
toxactinium; ctenactinium reduced or absent. 

6. A greatly enlarged, oval, concave pad, or pulvinulus, shghtly 
posterior to toxactinium. 

7. Vas deferens terminating in a large penis that projects con- 
siderably from the priapium. 

8. Pelvic spines or rays, if present, greatly reduced and modi- 
fied beyond recognition. 

9. Vas deferens highly coiled, forming a sort of epididymis. 

Comments on the family characters. Neostethids, while small 
as fishes go, are all or almost all larger when adult than phallo- 
stethids. Most, if not all, neostethids are hardier fishes than phal- 
lostethids and have relatively adherent scales. While they also 
are largely translucent, neostethids usually have relatively more 
melanophores than phallostethids. The epidermis paralleling the 
scale margins is often well provided with melanophores in neo- 
stethids but invariably devoid of melanophores in phallostethids. 
Neostethids (Ceratostethus and Neostethus), even at comparable 
sizes, lack a membranous dome on the dorsum of the head, or if 
one is present, it is not notably elevated. According to TeWinkel 
(1939) this region bears sensory canals in both Phenacostethus 
and Gulaphallus. In neostethids large sensory pores are evident 
in the frontal region, whereas the membranous dome in phal- 
lostethids is apparently entire. 

With regard to characteristic number 3 (bright orange-yellow 
markings at the base of the caudal fin and sometimes at the origin 
of the anal fin), these are present in Uving specimens of Ph. smithi 
and in Ph. posthon. There is no way of teUing whether such spots 
are also present in Phallostethus. The orangish yellow coloration, 
contained in chromatophores (approximately 50-75 chromato- 
phores constituting the caudal base mark) gradually disappeared 
after a few weeks of preservation in formalin. Similar markings 



1971 PHALLOSTETHIDAE 7 

were definitely absent in live specimens of Neostethus and Cera- 
tostethus observed by me, nor is there any mention of such marks 
in the literature on Neostethidae. 

Concerning character 4, Neostethidae usually have 5 branchio- 
stegal rays. The number of branchiostegal rays in Phallostethus 
is unknown. 

Characters 5-9 concern the priapium, which differs funda- 
mentally from that of Neostethidae. In Neostethidae the main 
"externalized" bony clasping element, the ctenactinium, is appar- 
ently a modified pelvic fin ray or spine. The mam "externalized" 
bony element in the priapium of phallostethids, the toxactinium, 
is not homologous with the ctenactinium. My observations con- 
firm Bailey's view (Bailey, 1936: 463, 471) that it is homologous 
with the pulvinular bone, one of the anteriormost internal bony 
elements in the priapium of neostethids. The homologies of this 
element are unclear, but it is almost certainly not a modified pel- 
vic ray or spine. The ctenactinia of phallostethids, which may or 
may not be homologous with the elements called ctenactinia in 
neostethids, are greatly reduced in size. The ctenactinium of Phal- 
lostethus dimckeri, while relatively short, bears several "teeth" 
or sharp projections; these are perhaps comparable to the single 
curved hook present near the base of the ctenactinium in Neo- 
stethus. The pulvinulus of phallostethids probably functions as a 
pad in conjunction with the toxactinium. A homologous but much 
smaller pulvinulus is present in neostethids. A striking character- 
istic of the phallostethid priapium is the development of a large 
penis. In Phenacostethus posthon the organ is entirely smooth; 
in Ph. smithi its distal half bears a series of stiff ruffled pleats. 
The development of a large penis evidently occurred independently 
in the neostethid Mirophallus bikolanus (Herre, 1926, pi. 3, fig. 
1 ) . In most neostethids a compUcated flap covers the opening of 
the vas deferens (Aurich, 1937). This flap is absent in PhaUo- 
stethidae. Various bony elements in the priapium of phallostethids, 
including a peculiar slender element lodged in the concave side 
of the penis bone in Ph. smithi, may be homologous with pelvic 
rays, but the priapium of phaUostethids does not bear any 
branched elements that obviously are relatively unmodified pelvic 
rays. Several branched pelvic rays of relatively normal appear- 
ance occur in the neostethids Ceratostethus, Neostethus, Soleno- 
phallus, and Gulaphallus (personal observations; Aurich [1937], 
TeWinkel [1939], Woltereck [1942 a, b]). 



8 BREVIORA No. 374 

The priapium of Phallostethus is clearly of the same general 
type as that of Ph. smithi and Ph. posthon. In Phallostethus the 
toxactinium and pulvinulus are very similar to these structures in 
Phenacostethus. It is likely that Phallostethus develops a large 
penis. The penis in phallostethids, like the ctenactinium of neo- 
stethids, only reaches its full development in the largest males. 

Regan (1916: 22) hypothesized that in Phallostethus the tox- 
actinium grips the female under the chin or is held in her mouth, 
while the serrated edge of the ctenactinium gives a firm hold on 
the pectoral region in front of and on the far side of the genital 
orifice, in order that the seminal papilla could be placed against 
it or introduced into it. In Neostethus he hypothesized that the 
female is held across the back of the head by the ctenactinium, 
the anterior descending part of which lies on the side of the female 
away from the male. Copulation has yet to be observed in Neo- 
stethus or in any phallostethids. It has been observed only in the 
neostethid Gulaphallus mirabilis. In this species the female is 
held across the back of the head by the ctenactinium; the "second 
ctenactinium" of Gulaphallus mirabilis, which actually is an exter- 
nalized pelvic bone, apparently rests or presses against the female's 
opercular region on the side next to the male (Villadohd and Man- 
acop, 1934: pi. 5, fig. 2). The reduced ctenactinium of Phallo- 
stethidae could hardly function in the same manner as the elongate 
ctenactinium characteristic of all neostethids. It may be that the 
toxactinium is held, not under the female's chin or in her mouth, 
but atop the front of her head. 

In Phallostethus (Regan, 1916: 19, fig. 14) the vas deferens 
is highly coiled within the abdominal cavity to form a sort of 
epididymis. TeWinkel (1939) reports a similar coiling of the 
vas deferens in Ph. smithi. In Neostethus lankesteri (Regan, 
1916: 10, fig. 6) and in Gulaphallus mirabilis (Villadolid and 
Manacop, 1934: pi. 3, fig. 4) the vas deferens is unconvoluted 
from its origin on the testis to where it enters the priapium, then 
forms an expanded loop inside the priapium. The sperm of Neo- 
stethus lankesteri (Regan, 1916: 13, fig. 9) are concentrated into 
"spermatophores," more properly called spermozeugmata (Niel- 
sen et al., 1968: 248). Regan (1916: 19) stated that Phal- 
lostethus evidently did not produce "spermatophores" like those 
of Neostethus. In mature Neostethus and Ceratostethus (per- 
sonal observation) the posteriormost portion of the priapium is 



1971 PHALLOSTETHIDAE 9 

sometimes greatly swollen with closely packed, adherent small 
vesicles that presumably are spermozeugmata. The priapium 
apparently does not become similarly swollen in phallostethids. 
Insofar as can be determined from examination of the bones 
only, the contributions of the first pair of ribs and of the 
shoulder girdle to the priapium is the same in Phallostethidae and 
Neostethidae. 

THE SPECIES OF PHALLOSTETHIDAE 
Phallostethus dunckeri Regan 1913 

Phallostethus dunckeri Regan, 1913: 550, figs. 1-4 (original description; 
types from mouth of Muar River at Bandar Maharani, Johore, Ma- 
laya; soft anatomy). — Regan, 1916 (soft anatomy, histology, oste- 
ology, comparison with Neostethiis). 

This species is known only from the specimens collected by 
G. Duncker at the mouth of the Muar River at Bandar Maharani, 
Johore, Malaya. The following statements are based on the two 
accounts of this species by Regan (1913, 1916). It is character- 
ized by an exceptionally long anal fin, with 26-28 elements 
(eight to ten rays more than are found in phallostethoids with 
the next highest number of anal fin elements), an anal base about 
30 per cent of the standard length (compared to anal base 20-25 
per cent of standard length in all other phallostethoids) and origin 
of anal considerably nearer to snout tip than to end of hypural 
fan (anal origin slightly to considerably nearer to end of hypural 
fan than to snout tip in all other phallostethoids), and by a ser- 
rated ctenactinium (Regan, 1916: fig. 13). Regan did not have 
very many specimens (some were used for histological preparations 
or cleared in oil of cloves for bone study). Dr. P. H. Greenwood 
informs me that the British Museum (Natural History) has four 
specimens (types?) of Phallostethus dunckeri in rather poor con- 
dition. Although Regan's specimens of Phallostethus dunckeri 
(at 23-29 mm in total length) are larger than Phenacostethus, 
and the males figured by him have well-developed priapia, perhaps 
the penis is not fully developed in them. This seems likely, be- 
cause in both species of Phenacostethus the largest females are 
only about one-half to one milUmeter longer than the largest 
males, whereas Regan's largest female of Phallostethus is six mil- 
limeters longer than his largest male. In Phenacostethus the penis 
is fully formed only in the largest males. 



10 BREVIORA No. 374 

The second dorsal fin of P. dimckeri has eight to ten elements 
(a number found in some Neostethidae); the highest number in 
Phenacostethus is seven. It is unknown whether Phallostethus has 
a first dorsal fin. Regan did not mention its presence, but he over- 
looked the first dorsal in his material of Neostethus lankesteri 
and Ceratostethus bicornis. Phallostethus probably has a small 
spinous first dorsal fin, but the absence of one would not be unique 
among Phallostethoidea: the first dorsal is lacking in the neosteth- 
ids Mirophallus bikolamis Herre (1926), (Herre, 1942: 141; 
Myers, 1937: 142) and Solenophallus thessa Aurich (1937: 265). 

Phenacostethus smithi Myers 1928 
(Figures 2, 4, 6) 

Neostethus lankesteri (not of Regan) Smith, 1927: 353-355 (misidenti- 
fication). 

Phenacostethus smithi Myers, 1928: 6, figs. 1 and 2 (original description; 
types from Bangkok; holotype in American Museum of Natural His- 
tory). — Bailey, 1936 (osteology).— TeWinkel, 1939 (soft anat- 
omy).— Smith, 1945: 475 (Bangkok; synonymizes Ph. thai Fowler; 
ecology). 

Phenacostethus thai Fowler, 1937: 219; figs. 189, 190 (original description; 
Bangkok; holotype in Philadelphia Academy). 

Material studied. MCZ 47055, 13 specimens, five females 
13.7-14.8 mm and eight males 13.6-14.9 mm (three with toxac- 
tinium arising on left side, five on right side), from Khlong Bang- 
khen at bridge on Nzarm Wong Wan Road, a few km west of 
Kasetsart University, Bangkhen, Bangkok, Thailand, 30 April 
1970; MCZ 47299, 20 specimens, three females 13.4-15.6 mm 
and 17 males 12.7-14.9 mm (12 with toxactinium arising on right 
side, five on left side), from Khlong Kee Nawn, behind Cathohc 
church in Chantaburi City, Chantaburi Province, Thailand, 5 
May 1970. 

Myers' figure 1 of Ph. smithi does not show the membranous 
dome of the dorsum of the head (Fig. 2) ; it is likely to be shrunken 
in alcoholic specimens. The adult male in Myers' figures 1 and 2, 
at 13.5 mm in standard length, does not have the penis as fully 
developed as in my specimens 14.3 (Fig. 2), 14.1 (Fig. 4), and 
14.5 (Fig. 6) mm in standard length. In these specimens the 
penis is much larger, and its distal end bears a series of a half- 
dozen or more crenulated radial folds or extensions resembling a 



1971 



PHALLOSTETHIDAE 



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12 BREVIORA No. 374 

set of ruffled lace cuffs (best shown in Fig. 4). These folds can 
be seen in one of Bailey's anatomical figures based on material 
of Ph. smithi collected by Hugh M. Smith. Direct comparison of 
Ph. smithi collected by Smith in Bangkok (deposited in the fish 
collection of the College of Fisheries, Kasetsart University, and 
in the MCZ fish collections) with my material from Bangkhen and 
Chantaburi indicates that only one species is involved. Live speci- 
mens of Ph. smithi of both sexes from Bangkhen and from Chanta- 
buri had a bright orange-yellow, anteroventrally-posterodorsally 
oriented bar on the lower half of the caudal peduncle. This bar 
disappeared from specimens kept a few weeks in formahn. The 
color was due to about 50-75 chromatophores. There is a small, 
shiny blue spot over the brain (well behind the eyes), and a very 
small silvery spot in the middle of the eyes' dorsal surface. 

Alizarin preparations reveal the first dorsal fin consists of a 
single tiny spine, as indicated by Myers. Most specimens are miss- 
ing many scales. Head scaleless. Abdominal keel scaleless in 
both sexes (abdominal keel scaled in females of Ceratostethus 
bicornis). Scales on body cycloid, number of scale rows corre- 
sponding closely with the number of myotomes. Teeth in both 
jaws in a single series; medial portion of premaxillary with about 
eight sharp conical teeth, lateral (expanded) margin of premaxil- 
lary with about seven to nine slightly larger conical teeth; medial 
portion of dentary with about a dozen conical teeth opposing but 
much smaller than those on medial portion of premaxillary. 

For counts of fin elements and vertebrae based on alizarin 
preparation see Table 1. 

Phenacostethus posthon, new species 
(Figures 3, 5, 7) 

Holotype. MCZ 47300, a 16.7-mm male from Khlong Kla Sohm 
about 15 km southwest of Pungah Town, where it is crossed by 
a bridge on the Pakasem Road (between Pungah Town and Phu- 
ket), Pungah, Thailand. 29 June 1970. 

Paratypes. MCZ 47301, 58 specimens, comprising two im- 
matures, 11.9 and 12.0 mm, 22 females, 12.3-17.7 mm, and 34 
males 12.7-17.0 mm (of which two males, 15.5 and 16.5 mm, are 
cleared and stained), same data as holotype; MCZ 47302, 20 
specimens, comprising three immatures 9.6-12.0 mm, 10 females 
12.7-18.0 mm, and 7 males 12.9-16.7 mm, from Khlong Langu 



1971 PHALLOSTETHIDAE 13 

at Langu Town, 48 km northwest of Satul Town (6° 52' 30" N, 
99° 48^' 10^' E). 23 June 1970. 

The most obvious differences between this species, from the 
Indian Ocean coast of Thailand (Fig. 1), and Ph. smithi involve 
the priapium and the position of the dorsal fin. Granted that both 
species have the characteristic priapial elements of the family 
Phallostethidae, the priapium is, in fact, so different in the two 
species that the question may even be raised as to whether separate 
generic status is indicated. 

Differences in the priapium of the two species involve external 
morphology of the penis, skeleton of the penis, ctenactinium, tox- 
actinium, and the nature of the laterality of the priapium itself. 
In Ph. smithi 1 ) the distal portion of the penis is ruflfled (see 
description above); 2) the penial skeleton includes a large papil- 
lary bone with a slender penial bone lodged in its concave surface 
(Fig. 6; see also Bailey, 1936: 3 and 4); 3) the ctenactinium is 
relatively large and externally evident; 4) the toxactinium is rela- 
tively slender and gently curved; and 5) the priapium itself may 
be either sinistral or dextral. In Ph. posthon, on the other hand, 
1 ) the penis is smooth; 2) the penial skeleton has a large papillary 
bone but the penial bone is absent; 3) the ctenactinium, if it is 
present at all, is reduced and hardly detectable externally; 4) the 
toxactinium is stouter and distinctly more sharply curved; and 5) 
the priapium is invariably sinistral (toxactinium arising on left 
side) in the material examined. 

Ph. posthon and Ph. smithi of both sexes can be distinguished at 
a glance by the position of the first dorsal fin relative to the anal 
fin base. In Ph. posthon the first dorsal (which has a single spine 
as in Ph. smithi) originates slightly posterior to the base of the 
last ray in the anal fin; in Ph. smithi it originates over the middle 
of the anal fin base. The first dorsal fin is somewhat closer to 
the second dorsal origin in Ph. posthon than in Ph. smithi. Ph. 
posthon is more elongate (depth of body at anal fin origin about 7, 
vs. 6 in Ph. smithi) and evidently a larger species. The average 
and maximum sizes of specimens in my two samples of Ph. 
posthon are definitely larger than in my two samples of Ph. smithi 
(which include specimens larger than those previously recorded). 
The largest male and female specimens of Ph. smithi are, respec- 
tively, 14.9 and 15.6 mm; of Ph. posthon, 17.0 and 18.0 mm 
(standard lengths). The largest specimens (both sexes) had a 
bright orange-yellow bar on the caudal peduncle, as in Ph. smithi, 



14 



BREVIORA 



No. 374 




Figure 4. Phenacostethus smithi Myers (1928), ventral view of pri- 
apium, 14.1-mm specimen, MCZ 47055 (formalin). 



and also a smaller orange-yellow bar on the body next to the anal 
fin origin. 

As in Ph. smithi, there appears to be a one-to-one correspon- 
dence between the scale rows and the myotomes. The thin scales 
are extremely difficult to see in specimens under alcohol or water; 
and most specimens are missing many scales. I find in several 
specimens eight oblique scale rows between dorsal midline and 
anal fin origin, and six oblique scale rows between dorsal fin 
origin and anal base. Shape of jaw bones and disposition of teeth 
as in Ph. smithi. 

For fin and vertebral counts based on alizarin preparations of 
Ph. posthon see Table 1. Ph. posthon seems to have, on the aver- 
age, one less ray in the dorsal fin (verified by counts of unstained 
specimens) and one more vertebra than Ph. smithi. 

Right- and left-handedness in the priapiiim of Phallostethidae. 



1971 



PHALLOSTETHIDAE 



15 




Figure 5. Ph. posthon n. sp., ventral view of priapium in 16.9-mm para- 
type, MCZ 47301 (formalin). 



That the priapium of Neostethus lankesteri may be either right- 
or left-handed is stated by Regan (1916: 5). Regan did not spe- 
cifically state that the priapium of Phallostethus may be either 
way, but in a general discussion of the priapium as compared to 
copulatory organs of other fishes, he refers to its being either 
dextral or sinistral (Regan, 1916: 23). Regan's figures of Phal- 
lostethus depict both right-handed and left-handed males. It is 
conceivable that one or more of them might be reversed images, 
the images being reversed either by the illustrator or by the printer, 
so the figures cannot be taken as definite proof that P. dimckeri 
may be either left-handed or right-handed. Concerning Phena- 
costethus smithi, Hubbs and Hubbs (1945: 294) found that in 
334 males (from material collected by H. M. Smith at Bangkok) 



16 



BREVIORA 



No. 374 



posttemporal 
c lei thrum 
coracoid 



supracleithrum 
scapula 




tozactiiiium 



antepleural 



papillary 



axial 



Figure 6. Ph. smithi Myers (1928), skeleton of priapium and pectoral 
fin in 14.5-nim specimen, MCZ 47301. Terminology of priapial elements 
according to Bailey (1936). 



posttemporal 

cleithrum 
coracoid 



supracleithrum 

scapula 

radial 




toxactinium 

pulvinulus 

antepleural 



ribs 
anal 

basipenial 
prepapillary 
uncus 
anterior infrasulcar' 



posterior infrasulcar 
ctenactinium 



Figure 7. Ph. posthon n. sp., skeleton of priapium and pectoral fin in 
16.5-mm paratype, MCZ 14301. Priapial elements of uncertain homology 
with those in Ph. smithi are unlabelled. 



1971 PHALLOSTETHIDAE 17 

the aproctal side was the left side in 155 and the right side in 
179. The deviation from equality is statistically insignificant. In 
my samples from Bangkhen and from Chantaburi (too small for 
statistical analysis) I find both left- and right-handed males. In 
Phenacostethus posthon the toxactinium arises on the left side 
in every male in which the priapium is sufficiently developed to 
have a toxactinium (27 specimens from Pungah and five from 
Satul). To my knowledge this is the only phallostethoid in which 
the sidedness of the priapium appears to be fixed. Females of Phal- 
lostethidae are bilaterally symmetrical, the genital openings lying 
in the middle of the throat. 

ECOLOGICAL OBSERVATIONS 

The only ecological information Regan had about Phallostethus 
dunckeri was that it came from brackish water from the Muar 
River at Bandar Maharani. Duncker also collected Neostethus 
lankesteri in the same general locahty. 

Smith (1927; 1945: 476) made brief ecological observations 
on Phenacostethus smithi but in restrospect it seems that he some- 
times confused this little fish in the field with Neostethus or Cera- 
tostethus and perhaps even with Oryzias. I did not observe either 
phallostethids or neostethids at the surface, and feel that they 
generally keep well below the surface. Smith's remarks (that 
Phenacostethus "normally remain at or close to the surface, where 
they would be difficult to see were it not for a glistening yellow 
area on the top of the head'') sound more like Oryzias. The glisten- 
ing area on the top of the head in phallostethoids is relatively small 
and bluish, compared to the large yellowish glistening area in 
Oryzias, which is comparable to the striking head spots in rivuline 
cyprinodontids of the genera Epiplatys and Aplocheilus. In any 
event. Smith records that Ph. smithi abounds in freshwater pools, 
ditches and smaller canals in the Bangkok region, Hving in water 
that is nearly always muddy or turbid, and that the species is 
oviparous (although spawning was not observed); the egg-bearing 
and spawning periods are protracted, corresponding with the rainy 
season, and may extend from May to December. Small numbers 
were maintained in aquaria for a month by the daily introduction 
of fresh ditch or canal water to provide food in the form of minute 
crustaceans, protozoans, worms, etc. Smith found the larvae of 
anopheline mosquitoes much too large for Ph. smithi to ingest. 



18 BREVIORA No. 374 

Undoubtedly Ph. smithi once lived in innumerable khlongs and 
ditches in Bangkok which are today so polluted that they are 
inhabited only by the hardiest air-breathing fishes such as Anabas 
testudineiis. In Khlong Bangkhen, a few kilometers from Kasetsart 
University, I found Ph. smithi in association with a variety of 
primary and secondary freshwater fishes, principal among which 
were cyprinids mainly of the genus Rasbora, Dermogenys, Xenen- 
todon, Oryzias, Gobiopterus chuno (a small translucent goby), 
young Fhita, and Chaudhuria. The Phenacostethus were mostly 
in a little backwater, close to the main current in the khlong, in 
very turbid water. I was unable to taste any salt in the water. 
At Chantaburi City, Phenacostethus was collected in a turbid 
ditch or small khlong, Khlong Kee Nawn, behind the Catholic 
church. There were a number of houses along the khlong at this 
point, and considerable rubbish had been thrown into it, so col- 
lecting efl'orts were confined to dip-netting for Phenacostethus. 
Dermogenys, Brachygobius and Gobiopterus were collected inci- 
dentally. About two kilometers downstream, where the khlong 
traversed a large open field, we found minnows such as Oxygaster, 
Esomus and Rasbora (but no Phenacostethus) which indicates the 
water in the khlong was not brackish. 

At Satul and at Pungah Ph. posthon was obtained along the 
margins of khlongs or tiny branches of khlongs in which the water 
was swiftly flowing, highly turbid, and probably completely fresh. 
A few of the largest females (collected June 1970) were replete 
with ripe ova. Both localities were at places fully subject to tidal 
fluctuations, but far upstream from branches having water the 
least bit sahy to the taste. At Khlong Langu in Satul Province 
the water level was undoubtedly high because of heavy rains for the 
preceding 12 hours or more; Phenacostethus were collected in 
the khlong both on the falling tide and rising tide. No primary 
freshwater fishes were obtained. Species in the khlong where 
Ph. posthon was collected included Oryzias, Dermogenys, Chanda, 
Gobiopterus, Butis, and Tetraodon. In Khlong Kla Sohm, near 
Pungah, Ph. posthon was coUected in a narrow side channel more 
or less uniformly 3-4 feet deep, swiftly flowing, with hard-packed 
mud bottom, well shaded by Nipa palm and mangrove. Oryzias, 
Dermogenys, Gobiopterus, Periophthalmus, Tetraodon, and young 
Scatophagus were the only other fishes collected or observed in 
this channel. 



1971 PHALLOSTETHIDAE 19 

In contrast, on the more numerous occasions when I obtained 
either Neostethus or Ceratostethus in Thailand, the water was 
usually brackish or even very salty to the taste. At one locality 
Neostethus and Ceratostethus were collected together in large 
numbers but neither were collected in association with Phenaco- 
stethus. I did not find Neostethus or Ceratostethus in association 
with primary freshwater fishes except on one occasion (afternoon, 
1 1 July 1970) when Ceratostethus was found in a khlong (strongly 
influenced by tides) about midway between Bangkok and Samutsa- 
korn, in association with Toxotes, Dermogenys, Rasbora and Eso- 
mus. The water was more or less fresh to the taste. A number 
of dead Esomus were carried by the current of the khlong, and 
a Rasbora or two may have been amongst them. I thought at 
the time that mortality of these minnows was perhaps due to in- 
cursion of salt water. The dead fish were carried by the out- 
going tide. 

My impression is that, in Thailand, phallostethids occur in 
water that is turbid and fresh; and neostethids in water that is 
turbid and brackish or even quite salty. I would guess that at 
some of the seven locahties where I collected neostethids the water 
was at least a third and perhaps one-half or more as salty as 
sea water. 

The only phallostethoid in which mating and egg-laying have 
been observed (but not in sequence) is the neostethid GulaphaUus 
mh-abilis Herre (VilladoUd and Manacop, 1934). It seems prob- 
able that all phallostethoids are oviparous. No females carrying 
embryos have been observed. It is unclear how much time elapses 
between copulation and egg-laying in G. mirabilis, or whether 
several egg-layings follow a single copulation. Judging from the 
range in size of young individuals found with adults in my collec- 
tions of phallostethoids, I suspect that in Thailand species some 
reproduction goes on throughout the year. It seems Hkely that 
reproductive peaks occur towards the latter part of the rainy sea- 
son (November and December). 

The distribution of phallostethoids is marginal to the rich East 
Indian marine and freshwater fish faunas. They do not occur in 
the sea, nor do they penetrate very far into fresh water where 
there is a continental fauna of primary freshwater fishes. The 
Phallostethidae penetrate further into waters inhabited by primary 
freshwater fishes than any other phallostethoids, but they do not 



20 BREVIORA No. 374 

get very far inland. Usually the canals or creeks they inhabit are 
strongly influenced by tides, and thus the faunal composition (with 
regard to fishes at any rate) is subject to considerable temporal 
variation, involving retreat of primary freshwater fishes and inva- 
sion of brackish-water forms, and vice versa. In places where the 
tidal changes are greatest, these invasions and counterinvasions 
would be a daily event, varying of course with the extent in the 
tides. In other places they might occur only during the strongest 
tides. Gulaphallus on the island of Luzon probably pass their en- 
tire lives in fresh water — where no primary freshwater fishes occur. 

DISCUSSION 

Selective advantage of internal fertilization in phallostethoids. 
One usually associates copulatory organs in teleostean fishes with 
viviparity, as in Poecihidae, Embiotocidae, and Brotulidae. It 
is a striking fact, however, that several groups of oviparous teleosts 
normally have internal fertilization. Among these are some Cot- 
tidae, some Scorpaenidae, probably some Clinidae, and probably 
some glandulocaudine characids. According to Nelson (1964) 
the evolution of internal fertihzation in the oviparous glandulo- 
caudine characids of tropical South America appears to be a 
response to well-marked wet and dry seasons. The presumed 
advantage of a temjxDral separation in mating and spawning is as 
follows: mating occurs during the dry season, when populations 
are crowded together in small pools, food is scarce and conditions 
for survival are generally unfavorable; spawning, on the other 
hand, occurs during the height of the rainy season, when the popu- 
lation is maximally dispersed (so much so that males and females 
may no longer be together) and conditions for survival of the 
young are optimum (abundance of food, well-oxygenated waters, 
access to areas where most predators are too large to enter). 
A very similar set of conditions may apply to the evolution of 
internal fertihzation combmed with oviparity in phallostethoids, 
with temporal separation of mating and spawning corresponding, 
respectively, with periods of low water and high water. This 
hypothesis should be extended to the oviparous atheriniform fishes 
Horaichthys setnai Kulkarni (1940) and Tomeurus gracilis, males 
of which have independently evolved excessively complicated 
copulatory organs through modification of the anal fin. Tomeurus 
occurs in brackish water along the northeastern coast of South 



1971 PHALLOSTETHIDAE 21 

America, including the mouth of the Amazon River, Horaichthys 
in brackish water along the Bombay and Kerala coast of India. 
The sperm in Tomeurus are transmitted in spermozeugmata (Niel- 
sen, et al., 1968: 253), as in the viviparous poecilioids (the nature 
of the phyletic relationship between Tomeurus and poecilioids is 
unclear; they probably are closely related). Horaichthys, on the 
other hand, is among the very few teleosts known to have a true 
spermatophore (Kulkarni, 1940; Nielsen, et al., 1968). (In true 
spermatophores the sperm are enclosed in a capsule. A spermo- 
zeugma is an unencapsulated group of sperm held together by 
a mucoid substance.) 

Trends in the reproductive biology of atherinijorm fishes that 
might be conducive to the evohition of internal fertilization. When 
oviparous fishes with internal fertilization exhibit a marked delay 
between mating and spawning, it may be presumed that fertiliza- 
tion actually occurs just before spawning, the sperm having been 
stored. Storage of sperm and delayed fertiUzation evidently char- 
acterize at least some viviparous fishes, such as those poecihoids 
(including forms with superfoetation and forms without it) in 
which females are capable of producing up to four or five suc- 
cessive broods after a single mating session. It should be noted, 
however, that the eggs of a number of atheriniform fishes with 
external fertilization normally exhibit arrested embryonic develop- 
ment or delayed hatching. A lengthening of the period between 
fertilization and hatching, particularly if it could be subjected to 
hormonal control, might be highly preadaptive to the evolution 
of internal fertilization with delayed spawning. While there is no 
evidence of arrested embryonic development or delayed hatching 
in atheriniforms with internal fertilization, it seems worthwhile 
to review briefly what is known about these phenomena in forms 
with external fertilization. 

Wourms (1967) found that the eggs of annual cyprinodont 
fishes of the subfamily Rivulinae (Cynolebias, Pterolebias, Racho- 
via, Nothobranchius, and Austrofundulus) are subject to develop- 
mental arrest at one or more stages. In Austrofundulus myersi 
dispersion of amoeboid blastomeres occurs early in development 
(stages 19-22) so that there is no embryo or aggregation of cells. 
This is followed by a slow reaggregation of cells and resumption 
of development. This arrested phase (Diapause I) is facultative, 
and also occurs in other annuals. Obligate developmental arrests 



22 BREVIORA No. 374 

in annuals were found in presomite embryos (stage 33, Diapause 
II) and in prehatching embryos (stage 44, Diapause III). The 
duration of these phases is rather variable. Wourms suggested that 
"the net effect of a developmental system which can undergo dia- 
pause of variable duration at several stages is to generate a wide 
distribution of eggs in any single developmental stage, and to make 
the transition from stage to stage a variable phenomenon. The 
continued survival of the population is ensured in spite of climatic 
cycles which are variable in periodicity and intensity" (Wourms, 
1967: 341 1 ). The eggs of annual cyprinodonts have exceptionally 
hard chorionic membranes. Harrington (1959) reported delayed 
hatching in stranded eggs of marsh killifish, Fundiilus confiuentus, 
a member of the cyprinodontid subfamily Fundulinae, and Jones 
(1944) reported delayed hatching in Oryzias melastigma, a mem- 
ber of the cyprinodontoid family Oryziatidae (see Rosen, 1964, 
for a characterization of this family). In O. melastigma hatching 
normally occurs in 8-14 days, yet can be delayed up to six weeks; 
hatching can be induced by adding water of lower salinity. The 
only noncyprinodontoid fishes in which delayed hatching has been 
reported as a normal phenomenon are one or two members of the 
atherinid subfamily Atherinopsinae, including the grunion, Leu- 
resthes tenuis. In this species, "spawning begins just after turning 
of tide during the lower (bright moon) series of high tides, but 
somewhat later than turn of tide during the higher (dark moon) 
series of high tides. Thus the eggs are always deposited near the 
same point on the beach profile so that after 2 weeks the lower 
series of high tides washes out the eggs deposited during the 
higher series, and vice versa. During the interim of low tides, the 
eggs are above tide level in moist sand 4 inches below the surface" 
(Harrington, 1959: 434-435, after Thompson and Thompson, 
1919; Clark, 1925). Grunion eggs presumably have a highly 
protective covering. It seems likely that more atheriniform fishes 
will be found with either delayed embryonic development or else 
deferred hatching (with viability of embryos sustained far beyond 
the usual incubation periods). The outer covering of the egg in 
many atheriniform fishes is highly protective. These reproductive 
features obviously could be advantageous to fishes such as 
cyprinodontoids, which generally exploit niches in ephemeral 
waters (Foster, 1967). 

Finally, it should be noted that Laale and McCallion (1968) 
experimentally induced developmental arrest in Brachydanio rerio, 



1971 PHALLOSTETHIDAE 23 

a cyprinid. Exposure to extracts from Brachydanio, frog, or chick 
embryos caused Brachydanio embryos at stages 17-18 to stop 
developing. Returned to buffered water, the embryos resumed 
normal development and hatched. Laale and McCallion suggested 
that the inhibitory factor might be a nuclease. 

Foster (1967) suggested that in cyprinodontoids the shift from 
expelling and fertilizing all of the ovulated eggs in one continuous 
spawning act to expelling and fertilizing them singly or in small 
batches greatly increased the amount of courtship behavior per 
fertilized egg and thereby the impact of sexual selection. The 
habit of expelling a few eggs at a time is also found among ather- 
inoids (see Breder and Rosen, 1966) and is apparently char- 
acteristic of phallostethoids (Villadolid and Manacop, 1934, for 
Gulaphallus mirabilis; Myers, 1935, for Plectrostethus palawanen- 
sis) , Horaichthys (Kulkarni, 1940), and Tomeurus (Myers, 1947: 
8-11; Breder and Rosen, 1966: 341-343). Whereas in many 
atheriniforms the tendency to deposit a few eggs at a time seems 
to have led to the evolution of prolonged courtship, in other lines 
it may have led to internal fertilization. Supposing females carry 
a fair number of eggs but lay only a few at a time, males that can 
impregnate the female and fertilize all of the eggs at once have 
an obvious selective advantage over males that can fertilize only 
a few eggs at a time. Even more to the point, there may be little 
to prevent the sperm from getting into the oviduct and fertilizing 
eggs retained inside the female. Thus, while fertilization normally 
is external in Oryzias, instances of O. latipes females with inter- 
nally fertilized eggs (developing embryos) do occur (Amemiya and 
Murayama, 1931). Oryzias evidently is ancestral to Horaichthys. 



24 



BREVIORA 



No. 374 



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1971 PHALLOSTETHIDAE 25 

LITERATURE CITED 

Amemiya. I., AND S. MuRAYAMA. 1931. Some remarks on the existence of 
developing embryos in the body of an oviparous cyprinodont, Oryzias 
{Aplocheiliis) latipes (Temminck et Schlegel). Proc. Imp. Acad. Japan 
(Tokyo), 7(4): 176-178. 

AuRiCH, H. 1937. Die Phallostethiden (Unterordnung Phallostethoidea 
Myers). Intnatl. Rev. Ges. Hydrobiol. Hydrogr., 34: 263-286. 

Bailey, R. J. 1936. The osteology and relationships of the phallostethoid 
fishes. J. Morph., 59(3): 453-483, 4 pis. 

Berg, L. S. 1940. Classification of fishes, both recent and fossil. Trav. 
Inst. Zool. Acad. Sci. URSS, 5: 87-517. 

Breder, C. M., and D. E. Rosen, 1966. Modes of Reproduction in Fishes. 
Garden City, New York, Nat. Hist. Press, xv + 941 pp. 

Duncker, G. 1904. Die Fische der Malayischen Halbinsel. Mitt. Naturh. 
Mus. Hamburg, 21: 135-207. 

Foster, N. R. 1967. Trends in the evolution of reproductive behavior 
in killifishes. Stud. Trop. Oceanogr. (Miami), 5: 549-566. 

Fowler, H. W. 1937. Zoological results of the third de Schauensee 
Siamese Expedition. Part VIII, — Fishes obtained in 1936. Prcc. 
Philadelphia Acad. Nat. Sci., 89: 125-308. 

Greenwood, P. H., D. E. Rosen, S. H. Weitzman, and G. S. Myers. 
1966. Phyletic studies of teleostean fishes, with a provisional classifi- 
cation of living forms. Bull. Amer. Mus. Nat. Hist., 131, art. 4: 

341-455. 

Harrington, R. W., Jr. 1959. Delayed hatching in stranded eggs of 
marsh killifish, Fimdulus confliientiis. Ecology, 40(3): 430-437. 

Herre, a. W. 1925. Two strange new fishes from Luzon. Philippine J. 

Sci., 27: 507-513, 2 pis. 
1926. Four new Philippine fishes. Philippine J. Sci. 31(4): 

533-543, 3 pis. 
1939. The senera of Phallostethidae. Proc. Biol. Soc. Wash- 



ington, 52: 139-144. 

1940. Manacopus, a new name for a genus of Phallosteth- 



idae. Copeia, 1940(2): 141. 

-. 1942. New and little known phallostethids, with keys to the 



genera and Philippine species. Stanford Ichth. Bull., 2(5): 137-156. 

HuBBS, C. L., AND L. C. HuBBS. 1945. Bilateral asymmetry and bilateral 
variation in fishes. Papers Michigan Acad. Sci. Arts Letters, 30: 
229-310, 1 pi. 



26 BREVIORA No. 374 

Jones, S. 1944. On the occurrence of diapause in the eggs of Indian 
cyprinodonts. Current Science (Bangalore), 13: 107-108. 

KuLKARNi, C. V. 1940. On the systematic position, structural modifica- 
tions, bionomics and development of a remarkable new family of 
cyprinodont fishes from the province of Bombay. Rec. Ind. Mus. Cal- 
cutta, 42: 379-423. 

Laale, H. W., and D. J. McCallion. 1968. Reversible developmental 
arrest in the embryo of the zebra-fish, Brachydanio rerio. J. Exp. Zool., 
167(1): 117-127, 3 pis. 

Myers, G. S. 1928. The systematic position of the phallostethid fishes, 
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1971 PHALLOSTETHIDAE 27 

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BREVIORA 



Miaseiiam of Comparative Zoology 

Cambridge, Mass. 15 June, 1971 Number 375 

STRUCTURAL HABITATS OF WEST INDIAN ANOLIS 
LIZARDS II. PUERTO RICAN UPLANDS 

Thomas W. and Amy Schoener^ 



Abstract. This paper reports differences in structural and climatic 
iiabitat between the commonest Anolis species of two upland localities — 
Maricao and El Verde — • in Puerto Rico. 

Five of the seven Anolis species recorded at Maricao were studied in 
detail: two- — cristatelhis and stratitlus — are major components of the 
warmer lowland fauna, and three — krugi, evcrmanni, and gundlachi — 
are representative of the cooler upland fauna. A. stratiihis and evermanni 
tended to occupy higher and thicker perches than the other species; krugi 
was found on especially thin perches and often on leaves. The trunk- 
crown species evermanni and stratiilus, of very different size, were virtually 
totally syntopic over the study area, while the trunk-ground species 
cristatelhis and gundlachi, of very similar size, were virtually allopatric. 
Similarities and differences in climatic habitat between the species reflected 
this microgeography: stratulus and evermanni were found in fairly similar 
situations, though the former tended to be in opener areas, while cristatellus 
and evermanni were confined to open and closed habitats, respectively. At 
El Verde the same species were studied, but the open-area species cristatel- 
his and stratulus were relatively rarer. Structural and climatic habitats 
paralleled those at Maricao, and the trunk-crown species were again more 
syntopic than the trunk-ground species. 

In a separate analysis, it is shown that the two trunk-crown species had 
significantly more collecting localities in common than did the two trunk- 
ground species. The grass-bush species pulchellus and krugi were inter- 
mediate in this respect. It is hypothesized that the greater body size 
difference of the often syntopic trunk-crown species may be an adaptation 
preventing food overlap, an adaptation which the nonsyntopic trunk-ground 
species neither have nor need. 



1 Biological Laboratories and Museum of Comparative Zoology, Harvard 
University, Cambridge, Mass. 02138. 



2 BREVIORA No. 375 

The possible evolution of climatic and size differences is discussed for 
the upland and lowland series. It is suggested that in the broken, drier 
forest often found in the lowlands, the trunk-crown species would occur in 
more shaded conditions on the average than would the trunk-ground species; 
whereas in the wetter, more continuous forests of middle and upper eleva- 
tions, the reverse situation would be true. Therefore, the trunk-crown 
species may have been predisposed for greater spatial overlap in advance of 
their coming together. That the lowland trunk-crown species should be 
smaller and less sexually dimorphic in size may be a result of greater aver- 
age overlap between it and the corresponding trunk-ground species: possibly 
the lower average vegetation height and the greater need to avoid desicca- 
tion makes separation by height more difficult in the opener vegetation of 
the lowlands. No evidence to support this latter speculation is found in 
this study, however. 

This is the second in a series of papers describing the structural 
habitats of some West Indian Anolis lizards. Rand (1964) has 
documented extensively differences between seven Puerto Rican 
species in their structural and chmatic habitats. Our study will 
also elucidate gross interspecific differences, but its primary pur- 
pose is to demonstrate how the size classes of each species studied 
are deployed over the vegetation, with respect both to others of 
the same species and to similarly sized lizards of other species. 
Its secondary purpose is to investigate the spatial relationship be- 
tween stratuliis and evermanni, two "trunk-crown" forms (after 
Rand and Williams, 1969; Williams and Rand, in preparation) 
of very different size and sexual dimorphism, occurring in differ- 
ent but overlapping climatic and geographic areas. 

FORMAT AND METHODS 

Data on the structural habitat were gathered in the way described 
previously (Schoener and Schoener, 1971): for each lizard seen 
in the area, the type of perch, perch height, and perch diameter 
were noted. In addition, when the sun was shining the lizard was 
scored as to whether it perched mostly in the sun or shade. Obser- 
vations during cloudy weather were lumped into a third chmatic 
category. As before, the two of us simultaneously canvassed an 
area in staggered fashion so as to minimize the possibility of miss- 
ing lizards. In addition, we were assisted during one afternoon at 
El Verde by E. E. Williams and W. P. Hall, III. 



1971 PUERTO RICAN ANOLIS 3 

Results are presented here in two ways: 1) standard, structural 
habitat tables are given for each area and lizard class of interest 
(Tables 3-7), and 2) the occurrence in sun, shade or clouds is 
given for each of the same classes (Table 2). 

In order to test for statistically significant differences in struc- 
tural and climatic habitat between the hzard classes, the multiway 
contingency approach used previously (Schoener, 1970; Schoener 
and Schoener, 1971) was again employed. This procedure deter- 
mines the strength of associations between the lizard classes and 
habitat variables while simultaneously taking into account possible 
associations between the habitat variables themselves. It is based 
on methods developed by Deming and Stephan (1940), Kullback 
(1959), and Bishop (1969), and is exposited for ecologists by 
Fienberg (1970); the appendix (page 18) outlines its particular 
application to our data. In addition, the appendix contains Tables 
9-11, indicating the statistical significance of the comparisons we 
make below. 

Our presentation begins with a description of the study sites 
and their anohne inhabitants, continues with a verbal summary of 
differences in habitat between the lizard classes, and terminates in 
a comparison of our results to previous ones and in a speculation 
on the evolution of size in relation to space for certain Puerto 
Rican anoles. 

THE SPECIES 

Ten species of Anolis are known from Puerto Rico (Table 1). 
These can be divided roughly into three groups on the basis of 
their climatic and correlated geographic ranges (Rand, 1964; Wil- 
liams, Rivero and Thomas, 1965; Heatwole et al., 1969; Web- 
ster, 1969). 

One group comprises those species which occur modally in rela- 
tively humid, dark vegetation at high, cool elevations. This group 
consists of 1 ) evermanni — a medium-large, green, trunk-crown 
species, relatively sexually dimorphic in size; 2) gundlachi — a 
medium-large, rust-brown, relatively dimorphic trunk-ground 
species; 3) krugi — a small, striped yellow and brown, relatively 
dimorphic grass-bush species; and 4) occultus — a very small, 
grey-white, relatively nondimorphic twig species. Two of the 
three species, evermanni and krugi, are also found at scattered wet 



4 BREVIORA No. 375 

lowland localities, probably in remnants of the nearly destroyed 
wet lowland forest. 

The second group occurs modally in more illuminated, drier 
forest at the warmer low to moderate elevations. This group 
consists of 1 ) stratulus — a small, grey-brown, relatively non- 
dimorphic trunk-crown species; 2) cristatelhis — a medium-large, 
brown, relatively dimorphic trunk-ground species; and 3) pulchel- 
lus — a small, striped yellow and brown, relatively dimorphic 
grass-bush species. This group is also widespread in the highly 
disturbed wet lowlands and overlaps the first most commonly at 
mesic to wet intermediate altitudes, such as the Maricao locality 
to be described below. Additionally, George Drewry (personal 
communication) has found cristatelhis predominating in high- 
altitude, mossy forest, most of which is above the altitudinal range 
of gundlachi. 

The third group is restricted to the arid southwestern lowlands 
in xeric vegetation. It consists of 1 ) cooki — a medium-large, 
grey-brown, relatively dimorphic trunk-ground species, occurring 
sympatrically with cristatelhis over much of its range; and 2) 
ponceiisis — a small, striped yellow and brown, grass-bush species 
of relatively moderate sexual dimorphism. Notice that in this 
group there is no trunk-crown representative. 

A final species, the nondimorphic green giant ciivieri, appears 
from museum records to be commonest at middle and upland ele- 
vations, with pockets of abundance in the wetter lowlands such as 
those along the north coast. 

LOCALITIES 

The study to be reported below concentrates on the three 
commonest mostly upland species — evennanni, gundlachi and 
knigi — and two of the three commonest widespread species — 
cristatelhis and stratulus. All five of these species were found in 
close proximity to one another in the Maricao Insular Forest, a 
preserve in the ''monadnock" region (Pico, 1950) of the Cordillera 
Central. Consequently, several adjacent study sites of varying 
shapes were marked ofl" in the preserve (altitude = 860-900 m, 
slightly less than 4 km due south of the town of Maricao), and 
the anoles were observed therein. We distinguished four such areas: 

1. Forest interior. This area was the most natural of the four 
studied. It contained forest of medium height and somewhat 



1971 PUERTO RICAN ANOLIS 5 

broken canopy, clinging to a 20-40° mountainside. The under- 
story in many places was quite sparse and easily traversed, but 
where the canopy had broken, tangled grasses and ferns obstructed 
passage. The commonest species seen in this area was gundlachi 
(Table 2). The two trunk-crown species, evermanni and stratuliis, 
were also common and appeared to be of nearly equal abundance. 
In addition, krugi, cristatelliis, and cuvieri occurred as "trace" 
species. We saw no occultus though they have been collected there 
(Williams, Rivero, and Thomas, 1965). 

2. Forest with cleared understory. This area was adjacent to 
the more undisturbed forest and consisted of a strip about 30-40 
feet wide that bounded an open, grassy parking area. Although 
the understory had apparently been cleared, nearly all the large 
trees were left standing and very little sun penetrated to the ground, 
which itself consisted mostly of bare mud. In this area, gundlachi 
was again the most abundantly seen species, followed by evermanni 
and stratuliis, again in nearly equal proportions. A few cristatellus 
were also seen at the edge of the area. 

3. Open forest. This area was less elongated than Area (2) 
and faced it from directly across the parking area. Trees were 
arrayed in an open, parklike fashion; some overlaid a 2-to-3-foot 
herbaceous understory while others grew among short grass. Much 
sun penetrated to the ground, in contrast to Area (2). The most 
abundant species seen here was cristatellus. Again, evermanni 
and stratulus occurred in strikingly similar proportions. A few 
gundlachi were seen along the border between this area and Area 
(1). In addition, a few krugi inhabited the understory where it 
had not been chopped away. 

4. Secondary road edge. This area comprised a strip about 
1 0-20 feet wide bordering Area ( 1 ) . The understory graded 
from a lawnlike growth to dense, tangled typical forest-margin 
vegetation. The area faced full sunlight during the morning hours, 
that time of day when the sun was most likely to be shining during 
the period of our study. Above the understory rose trees of varying 
heights, with 40- to 60-foot Cecropia emerging above the rest. 
This area showed the most equitable distribution of apparent abun- 
dances for the five species. A. stratulus was commonest, but gund- 
lachi and evermanni were also rather frequently observed. Less 
abundant but far from rare were cristatellus and krugi. 

Wc studied the Maricao area during the period June 23-26, 



6 BREVIORA No. 375 

1969. Weather throughout this time was mostly sunny during the 
morning, generally partly cloudy during midday, and somewhat 
rainy during the afternoon — on one occasion in the form of a 
severe thunderstorm. Rainfall at the nearby but lower town of 
Maricao averages 111 inches per year (Pico, 1950). 

To further elucidate the relationships between the upland species, 
a second, more humid area was investigated at El Verde in the 
Luquillo rainforest (340-440 m). The study sites were in parts 
of the forest that were and are still the subjects of intensive and 
extensive ecological investigation, including a study of its two 
commonest Anolis species by Turner, Gist, and Rowland (Odum, 
1965). The area is described in detail in various reports (Odum, 
1965; Kline, Jordan, and Drewry, 1967, 1968). In comparison 
to the Maricao forest, that at El Verde was considerably taller 
and of more continuous but still somewhat broken canopy; the 
understory was consequently sparser and there were frequent 
boulders strewn about the forest floor. Two study sites are dis- 
tinguished in Table 2. 

The first begins near the biological station and penetrates the 
interior of the forest along a trail that climbs upward, eventually 
terminating at an observation tower. Our records were all taken 
adjacent to the bottom third of the trail where the grade was 
closest to horizontal. This area was in coffee plantation until the 
early 1930's and had not reached climax but was still in middle 
succession at the time of our study (G. E. Drewry, personal com- 
munication). The second study site contained roadside secondary 
vegetation along the forest margin, very close to the first study area. 

In both study areas, gimdlachi was the species most frequently 
seen, although it appeared more dominant in the forest interior. 
The next most frequently encountered species was evermanni, rela- 
tively more abundant along the forest edge. Three other species, 
stratulus, knigi, and ciivieh, were rarely encountered in the forest 
interior; the first two were always observed in relatively open, 
sunny areas. The margin had, however, a more equitable distribu- 
tion of species: stratulus, cristatellus and krugi did not appear 
uncommon. One cuvieri was also seen. All the relative abundances 
given in Table 2 are, of course, apparent only — they represent 
what we saw and are therefore biased in favor of three species 
{gundlachi, cristatellus, and krugi) frequently occurring at or 
below eye level. 

Observations were made June 29 -July 1, 1969. Weather dur- 
ing this time was, in general, considerably overcast and rainy. 



1971 PUERTO RICAN ANOLIS 7 

the rain occurring intermittently at all times of the day. Even 
though we tried to avoid sunless periods, a heavy incidence of 
clouds is apparent in Table 2. Rainfall in the vicinity was esti- 
mated from the weekly tables in Kline, Jordan, and Drewry ( 1967, 
1968) as 189 inches per year from September 1964 through 
August 1966. 

RESULTS 

Differences between lizard classes. In the following discussion, 
all comparisons, unless otherwise stated, are statistically significant 
in the sense explained in the appendix. Each species dealt with is 
divided into two classes: 1) small individuals, comprising adult 
females, subadults, and juveniles, and 2) adult males. The great 
majority of the former class (85-100%) were too large to be 
labelled "juveniles." 

Maricao open areas (Tables 3, 4, 9). In order to compare spe- 
cies classes from relatively open areas with respect to their struc- 
tural and climatic habitats, observations from the "open forest" 
and "secondary road edge" were lumped together. Only the three 
commonest species of these areas — evermanni, stratulus and cris- 
tatellus — were treated statistically. 

Male evermanni perched higher than did all other groups and 
were significantly higher than all but male stratulus. The latter 
class occurred higher than small evermanni or cristatellus. Small- 
sized stratulus were higher than small evermanni and all cristatel- 
lus. Small evermanni perched higher than either male or small 
cristatellus. 

Male evermanni occurred on thicker perches than all other 
classes. Male stratulus were on thicker perches than all classes but 
male evermanni. Small evermanni were on thicker perches than 
small stratulus and small cristatellus. Male cristatellus occupied 
thicker perches than did small stratulus. 

Within each of the three species, males perched on both higher 
and thicker branches than did small-sized individuals. 

There were significant differences in the climatic habitats of 
stratulus males and the two classes of cristatellus (Table 2). The 
former occurred more often in the sun and less often in the shade 
than did either of the latter. There was also an overall tendency 
for male stratulus to be seen more often on cloudy days. Small 
stratulus too occurred more often in the sun than did either class 



8 BREVIORA No. 375 

of cristatellm and were seen less often in the shade and on cloudy 
days. Small-sized evermanni were observed more often in the 
shade and less often on cloudy days than were male stratulus; 
sunny observations were of about equal proportions in the two 
classes. Small evermanni were seen more frequently in the sun 
than male cristatellus and less frequently on cloudy days; the per- 
cent observations in the shade were nearly identical. Small ever- 
manni also occurred more frequently in sunny positions than did 
female cristatellus; the latter appeared more often during cloudy 
weather and, to a lesser extent, in the shade. No significant climatic 
differences were found between the classes of the same species. 

Maricao closed area (Tables 5, 6, 10). Observations for two 
study sites, the interior forest and the forest with cleared under- 
story, were lumped to compare the three most common species — 
gundlachi, evermanni and stratulus. 

There was no significant difference in perch height between male 
stratulus and male evermanni, the two uppermost classes of anoles. 
Male evermanni were, however, seen significantly higher than small 
stratulus or the classes of gundlachi. Male stratulus did not differ 
significantly in height from small evermanni but were observed 
higher than either class of gundlachi. Small evermanni were seen 
slightly higher than small stratulus and all gundlachi; small stratu- 
lus also occurred higher than did the classes of gundlachi. 

In perch diameter, male evermanni significantly exceeded all 
interspecific classes but male stratulus. Male stratulus, in turn, 
significantly exceeded all other interspecific classes but male gund- 
lachi. Small evermanni were next in perch diameter, occupying 
thicker perches than either class of gundlachi. Small stratulus and 
male gundlachi were similar in perch diameter, and the former 
occurred on thicker perches than small gundlachi. 

Once again, within the same species, the larger classes occurred 
on higher and thicker perches than did the smaller-sized classes. 

Compared to the other species, both classes of gundlachi 
strikingly avoided sunny places. Small gundlachi were found sig- 
nificantly more often in the shade or on cloudy days than any 
class of stratulus or evermanni. Male gundlachi were found more 
often in the shade than small stratulus, and more often in the 
shade and on cloudy days than either class of evermanni. As was 
the case for the more open area, small evermanni were found 
considerably more often in the shade and less often during cloudy 



1971 PUERTO RICAN ANOLIS 9 

weather than male stratidus; inside the forest, however, they were 
also seen slightly more often in the sun. In contrast to the opener 
areas, here small evermanni as well differed significantly in the 
above respects from small stratidus. No intraspecific comparisons 
were significant. 

El Verde (Tables 7, 11). Observations for the two areas dis- 
tinguished in Table 2 were combined to test structural habitat 
differences at El Verde. Only the two most abundant species, 
evermanni and gundlachi, were considered. 

As before, male and small evermanni were higher than either 
class of gundlachi. Male and small evermanni also occupied 
thicker perches than did small gundlachi. Male gundlachi, how- 
ever, were on greater-diametered perches than small evermanni 
and did not differ significantly from male evermanni in this respect, 
though the latter at Maricao occupied thicker perches. Intraspe- 
cifically, males once again were distributed over greater perch 
heights and diameters than small individuals. 

There were no significant climatic differences between the lizard 
classes — this is unsurprising because of the small sample size 
and preponderance of cloudy weather at El Verde. 

The common species at El Verde, evermanni and gundlachi, 
are similar in size and sexual dimorphism (Table 1) and appear 
to stagger their sizes in such a way as to overlap most small ever- 
manni and large gundlachi, with respect to both perch height and 
perch diameter. 

The situation becomes more complex where a third species, 
stratulus, is more abundant, as in the Maricao interior forest. The 
two species evermanni and gundlachi still maintain the same spatial 
relationship between their size classes. However, male stratulus 
are now inserted between male evermanni and small-sized ever- 
manni. They differ markedly from the former in size (Table 1) 
but are only slightly smaller than the latter. There is also rather 
strong overlap between small stratulus and small evermanni; the 
latter, however, average a good bit larger. Small stratulus also 
extensively overlap male gundlachi but are very different in size. 
They differ greatly in both perch height and diameter from the 
similarly sized small gundlachi. 

In the opener areas at Maricao, the situation is essentially the 
same for both diameter and height except that cristatellus virtually 
replaces gundlachi. Given that substitution, the only difference 



10 BREVIORA No. 375 

that appears to exist is a reversal in relative height of small stratii- 
liis and small evermanni. This reversal allows a more nearly per- 
fect staggering of sizes: now male stratulus are further from small- 
sized evermanni . All overlaps, of course, are further reduced by 
the existence of climatic differences between the niches of the 
species. 

It is important to point out that in many places in the lowlands 
evermanni is absent; there, presumably, cristatelliis and stratulus 
often stagger their sizes in much the same way as do evermanni 
and gundlachi. However, even if the classes of adult males over- 
lapped the most (see below), the two lowland species probably 
do not take very similar food since they are so different in size — 
in contrast to gundlachi and evermanni. Moreover, it is interesting 
to note that where stratulus and evermanni overlap extensively, as 
at Maricao, there is only a slightly greater tendency than at "pure" 
upland or lowland localities for similarly sized classes to overlap, 
as a result of the great difference in size between the two trunk- 
crown species. 

Because of their small sample size, classes of krugi were not 
tested against any other. However, if all observations for krugi 
from the three areas are lumped, and to these are added observa- 
tions made in high grass and other secondary growth near the mid- 
elevation town of Adjuntas, it is possible to compare large and 
small krugi in structural habitat. Table 8 shows that males of 
krugi occurred significantly higher and on thicker diameters than 
did small-sized lizards. However, even more striking was the 
much greater frequency of small krugi on leaves. This result is 
consistent with those for other species that occupy the leaf habitat 
in a major way: carolinensis on Bimini (Schoener, 1968) and 
grahami aquarum on Jamaica (Schoener and Schoener, 1971). 
No climatic difference was found between the two classes. 

Differences between habitat variables (Tables 9-11). In the 
Maricao open area the only significant height-diameter associations 
were those in which thinner perches tended to be high and thicker 
perches tended to be low. Fewer comparisons were significant in 
the interior forest at Maricao, but those that were showed a uni- 
formly opposite tendency. This could easily reflect our observa- 
tional bias: fewer lizards can be seen in the canopy when within 
the forest. The one significant interaction at El Verde was the 
same as those for the Maricao closed area. 



1971 PUERTO RICAN ANOLIS 11 

In the open area at Maricao, there was a tendency, when we 
combined male-evermanni perches with those of interspecific 
classes, for the highest perches to occur in the sun and the lowest 
in the shade, as would be expected from the physiognomy of the 
vegetation. A somewhat different result was true for the three 
significant interactions in the interior vegetation: high perches 
were more often used on cloudy days; the lowest perches were 
still more frequently found in the shade, however. At El Verde, 
the one significant interaction (for male evermanni vs. small gimd- 
lachi) was the same as those for the Maricao open area. 

There were no significant interactions at all between perch 
diameter and insolation in the Maricao closed area, and only one 
such interaction was significant for the Maricao open area. This 
was a tendency for the combined perches used by small stratulus 
and small cristatellus to be thinnest in the sun and thickest on 
cloudy days. At El Verde, in contrast, perches of male evermanni 
and male giindlachi were significantly thickest in the sun and thin- 
nest in the shade. The combined perches for male evermanni and 
male gimdlachi also were thinnest in the shade, but the thickest 
perches were used during cloudy weather. Both these interactions 
may again primarily represent the greater ease of seeing a lizard 
on the thin branches and twigs of the understory than on similarly 
sized branches belonging to the high canopy of the El Verde rain- 
forest. They could, however, also reflect real differences in utili- 
zation of the habitat by lizards: for example, during the rather 
brief sunny periods at El Verde, lizards may have moved onto 
broader surfaces to bask more effectively. 

CONCLUSION 

Although we have concentrated on differences between the size 
classes of the lizards at Maricao and El Verde, our results for 
species agree well with those reported by Rand (1964) in his 
pioneering study of the structural habitat of species from all areas 
of Puerto Rico. In that study Rand pointed out the size difference 
between the two trunk-crown species, stratulus and evermanni, 
and suggested that, because of their similarity in climatic habitat 
(as measured by body and air temperature, as well as shade vs. 
sun records), these two species should in general show a greater 
amount of spatial overlap than the trunk-ground or grass-bush 



12 BREVIORA No. 375 

species. Although in an area near the town of Maricao the few 
stratulus seen by Rand did not seem to overlap evermanni much 
in horizontal habitat, we have shown above that in our areas at 
the Maricao Insular Forest, the two species were quite syntopic 
and sometimes were of nearly identical apparent abundance (Table 
2). Thus we saw 62 evermanni and 66 stratulus in the forest in- 
terior, 20 evermanni and 17 stratulus in the forest with cleared 
understory, 70 evermanni and 72 stratulus in the open forest, and 
36 evermanni and 138 stratulus along the road edge. Even at 
our study site at El Verde, where evermanni was seen more fre- 
quently (67 evermanni and 7 stratulus in the interior and 31 
evermanni and 11 stratulus along the forest margin), stratulus was 
interspersed throughout evermanni's horizontal range, although in 
the interior it was seen only in fairly open places, such as on 
sunny spots along the trail, high on emergent trees, and on stream- 
side boulders. G. E. Drewry (personal communication) has, how- 
ever, seen stratulus more commonly than evermanni in the more 
closed, relatively less leafy canopy of certain other areas at El 
Verde. 

The extensive syntopy of the trunk-crown species is in striking 
contrast to the trunk-ground species we studied. For example, in 
the forest interior at Maricao we saw 243 gundlachi and 1 cristatel- 
lus. In the open forest at Maricao we saw 175 cristatellus and 8 
gundlachi. In the interior forest at El Verde we saw 243 gundlachi 
and cristatellus. All three of these areas were relatively equi- 
lateral in shape. In the more elongated, marginal areas we saw 
more equitable proportions of the two: 33 gundlachi and 6 cris- 
tatellus in the forest with cleared understory at Maricao, 50 gund- 
lachi and 25 cristatellus along the Maricao secondary road edge, 
and 51 gundlachi and 14 cristatellus along the edge locality of El 
Verde. At the second of these areas, where the numbers are closest 
to identity, we noted that along a strip about ten feet wide cris- 
tatellus and gundlachi were perching upon the same vegetation, 
although under different climatic conditions: cristatellus was espe- 
cially common during sunny days, whereas the majority of the 
gundlachi individuals were seen under overcast skies. Thus, even 
though there is spatial overlap of cristatellus and gundlachi in 
marginal areas, it is largely nonsynchronous. 

We can test differences in the relative abundances of trunk- 
ground vs. trunk-crown species by constructing 2x2 contingency 



1971 PUERTO RICAN ANOLIS 13 

tables and running chi-square or exact tests. If this is done for 
the six study areas, it is seen that the relative proportions of the 
two trunk-ground species are significantly different from those of 
the two trunk-crown species in the El Verde interior forest, 
Maricao interior forest, Maricao road edge, and Maricao open 
forest at the 1 percent level and in the Maricao forest with cleared 
understory at the 5 percent level. Only the ecomorphs in the El 
Verde forest margin show nonsignificant differences in propor- 
tions. In summary, we can conclude that at our study sites the 
trunk-ground species were practically allopatric, whereas the 
trunk-crown species overlapped broadly. 

There exists a second way in which the degree of horizontal 
spatial overlap between the species belonging to various habitat 
categories may be detected. Museum localities are usually dis- 
tinguished horizontally, that is, as points on a map. Therefore, we 
have Usted all the localities at which specimens of the six common 
Puerto Rican species from the Museum of Comparative Zoology 
(Harvard) and the University of Michigan Museum have been 
collected. There were 91 such localities for cristateUus and gund- 
lachi combined, and only 7 of these (7.7% ) were held in common 
between the two species. In contrast, 9 of 45 locahties (20%) 
were held in common between evermawu and stratiilus. This pro- 
portion was significantly different by a chi-squared test (P < 0.05). 
The grass-bush species, kriigi and pulchellus, were intermediate in 
this regard: 8 of 59 localities (13.6%) were held in common. 
This proportion did not differ significantly from trunk-crown or 
trunk-ground species. While the comparisons involve the error 
that not all species inhabiting a given locality will be taken by 
collectors, usually because of differential abundance and/or acces- 
sibility, that error should counteract the pattern brought out in 
this analysis. That is to say, because the two trunk-crown species 
are seen less often and are more difficult to capture, there is less 
likelihood of both being collected at any given locality than both 
trunk-ground forms. 

It therefore appears clear that the relatively great body-size 
difference between the trunk-crown species in Puerto Rico is 
associated with their relatively great spatial overlap. Presumably 
this size difference in part helps the species to avoid resource com- 
petition by being associated with and facilitating differences in the 
diet, especially with regard to prey size. However, while the asso- 
ciation is presumably adaptive, the mechanism whereby it came 



14 BREVIORA No. 375 

about is unclear. That is, did the species differ in size to begin 
with and so were able to overlap spatially when they came together 
to a great degree, or were the size differences largely evolved in 
response to a predisposition for spatial overlap in the trunk-crown 
forms? We can crystallize the relevant problems by asking three 
questions: 

1. (a) Why should any of the three structural habitat 
groups — trunk-crown, trunk-ground, and grass-bush — 
contains species which differ markedly in size? (b) Why 
should it be the trunk-crown group, and that only, which 
contains such species? There is thus an existence and 
uniqueness part to this question. 

2. Given that the trunk-crown species show the 
greatest size differential, why should the lowland dry- 
area form be the smaller, and the upland wet-area form 
be the larger? 

3. Why should the lowland trunk-crown species be 
much less sexually dimorphic in size than the upland 
species? 

We can gain some insight into the first question by ranking 
separately for upland and lowland forest the modal habitats of 
the three kinds of species on a darkness or humidity or coolness 
gradient (we assume the three to be highly correlated). In middle 
and upper elevation forest, such as that at El Verde and Maricao, 
the darkest vegetation is the understory, and the most exposed 
vegetation lies along margins and in the canopy. Therefore we 
would expect the trunk-ground species, which primarily inhabit 
the lowest layer of the forest, to be better adapted to dark, cool 
conditions than either the trunk-crown species — found largely 
in the canopy or somewhat lower — or the grass-bush species, 
found mostly along margins. However, the situation is different 
for the lowland forest. Much lowland forest in Puerto Rico, par- 
ticularly in the south, is and must have been for some time of 
xeric aspect. It is characteristic of such forest, as well as of much 
coastal woodland elsewhere, to have a relatively broken canopy, 
with much light penetrating to the understory and with the largest 
trees being often quite dispersed. The patchiness is intensified 
during the dry season by some but not all trees undergoing partial 
or complete leaf drop. The darkest places for an arboreal lizard 
in such veeetation are often associated with the largest trees, 



1971 PUERTO RICAN ANOLIS 15 

especially often within or directly under the crown. Although that 
fraction of the understory immediately beneath such trees will 
also usually be shaded, the average degree of shading of the under- 
story as a whole should be considerably less than in the humid 
forest of middle and upper elevations. The grass-bush habitat 
should be even less shaded. Consequently, the trunk-crown habi- 
tat should in the lowlands be on the average the darkest and cool- 
est; the trunk-ground habitat should be intermediate and the 
grass-bush habitat should be on the average the hottest and most 
illuminated, even though there are places in these latter two habi- 
tats as shaded as any in the crown and on the upper trunk. It 
also follows that within the lowland trunk-ground habitat, there 
should be a greater diversity of shade regimes than in the upland 
trunk-ground habitat. This implies that in the lowlands large 
adult males, which prefer thick perches, are more likely to find 
such perches shadier than the average small-diametered perch 
preferred by the females. This difference should scarcely exist for 
the upland species. Therefore, there should be a greater intersexual 
difference in climatic habitat for the lowland trunk-ground form 
than for the upland trunk-ground form. 

Matching species with structural habitat and combining the 
upland and lowland species into a single ranking, as would be 
appropriate for the many intermediate localities on the island, we 
should obtain from sunniest to shadiest: piilchelliis > cristatel- 
lus > stratulus >= evermanni = krugi > gundlachi. Notice 
that the trunk-ground and grass-bush species are widely separated, 
but that the trunk-crown species are adjacent. That is, the 
lowland trunk-crown species should occur in the darkest part 
of its habitat and the upland trunk-crown species in the sunniest 
part of its habitat. Consequently, there should be a great deal of 
spatial overlap in intermediate areas on the basis of climatic habi- 
tat alone. This means that much of the size difference could 
well have evolved as a necessary adjunct to climatic preferenda 
of the trunk-crown species, preferenda which have developed inde- 
pendently of one another as adaptations to the prevalent vegeta- 
tional structure. No such size difference need have evolved for 
the trunk-ground or grass-bush species, farther apart on the 
climatical spectrum. 

The temperature data of Rand (1964, fig. 4), particularly those 
for the air, fit for the most part the inequality stated above. Thus, 



16 BREVIORA No. 375 

among the primarily lowland species, pulchellus occurs at the 
warmest temperatures, cristatellus at cooler temperatures, (with 
great variance, perhaps because of intersexual differences) and 
stratulus the coolest. Almost identical to stratulus is evermanni, 
whereas gundlachi is about the same as evermanni and therefore 
warmer than predicted, possibly because the highest evermanni 
could not be sampled. Values for gundlachi fall below the bulk 
of the cristatellus observations. Air temperatures for krugi are 
somewhat higher than those for evermanni but markedly below 
the majority of the pulchellus observations. 

Rand (1964) also provides information on species within five 
locahties as to their degree of occurrence in shade. This again 
depicts stratulus and evermanni as differing little, while the other 
groups differ a good deal. Also shown is that cristatellus and 
stratulus can be fairly similar in their shade occurrences, though 
in all cases stratulus occupied the deeper shade. A. gundlachi and 
evermanni are, however, very different, the former being, of course, 
more often in shady positions. In the two localities where both 
krugi and pulchellus were found, they showed practically no over- 
lap in their shade occurrences. 

The climatic data we have gathered at Maricao, which are of 
a different sort than those presented by Rand, also support the 
greater similarity of the trunk-crown species in their climatic 
habitats than the trunk-ground forms. There is not even any 
consistent tendency for one or the other of stratulus or evermanni 
to be found more often in the sun among the Maricao localities, 
although evermanni, if any, appears commoner there. This may 
in part, of course, be an artifact of observation; at El Verde, as 
we judge from the few stratulus data, the situation appeared to 
be reversed. The two trunk-ground species cannot be compared 
in most places because one or the other is nearly absent, but along 
the secondary road edge, as mentioned, gundlachi was much more 
likely to be seen during cloudy weather. At El Verde, despite 
the preponderance of overcast skies, cristatellus were seen several 
times more frequently in the sun than gundlachi. 

A second aspect of the above scheme that can be checked from 
our data is the climatic relation between trunk-ground and trunk- 
crown forms. Although evermanni and gundlachi showed striking 
differences in the expected direction, stratulus and cristatellus did 
not. In fact, stratulus were seen significantly more often in the 



1971 PUERTO RICAN ANOLIS 17 

sun in the open area at Maricao (see above). Possibly this was 
an artifact of observation, but it is more likely that in the shade 
cristaielliis perches averaged warmer than did those of stratidus 
because of the more exposed nature of the vegetation on which 
it perched. But Heatwole (1968; Heatwole et ai, 1969) showed 
that individuals of stratidus and cristatellus in "an open park-like 
situation" at Rio Piedras did not differ significantly in their air 
or substrate temperatures. However, Heatwole et al. (1969) 
have found that even under apparently identical mean environ- 
mental temperatures, the body temperatures of stratulus average 
lower than those of cristatellus. Furthermore, cristatellus shows 
greater resistance to high temperatures and does not tolerate low 
ones as well as stratulus. 

Heatwole et al. conclude both from these physiological prop- 
erties and Rand's data that "although the two species have similar 
ecologies and distributions, in some cases coexisting under appar- 
ently identical conditions, there is a tendency for A. cristatellus to 
utilize the warmer (less shaded) habitats than A. stratulus." Their 
conclusion agrees well with the scheme we have outlined above. 

The second question posed above may be related to the relative 
degree of overlap between trunk-ground and trunk-crown forms 
in the two areas. If we could show that the lowland species are 
more likely to overlap spatially than the upland forms, then we 
could argue that the smaller size of stratulus may have evolved in 
part as a response to that overlap and thus served as a preadapta- 
tion for any further displacement that might have occurred between 
the trunk-crown species. Rand's structural habitat grids show 
practically no differences in percent overlap (62.5% vs. 61%) 
between the two species pairs. However, his data were from sev- 
eral localities and all size classes combined. Even if only adult 
males are considered and our data for particular locahties used, 
results are inconsistent: percent overlap for evermanni and gund- 
lachi is 35 percent in the forest interior at Maricao and 72 per- 
cent at El Verde, whereas that for stratulus and cristatellus is 30 
percent along the Maricao road and 50 percent in the Maricao 
open forest. It is possible that these results are artifacts of the 
greater difficulty of seeing a trunk-crown species in the canopy 
when within a continuous forest than when along a forest margin 
or in a very open area. That error would tend to minimize differ- 
ences between evermanni and gundlachi and is almost certainly 



18 BREVIORA No. 375 

in part responsible for the high overlap value at El Verde. One 
might argue, a priori, that because of the greater average height 
of rainforest such as that at El Verde, overlap between two spe- 
cies segregated mainly by height should be less than in drier forest. 
Furthermore, even though the species are physiologically adapted 
to different thermal environments, it is possible that in the dry 
lowlands the greater danger of desiccation forces cristatelliis and 
stratuliis together in shaded situations during a large portion of 
the day; in the uplands, however, no such problem need arise, 
and the more exposed species, in this case evermarmi, can occur 
in sunny or open places most of the day. This is perhaps the rea- 
son why less difference was found between the climatic habitats 
of cristatellus and stratuliis than between gnndlaclii and evermanni 
in our study. Any overlap between the first pair should be espe- 
cially severe for male cristatellus because they more frequently 
occupy the relatively large trees which stratulus inhabit. 

If the explanation above be correct, that is, had stratulus evolved 
small size in part to alleviate competition with male cristatellus, 
then the reduced sexual dimorphism of stratulus would automati- 
cally follow, since it is the male that would be displaced. 

ACKNOWLEDGMENTS 

We thank G. E. Drewry, A. S. Rand, T. P. Webster, and E. E. 
Williams for critical comments on the manuscript and S. D. Fien- 
berg for statistical advice. We also thank G. E. Drewry for his 
hospitality at the Puerto Rican Nuclear Center field station at 
El Verde and K. Horton for typing the tables photographed directly 
for this article. Rand, Webster and Williams were all in the field 
with us during some part of this study, and their previous experi- 
ence with the island greatly facilitated our work. In addition, 
Williams and W. P. Hall III contributed some observations to our 
data from El Verde. Research was partly supported by NFS 
grants GB 6944 and B 01 980 IX to E. E. Williams. 

STATISTICAL APPENDIX 

This appendix briefly reiterates the description of the statistical 
treatment of the structural and climatic habitat data given in detail 
elsewhere (Schoener and Schoener, 1971). Four variables — 
lizard class, climatic category, perch height and perch diameter — 
were used to set up 4-way contingency tables. For the lizard and 



1971 PUERTO RICAN ANOLIS 19 

climatic variables, two (the classes being compared) and three 
(sun, shade, and clouds) categories (levels), respectively, were 
used. For perch height and diameter, two levels each were chosen 
by separately determining the point of maximum difference in 
cumulative frequency between the distributions of the habitat 
variable for the two lizard classes being compared. Data were 
broken at this point, all observations less than or equal to that 
number being cast into one category and all greater than that 
number being cast into the other. Table 12 lists critical values 
for height and diameter groupings. As before, an iterative pro- 
cedure (Deming and Stephan, 1940; Bishop, 1969; Fienberg, 
1970) was used to fit the data to models containing all six 2-way 
interactions. One by one, interactions were dropped if differences 
between models were not significant at the 5 percent level accord- 
ing to difference in the log-likelihood ratio chi-square (Kullback, 
1959; Ku and Kullback, 1968). Results are summarized in 
Tables 9-1 1 . The following key applies to the numbers in the 
body of the table: 

1 — the interaction was significant every time it was tested in 
the removal procedure; 

2 — the interaction was significant at least at the termination 
of the procedure; 

3 — the interaction was significant when removed from the most 
inclusive model (with six interactions) but not at termination; 

4 — the interaction was significant sometime during the pro- 
cedure but not at the beginning or end; 

— the interaction was never significant. 
As can be seen, nearly all interactions could be labelled "0" or 
"l." There was no set of models for a particular 4-way table 
which never gave a x" value denoting a satisfactory fit of the model 
at the 5 percent level, regardless of what interactions were re- 
moved. Therefore we did not test for 3-way interactions. There 
were only three tables with zero margins. These could be, and 
therefore were, handled in the way given by Fienberg (1970). 

LITERATURE CITED 

Bishop, Y. M. M. 1969. Full contingency tables, logits, and split con- 
tingency tables. Biometrics, 25: 383-400. 

Deming, W. E., and F. F. Stephan. 1940. On a least squares adjustment 
of a sampled frequency table when the expected marginal totals are 
known. Ann. Math. Stat., 11: 427-444. 



20 BREVIORA No. 375 

FiENBERG, S. E. 1970. The analysis of multidimensional contingency 
tables. Ecology, 51: 419-433. 

Heatwole, H. 1968. Relationship of escape behavior and camouflage in 

anoline lizards. Copeia, 1968: 109-113. 
, T. Lin, E. Villalou, A. Muniz, and A. Matta. 1969. 

Some aspects of the thermal ecology of Puerto Rican anoline lizards. 

J. Herpetology, 3: 65-78. 

Kline, J. R., C. F. Jordan, and G. E. Drewry. 1967, 1968. The rain 
forest project annual reports. Puerto Rico Nuclear Center, Puerto Rico. 

Ku, H. H., and S. Kullback. 1968. Interactions in multi-dimensional 
contingency tables: an information theoretic approach. J. Res. Natl. 
Bur. Standards - Mathematical Sciences, 728: 159-199. 

Kullback, S. 1959. Information Theory and Statistics. Dover Publica- 
tions, New York. 

Odum, H. T. 1965. The rain forest project annual report FY-65. Puerto 
Rico Nuclear Center, Puerto Rico. 

Pico, R. 1950. The geographic regions of Puerto Rico. Univ. Puerto Rico 
Press. Rio Piedras, Puerto Rico. 256 pp. 

Rand, A. S. 1964. Ecological distribution in anoline lizards of Puerto 
Rico. Ecology, 45: 745-752. 

, and E. E. Williams, 1969. Anoles of La Palma: aspects of 

their ecological relationships. Breviora, No. 327: 1-19. 

Schoener, T. W. 1968. The Anolis lizards of Bimini: resource partition- 
ing in a complex fauna. Ecology, 49: 704-726. 

. 1969. Size patterns in West Indian Anolis lizards. I. Size 

and species diversity. Syst. Zool., 18: 386-401. 

1970. Nonsynchronous spatial overlap of lizards in 



patchy habitats. Ecology, 51: 408-418. 
, AND A. Schoener. 1971. Structural habitats of West 



Indian Anolis lizards. I. Lowland Jamaica. Breviora, No. 368: 1-53. 

Webster, T. P. 1969. Ecological observations on Anolis occult us Wil- 
liams and Rivero (Sauria, Iguanidae). Breviora, No. 312: 1-5. 

Williams. E. E.. and A. S. Rand. The structure of diversity in Anolis liz- 
ards, in prep. 

, J. A. RivERO, AND R. Thomas. 1965. A new anole 

(Sauria, Iguanidae) from Puerto Rico. Breviora, No. 231: 1-18. 



1971 PUERTO RICAN ANOLIS 21 



TABLES 



22 



BREVIORA 



No. 375 



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PUF.RTO RICAN ANOI.IS 



23 



Table 2. cliiratic and geographic occurrence of Puerto Rican anoles. 



Percent Occurrence 



Lizard Class 



Sun 



Shade Clouds 



Maricao, forest interior 



evermanni 


adult 
male 


everraanni 


small 


gundlachi 


adult 
male 


gundlachi 


small 


stratulus 


adult 
male 


stratulus 


small 


cristatellus 


adult 




male 


crista tellus 


small 


krugi 


adult 
male 


krugi 


small 


cuvieri 


large 


aricao, forest, clea 


evermanni 


adult 
male 


evermanni 


small 


gundlachi 


adult 
male 


gundlachi 


small 


stratulus 


adult 
male 


stratulus 


small 


cristatellus 


adult 




male 


cristatellus 


small 


krugi 


adult 
male 


I-.rugi 


small 


cuvieri 


large 



53.8 



11.5 



50.0 



28.6 




33.3 

9.1 



66.7 



16.7 

57.1 
25.0 

16.0 


18.2 



33.3 



Sun or Sample 
Shade Size 



34.6 



44 


.4 


22 


.2 


27.8 


17 


1 


34 


.3 


45.7 


15 


6 


32 


4 


48.0 


31 


8 


4 


5 


63.6 


31 


8 


13. 


6 


47.7 












100.0 



50.0 



83.3 

14.3 
75.0 

84.0 
66.7 

72.7 



5.6 
2.9 

4.0 


6.8 




26 

36 
70 

173 
22 

4 4 

1 


2 



1 



14 
8 

25 
6 

11 


6 







Percent 

Compo- 
sition 



6.9 

9.6 

18.7 

46.1 
5.9 

11.7 
0.3 



0.5 

0.3 

7.9 

18.4 
10.5 

32.9 
7.9 

14.5 
7.9 



24 






BREVIORA 






No. 375 




ass 




Percent 


Occurrence 




Sample 
Size 




Lizard CI 


Sun 


Shade 


Clouds 


Sun or 
Shade 


Percent 
Compo- 
sition 


Maricao, open 


forest 














evermanni 


adult 
male 


33.3 


28.6 


33.3 


4.8 


21 


6.2 


evermanni 


small 


44.9 


28.6 


20.4 


6.1 


49 


14.5 


gundlachi 


adult 
male 















gundlachi 


small 


12.5 


50.0 


25.0 


12.5 


8 


2.4 


stratulus 


adult 
male 


40.5 


8.1 


45.9 


5.4 


37 


11.0 


stratulus 


small 


22.9 


37.1 


37.1 


2.9 


35 


10.4 


crista tellus 


adult 
male 


22.0 


26.0 


50.0 


2.0 


50 


14.8 


cristatellus 


small 


22.4 


32.0 


41.6 


4.0 


125 


37.1 


krugi 


adult 
male 


28.6 


42.9 


28.6 





7 


2.1 


krugi 


small 





60.0 


40.0 





5 


1.5 


cuvieri 


large 















Maricao, secondary road 


edge 












evermanni 


adult 
male 


78.3 





21.7 





23 


8.3 


evermanni 


small 


69.2 


7.7 


23.1 





13 


4.7 


gundlachi 


adult 
male 


11.1 


27.8 


61.1 





18 


6.5 


gundlachi 


small 


15.6 


3.1 


78.1 


3.1 


32 


11.5 


stratulus 


adult 
male 


55.6 


7.4 


33.3 


3.7 


54 


19.4 


stratulus 


small 


59.5 


8.3 


31.0 


1.2 


84 


30.2 


cristatellus 


adult 
male 


33.3 


33.3 


16.7 


16.7 


6 


2.2 


cristatellus 


small 


36.8 


21.1 


31.6 


10.5 


19 


6.8 


krugi 


adult 
male 





25.0 


50.0 


25.0 


4 


1.4 


krugi 


small 


4.0 


16.0 


76.0 


4.0 


25 


9.0 


cuvieri 


large 















El Verde, interior 














evermanni 


adult 
male 


5.6 


33.3 


61.0 





18 


5.6 


evermanni 


small 


3.9 


27.6 


68.6 





51 


15.7 


gundlachi 


adult 
male 


7.1 


32.5 


59.8 


0.6 


169 


52.2 


gundlachi 


small 


5.4 


41.9 


52.7 





74 


22.8 



1971 PUERTO RICAN ANOLIS 25 



stratulus 


adult 
male 


100.0 











1 


0.3 


stratulus 


small 


33.3 


33.3 


33.3 





6 


1.9 


cristatellus 


adult 
male 















cristatellus 


small 















krugi 


adult 
male 


50.0 





50.0 





2 


0.6 


krugi 


small 








100.0 





4 


1.2 


cuvieri 


small 








100.0 





1 


0.3 


El Verde, edge 
















evermanni 


adult 
male 


46.2 


23.1 


30.8 





13 


9.5 


evermanni 


small 


27.8 


16.7 


55.6 





18 


13.1 


gundlachi 


adult 
male 


8.3 


36.1 


52.8 


2.8 


36 


26.3 


gundlachi 


small 


13.3 


26.7 


60.0 





15 


10.9 


stratulus 


adult 
male 


67.7 





33.3 





3 


2.2 


stratulus 


small 


37.5 


12.5 


37.5 





8 


5.8 


cristatellus 


adult 
male 


50.0 





50.0 





6 


4.4 


cristatellus 


small 


25.0 


25.0 


50.0 





8 


5.8 


krugi 


adult 
male 


16.7 


16.7 


66.7 





6 


4.4 


krugi 


small 


21.7 


26.1 


52.2 





23 


16.8 


cuvieri 


small 


100.0 











1 


0.7 



26 



BREVIORA 



No. 375 



Table 3. Maricao secondary road edge. Percent observations in 
various structural habitat categories. H = >20'; G = ground; R = 
rocks; N = sample size. 



^^^^iameter 
















Ht. ^-^in.) 
















(feet) ^-v,^^^ 


>5 


5-2 1/2 2 


1/4-7/8 


7/8-1/8 


le 


aves 


Total 


N = 54 


male 


stratulus H = 11 


G = R = 


• 






10.5-20 


4 


17 


4 










25 


5-10 


9 


17 


6 










32 


3-4 3/4 


9 


4 


4 










17 


<3 


9 


4 


4 










17 


Total 


31 


42 


18 












N = 84 


small 


stratulus 


H = 2 


G = R = 


= 






10.5-20 


4 


8 


7 


1 







20 


5-10 


4 


13 


13 


6 







36 


3-4 3/4 


2 


6 


5 


5 







18 


<3 


10 


6 


6 


1 




2 


23 


Total 


20 


33 


31 


13 




2 




N = 6 


male 


cristatellus 


H = 


G = R 


= 






10.5-20 






















5-10 






















3-4 3/4 


17 


17 













34 


<3 


33 


17 


17 










77 


Total 


50 


34 


17 












N = 19 


small 


cristatellus H = 


G = 11 


R = 







10.5-20 






















5-10 






















3-4 3/4 


5 
















5 


<3 


16 


26 


26 


16 







84 



Total 



21 



26 



26 



16 



97: 



PUERTO RICAN ANOLIS 



27 



N = 23 


male 


everinanni 


H 


= 4 


G = 


R = 







10.5-20 


22 


17 















39 


5-10 


9 


13 












4 


26 


3-4 3/4 


17 


















17 


<3 


13 


















13 


Total 


61 


30 

















N = 13 


small 


evermanni 


H 


= 


G = 


R = 







10.5-20 





8 















8 


5-10 





15 












8 


23 


3-4 3/4 


8 


















8 


<3 


46 


15 















61 


Total 


54 


38 












8 





Table 4. Maricao open forest. Percent observations in various 
structural habitat categories. H = >20'; G = ground; R = rocks; N = 
sample size. 



JDiameter 
Ht. ^\^(in.) 
(feet) 



>5 5-2 1/2 2 1/4-7/8 7/8-1/8 leaves Total 



N = 37 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 



male stratulus 


H 


= 


G = 


= 


R = 


= 




22 



















8 16 




11 






5 







3 3 











5 







5 19 




3 















22 

40 
11 
27 



14 



10 



N = 35 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 



small stratulus 


H = 





G = 


= 


R = 


= 




3 



















3 6 


19 






13 









9 


11 






9 









14 9 


6 

















3 

41 
29 
29 



26 



18 



36 



22 



28 



BREVIORA 



No. 375 



N = 50 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 

•M = 12 5 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 

N = 21 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 



male 


cristatellus 


H = 


= 


G 


= 6 


R = 


= 





6 

















4 


4 


10 






2 







8 





12 






2 







.20 


10 


7 






7 




2 



32 



20 



29 



11 



small 


crista 


te 


llus 


H = 





G = 


12 


R 


= 1 





2 
























2 






5 




2 









2 


2 






2 




3 






1 


11 


23 






16 




15 






2 



13 



29 



23 



20 



male 


evermanni 


H 


= 


G = 


= 10 


R = 







5 


19 




7 




2 









5 


5 




14 




5 









10 


5 



















14 























6 
20 
22 

46 



2 

9 

9 

67 



33 
29 
15 

14 



34 



29 



21 



N = 49 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 



small 


evermanni 


H = 


6 


G 


= 2 


R = 







2 


6 


2 






4 









4 


6 


12 






10. 












2 


4 
















16 


10 


8 






2 






2 



14 

32 

6 

38 



22 



24 



26 



16 



1971 



PUERTO RICAN ANOLIS 



29 



Table 5. Maricao forest with cleared understory. Percent 
observations in various structural habitat categories. H = >20' 
G = ground; R = rocks; N = sample size. 



^iameter 
Ht. ^^-.^^in.) 
(feet) 



>5 5-2 1/2 2 1/4-7/8 7/8-1/8 leaves Total 



N = 6 

10.5-20 
5-10 
3-4 3/4 
<3 

Total 



male 


stratulus 


H 


= 50 


G = 





R = 







17 

















17 


17 




























































17 

34 







N = 11 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 



small 


stratulus 


H 


= 





G = 





R = 







9 



















9 


18 




9 






9 






























18 


18 




9 















9 

45 



45 



27 



45 



N = 8 

10.5-20 
5-10 
3-4 3/4 
<3 

Total 



male gundlac 


hi 


H 


= 


G = 


= R = 



























12 






12 




25 







12 











12 














19 




6 









49 
24 
25 



24 



31 



43 



N = 25 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 



small gundlachi 


H = 





G = 


= 


R = 


= 
























4 4 


4 






4 









16 


8 






4 









4 12 


28 






12 











16 
28 
56 



32 



40 



20 



30 






BREVIORA 




No 


. 375 


N = 6 


male 


evermanni 


H = 


G = R = 






10.5-20 


17 













17 


34 


5-10 





33 




17 








50 


3-4 3/4 






















<3 





17 













17 


Total 


17 


50 




17 





17 




N = 14 


small 


evermanni 


H = 


G = 7 R = 






10.5-20 






















5-10 


7 


14 




14 








35 


3-4 3/4 






















<3 


36 


21 













57 


Total 


43 


35 




14 











Table 6. Maricao forest interior, 
various structural habitat categories, 
rocks; N = sample size. 



Percent observations in 
H = >20'; G = ground; R = 



^\Diameter 
Ht. ^\(in.) 
(feet) ^v^ 


>5 


5-2 1/2 


2 1/4-7/8 7/8-1/8 


leaves 


Total 


N = 22 


male 


stratulus 


H = 5 G = 


R = 









10.5-20 





32 


5 









37 


5-10 


5 


14 


7 11 






5 


42 


3-4 3/4 








9 









9 


<3 


5 


5 












10 


Total 


10 


51 


21 11 






5 




N = 44 


small 


stratulus 


H = 2 G = 2 


R 


= 






10.5-20 


2 


2 


2 2 






2 


10 


5-10 


5 


5 


16 11 






7 


44 


3-4 3/4 








2 2 









4 


<3 


2 


9 


20 2 






2 


35 



Total 



16 



40 



17 



11 



1971 



PUERTO RICAN ANOLIS 



31 



N 


= 70 




10.5-20 




5-10 




3-4 3/4 




<3 




Total 


N 


= 173 




10.5-20 




5-10 




3-4 3/4 




<3 




Total 


N 


= 26 




10.5-20 




5-10 




3-4 3/4 




<3 



Total 

N = 36 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 



male gundlachi 


H 


= 


G = 


1 R = 




















4 4 




6 




4 





1 11 




13 




7 


1 


9 11 




11 




13 


1 



14 



26 



small gundlachi 



1 1 
1 
3 9 



30 

H = 





5 

23 



G = 



24 

8 

3 
4 

29 



R = 1 







1 

11 



35 



24 



20 



4 11 




28 




36 




12 


male evermanni 


H 


= 8 


G = 


= R = 


= 




15 4 




8 












12 12 




12 




8 







8 














8 


8 



















18 
33 
45 




5 

11 
75 



27 
44 
16 



small 


evermanni 


H = 


3 


G 


= 3 


R = 










8 


11 



















6 


17 






14 






3 





3 


6 






3 






3 





6 


8 






8 










19 
40 
15 
24 



23 



42 



25 



32 



BREVIORA 



No. 375 



Table 7. El Verde. Percent observations in various structural 
habitat categories. H = >20'; G = ground; R = rocks; N = sample size. 



^^"'----.Diaineter 


















Ht.^^^in.) 


















(feet) ^^..^^ 


>5 


5-2 1/2 


2 1/4-7/0 


7/8-1/8 


leaves 


Total 


N = 205 


male 


gundlachi 


H = G = 2 


R = 


1 






10.5-20 





3 















3 


5-10 


15 


10 


12 


7 









44 


3-4 3/4 


8 


12 


9 


3 









32 


<3 


9 


4 


2 


1 









16 


Total 


32 


29 


23 


11 











N = 89 


small 


gundlachi 


H = G 


= 4 


R 


= 3 






10.5-20 
























5-10 





8 


8 


6 






1 


23 


3-4 3/4 


4 


5 


9 


10 









28 


<3 


6 


12 


9 


12 









39 


Total 


10 


25 


26 


28 






1 




N = 31 


male 


evermcinni 


H = G = 


= 3 


R = 









10.5-20 


6 





6 












12 


5-10 


16 


3 


10 


6 






3 


38 


3-4 3/4 


13 


3 


13 












29 


<3 


10 


3 


3 












16 


Total 


45 


9 


32 


6 






3 




N = 69 


small 


evermanni 


H = 1 G 


= 6 


R 


= 3 






10.5-20 


6 


1 





1 






1 


9 


5-10 


1 


4 


12 


9 






6 


32 


3-4 3/4 


4 


3 


3 


9 









19 


<3 


13 


9 


2 


4 









28 


Total 


24 


17 


17 


23 






7 





1971 



PUERTO RICAN ANOLIS 



33 



Table 8. A. krugi , all localities combined. Percent observa- 
tions in various structural habitat categories. H = >20'; G = ground; 
R = rocks; N = sample size. 



^iameter 
Ht. ^\(in.) 
(feet) 



>5 5-2 1/2 2 1/4-7/8 7/8-1/8 leaves Total 



N = 33 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 

N = 83 
10.5-20 
5-10 
3-4 3/4 
<3 

Total 



male krugi 
3 






H = G 



6 

12 

3 







R = 
3 
30 
6 

12 



21 



51 





15 

6 

3 



24 



small krugi 


H = 







G = 


4 


R = 






































1 


5 
















7 


16 









2 






11 


54 



6 
51 
24 
18 





6 

23 

67 



19 



75 



34 



BREVIORA 



No. 375 



w 

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to 

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tn 
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en 0) 
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0) 






ITS 





tn 









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0) 


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1971 



PUERTO RICAN ANOLIS 



35 



t( Cn Cm fc, 
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M 










w 


3 










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nj 


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nJ 


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w 


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36 



BREVIORA 



No. 375 



0) 

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1971 



PUERTO RICAN ANOLIS 



37 



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38 



BREVIORA 



No. 375 



Table 11. Statistical significance for El Verde." 



^^^^Group vs. 










Gro^i^^i^ht 










vs. ^""~\^ 


male 


small 


male 


small 


Diameter ^""^ 


evermanni 


evermanni 


gundlachi 


gundlachi 


male evermanni 




1 


2 


1 


small evermanni 


1* 




1* 


1 


male gundlachi 





1 




1 


small gundlachi 


1* 


1* 


1* 




^"^^^Group vs. 










Hei^h^-^°1^^^°'^ 










vs. ^"^-^^ 










diameter ^~^--^^^ 










male evermanni 













small evermanni 













male gundlachi 













small gundlachi 


1(A) 










^""--.^eight vs. 










^^^^insolaticn 










Diameter^^^^^ 










vs. ^^-^^^ 










insolation ^~^^ 


-^ 








male evermanni 










1(F) 


small evermanni 













male gundlachi 


1(K) 










small gundlachi 


2(L) 











" * = species at top has larger value; A = small diameters at low perches; 
F = highest in sun and lowest in shade; K =: thickest in sun and thinnest 
in shade; L r= thinnest in shade and thickest in clouds: for interpretation 
of numbers, see "Statistical appendix." 



1971 



PUERTO RICAN ANOLIS 



39 



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BREVIORA 

Mmseiuinii of Coiniiparative Zoology 

Cambridge, Mass. 15 June, 1971 Number 376 



Podocnemis venezuelensis, a new fossil pelomedusid (Tes- 
tudines, Pleurodira) from the Pliocene of Venezuela and 
a review of the history of Podocnemis in South America 

Roger Conant Wood^ 

and 

Maria Lourdes Diaz de Gamero- 

Abstract. Podocnemis venezuelensis, a new species of pelomedusid 
turtle from the mid-Pliocene (Huayquerian) of Venezuela is described. 
Present evidence is insufficient for determining whether it was a marine 
or a fresh water form. Previously described South American fossil species 
that have been attributed to Podocnemis are discussed. Of these, only 
two — P. bassleri and P. elegans — are surely referable to this genus. It 
is concluded that the fossil record of Podocnemis is not yet adequate for 
reconstructing its evolutionary history on this continent. 

Resumen. Se describe una nueva especie de tortuga pelomedusida 
del Plioceno medio (Huayqueriense) de Venezuela, Podocnemis venezu- 
elensis. Las presentes pruebas son insuficientes para determinar si fue de 
aguas marinas o de agua dulce. Se discuten las especies suramericanas 
fosiles que han sido atribuidas a Podocnemis. De estas, solo dos — P. bass- 
leri y P. elegans — son valederas. Se concluye que el registro fosil de 
este genero no es aiin adecuado para la reconstrucion de su historia evo- 
lutiva en este continente. 

INTRODUCTION 

Only one species of fossil turtle, Podocnemis geologorum 
(Simpson, 1943), has ever been formally described from Vene- 
zuela. Other occurrences of Venezuelan fossil chelonians have, 



1 Museum of Comparative Zoology, Harvard University. 

2 Escuela de Geologia y Minas, Universidad Central de Venezuela, 
Caracas. 



2 BREVIORA No. 376 

however, occasionally been mentioned: Swinton (1928) referred 
three specimens "too fragmentary for specific determination," of 
Pliocene or Pleistocene age (Van Frank, 1957: 22n), to "Testuclo 
sp."; and Royo y Gomez (1960) published a faunal list of fossil 
vertebrates discovered in what is now known as the upper member 
of the Urumaco Formation, that included ". . . varios capara- 
zones completos . . . de tortugas palustres (Podocnemys) . . . ." 
which he believed to be of mid-Miocene age. Unfortunately, the 
untimely death of Royo y Gomez in 1961 prevented his describing 
any of this material. The specimens, however, are preserved in 
the collections of the Universidad Central de Venezuela in Ca- 
racas. Except for one report on rodent remains (Pascual and Diaz 
de Gamero, 1969) and another on a new gavial (Sill, 1970), 
nothing has been published on them. The fossil turtles are de- 
scribed here. 

Abbreviations used in this paper are: 
AMNH — the American Museum of Natural History, New York 
MCN — Museo de Ciencias Naturales, Caracas 
VF — Laboratorio de Paleontologia, Escuela de Geologia de la 
Facultad de Ingeniera de la Universidad Central de Venezuela 
(Caracas). 

CLASSIFICATION AND DESCRIPTION 

Order Testudines 
Suborder Pleiirodira 
Family Peloiiiedusidae 

Genus Podocnemis 

A cautionary word is appropriate concerning the attribution of 
fossil material to Podocnemis. Most extinct species of this genus 
are known solely from shell material. However, at least one other 
fossil genus, Botliremys, has a shell that is virtually indistinguish- 
able from that of Podocnemis. In fact, two purported species of 
Podocnemis, P. barberi (Schmidt, 1940) and P. alabamae (Zan- 
gerl, 1948), were originally described on the basis of shell material 
that, upon the later discovery of associated skull material, has 
subsequently been referred to the genus Botliremys (GafTney and 
Zangerl, 1968). Conceivably, therefore, when skulls become 
known for some of the fossil species now referred to Podocnemis 



1971 NEW VENEZUELAN FOSSIL PELOMEDUSID 3 

on the basis of their shells, it may be necessary to transfer them 
elsewhere. The new species described in this paper is placed in 
Podocnemis with this caveat. 

Podocnemis venezuelensis sp. nov. 
(Figures 1-3 and Plates I-V ) 

Type. VF 1176, a complete carapace, slightly flattened, includ- 
ing much of the axial buttresses and the pelves, the latter badly 
damaged. Also, VF 1173, a fairly complete but badly fractured 
plastron lacking only the entoplastron and epiplastra. Although 
bearing a diff'erent number, the plastron is of an appropriate size 
and state of preservation so that we believe it highly probable 
that both of these shell elements are from the same individual 
(see Plate IV). Unfortunately, none of Royo y Gomez's notes 
contain information bearing on this point. 

Hypodigm. The type, and VF 1174, a plastron lacking the 
posterior lobe; VF 1175, the anterior one-third of a carapace; VF 
1177, a complete carapace and plastron, considerably flattened, 
of a relatively small individual; VF 1177a, a nearly complete 
carapace and plastron of the largest individual in the sample, 
lacking only the pygal and posterior portions of both eleventh 
peripherals; VF 1177b, the left epiplastron, hyoplastron, and left 
one-half of the entoplastron, plus several pleurals attached to part 
of the bridge, probably all belonging to the same individual; VF 
1059, the distal end of a right humerus. 

Horizon and locality. The "capa de huesos" or "capa de tor- 
tugas" (Pascual and Diaz de Gamero, 1969: 373 and map) of 
the upper member of the Urumaco Formation, probably of mid- 
Pliocene (Huayquerian) age, north of Campo El Mamon, state 
of Falcon, Venezuela. 

The Uramaco Formation is divided into three members, desig- 
nated as lower, middle, and upper. The lower and middle mem- 
bers are largely, if not entirely, of marine origin while the upper 
member apparently includes both littoral or deltaic as well as more 
strictly terrestrial facies. Marine molluscs from the middle mem- 
ber were the basis for the original age determination of mid- 
Miocene for this formation. This was subsequently revised to late 
Miocene. However, the recent study of Pascual and Diaz de 
Gamero (1969: 379) indicates that at least the "bone bed" of 
the uppermost part of the upper member is probably of middle 



BREVIORA 



No. 376 




Figure. 1 Reconstruction of the shell of Podocnemis venezuelensis 
(dorsal view). The scale represents a length of 15 centimeters. The posi- 
tions of the axial and inguinal buttresses as well as of the iliac scars of 
the pelvis on the visceral surface of the carapace are indicated by the 
broken lines. 



1971 



NEW VENEZUELAN FOSSIL PELOMEDUSID 




Figure 2. Reconstruction of the shell of Podocnemis veneziielensis 
(ventral view). Same scale as in Fig. 1. The positions of the pelvic scars 
on the visceral surface of the plastron are indicated by the broken lines. 



6 BREVIORA No. 376 

Pliocene (Huayquerian) age. Palynological evidence appears to 
confirm this date (A. E. Gonzalez Guzman, personal communica- 
tion). It is possible that there may be a temporal hiatus between 
the middle and upper members of the Urumaco Formation that 
cannot be detected structurally; an explanation of this nature 
would account for the different age determinations of the middle 
and upper members of the Urumaco Formation. 

Diagnosis. Differs from all other species of Podocnemis in 
totally lacking neural bones. 

Description. It is unfortunate that a gypsiferous encrustation 
on the external surfaces of all of the specimens obscures most of 
the bone sutures and virtually all scute sulci. Nevertheless, an 
essentially complete osteological description of the shell is possible 
from examination of the visceral surfaces of the type and some 
other, less complete specimens. Although the outlines of any par- 
ticular bone may differ somewhat from the external to the internal 
surface of the shell, as Dacque (1912: 290 and fig. 7) has demon- 
strated, it is nonetheless possible to make a reasonable reconstruc- 
tion of the shell of a typical representative of the species (see 
Figures 1 and 2 ) . 

Adult specimens of Podocnemis venezuelensis attained a rather 
large size. The three complete carapaces in our sample range 
from approximately 46 to 67 centimeters' in length. Of the eight 
living species of Podocnemis, only two, P. expansa and P. unifilis, 
are reported to reach a larger maximum size. 

In cross section, the arch of the carapace is very flat; in outline 
it is somewhat oval and greatly expanded posteriorly. The external 
surface of the carapace is completely smooth. No significant in- 
dentation occurs in the nuchal region. Well-developed axial and 
inguinal buttresses unite the carapace to the plastron. The plastron 
itself is essentially flat and of nearly uniform thickness throughout. 

The outstanding feature of the carapace, and indeed the char- 
acter permitting definition of a new species, is the complete ab- 
sence of neural bones. Otherwise, the carapace is typical of other 
South American representatives of the genus. The nuchal bone 
is roughly pentagonal and slightly broader than long in its maxi- 
mum dimensions; its postero-lateral borders are bowed outwards 



1 The larger number represents the estimated total length of VF 11 77a; 
its actual midline length as preserved is 60.1 centimeters. 



1971 



NEW VENEZUELAN FOSSIL PELOMEDUSID 



slightly. There is no indentation at the midline of the anterior 
margin. The eight pairs of pleurals meet in the midline. As in 
all pelomedusids, there are eleven pairs of peripherals. The pygal 
is trapezoidal and the suprapygal is roughly subtriangular. But- 
tresses of the axial and inguinal notches are attached to the under- 
sides of the first and fifth pleurals respectively. The iliac scars of 
the pelvis are situated on the visceral surfaces of the seventh and 
eighth pair of pleurals. 

Of the three elements of the plastron, the bridge is the longest 
while the anterior lobe is the shortest. The anterior plastral lobe 
is U-shaped and does not extend beyond the anterior lip of the 
carapace. The lateral margins of the posterior lobe are straight 
rather than curved and are inclined medially so that the posterior 
lobe becomes narrower toward the rear. The entoplastron is 
diamond-shaped and has a slight U-shaped ridge with the open 
end facing anteriorly on its visceral surface; this is presumably 
for the attachment of neck muscles. At the midline junction of the 
epiplastra there is a pronounced protuberance on the visceral side. 
The mesoplastra are subrounded to hexagonal elements situated 




^ 



^ 



Figure 3. The shape of the anal notch in three specimens of Podocnemis 
veneziielensis (from left to right, VF 1177, VF 1173 and VF 1177a). The 
arrow points toward the anterior end of the shell. The scale represents 
a length of 10 centimeters. 



8 BREVIORA No. 376 

laterally at the base of the bridge. (These can best be observed 
on the internal surface of VF 1174; see Plate V.) There is some 
variation in the shape of the anal notch; in the smallest specimen, 
VF 1 177, it is V-shaped, but in the two larger examples, VF 1 173 
and VF 11 77a, it is broader at its base and thus tends to be more 
U-shaped (Fig. 3). This structural difference may be due to sexual 
dimorphism. If so, however, it is not possible to specify which 
type represents the males and which the females in this species. 
Normally, male turtles can be distinguished from females by the 
characteristic depression on the posterior lobe of their plastrons, 
but it is not possible to determine whether or not these existed in 
the present sample because, in the course of fossilization, all the 
plastra have been somewhat depressed inward along the midline. 
Size alone is not a useful criterion for identifying the sexes in 
Podocneinis. In all but one of the living South American species 
of this genus mature females are invariably larger than males. The 
reverse is true, however, for P. dumeriliana (F. Medem, personal 
communication ) . Nor does the shape of the anal notch necessarily 
provide a reliable method of sex determination. Although in at 
least one species, P. lewyana, males can be identified solely on 
the basis of this character, there are other species (e.g., P. vogli) 
in which the two sexes appear to have similarly shaped anal 
notches, while in still others (e.g., P. unifilis) the shape of the 
anal notch varies considerably but evidently also randomly with 
respect to sex. 

Pelvic scars on the plastron appear to be disposed in essentially 
the same positions as in the living South American species. 
Although partial pelves have been preserved in several of the 
specimens (VF 1173, 1176, 1177, and perhaps also 1177a), none 
of these are well enough preserved to describe in detail. 

The distal half of a right humerus (VF 1059) is all that is 
known of the appendicular skeleton. Nothing serves to distinguish 
this limb fragment from comparable portions of this same bone 
in other species of Podocnemis. 

Virtually no scute sulci can be detected in any of the specimens 
available for study. This is disappointing because their arrange- 
ment, particularly on the anterior plastral lobe, is sometimes of 
taxonomic sianificance. 



1971 NEW VENEZUELAN FOSSIL PELOMEDUSID 9 

DISCUSSION 

Taxonomic considerations. Within the suborder Pleurodira, 
the presence or absence of neural bones has been accorded vary- 
ing taxonomic significance. Those chelyid species that do possess 
neurals usually have a variable number, and in certain species of 
this family neurals evidently may or may not be present in diff"erent 
individuals of the same population. Consequently, whether or 
not a chelyid carapace includes some neurals, and if so, how many, 
has never been considered a useful taxonomic character ^ Most 
pelomedusid species, however, have a neural series that does not 
deviate from a modal number (usually 6-8) by more than one 
or, occasionally, two. Only two exceptions to this typical condition 
are known within the family, both involving extinct taxa from the 
Eocene of Tunisia-. Gajsachelys (de Stefano, 1903; Bergounioux, 
1952; 1955; 1956), hke some chelyids, appears to have had a 
rather variable number of irregularly shaped neurals. Eusarkia 
(Bergounioux, 1952; 1956), described on the basis of a single 
specimen, has no neurals and on the basis of this and several other 
characters noted by Bergounioux we believe that it was probably 
appropriate to propose a new genus. But in no case has the 
absence of neurals alone been used as a taxonomic character, 
either at the generic or the specific level, within the Pleurodira 
(or among any other chelonians for that matter). 

Why, then, have we described the Urumaco fossil pelomedusids 
as a new species of Podocnemis? In view of their strong overall 
resemblance to the living South American species of this genus 
it seems inappropriate to propose a new genus on the basis of a 
single character which, by itself, is not highly unusual nor of 
particularly great taxonomic significance among other members 
of the suborder. On the other hand, since the absence of neurals 
is clearly a constant character within the Venezuelan sample, this 



1 No adequate osteological descriptions of any living chelyid species 
have ever been published, so that reliable data are not actually available 
regarding the extent of intraspecific variation in the number of neurals. 

-One of us (RCW) is preparing a discussion of the taxonomic status 
of the Tunisian fossil turtles for publication elsewhere. In this paper 
Euclastochelys (Bergounioux, 1955; 1956) is considered to be synonymous 
with Gajsachelys. 



10 BREVIORA No. 376 

feature can hardly be regarded as an aberrant condition of no 
taxonomic consequence. Thus, by a process of elimination, the 
only alternative is to choose a procedure intermediate between 
regarding the lack of neurals as of enormous taxonomic impor- 
tance or as of none at all and describe the Venezuelan material 
as a new species. 

Ecological considerations. The small vertebrate fauna with 
which Podocnemis veneziielensis is associated (Royo y Gomez, 
1960: 509; Pascual and Diaz de Gamero, 1969: 370 and 374) 
is not adequate for determining with any degree of certainty what 
the probable habitat of this species might have been. The mam- 
mals — a eumegamyine rodent and a toxodontid — were un- 
doubtedly strictly terrestrial forms, while the crocodilians pre- 
sumably spent most of their time in streams, lakes, or swamps. 
The fish — sharks, sawfish, rays, catfish, and an unidentified 
teleost — appear to be a mixture of marine and fresh water forms. 
If all these fossils were collected from a single horizon, as the 
scanty field evidence would suggest, then the stratum in which 
they occur must represent an estuarine facies. On the basis of 
present evidence, therefore, it is impossible to determine unequiv- 
ocally whether P. veneziielensis was a marine or a fresh water 
form. To be able to do so would be particularly interesting be- 
cause, while all living pelomedusids are inhabitants of fresh waters, 
in the past some were marine and others were fresh water forms 
(Wood, MS). If P. veneziielensis were, in fact, marine, it would 
be the last recorded pelomedusid so adapted. 

No hving species of Podocnemis (or any other fresh water 
turtle) are found in the Maracaibo basin, in which the type local- 
ity of P. veneziielensis lies, although they are common to the 
south and east of this enclave in Venezuela as well as to the west 
of it in Colombia. Thus, P. veneziielensis occurs outside the pres- 
ent range of the genus. Should P. veneziielensis eventually prove 
to be a fresh water rather than a marine form, its extinction may 
be explicable in terms of the Pleistocene climatic history of tropical 
South America. The Maracaibo basin is ringed by mountains 
except on its seaward side and hence is effectively isolated from 
adjacent land areas. Conceivably, a period or periods of aridity 
during the Pleistocene (and evidence for severe climatic fluctua- 
tions in the tropics during this epoch is accumulating — cf . Van- 
zolini and Williams, 1970: 94-103) may have eliminated P. 



1971 NEW VENEZUELAN FOSSIL PELOMEDUSID 11 

venezuelensis, a form presumably endemic to the basin, while the 
surrounding mountain barrier prevented subsequent recolonization 
by other species. 

The fossil record of Podocnemis in South America. Few fossil 
species of Podocnemis have been described from this continent 
and several of these are known from such inadequate material 
that it is questionable whether or not they should be referred to 
the genus. 

As previously noted, Simpson (1943) has described a partial 
carapace and plastron from Venezuela as Podocnemis geolo- 
gorum^. The single known specimen was recovered from fluvia- 
tile beds of Miocene age. Without a doubt, this fossil represents 
some kind of pleurodire because of the union of its pelvis with 
both carapace and plastron. Whether this specimen actually rep- 
resents a pelomedusid instead of a chelyid, however, is not entirely 
clear. Although Simpson (1943: 57) commented "Es muy po- 
sible la existencia en esta especie de un mesoplastron tipo Podoc- 
nemis de buen tamafio," the presence or absence of this pair of 
bones, the critical character for distinguishing members of one 
pleurodiran family from the other, cannot be determined. Very 
few potentially useful taxonomic characters can, in fact, be dis- 
cerned. On the carapace, only two pleurals separate the last 
neural from the suprapygal. There appears to be a deep indenta- 
tion in the posterior edge of the pygal at the midline, and this, 
together with similar but not quite so pronounced indentations 
in the tenth and eleventh peripherals, gives the rear margin of 
the carapace a serrated appearance. Whereas the last vertebral 
was broader than long, the two preceding ones were longer than 
broad. The anal notch of the plastron is rather deep and narrow, 
and the lateral margins of the posterior lobe are sinuous. As a 
consequence, the xiphiplastral tips are much more elongate than 
in any other taxon yet described as a pelomedusid. Simpson 
(1943: 61) considered the deep anal notch and serrations along 
the posterior border of the carapace to be the species-specific 
characters of P. geologorum, and indeed, these are quite distinctive 
and indicate the validity of the species. Unfortunately, however, 



1 When Simpson described the type of P. geologorum. it was catalogued 
as AMNH 6781. It now belongs to the collections of the Museo de Ciencias 
Naturales, Caracas, and bears the number MCN 915. 



12 BREVIORA No. 376 

on the basis of present evidence there is no reason to believe that 
P. geologorum is really a species of Podocnemis or, for that mat- 
ter, of any pelomedusid. It cannot yet be confidently allocated to 
either of the two pleurodiran families to which it must belong, 
the Chelyidae or the Pelomedusidae. Thus, until better material 
of this taxon becomes available, P. geologorum should be listed 
as Pleurodira incertae sedis. 

Three species of Podocnemis — P. harrisi (Pacheco, 1913), P. 
brasiliensis (Staesche, 1937)\ and P. elegans (Suarez, 1969) — 
have been described from three widely separated localities within 
the Bauri'i Formation of southern Brazil. These sediments repre- 
sent terrestrial deposition, with fluvial and alluvial plain beds 
predominating, and are probably of late Cretaceous (Senonian) 
age (Oliveira, 1956: 53-54). The only specimens ever referred 
to P. harrisi were a nearly complete right xiphiplastron and sev- 
eral peripherals (Pacheco, 1913: 37, pi. 3 [figs. 6a-e], pi. 4 
[fig. 6]). Ischial and pubic scars on the visceral surface of the 
xiphiplastron clearly indicate that some kind of pleurodire is rep- 
resented, but no other taxonomically useful evidence exists. It 
is therefore impossible to determine whether P. harrisi is a chelyid 
or a pelomedusid. Reference of this species to Podocnemis was 
unjustifiable, as Schmidt noted long ago (1931: 253). Further- 
more, since the type material is now apparently lost (Price, 1953: 
10), "P. harrisi" must be regarded as a nomen vanum. 

On the basis of some photographs of a partial plastron, a car- 
apace fragment-, and three associated pleurals, Staesche (1937) 
described P. brasiliensis. The xiphiplastra of this species do not 
appear to dift'er in any appreciable way from those of P. harrisi, 
and therefore Simpson (1943: 61) may well have been correct 
in suggesting that P. brasiliensis is a synonym of P. harrisi, 
although Staesche (1937: 302-303) noted that his material dif- 
fered in that it represented a somewhat larger individual with a 
difl'erent kind of sculpturing on the external surface of the shell, 
factors which might or might not be of taxonomic significance. 

1 Staesche (1944) is merely a translation of Staesche (1937) from 
German into Portuguese. 

-This carapace fragment, together with a previously undescribed ante- 
rior lobe of a plastron from the same locality, was subsequently referred 
to a new genus and species, Roxochelys wanderleyi, by Price (1953). 



1971 NEW VENEZUELAN FOSSIL PELOMEDUSID 13 

Small, laterally placed mesoplastra were present, even though no 
longer preserved, so that P. brasiiiensis is clearly a pelomedusid. 
An appropriate generic determination cannot at present be made, 
however, because much of the anterior plastral lobe, so critical 
for pelomedusid shell taxonomy, is missing. Thus, the specimen 
can neither be certainly referred to Podocnemis nor, owing it its 
imperfect preservation, can any species-specific characters be 
established. Until better material is available, therefore, the plas- 
tron and pleurals to which the name P. brasiiiensis now applies 
should be designated as Pelomedusidae gen. et sp. indet. {"Podoc- 
nemis brasiiiensis" Staesche). 

Unlike the other two dubious "species" of Podocnemis from the 
Baurii Formation, P. elegans is clearly valid and referable to this 
genus. It is the only South American fossil pelomedusid yet 
described for which associated shells and skulls have been re- 
covered. Furthermore, it is the oldest representative of Podoc- 
nemis known anywhere. It was described on the basis of two 
specimens, an essentially complete shell and a well-preserved skull 
belonging to a different individual. A detailed description of this 
species will not be presented here since an account, based on addi- 
tional new material as well as the original hypodigm, is being pre- 
pared by one of us (RCW) for separate publication. Some of the 
salient characters may be briefly noted, however. In most respects 
the shell is typical of all South American species of Podocnemis, 
but the shapes of the first two neurals are unique: instead of being 
spindle-shaped, the first is hexagonal, with the postero-lateral sides 
much shorter than the antero-lateral ones; and the second, rather 
than being hexagonal, is subrectangular. A unique feature of the 
skull is the total absence of triturating ridges on the palatal surface 
of the upper jaw. All other species have from one to three triturat- 
ing ridges, the exact number being characteristic of different spe- 
cies. In addition, there does not seem to be an antero-posterior 



1 Suarez (1969: 37) stated: "Designamos como tipo da nova especie a 
carapaca e plastrao com craneo e diversos elementos esqueletais . . ." 
The shell and skeletal elements belong to one individual and there is in 
fact a badly crushed skull (which was not illustrated or discussed) asso- 
ciated with them, but it is not the skull described by Suarez. This is an 
isolated one from a much larger individual. Both specimens are in the 
paleontological collections of the Faculdade de Filosofia. Ciencias e Letras 
de Presidente Prudente: they bear no catalog numbers. 



14 BREVIORA No. 376 

forehead groove between the orbits. Of the other South American 
species of Podocnemis, only P. dumeriliana lacks this groove. 
Perhaps the most extraordinary aspect of the skull of P. elegans 
is its modern appearance; archaic or ancestral features that one 
might expect to find in such an ancient species are notably lacking. 
Cattoi and Freiberg (1958) described Podocnemis argentinensis 
from the Santa Barbara Formation^ in the Province of Jujuy, 
Argentina. It is known from a large part of a plastron, lacking 
the terminal portions of the anterior and posterior lobes as well 
as much of the bridges, and most of the right epiplastron of a 
second individual. The systematic position of this form is uncer- 
tain. Laterally placed mesoplastra were definitely present, as 
evidenced by the semicircular excavations on either side of the 
plastron at the base of the bridge, so that argentinensis clearly 
represents some kind of pelomedusid. Too little of the shell has 
been preserved, however, to permit assignment to Podocnemis 
with any degree of confidence. At a lower taxonomic level, the 
characters used to define the species are in some cases questionable 
and in others of little or no taxonomic significance. Cattoi and 
Freiberg described the entoplastron as cordiform, but in their 
figure and plate it appears to be quadrangular. Examination of 
the specimen itself indicates that the entoplastron is slightly dam- 
aged anteriorly and that it was probably diamond-shaped orig- 
inally. Small, triangular gular scutes are characteristic of most 
pelomedusids, but the relatively small intergular, which was prob- 
ably pentagonal, is certainly reminiscent of the condition typical 
of South American species of Podocnemis and the North American 
Bothremys (Gaftney and Zangerl, 1968). The various scute pro- 
portions cited by Cattoi and Freiberg in their diagnosis yield no 
useful taxonomic information. Anastomosing vermiculations cover 
the external plastral surface as in the majority of pelomedusid 



1 Various ages have been assigned to this stratigraphic unit, formerly 
referred to as the Margas Multicolores. Cattoi and Freiberg placed it in 
the late Cretaceous, while Bardack (1961) considered it to be middle 
Tertiary. The recent discovery of a mammal skull high in the formation 
indicates a Paleocene or early Eocene age (R. Pascual, personal com- 
munication). There is some uncertainty as to whether these beds are of 
marine or terrestrial origin (Cattoi and Freiberg, 1958: 59). 



1971 NEW VENEZUELAN FOSSIL PELOMEDUSID 15 

genera'. Until better material becomes available, it will not be 
possible to determine the systematic position of this turtle. In 
the meantime, it must be referred to as Pelomedusidae gen. et sp. 
indet. {'Podocnemis argentinensis" Cattoi and Freiberg). 

The type and only specimen of Podocnemis bassleri (Williams, 
1956) is a large, exceedingly well-preserved skull. It was collected 
in eastern Peru from beds of the Contamana Group, which in- 
cludes sediments believed to range in age from Eocene to possibly 
at late as Pliocene. Williams, on the basis of information supplied 
by Kummel, reported that the skull "came from the uppermost 
part of the . . . group," which suggests that its age falls within 
the latter part of the Tertiary. He further remarked that "The 
fossil itself is so close to a Recent species as to tend to support 
the latest date geologically permissible." The skull differs only 
in minor details from that of the living P. expansa. It seems fairly 
certain that P. bassleri was closely related, if not directly ancestral, 
to this species. 

Unfortunately, the evolutionary history of Podocnemis in South 
America cannot be reconstructed on the basis of present informa- 
tion. Only three fossil species — P. bassleri, P. elegans, and P. 
venezuelensis — are of unquestionable validity. One of these, 
P. bassleri, is clearly very closely related to P. expansa. The rela- 
tionships of the other two extinct species to living South American 
forms are uncertain, owing to their distinctive shell characters. 
With the exception of P. lewyand'-, the living South American 
species of Podocnemis are all strikingly similar in terms of shell 



1 Cattoi and Freiberg's figure I shows the entoplastron as being nearly 
encompassed by unusually large epiplastra. a condition unknown in any 
other chelonians that we are aware of. However, their sketch does not 
accurately represent the positions of the sutures between the epiplastra 
and hyoplastra; these are, in fact, disposed in typical pelomedusid fashion, 
extending outward from the lateral apices of the entoplastron. 

-Through the courtesy of Professor F. Medem, one of us (RCW) has 
been able to examine a series of six P. lewyana shells in the collections 
of the Instituto Roberto Franco at Villavicencio, Colombia. None of these 
has a suprapygal bone on the carapace; instead, each of the last (eighth) 
pleurals is subtriangular, not trapezia! as is the case in other species of the 
genus, and these pleurals are in continuous contact along the midline from 
the posterior end of the seventh pair of pleurals to the pygal. 



16 BREVIORA No. 376 

morphology. Only small structural details characteristic of each 
taxon permit differentiation among them on the basis of shells 
alone. P. venezuelensis stands markedly apart from all other spe- 
cies of the genus in its total lack of neurals, and certainly could 
not have given rise to any of the living forms. Nothing remotely 
resembling the shapes of the first two neurals in P. elegans is en- 
countered elsewhere in the genus. So conservative in structure is 
this part of the shell in all other species (except, of course, for 
P. venezuelensis ) , and so radically different is it in P. elegans, that 
this species could hardly have been ancestral to any or all of the 
later species known from South America. Thus, neither P. elegans 
nor P. venezuelensis has any obvious relationship to living species 
of the genus or to each other. A much better fossil record for 
Podocnemis will be necessary before a meaningful picture of its 
evolutionary history in South America can be formulated. 

ACKNOWLEDGMENTS 

We are particularly grateful to Senora Frances Charlton de 
Rivero, retired professor of paleontology at the Escuela de Geo- 
logia y Minas in Caracas, not only for her gracious hospitality but 
also for having provided laboratory facilities while the material 
here described was being studied. Both authors have examined 
the type specimen of "Podocnemis'' geologorum and one of us 
(RCW) has also been able to examine the types of "P. argen- 
tinensis," P. bassleri, and "P. brasiliensis." We would like to thank 
the curators of the various institutions at which these fossils are 
housed for permission to study them. Through the kindness of 
Professor Jose Martin Suarez, RCW has not only been able to 
study the type material of P. elegans but also to visit the locality 
from which it was recovered. Without a generous grant to RCW 
from the National Geographic Society, none of this work would 
have been possible. We are much obliged to Professors F. Medem, 
B. Patterson, P. E. Vanzolini, and E. E. Williams, and to Dr. M. 
Freiberg for their comments and discussions on various aspects 
of this manuscript. 



1971 NEW VENEZUELAN FOSSIL PELOMEDUSID 17 

LITERATURE CITED 

Bardack, D. 1961. New Tertiary teleosts from Argentina. American 
Mils. Novitates. No. 2041: 1-27. 

Bergounioux, F. M. 1952. Les cheloniens fossiles de Gafsa. Appendix 
to: Arambourg, C, and J. Signeux. Les vertebres fossiles des gise- 
ments de phosphates ( Maroc-Algerie-Tunisie). Notes et Memoires 
No. 92, Service Geologiqiie de Maroc: 377-396, pis. 45-46. 

. 1955. La famille des Eusarkiides. Comptes Rendus de 

I'Acad. Sci.. 240: 1455-1457. 

1956. Les reptiles fossiles des depots phosphates sud 



tunisiens. Annales des Mines et de la Geologie (Tunis), No. 15: 
1-105, pis. 1-17. 

Cattoi, N., and M. a. Freiberg. 1958. Una nueva especie de "Podoc- 
nemis" del cretaceo argentino. Physis. 21(60): 58-67. 

Dacque, E. 1912. Die fossilen Schildkroten Aegyptens. Geol. Palaont. 

Abhandl., N. F., 10(4): 275-337, pis. 36-37.^ 
Gaffney, E. S., and R. Zangerl. 1968. A revision of the chelonian 

genus Bothremys (Pleurodira, Pelomedusidae). Fieldiana. Geol., 

16(7): 193-239. 

Oliveira, a. I. DE. 1956. Brazil. //; W. F. Jenks (ed.). Handbook of 
South American Geology. Geol. Soc. Amer. Mem. 65: 1-378. 

Pacheco, J. A. 1913. Notas sobre a geologia do valle do Rio Grande, a 
partir da foz do Rio Pardo ate a sua confluencia com o Rio Paranahyba. 
/// J. dos Dourados (ed.). Explora^ao do Rio Grande e de seus afflu- 
entes. Commisao Geographica e Geologica do Estado de Sao Paulo: 
33-38. 

Pascual, R.. and M. L. Diaz de Gamero. 1969. Sobre la presencia del 
genero Eiimegamys (Rodentia, Caviomorpha) en la formacion 
Urumaco del Estado Falcon (Venezuela). Su signification cronologica. 
Bol. Informativo, Assoc. Venezolana de Geol.. Min. Pet.. 12(10): 
369-387. 

Price, L. I. 1953. Os quelonios de forma<:ao Baurii, Cretaceo terrestre 
do Brasii meridional. Dept. Nac. Prod. Min., Div. Geol. Min., Bol. 
147: 1-34. 

RoYO Y Gomez, J. 1960. Les vertebrados de la formacion Urumaco, 
estado Falcon. Mem. Ill Congr. Geol. Venezolano, 2: 506-510. 

Schmidt, K. P. 1931. A fossil turtle from Peru. Field Mus. Nat. Hist. 
Publ. 299, Geol. Ser., 4(8): 251-254. 

1940. A new turtle of the genus Podocneniis from the 

Cretaceous of Arkansas. Geol. Ser. Field Mus. Nat. Hist.. 8( 1): I-I2. 



18 BREVIORA No. 376 

Sill, W. D. 1970. Nota preliminar sobre un nuevo gavial del Plioceno 
de Venezuela y una discusion de los gaviales sudamericanos. 
Ameghiniana, 7(2): 151-159. 

Simpson, G. G. 1943. Una tortuga del Terciario de Venezuela. Rev 

Ministerio de Fomento, Caracas, Venezuela, ano 5, nos. 51-52, 

April -Sept. 1943: 53-64. 
Staesche, K. 1937. Podocneinis hrasiliensis n. sp. aus der Oberen Kreide 

Brasiliens. Neues Jahrb. Min., Geol. Palaont., 77: 291-309. 
. 1944. Uma tartaruga do cretaceo superior do Brasil. Dep. 

Nac. Prod. Min., Div. Geol. Min., Bol. 114: 1-24, pis. 16-20. 

Stefano, G. de. 1903. Nuovi rettili degli strati a fosfato della Tunisia. 
Bol. Soc. Geol. Ital., 22: 51-80. 

Suarez, J. M. 1969. Urn quelonio da formagao Bauru. Dept. Geografia, 
Fac. de Filos., Cien. Letras Pres. Prudente, No. 2: 35-54. 

SwiNTON, W. E. 1928. Note on the fossil reptilia collected by Mr. Don- 
ald Stewart in Venezuela. Quart. Jour. Geol. Soc, 84, Pt. 3: 583. 

Van Frank. R. 1957. A fossil collection from northern Venezuela. 

1. Toxodontidae (Mammalia, Notoungulata). American Mus. Novi- 

tates. No. 1850: 1-38. 
Vanzolini, p. E., and E. E. Williams. 1970. South American anoles: 

the geographic differentiation and evolution of the Anolis chrysolepis 

species group (Sauria, Iguanidae). Arq. Zool.. S. Paulo, 19(1-2): 

1-124. 
Williams, E. E. 1956. Podocneinis bassleri, a new species of pelomedusid 

turtle from the late Tertiary of Peru. American Mus. Novitates, No. 

1782: 1-10. 
Zangerl, R. 1948. The vertebrate fauna of the Selma Formation of 

Alabama, part 11. The pleurodiran turtles. Fieldiana: Geol. Mem. 

3(2): 19-56. 



197 



NF.W VENEZUELAN FOSSIL PELOMEDUSID 



19 




15 cm 



Plate L Dorsal view of the type carapace (VF 1176) of Podocnemis 
veneziielensis. 



20 



BREVIORA 



No. 376 




15 cm 



Plate II. View of the visceral surface of the type carapace (VF 1176) 
of Podocnemis venezuelensis. Note the absence of neural bones. 



1971 



NEW VENEZUELAN FOSSIL PELOMEDUSID 



21 




-^ 




^•^^. 










V:^'' 












i 



t-r '■ 









15 cm 



Plate ill. View of the visceral surface of the type plastron of Pocloc- 
neinis veneziielensis (VF 1173). showing the disposition of the pelvic 
attachments to it. 



22 



BREVIORA 



No. 376 



■^- '^■■<%5 




15 cm 



Plate IV. Ventral view of the type shell of Potlocneiuis vcnezuelensis, 
with the plastron (VF 1173) positioned correctly in relation to the carapace 
(VF 1176). 



1971 



NEW VENEZUELAN FOSSIL PELOMEDUSID 



23 




Plate V. The visceral surface of VF 1174. a partial plastron of Podoc- 
nemis venezneleii.sis, showing clearly the outlines of the laterally placed 
mesoplastra. 



BREVIORA 

MmseiLim of Comparative Zoology 

CAMBRrocE, Mass. 15 June. 1971 Number 377 

THE CHANARES (ARGENTINA) TRIASSIC REPTILE FAUNA 
IX. THE CHANARES FORMATION 

Alfred Sherwood Romer 



Abstract. The term "Chanares Formation" should be retained for the 
fossihferous beds so named by Romer and Jensen; the type section of the 
"Ischichuca Formation" is homologous with part of the overlying Los 
Rastros Formation. 

With the discovery of a rich Triassic reptilian fauna in the 
Chafiares-Gualo region of La Rioja Province, Mr. James Jensen 
and I set about the task of determining the stratigraphic sequence 
of the area (Romer and Jensen, 1966). It was soon apparent that, 
despite complex faulting, a series of formations with clear-cut 
boundaries could be distinguished, and in the Arroyo del Agua 
Escondida the entire local series could be seen in proper sequence. 

The area is part of a basin of late Paleozoic and early Mesozoic 
deposition lying in western La Rioja Province and an adjacent 
portion of San Juan, extending roughly from the western flanks 
of the Sanogasta Range on the east to the Rio Bermejo on the 
west, and from the region of Villa Union south to the northern 
end of the Valle Fertil range. The center of this area is the flat 
Campo de Talampaya, and I shall term this cuenca the Talampaya 
Basin. Little attention had ever been given to the geology of our 
area of interest in the eastern part of the basin, but considerable 
work had been done in the western part. It was obvious that the 
thickness and nature of the sediments varied greatly from one 
basin area to another, and the situation was further complicated by 
the fact that there had been much volcanic activity. As far as 
possible we utilized formation names already in the literature; 
\vhcn no similarities to named formations in other areas in the 
hasin were discernible, new names were given. The formations 
named by us are shown in the right hand column of the table. The 



2 BREVIORA No. 377 

three formations latest in time — Los Colorados, Ischigualasto^ 
and Los Rastros — are comparable to those so named to the west, 
across the Campo de Talampaya, although much thinner in our 
area in each instance. Below the normal beds of the Los Rastros, 
strongly carbonaceous in nature, are some 70 meters of evenly 
bedded volcanic ash sediments in which fossil reptiles are abun- 
dant. Despite the fact that these strata are quite conformable 
with the overlying Los Rastros deposits, they are, as layers of 
white to bluish white ash, quite distinctive in character and, since 
they are the bearers of our fauna, we ventured to separate them 
from the Los Rastros as a distinct Chanares Formation. Below 
them, unconformably, are red and white sandstones which are 
roughly comparable to those generally assigned to "Paganzo IIL" 
Since this is not a proper stratigraphic term, we have given them 
the name of the Tarjados Formation. Beneath them, again, are 
thick series of soft sandstones, perhaps also part of the "Paganzo 
III" complex, for which we have found no clear equivalents in 
other parts of the basin, and which we have named the Talam- 
paya Formation. 

In general, I think, this terminology has been accepted. The 
one exception is that Sr. Bonaparte (1967, 1969, etc.) has ob- 
jected to our term "Chaiiares Formation," and maintains that 
these beds should bear the name "Ischichuca Formation." Despite 
the high regard I have for Sr. Bonaparte's work in the collection 
and description of Triassic fossils, I believe that this usage is inde- 
fensible. A review of the history of stratigraphic work in this 
region is necessary. 

The first serious study of this region was that of Bodenbender 
(1911). His stratigraphic section in this basin is given in the first 
column of the table. He believed that the sediments in this area 
extended from the Carboniferous to the Cretaceous, and for the 
lower beds in the region invented the term "Paganzo," divided 
into "Paganzo I" for light colored sediments which he believed 
(apparently correctly) to be of Carboniferous age, "Paganzo II," 
for red sandstones which (again probably correctly) he thought 
were Permian, and "Paganzo III," for beds, mainly reddish sand- 
stones, which (with less assurance) he claimed to be Triassic. 



^ Sr. R. R. de la Vega has pointed out to me that the correct spelling 
should be Ichigualasto, but the "improper" version has become so embedded 
in the literature that it seems impossible to eradicate it. 



1971 THE CHANARES FORMATION 3 

"Rhaetic" was a favorite term with early German workers in South 
American geology, favored perhaps because of its rather vague 
meaning, and to the "Rhaetic" he assigned a very considerable 
thickness of beds including yellow and variegated shales, coal 
shales, and coal seams. Above these (beyond some indeterminate 
beds in the region of Cerro Morado, which he suggested were 
possibly Jurassic) the depositional series terminated with thick 
red sandstones which he believed to be Cretaceous in age and 
termed the "Cretaceo Andino." 

A more thorough study of the beds of the western part of the 
basin was undertaken in the 1940's by Frenguelli and by de la 
Mota. Frenguelli mainly visited the region of the Ischigualasto 
Valley, drained to the west by the Rio de la Pena, and published 
his results in 1948. Bodenbender's "Cretaceo Andino" beds were 
termed by him the "Estratos de Gualo," and their presumed age 
reduced, reasonably, from Cretaceous to "Rhaetic." In Boden- 
bender's erstwhile "Rhaetic" series he distinguished an upper mem- 
ber as the Ischigualasto Formation — a series of variegated shales 
and some sandstones characteristic of the Ischigualasto Valley west 
of the red bluffs of the "Gualo." These beds are now known to 
possess a very considerable fauna of Triassic (? Ladinian or pos- 
sibly Carnian) age. Below the Ischigualasto, to the west, and 
traversed by the difficult gorge of the La Pena, are rugged hills of 
sandstones and shales including coal seams, in which footprints 
had been discovered (Huene, 1931). As Frenguelli notes (1948: 
191), he did not penetrate much farther to the west through the 
rugged country in the Ischigualasto-La Pena region than the Que- 
brada de los Rastros, where a coal mine is located and where the 
footprints were found; some data were furnished him by Ramac- 
cioni and Heim, who studied the coal beds (Heim, 1949). They 
informed him that these "Rhaetic" beds were underlain, to the 
west, by red "Paganzo" sandstones which he cites as "Paganzo 11" 
(they are actually of "Paganzo III" age). 

The total thickness of the "Rhaetic" beds below the Ischigua- 
lasto Formation in this region was estimated as 600-650 meters. 
Frenguelli made this area the type section of the Los Rastros 
Formation, to which he assigned the upper 400-450 meters of 
these beds — i.e., about two-thirds, on his reckoning. As can be 
seen from the sections of Ortiz, mentioned later, under this defini- 
tion of the Los Rastros the formation would include essentially 



4 BREVIORA No. 377 

the whole of the coal-bearing portion of the "Rhaetic" beds. In de- 
fault of personal knowledge of the lower beds in the Ischigualasto- 
La Pena region, Frenguelli turned to the region of Cerro Bola, 
some 70 km to the north, which had been studied in detail by de 
la Mota (whose results are recorded in an unpublished thesis at 
the University of La Plata ).^ Equivalents of the "Gualo" and 
Ischigualasto beds are readily determinable in the Cerro Bola 
region. Between the Ischigualasto and "Paganzo III" there are 
here, much as in the Ischigualasto region, some 500-550 meters 
of "Rhaetic" beds of sandstones, shales, and coal seams. The 
upper 250-300 meters of these beds were equated by de la Mota 
and Frenguelli with the type Los Rastros; they contain occasional 
carbonaceous seams, but consist mainly of shales and fine-grained 
olive-green sands. The beds below, with a thickness of about 250 
meters, are here the main coal-bearing strata, dominantly black 
or grey-black in color, with some intercalations of thin olive-green 
sands. These beds were named the Ischichuca Formation, the 
type section being located in the quebrada of that name south of 
Cerro Bola. Below the Ischichuca Formation lies "Paganzo III." 
This consists mainly of coarse red sandstone and intercalated 
volcanic beds; between the beds of "Paganzo 111" proper and the 
Ischichuca are 30-40 meters of coarse grey to reddish conglom- 
erates which de la Mota assigned to "Paganzo III." 

Frenguelli's sections of the basin, derived from two areas 70 
km apart, are given in the second and third columns of our table. 
In 1953 Groeber and Stipanicic (pp. 87-93), in their review of 
the Triassic, followed FrengueUi, as given in our column 4, ex- 
cept that his "Estratos de Gualo" are renamed "Estratos de los 
Colorados," (since de la Mota had pointed out to them that the 
Mogote del Gualo lies at a much lower stratigraphic position than 
FrengueUi beheved). 

A decade later than the visit of Frenguelli to the Talampaya 
Basin, study of the region to the west of Ischigualasto, down the 
La Peiia, was undertaken by Ortiz on behalf of the Yacimientos 
Petroliferos Fiscales. His work was done in 1964, and his sections 
and maps were promptly circulated, although publication of his 
work was not made until 1968. As his sections show, the actual 



1 Resumes of de la Mota's findings are given by Frenguelli (1948: 197- 
208) and by Groeber and Stipanicic (1953: 93-95). 



1971 TMF CHANARES FORMATION 5 

sequence of the "Rhaetic" beds here, below the Ischigualasto, dif- 
fers considerably from that imagined by Frenguelli and studied 
by him in the Cerro Sola region, and the strata are considerably 
thicker than had been believed. The upper part of the type Los 
Rastros Formation, to about 250 meters, consists mainly of grey 
sandstones with intervening shales and only a few coal seams. 
Below this, but also included by Frenguelli — entirely or at least 
for their most part — in the type section of the Los Rastros For- 
mation are about 400 meters of beds in which dark carbonaceous 
shales and coal seams predominate, with intervals of olive-green 
shales. Below the coal beds, again, are about 450 meters of con- 
glomeratic sandstones, light in color, in which coals are little 
developed. Still farther down to the west appear the red sand- 
stones of "Paganzo IIL" 

It is clear that Frenguelli's nomenclature of the Los Rastros 
and Ischichuca beds in the two regions, that of the La Pena and 
the Ischichuca quebrada, is conflicting. The beds assigned to the 
Los Rastros in the Ischichuca region include only the upper part 
of the type Los Rastros; the middle, coal-bearing section of the 
beds which were included in the type Los Rastros in the La Pena 
region, form to the north practically the entire Ischichuca Forma- 
tion. The lowest portion of the "Rhaetic" beds in the La Peiia 
area has no counterpart in the north, unless it be the thin series 
of conglomerates that were mentioned above as transitional from 
"Paganzo III" to Ischichuca. As Ortiz points out, the entire series 
of beds from "Paganzo III" up to the Ischigualasto forms a single 
cycle of deposition, to the whole of which the formation name 
Los Rastros should properly be applied. Further, since the sup- 
posed Ischichuca Formation is merely a portion of the Los Ras- 
tros — the lower portion by Frenguelli's definition, the middle 
portion under Ortiz's suggestion — the term "Ischichuca" should 
be abandoned, as simply a partial synonym of Los Rastros. 

The Triassic sequence in the Talampaya-Ischigualasto basin as 
interpreted by Ortiz is given in column 5 of our table. Our own 
interpretation, given in column 7 and mentioned earlier, is in 
most regards comparable. The identity of the Los Colorados and 
Ischigualasto formations is perfectly clear; we have given names, 
as the Tarjados and Talampaya formations, to the red sandstones 
and underlying finer sandstone beds that have previously been 
referred to under the vague generic term "Paganzo III." We have, 
with Ortiz, agreed that the coal-bearing sandstones and shales of 



6 BREVIORA No. 377 

the "Rhaetic" should be considered as a single Los Rastros For- 
mation rather than be subdivided in two in a confusing fashion. 
Our one difference has been in distinguishing the lowest part of 
this cycle as a separate Chanares Formation because of its dis- 
tinctive nature and, especially, because of the paleontological 
importance of this unit. 

Bonaparte, independently of Ortiz, studied the lower western 
portion of the beds which Ortiz has described and, like Ortiz and 
in contrast to Frenguelli's hypothetical interpretation, finds that 
the lower part of the Los Rastros complex consists of light colored 
shales without coal seams, and thus is somewhat comparable to 
our Chanares beds. He is, further, to be congratulated for finding 
in them fossils which are presumably comparable to those from 
the Chanares. Quite probably the lowest section of the Los Ras- 
tros of Ortiz and the Chanares beds are homologous (although 
the Los Rastros beds contain conglomerates, quite in contrast with 
the even bedding of the Chanares). How should the matter be 
treated? It may be advocated either that the Chanares be con- 
sidered as a lower member of the Los Rastros or that the lower 
segment of the Los Rastros in the La Peiia area be considered as 
a separate Chanares Formation. 

Bonaparte, however, would go further and revive the term 
"Ischichuca" for these beds. Essentially, his argument is that 
since these beds in the La Pena region were termed Ischichuca 
by Frenguelli (who had never seen them and was ignorant of 
their nature), the name should be retained. To so argue, however, 
is to violate the basic principles of stratigraphic nomenclature. 
One should refer to the type section of the Ischichuca, 70 km to 
the north. The type Ischichuca consists of the main coal-bearing 
section of the "Rhaetic." As Ortiz has shown, the supposed 
"Ischichuca" in the La Pena region is at a higher stratigraphic 
level than the beds with which we are concerned and is, by Fren- 
guelli's definition, equivalent to part of the Los Rastros. No two 
sets of beds could differ more in nature than the blackish "coal 
measures" of the Ischichuca and the clear white ash of the 
Chaiiares. Both the nature of the beds and their stratigraphic 
position distinguish clearly the type "Ischichuca" from the lower 
Los Rastros and Chanares beds. The use of "Ischichuca" for the 
latter strata cannot be defended. 



1971 



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REFERENCES CITED 

BoDENBENDER, G. 1911. Constitucion geologica de la parte meridional de 
la Rioja y regiones limitrofes (Republica Argentina). Bol. Acad. Nac. 
Cienc. Cordoba, 19: 1-220. 

Bonaparte, J. F. 1967. Comentario sobre la "Formacion Chanares" de 

la cuenca Triasica de Ischigualasto-Villa Union. (San Juan-La Rioja). 

Acta Geol. Lilloana, 9: 115-119. 
1969. Datos sobre la evolucion paleoecologica en las forma- 

ciones Triasicas de Ischigualasto-Villa Union (San Juan-La Rioja). 

Acta Geol. Lilloana, 10: 189-206. 

Frenguelli, J. 1948. Estratigrafia y edad del llamado Retico en la 
Argentina. Gaea, An. Soc. Argentina Est. Geogr., 8: 159-309. 

Groeber, P.F.C, and p. N. Stipanicic. 1953. Geografia de la Republica 
Argentina, II (Primera Parte): Triasico. Buenos Aires. Pp. 13-141. 

Heim, a. 1949. Estudio geologico del carbon "Retico" y del Valle de 

la Pena (provincias de San Juan y La Rioja). Bol. Dir. Gen. Ind. 

Min., 69: 1-31. 
Huene, F. 1931. Die fossilen Fahrten im Rhat von Ischigualasto in 

Nordwest-Argentinien. Palaeobiologica, 4: 99-112. 
OrtIz, a. 1968. Los denominados Estratos de Ischichuca como seccion 

media de Formacion Los Rastros. Actas III, Jorn. Geol. Argentina, 

1: 333-339. 
RoMER, A. S., AND J. A. Jensen. 1966. The Chanares (Argentina) Trias- 

sic reptile fauna. II. Sketch of the geology of the Rio Chanares-Rio 

Gualo region. Breviora, No. 252: 1-20. 



BREVIORA 

Musenim of Compsirative Zoology 

Cambridge, Mass. 15 June, 1971 Number 378 

THE CHANARES (ARGENTINA) TRIASSIC REPTILE FAUNA 

X. TWO NEW BUT INCOMPLETELY KNOWN 
LONG-LIMBED PSEUDOSUCHIANS. 

Alfred Sherwood Romer 



Abstract. Two types of hind limbs, with which incomplete remains 
of other skeletal parts are associated, are described as new genera and 
species, Lagerpeton chanarensis and Lagosiichus talampayensis. Both have 
long and slender legs, with the tibia longer than the femur, and a long 
slender foot. They differ, however, in foot construction, for in Lagerpeton 
digit II is short and digit IV the longest of the series, whereas in Lago- 
siichus metatarsals II-IV are subequal in length and digit III the longest 
in the foot. 

INTRODUCTION 

In the pseudosuchian material collected by the La Plata-Harvard 
expedition of 1964-1965, there are several forms represented by 
nearly complete skeletal material. In addition, however, in this 
collection and among specimens collected later by Sr. Bonaparte 
of the Instituto Lillo of Tucuman, there are less complete remains 
of further pseudosuchians. Two such forms are represented by 
materials including hind limbs of unusual and advanced char- 
acter; these will be described here. 

Lagerpeton chanarensis gen. et sp. nov. 

Holotype. La Plata Museum No. 64-XI-14-10 (field number 
64), a hind leg, collected from the Chanares Formation in La 
Rioja Province, Argentina, about AVi miles east of the mouth 
of Rio Chaiiares. 

Combined generic and specific diagnosis. A pseudosuchian; 
hind limb very long and slender; femur with articular head sharply 
set off from shaft; tibia and fibula longer than femur; astragalus 



BREVIORA 



No. 378 



and calcaneum fused and applied closely to tibia and fibula; toe 
IV longest of the hind leg digits; toe II much shorter than III or 
IV; toe V represented by short metatarsal only. 

Description. The type specimen (Fig. 1 ) was found quite 
isolated, not articulated with or accompanied by other skeletal 
materials. The femur is long and slender, with a length of 77 mm. 
It has the typical sigmoidal archosaur shape. The well-ossified 
curved articular area of the head is pronounced and set off at a 
sharp angle from the shaft. A marked angulation of the posterior 




Figure 1. Right hind leg of Lagerpeton, holotype. Left, external view; 
center, extensor surface of foot; right, internal view. X 1/2. 



1971 LAGERPETON AND LAGOSUCHUS 3 

margin of the shaft indicates the point of insertion of muscula- 
ture, presumably the iliofemoralis. On the medial surface below 
the head, there is a well-developed fourth trochanter in the shape 
of a pronounced ridge, presumably for the insertion of the 
caudifemoralis. 

The epipodials are even more elongate and slender than the 
femur; the tibia measures 92 mm in length, and is thus about 120 
per cent the length of the femur. The tibia is well expanded 
proximally for a broad double articulation with the distal end of 
the femur. The fibula is incomplete in the type, and I have in 
my figure restored the proximal end from a specimen, discussed 
below, in the Instituto Lillo collection. It is, as always, a slender 
strap of bone expanded at either end; proximally, it articulates 
with the lateral surface of the distal end of the femur. 

The proximal tarsals are of unusual construction for a theco- 
dont. Astragalus and calcaneum are completely fused in the type 
specimen; in their combined outline they conform to the area of 
the distal end of tibia plus fibula, and this astragalo-calcaneum is 
closely applied to these two elements, although not fused with 
them. Further contributing to the close union of the astragalo- 
calcaneum with the epipodials is a triangular flange of bone extend- 
ing upward from this element posteriorly over the lower ends of 
tibia and fibula. There is here no indication of the crocodiloid 
calcaneal tuber frequently found in pseudosuchians. 

The usual two distal tarsals are present. A more medial and 
larger element is present on the ventral surface, above the third 
metatarsal; the lateral element caps metatarsal IV. 

Like the main limb elements, the foot is long and slender, the 
toes apparently lying close together in life. Toe V is represented 
only by a short, pointed metapodial; the other toes are complete, 
with the primitive phalangeal formula of 2, 3, 4, 5. The terminal 
phalanges of toes I-IV are sharp claws, somewhat curved. Most 
unusual for an archosaur, the toes are primitive in one regard, 
namely that toe IV is the longest of the series. Digit I is, as often, 
short; digit II is also shortened, its metapodial having but about 
half the length of those of its lateral neighbors. The total lengths 
of the digits^ from toe I outward, are 21, 49, 69, 85, and 18 mm. 
Metapodial lengths are 8, 24, 45, 48, and 18 mm. 

In the Instituto Lillo collections is a specimen that includes a 
hind Ice similar to that of the type in size, bone proportions, and 



4 BREVIORA No. 378 

structure. The femur is 75 mm in length, the tibia (not perfectly 
preserved) about 90 mm. The femur is closely comparable to 
that of the type with its sharply set off head and prominent 
trochanteric ridge. Toe I is not preserved, but toes II-IV resemble 
closely those of the type, with metapodial lengths of 23, 42, and 
47 mm, and total toe lengths of 48, 74, and 87 mm. 

With this specimen is a pelvis which is apparently nearly com- 
plete, but in its present state of preparation is seen only from 
its ventral aspect. The ischia are well developed and extend far 
backward with a long symphysis. Below and somewhat to the 
rear of the level of the acetabulum their broad external surfaces 
are convex in section, giving this region a "swollen" appearance. 

Lagosuchus talampayensis gen. et sp. nov. 

Holotype. La Plata Museum No. 64-XI-14-11 (in part). 
Remains included in a slab collected from the Chaiiares Forma- 
tion in La Rioja Province, Argentina, about 2 km north of the 
mouth of Rio Chaiiares. 

Combined generic and specific diagnosis. A pseudosuchian; 
hind limb similar in many regards to that of Lagerpeton; limb 
long and slender; femur with articular head sharply set off from 
shaft; tibia and fibula longer than femur; astragalus and calcaneum 
fused and applied closely to tibia and fibula. Digit I short, digit 
V represented by short metatarsal only; digits II-IV subequal in 
metatarsal length, but digit III longest of the series. 

Description. A slab from the Chaiiares exhibits on one surface 
the greater part of the skeleton of a small ornithosuchid which I 
hope to describe in a later number of this series. On the other 
surface of the slab are scattered materials pertaining to a still 
smaller pseudosuchian. Best preserved are nearly complete and 
articulated hind limbs (Fig. 2). Although considerably smaller, 
these limbs in their proportions resemble those of Lagerpeton, and 
I at first assumed that the specimen was an immature individual 
of that genus. The foot structure, however, shows that we are 
dealing with a discrete form of smaller size. 

As in Lagerpeton, the limbs are long and slender; the head of 
the femur is set off sharply from the shaft and the trochanteric 
ridge is well developed. As in Lagerpeton the lower leg is longer 
than the femur, the two femora, as preserved, having lengths of 
38 and 39 mm, the associated tibiae 47 and approximately 48 mm. 



1971 



LAGERPETON AND LAGOSUCHUS 




Figure 2. Hind foot of Lagosuchus, in ventral view. Composite of type 
and a specimen in the Instituto Lillo. 1 1/2 X size of holotype. 



The proximal tarsal region is poorly preserved in the type. Two 
well-developed distal tarsals are present. Of the right foot, only 
metapodials, incomplete distally, are visible. The left foot is well 
preserved as regards the metatarsals and a portion of the pha- 
langes. The digits are elongate and slender; metapodials II-IV are, 
as preserved, parallel to one another and closely apposed. Digit 
I, with a metapodial length of 15 mm, is short; metapodials II-IV 
have lengths of 23, 26, and 25 mm; metapodial V, broad at its 
head, tapers, as preserved, to a point at 11 mm. The two pha- 
langes appropriate to digit I are present, as are single proximal pha- 
langes articulated with metatarsals II and III, and several disarticu- 
lated phalanges (one a clawed ungual). 

Scattered about the slab are disconnected series of vertebrae 
with average lengths of centra of 7.5 mm in the best preserved 



6 RREVIORA No. 378 

region. There are, further, remains of pectoral limbs. In the 
better preserved of these the humerus has a length of 26 mm, 
the radius 16 mm. As one might expect from the nature of the 
long hind legs, the front limbs thus appear to be much reduced 
in size, the combined length of the long bones of the "arm" being 
less than half that of the corresponding hind leg elements. 

A specimen in the Instituto Lillo collection includes much of 
the posterior part of a skeleton that is closely comparable to the 
type of Lagosiichus except for somewhat larger size. Much of 
both hind legs is preserved in articulation. Right and left femora 
measure 55 and 56 mm in length, the tibiae 72 and 70 mm. 

As in Lagerpeton, astragalus and calcaneum are united and 
closely applied to tibia and fibula. Here, however, the line of 
suture between the two proximal tarsals is still visible, and a 
small spur of bone (not seen in Lagerpeton) projects backward 
from the fibular edge of the astragalo-calcaneum. There is no 
proximal extension of the astragalo-calcaneum of the sort seen 
in Lagerpeton. The two distal tarsals are present lying above the 
metatarsal heads. 

The feet are incompletely preserved, but except for somewhat 
larger size, they compare well with those of the type. On the right 
foot metatarsals II and IV have lengths of 34 and 38 mm, respec- 
tively; lengths of metatarsals I-IV on the left foot are: 23, 35, 
39, and 38 mm. No phalanges are present on metatarsal I, but 
two phalanges, with lengths of 9 and 7 mm are present on the 
second digit, three phalanges with lengths of 12, 8, and 5 mm on 
digit III, and four phalanges with lengths of 6, 5, 4, and 4 mm 
on digit IV. Metatarsal V, broad at the base and tapering distally, 
is incomplete, with a length as preserved of 10 mm. 

In Figure 2 the foot is restored as a composite of the type and 
the Instituto Lillo specimen just described, with allowance made 
for the difference in size of the two specimens. The more distal 
phalanges are restored on digits II-IV. As restored, digital lengths 
of the Instituto Lillo specimen are, from digit I outward: 36, 56, 
69, and 62 mm. Here, in contrast to Lagerpeton, there has de- 
veloped the "typical" archosaur foot, with toe I relatively short, 
toe V reduced, and toe III the longest of the II-III-IV series. 

Associated are remains of the pelvic girdle. The acetabula (into 
which the femoral heads were inserted when the specimen was 
recovered) are small and deep, strongly overhung dorsally by 



1971 LAGERPETON AND LAGOSUCHUS 7 

the iliac rim. The acetabular construction plus the nature of the 
femoral head indicate rather surely that the femur moved in a 
fore-and-aft plane close to the body. The ilium (Fig. 3) is of 
peculiar structure. Above the acetabulum it constricts to a rela- 
tively narrow neck. Here there projects anterolaterally a short 
but stout, blunt-ended process of a sort otherwise unknown to me; 
it is possible that it afforded an origin for an iliofemoralis externus 
muscle as in the case of a somewhat similar process in some 
ornithischians (cf. Romer, 1927) and Poposaurus (Colbert, 




Figure 3. Right ilium and head of femur of Lagosiichiis: external 
process on ilium restored from left side. From a specimen in the Institute 
Lillo. X 4/3. 



1961). Above the "neck," the ihum expands to form a short 
blade. In all "normal" thecodonts the iliac blade is a simple single 
vertical structure; here, however, there lies, internal to the normal 
external blade, a broad trough, comparable to that seen in ophia- 
codonts, presumably for accommodation of dorsal axial muscles. 
Shallow posteriorly, this trough deepens and broadens anteriorly. 
Medial to this trough is a second iliac blade, tilted somewhat 
medially, to the inner surface of which the sacral ribs pre- 
sumably articulated. Lateral and medial blades join anteriorly, 
closing the dorsal trough at this end. I know of such an iliac 
"trough" structure in only one other archosaur. In Hesperosuchus, 
Colbert (1952) found in the pelvic region an element which should 
have been an ihum but which, because of its pecuHar nature, he 
concluded could not be that element. Its main peculiarity is its 
possession of a dorsal "trough" comparable to that of Lagositchus. 
Parts of pubis and ischium are present in this specimen. It is 



8 BREVIORA No. 378 

clear that both pubis and ischium take part in the acetabulum, 
but in default of a better preserved specimen I refrain from dis- 
cussion of this portion of the girdle. 

Found close to the limbs and pelvic remains were two series of 
vertebrae. One appears to include sacrals, followed by nine prox- 
imal caudals. The mean length of these caudal centra is approx- 
imately 7 mm. A first chevron is present between caudals three 
and four; its length is 13.5 mm; those following decrease in length, 
the fourth of the series measuring 10 mm. A second series of 
vertebrae includes 30 segments, apparently running to the tip of 
the tail. The first dozen, poorly preserved, appear to have a mean 
length of centra of about 7 mm; more posteriorly, the length 
increases to about 1 cm per segment. Chevrons, gradually decreas- 
ing in length to a nubbin, are present, as preserved, to a position 
between the tenth and eleventh from the end of the series. 

A further Instituto Lillo specimen that may pertain to Lago- 
suchus includes an imperfect pelvis and much of the hind legs. 
As in both genera described in the present paper, the tibia is longer 
than the femur, with measurements of the right leg elements of 
48 and 42 mm, respectively. As in Lagosuchus, metatarsals II-IV 
are subequal in length, with measurements of 24, 28, and 27 mm 
for these metapodials in the left foot. Possibly associated is a 
fragment of maxilla or dentary bearing small teeth spaced a bit 
more than a millimeter apart. A number of posterior dorsal verte- 
brae are present, with an average central length of 5.5 mm and a 
height of 7.5 to 8 mm. 

DISCUSSION 

So distinctive are the hind legs which are the major preserved 
portions of the two forms described above that formal systematic 
description of them seems justified despite the paucity of further 
associated anatomical structures. Greater length of tibia than of 
femur is generally regarded as associated with speed. Greater 
length of lower leg than thigh is present in relatively few cases 
among even presumably bipedal archosaurs — a few thecodonts, 
such as Scleromochlus, small coelurosaurs, and to a slight degree 
in some camosaurs. The sharply inturned head of the femur indi- 
cates that the hind legs were carried close to and beneath the 
trunk and the suggestion that we are dealing with a biped is in- 
creased by the shortness of the front legs of Lagosuchus. 



1971 LAGERPETON AND LAGOSUCHUS 9 

It is surprising to find so advanced a type of limb at such an 
early stage of the Triassic (probably Anisian in terms of the marine 
series). In the preceding Cynognathiis stage of the "Eotriassic," 
thecodonts more advanced than protcrosuchians such as Chasma- 
tosaurus and Erythrosuchus were represented only by Euparkeria, 
as recently ably described by Ewer (1965). Euparkeria was ad- 
vancing toward a bipedal habitus, but was still relatively primitive. 
One would have expected that, in the Anisian, pseudosuchians 
would not have advanced far beyond this level, and that forms 
with limbs of such an advanced sort as seen in the two types just 
discussed should have been characteristic only of a much later 
stage of the Triassic. Obviously, as these forms indicate, this 
assumption is incorrect. It would seem that advance and radiation 
among thecodonts occurred rapidly in early Triassic times; beliefs 
to the contrary were due to our lack of knowledge of middle 
Triassic faunas; study of South American forms is now bringing 
such faunas into the picture. 

As was first clearly brought out by Krebs (1963), two distinct 
types of tarsal joints developed among thecodonts. In one, re- 
tained by crocodilians, the main joint between lower leg and foot 
lay between astragalus and calcaneum. The second type of joint 
is that found in dinosaurs, in which the proximal tarsals were 
functionally combined with the lower leg, the distal tarsals united 
with the foot. Both forms here described are of the second type. 
However, the presence of a small spur on the calcaneal region of 
Lagosuchus suggests the possibility that a transition from one type 
to the other may have been possible. Fusion of the two proximal 
elements is a condition rare even in "advanced" dinosaurs. The 
development of a proximal flange from the astragalo-calcaneum, 
seen in Lagerpeton, is a condition found in various theropods, but 
in these forms the flange is developed on the extensor rather than 
the flexor surface of the lower leg. 

With the marked expansion of our knowledge of thecodonts 
that is currently taking place, classification of the group can be 
at best but a provisional matter, and an attempt to place the two 
genera just discussed in a "solid" systematic position is unjustified. 
It is certain that the two have no association with the series of 
forms which appear to have crocodilian relationships, and the tar- 
sal construction suggests that the two are connected in some 
fashion with a radiation leading toward the dinosaurs and, par- 
ticularly, toward the coelurosaurian group of the Saurischia. 



10 BREVIORA No. 378 

Whether either of the two, however, can be regarded as close to 
the direct line leading to such dinosaurs is doubtful. Lagerpeton 
is, on the one hand, advanced in tarsal construction and, on the 
other, primitive or specialized in the matter of relative length of 
digit IV. Lagosuchus is more orthodox in digital construction, 
but precocious in astragalo-calcanear fusion, and specialized in 
iliac construction. 

There is a classic story of the man who "mounted his horse 
and galloped off in all directions." The history of thecodonts, we 
are coming to realize, seems to have followed this pattern. We 
have as yet no clues as to the course followed toward birds or 
pterosaurs. Various thecodonts seem to have trended toward a 
crocodilian type of organization. The ornithischian pattern is so 
distinctive that at the present we can reasonably consider the 
Ornithischia as definitely monophyletic in origin. This is not the 
case with the Saurischia. The presence in the later Triassic of 
apparent sauropod ancestors of seemingly primitive quadrupedal 
nature suggests a polyphyletic origin of that order. What of the 
"prosauropods" of the late Triassic, the coelurosaurs, the advanced 
theropods of the Jurassic and Cretaceous? Quite possibly the 
Saurischia are a polyphyletic group that took origin from a "mixed 
grill" of thecodonts — a varied assemblage amongst which the two 
forms here described are to be included. 

I am indebted to the National Science Foundation, grants 
GB-2454 and GB-8171, for aid in the collection, preparation, 
and publication of the La Plata-Harvard materials, and I am grate- 
ful to Sr. Bonaparte for the privilege of studying the Chan ares 
thecodont material which he has collected. 

REFERENCES CITED 

Colbert, E. H. 1952. A pseudosuchian reptile from Arizona. Bull. 

American Mus. Nat. Hist.. 99: 561-592. 
. 1961. The Triassic reptile, Poposaiints. Fieldiana. Geol- 
ogy, 14: 59-78. 
Ewer, R. F. 1965. The anatomy of the thecodont reptile Eiiparkeria 

capensis Broom. Philos. Trans. Roy. Soc. London, Ser. B, 248: 

379-435. 
Krebs, B. 1963. Bau imd Funktion des Tarsus eines Pseudosuchiers aus 

der Trias des Monte San Giorgio (Kanton Tessin, Schweiz). Palaont. 

Z., 37: 88-95. 
Romer, a. S. 1927. The development of the thigh musculature of tlic 

chick. Jour. Morph. Physiol., 43: 347-385. 



BREVIORA 

Museum of Comparative Zoology 

CAMBRrocE, Mass. 15 June, 1971 Number 379 

THE CHANARES (ARGENTINA) TRIASSIC 

REPTILE FAUNA XI. TWO NEW LONG-SNOUTED 

THECODONTS, CHANARESUCHUS AND GUALOSUCHUS 

Alfred Sherwood Romer 



Abstract. A description is given of the skull and jaws of two new 
thecodonts, Chanaresuchiis bonapartei and Gualosuchus reigi. from the 
early Middle Triassic Chanares Formation of Argentina. The two forms 
here described plus Cerritosaurus and Proterochampsa are closely related 
and may be included in the single family Proterochampsidae. Their 
structure is in many regards so primitive that this family should be in- 
cluded in the thecodont suborder Proterosuchia. Suggested relationships 
of members of the family to crocodilians and phytosaurs are discussed. 

INTRODUCTION 

Commonest of all thecodont remains so far discovered in the 
Chaiiares Formation are those of Chanaresuchus bonapartei and 
Gualosuchus reigi. Considerable material, particularly of Cha- 
naresuchus, was found by the La Plata-Harvard expedition of 
1964-65, and further specimens, which Sr. Bonaparte has been 
kind enough to let me study, are in the collections of the Instituto 
Lillo of Tucuman. In the present paper I will confine myself to 
description of the skulls and jaws of these two closely related 
forms; I hope shortly to give an account of the postcranial skel- 
eton of Chanaresuchus. 

I gratefully acknowledge grants from the National Science 
Foundation that covered most of the expenses of collection and 
preparation of the materials, and for aid in publication. 

Chanaresuchus bonapartei, gen. et sp. nov. 

Holotype. La Plata Museum 1964-XI-14-12 (field no. 47), 
a skull and jaws together with postcranial remains. Collected 



2 BREVIORA No. 379 

from the Chanares Formation, in La Rioja Province, about half 
a mile southeast of a volcanic plug in the valley of the south fork 
of the Chanares River. 

Combined generic and specific characters. A thecodont of 
modest size (largest known skull about 260 mm in length). 
Skull long and low; broad posteriorly; slithke external nares 
placed close together dorsally some distance back of tip of snout; 
antorbital vacuity small; postfrontal absent; no pineal opening; 
parietals swing sharply outward posteriorly, above superior tem- 
poral fenestrae, toward meeting with squamosals; suspensorium 
far back of occiput, and lateral fenestra hence elongate antero- 
posteriorly. Very elongate choanae partially covered below by a 
secondary palate. Pterygoid and palatine toothed. Basal articu- 
lation of braincase and palate movable. A long if narrow inter- 
pterygoid vacuity, exposing a slender parasphenoid rostrum. 

The generic name refers to the Chanares River and Forma- 
tion. The specific name is given in honor of Sr. Jose Bonaparte, 
able collector and describer of Triassic reptiles. 

Description (Figs. 1-3). Considerable skull material of 
Chanaresuchus is available. Most notable in the La Plata-Harvard 
collection, in addition to the holotype, are MCZ 4037 (field no. 
154), which includes a large skull and jaws, and MCZ 4039 
(field no. 81), the well-preserved left half of a small skull. Skull 
lengths of these three specimens (measured to the quadrate) are, 
respectively, 211 mm, 260 mm, and 155 mm. MCZ 4036 con- 
sists of a slab containing, as well as considerable postcranial 
material, two rather poor skulls of about the size of the holo- 
type. 

The dermal bones of the skull are ornamented, particularly on 
the skull table, with ridges radiating from centers of ossification. 
The degree of sculpturing appears to vary with size and presumed 
age; it is little developed on MCZ 4039, somewhat more prom- 
inent on the type, and the largest skull, MCZ 4037, is quite 
rugose. 

The skull is long, low, slender-snouted, broad posteriorly. 
Snout elongation is clearly shown by the length of premaxillae, 
nasals, and frontals, and by proportionate measurements. If, for 
example, the anteroposterior diameter of the orbit be taken as a 
base, the facial length, anterior to the orbit, is about AVi times 
the length of the orbit itself, whereas in other thecodonts 



1971 CHANARESUCHUS AND GUALOSUCHUS 3 

(phytosaurs excepted) this measurement is typically no more 
than two or three times the orbital diameter. There is, further, 
a considerable degree of postorbital length. From the post- 
orbital bar to the tip of the quadrate, the distance is about 21/2 
times the orbital diameter, whereas in pseudosuchians this dis- 
tance is almost invariably considerably less, and is sometimes 
not even equal to orbital diameter. It is difficult to select a 
standard against which skull height may be objectively measured, 
but it may be noted that even in the postfacial region of the 
skull, where flattening is less pronounced than in the snout, the 
skull height is not sufficient to give space for the eyes in the 
lateral wall and the orbits are, in consequence, incised into the 
skuU roof. 

The tip of the snout is sUghtly decurved. Dorsal and lateral 
surfaces of the skull are clearly marked off from one another. 
The dorsal surface is nearly flat, although rising along the length 
of the snout to then become horizontal in plane along the length 
of the skull table. On either side a well-marked ridge, separating 
lateral and dorsal surfaces, develops at the level of the nares 
and continues back to the anterodorsal angle of the orbit, where 
there is a modestly developed lateral projection. A similar pro- 
jecting angle is present at the posterior margin of the orbit, and 
a clear-cut angle separating roof from "cheek" continues along 
the bar separating the temporal fenestrae. 

The external nares are elongate slitlike structures, dorsally 
placed and close together, separated only by a narrow bony bar. 
In contrast to the subterminal position seen in many thecodonts, 
they are placed well back of the snout tip; grooves leading into 
the narial openings are present anteriorly and posteriorly. Deep 
to the external nares, and separated from the narial margins at 
all points, is seen a sheet of bone within which is found, on 
either side, an opening of considerably smaller size than the 
narial opening. At first glance one would assume that these 
openings are the choanae; however, as discussed below, they are 
apparently anterior palatal foramina for the vomeronasal organs, 
and this bony sheet forms a short secondary palate. This sec- 
ondary palate is separated from the bone rimming the narial 
margin for only a short distance on the anterior and lateral 
margins; medially, however, the bony sheets of the two sides 
appear to meet one another below and free from the bar sepa- 
rating the two nares, and the opening posteriorly between the 



BREVIORA 



No. 379 



narial margin and the secondary palate leads into a short naso- 
palatine duct. 

The antorbital fenestra is a small triangular opening, the apex 
of the triangle lying anteriorly, at about one-third the distance 
from orbit to snout tip, the posterior base separated from the 
orbit by a narrow bony bar. The orbits are large (as, presumably 
were the eyes) and are subcircular in shape; on the lateral sur- 
face they occupy nearly the whole height of the skull, leaving 
but a narrow bar of bone between them and the lower skull 
margin. Dorsally their semicircular margins cut far into the 
sides of the skull table. The upper rim is slightly elevated; as 
mentioned, there are pronounced projections anteriorly and pos- 
teriorly at the junction of dorsal and lateral portions of the 
orbital boundaries. 

There is no parietal foramen. The superior temporal fenestra 
is well developed, facing directly dorsally, and is triangular in 




Figure 1. Chanaresuchus bonapartei, skull in dorsal view. This and 
Figs. 2-5 are based on the holotype, with additions from other specimens. 
Abbreviations for Figs. 1-7: an, angular; ar, articular; bo, basioccipital; 
c, coronoid; d, dentary; ec, ectopterygoid; /, frontal; ;, jugal; /, lacrimal; 
m, maxilla; n, nasal; op, opisthotic; p, parietal; part, prearticular; pi, pala- 
tine; pm, premaxilla; pa, postorbital; pp, postparietal; prf, prefrontal; 
ps, parasphenoid; pt, pterygoid; q, quadrate; qj, quadratojugal; san, sur- 
angular; sac, supraoccipital; sp, splenial; sq, squamosal; v, vomer. 



1971 CHANARESUCHUS AND GUALOSUCHUS 5 

shape, with an anterior base and a posterior apex. The lateral 
temporal opening is, as noted above, elongate anteroposteriorly, 
in contrast to its much shorter span in most archosaurs; its pos- 
terior margin is somewhat convex in outline, suggestive of the 
initiation of the V-shape of this border in many archosaurs. In 
strong contrast with most archosaurs, the suspensorial region 
slants far back ventrally, the jaw articulation lying some distance 
back of the level of the occiput. The back margin of the sus- 
pensorial region is somewhat concave; this, plus a slight dorsal 
spur, shows the initiation of the type of otic notch characteristic 
of many more advanced archosaurs. The occiput slants diago- 
nally downward and backward from the posterior margin of the 
narrow medial portion of the skull table. 

Of individual dermal roofing elements, the premaxillae are 
elongate, in conformity with general snout elongation. They 
form most of the boundaries of the external nares. The pre- 
maxilla sends a long and well-developed process backward ex- 
ternal to the naris, excluding the maxilla from the narial border 
and terminating in a slender tip between maxilla and nasal. 
Medially, conjoined slender processes from the two premaxillae 
form a narrow bar separating the nares and extending back some 
distance beyond tht narial region to taper between and below 
the anterior tips of nasal processes that meet them. There is no 
evidence of a separate septomaxilla, reported as existing in this 
region in phytosaurs. Like the premaxillae, the nasals are elon- 
gate They enter into the posterior border of the external nares 
for a short distance and extend far backward to meet the frontals 
in a zig-zag transverse suture; laterally there is a long line of 
suture with the maxillae and a short contact with the prefrontals. 
The frontals, as indicated by the development of their radiating 
surface ridges, are somewhat elongated anteriorly. Laterally they 
have a long contact with the prefrontals anteriorly and a short 
posterior contact with the postorbitals; they enter broadly into 
the dorsal rims of the orbits. The parietals are short anteropos- 
teriorly, as regards their development on the skull table. They 
have a transverse suture with the frontals in the middle portion 
of the roof; lateral to this, the line of suture with the frontals 
retreats sharply posteriorly, then turns forward again, allowing 
the parietals contact with the postorbitals. This lateral extension 
of the parietal forms the anterior border of the superior temporal 



6 BREVIORA No. 379 

fenestra. The posterior end of the skull roof is narrow; on 
either side, however, each parietal sends, posterolaterally, a long 
process to meet and overlap the medial surface of the squamosal 
behind the superior temporal fenestra. Narrow dorsally but 
broadening below, the medial surface of this process forms the 
upper lateral boundary of the occipital plate and laterally forms 
the medial boundary of the superior temporal fenestra. This 
boundary is sharply marked off dorsally; more ventrally, how- 
ever, the parietal slants outward to meet, obviously, the prootic 
area of the otic region of the braincase. 

Laterally, the premaxilla continues back some distance along 
the margin of the upper jaw before being succeeded by the elon- 
gate maxilla. The latter element gradually increases in depth, 
posteriorly, to occupy the entire height of the side of the snout 
anterior to the antorbital fenestra. The maxilla extends upward 
beyond the ridge separating lateral and dorsal skull surfaces to 
form a lateral strip of the dorsal surface for, roughly, the length 
of the nasal. When the antorbital opening is reached, the maxilla 
extends but a short distance backward above this opening. Below, 
however, it forms the fenestral border for most of its length, to 
be finally succeeded by the jugal. Posteriorly the maxilla tapers 
downward in depth to terminate at about the level of the posterior 
border of the orbit. The lacrimal forms most of the bar sepa- 
rating orbit and antorbital fenestra and (although the line of 
suture is none too clear) appears to extend forward above this 
fenestra for most of its length on the lateral skull surface. 

The prefrontal forms a triangular area on the skull roof, 
bounded medially by nasal and frontal, posterolaterally by the 
orbital margin and laterally by the ridge separating dorsal and 
lateral margins of the snout. It forms a prominent projection 
over the anterodorsal margin of the orbit and sends a process. 




Figure 2. Chanaresiichus bonapartei, type skull in side view. X 4/9. 



1971 CHANARESUCHUS AND GUALOSUCHUS 7 

reinforcing the lacrimal, part way down the bar separating orbit 
and antorbital fenestra. There is no postfrontal clement. The 
postorbital is well developed. Its center of ossification is a prom- 
inent elevation at the posterodorsal corner of the orbit, whence 
it extends in three directions. Medially, it extends over the skull 
roof surface to meet the frontal anteriorly and, more posteriorly, 
the parietal. This process forms anteriorly part of the orbital 
rim, and posteriorly a small portion of the boundary of the upper 
temporal fenestra. A posterior flange extends backward to form 
much of the upper border of the lateral temporal fenestra, grad- 
ually tapering backward to give place to the squamosal. Ven- 
trally the postorbital extends downward to form the upper part 
of the bar separating orbit and lateral temporal fenestra. The 
jugal, in normal fashion, forms the lower margin of the orbit 
and much of the lower margin of the lateral temporal fenestra. 
Anteriorly it reaches the posteroventral margin of the antorbital 
fenestra, and it forms the lower part of the postorbital bar. 

The squamosal, in a fashion somewhat analogous to the post- 
orbital, sends out three processes from a center located dorso- 
posterior to the lateral temporal fenestra. An anteromedial 
process runs forward to join laterally the process of the parietal, 
which forms the medial wall of the superior temporal fenestra. 
A long and strong process runs anteriorly to meet the postorbital 
in a long diagonal suture and to form, in conjunction with that 
element, the bar lying between the lateral margin of the upper 
temporal fenestra and the upper boundary of the lateral temporal 
fenestra. A broad but thin process runs ventrally to form the 
posterior boundary of the lateral temporal fenestra; this meets 
the quadratojugal ventrally and posteriorly has a long suture 
with the quadrate. The squamosal, as in thecodonts generally, 
sends a short spur backward above the head of the quadrate. 
The quadratojugal forms the posterior part of the bar below the 
lateral temporal fenestra and then curves sharply upward to meet 
the squamosal and to form the lower part of the posterior mar- 
gin of this fenestra. Posteriorly, at the junction of its two limbs, 
the quadratojugal is thickened and is in intimate contact with 
the quadrate. 

As noted above, the occipital surface of the skull slants back- 
ward as well as downward. The posterior rami of the parietals 
form vertical walls that bound the occiput on either side. At the 



8 BREVIORA No. 379 

apex of the occipital surface is a small triangular postparietal, 
which faces backward as much as upward and plays no part in 
the dorsal surface of the skull. Below this is a large supraoc- 
cipital, essentially triangular except for truncation of its narrow 
anterodorsal extremity. On either side this plate articulates with 
the proximal part of the posterior processes of the parietals. 
Dorsally the bone has a prominent medial ridge; ventrally this 
element forms the upper margin of the foramen magnum. The 
lateral margins of the foramen are formed by the exoccipitals, 
which are fused with the opisthotics to form long and slender 
paroccipital processes extending laterally to abut against the 
inner surfaces of the squamosals dorsally; this articulation is a 
loose one, with the presence of kineticism. Possibly a small post- 
temporal fenestra may have been present above the paroccipital 
process; if present, however, it cannot have been more than a 
slender slit. The exoccipital forms a dorsolateral fraction of the 
occipital condyle; the condyle is, however, mainly formed by the 
basioccipital. The condyle is circular in outline and essentially 
convex with, however, a slight median excavation, presumably 
for the anterior termination of the notochord. I regret that the 
condition of the material is such that I have been unable to make 
out the vagus and hypoglossal foramina nor the lateral surface 
of the braincase in the otic region. I have not found a stapes, 
and can say nothing regarding the possible presence of epiptery- 
goid or laterosphenoid. 

In correlation with snout elongation, the anterior part of the 
palate is much modified. Medially a pair of stout processes 
formed by the premaxillae extend backward in the midline; be- 
hind them, the central area is continued by narrow paired vomers, 
bearing a row of small teeth. Posteriorly the vomers diverge 
somewhat to accommodate between them the anterior tips of 
the pterygoids. At their posterior ends the vomers are in contact 
with the palatines, the anterior ends of which have a concave 
border, meeting the vomers medially and the elongate maxillae 
laterally. 

In "typical" tetrapods the choanae are situated well forward, 
as rounded or oval openings, bounded anteriorly by the pre- 
maxillae, laterally by the maxillae, posteriorly by the palatines 
and medially by the vomers. If we look for the equivalent of 
the normal choanae here, we find a pair of long and narrow areas 



1971 



CHANARESUCHUS AND GUALOSUCHUS 




Figure 3. Chanaresuchiis bonapartei, type skull in palatal view. X 4/9. 



reaching about half the length of the skull, from the premaxillary 
region to the position of the "incised" anterior ends of the 
palatines. This elongation of the original choanal region is ob- 
viously related to snout elongation. From the palatines for some 
distance forward there are open choanae. But, farther forward, 
there is a sheet of bone apparently pertaining to the maxillae, 
which extends medially across the choanal areas from the max- 
illae to gain a contact with the posterior portions of the stout 
ventral processes of the premaxillae and the edges of the vomers. 
More anteriorly this sheet is broken by oval openings, already 
mentioned in connection with the skull roof. It is reasonable to 
believe that these openings are anterior palatine foramina for 
access to the mouth cavity of vomeronasal organs (Jacobson's 
organs), and that the transverse sheet of bone between these 
openings and the true choanae is a definite, if short, secondary 
palate formed for facilitation of underwater breathing in this 
long-snouted animal. 

Much more normal and primitive in construction is the pos- 
terior portion of the palatal surface. Anterior to the occipital 
condyle, there are projecting basisphenoidal tubera, connected 
by an incised transverse fine, concave posteriorly, which pre- 
sumably marked the anterior limit of subvertebral musculature. 



10 BREVIORA No. 379 

Lines extending posteromedially from the tubera suggest an ex- 
tension of parasphenoidal dermal ossification backward over part 
of the basioccipital area. Anterior to the tubera, the combined 
basisphenoid-parasphenoid contracts somewhat in width, then 
expands again to the projecting spherical basal articular proc- 
esses, on which it is obvious the pterygoids had considerable 
freedom of movement. Paired foramina for the carotid arteries 
are present between these processes. A slender parasphenoid 
rostrum extends far forward along the midline of the interptery- 
goid vacuity. Of the elements of the posterior part of the palate, 
the palatine occupies an area between the posterior end of the 
choana anteriorly and the palatine fenestra posteriorly, and be- 
tween the maxilla laterally and the pterygoid medially. It bears 
ventrally an anteroposterior row of small teeth. The pterygoids 
are highly developed. Their slim anterior ends extend far forward 
between the vomers. A short distance back of their anterior 
termination the two pterygoids diverge slightly, so that a long 
but narrow interpterygoid vacuity is developed. Along the 
medial border each pterygoid carries a long row of small teeth; 
this series terminates just above the region of the basal articula- 
tion with the braincase. A second row of small teeth is present 
on a distinct ridge that slants diagonally backward and medially 
from a point near the posterior end of the palatine to terminate 
somewhat short of the basal articular region. The palatal fenestra 
is of considerable extent, bounded laterally by the jugal and incised 
medially into the posterior part of the palatine and the adjacent 
portion of the pterygoid. Back of the fenestra the palatal ramus 
of the pterygoid expands widely laterally. Part of this expansion 
is presumably formed by an ectopterygoid, but I have not been 
able to detect a pterygoid-ectopterygoid suture. Anteriorly the 
lateral margin of this expansion is sutured to the jugal; posteriorly 
there is a constriction in width, and the bone slants ventrally to 
form a stout transverse pterygoid flange, broadening distally. The 
palatal portion of the pterygoid terminates medially and pos- 
teriorly in a short spur beneath which is the socket for reception 
of the articular process of the basisphenoid. Lateral to this area, 
there arises a typical quadrate flange of the pterygoid, of modest 
height, which posteriorly meets the quadrate. 



97: 



CHANARESUCHUS AND GUALOSUCHUS 



The quadrate bone is well developed. Its posterior end is a 
thickened articular area, widened transversely and convex at both 
internal and external ends; it appears that the quadratojugal (as 
often) takes part to some degree in the lateral condyle. The 
main shaft of the quadrate extends upward, to terminate in a 
recess on the under surface of the squamosal at and close to its 
posterior spur. This ascending ramus of the quadrate is broad 
ventrally, gradually contracting in width dorsally, and has a 
concave posterior margin. It faces as much posteriorly as later- 
ally, at an angle to the adjacent areas of the quadratojugal and 
descending ramus of the squamosal. As generally, a foramen is 
present on this surface between quadrate and quadratojugal. The 
ascending ramus presents a broad, forward-slanting, medial sur- 
face that is covered anteriorly by the quadrate ramus of the 
pterygoid. 

In correlation with skull length, the jaw is long and slender 
anteriorly (Figs. 4, 5). The symphysis is poorly represented in 
available material but was obviously weak and formed mainly — 
perhaps entirely — by the dentary. For much of the length of 
the muzzle the dentary forms almost the entire outer surface of 
the ramus — a surface that slants markedly inward below, rather 
than being directed vertically downward. Posteriorly the bone 
forks, the two branches enclosing between them the anterior end 
of the long external mandibular fenestra. The upper branch ex- 
tends along the upper margin of the ramus to the end of the tooth 




Figure 4. Cluijuircsiicliiis bonapartei, jaw of type in lateroventral view. 
X 4/9. 



row, where it is replaced by the surangular; the lower branch 
extends backward below the fenestra for some distance, applied 
to the outer surface of the angular. The splenial is exposed at 
the lower edge of the external surface. The posterior portion of 
the external surface is made up almost entirely by the surangular 
and angular. The former bone runs backward along the curving 



12 



BREVIORA 



No. 379 



upper margin of the ramus, whence a dorsally facing area of the 
surangular extends inward above the lateral border of the man- 
dibular fossa. The angular extends backward below the lateral 
mandibular fenestra, the two elements meeting at the posterior 
end of the fenestra, whence a ridge, with which the suture be- 
tween the two elements is associated, runs posteriorly. The 
suture is indistinct posteriorly but the conjoined angular and 
surangular extend backward nearly to the posterior end of the 
jaw, sheathing the articular laterally. On the inner surface the 
splenial lines the jaw for nearly its full height for most of the 
length of the tooth row. Beyond this point its upper margin 
slants gradually downward to the termination of the bone well 
posteriorly. It is succeeded posteriorly on the inner surface by 
the prearticular, which, narrow anteriorly, follows the splenial 
downward and backward. The prearticular forms the inner bor- 
der of the mandibular fossa, the surangular the outer border. 
A coronoid is present, but seen only as a disarticulated element. 
I have restored it, in Figure 5, with some doubt, in its probable 
position. It appears to have extended forward as a thin sliver 




Figure 5. Chanaresuchus bonapartei, jaw of type in medial view. 
X 4/9. 



of bone between the dentary and splenial and more posteriorly 
appears to have been applied to the inner surface of the surangu- 
lar. Posteriorly, the surangular thickens on its inner surface to 
form the back margin of the mandibular fossa. The prearticular 
fuses posteriorly with the articular. This stout element appears 
to have been but loosely attached to the surangular and angular, 
since it has separated from them in the two available specimens 
with jaws in the La Plata-Harvard collection. The articular oc- 
cupies the full height of the inner surface of the jaw at its pos- 
terior end; it is braced anteriorly by the medial extension of the 
surangular mentioned above, and is nearly completely covered 
externally by the thin posterior extension of the conjoined angular 



1971 CHANARESUCHUS AND GUALOSUCHUS 13 

plus surangular. There is little development of a retroarticular 
process, but the bone extends somewhat ventroposteriorly. The 
articular surface of the articular, as of the quadrate, is trans- 
versely broadened, with median and lateral concavities corre- 
sponding to the pair of convexities on the quadrate. There is a 
pronounced process developed on the medial surface just below 
the level of the articular surface. 

The marginal dentition is but imperfectly preserved in avail- 
able specimens. The teeth are of a common archosaurian type, 
somewhat compressed mediolaterally, hence with an oval section, 
sharp-pointed, and backwardly curved distally. The insertion is 
protothecodont. There appear to have been six teeth, the last 
small, on the elongate premaxilla, about 18 on the maxilla, and 
about the same number on the dentary. As in many reptiles, 
there appears to have been a high degree of replacement of teeth 
in essentially alternating fashion, so that for much of the jaw 
length alternate teeth are well developed, those between barely 
erupted or represented by empty sockets. 

GuALOSUCHUS REiGi, gen. et sp. nov. 

Holotype. La Plata Museum 1964-XI-14-13 (field no. 75), 
including most of the right half of skull and jaws and a limited 
amount of postcranial material. Collected from the Chanares 
Formation, from the valley of the north fork of the Chanares 
River, La Rioja Province, about five miles east of the point where 
this stream debouches into the Talampaya plain. 

Combined generic and specific characters. Similar to Cha- 
naresuchus in nearly all regards, but larger; posterior portion of 
skull deeper but with a narrower skull table than in Chanare- 
suchiis; orbit taller than in that genus and less incised into skull 
roof; parietals extend in paired fashion farther back on skull 
table than in Chanaresuchus and diverge less sharply posteriorly 
toward the squamosals; superior temporal openings proportion- 
ately narrow and more elongate. 

The generic name, by analogy with Chanaresuchus, refers to 
the Gualo River, which, with the Chanares, drains most of the 
known area of exposure of the Chanares Formation. The specific 
name is in honor of Sr. Osvaldo A. Reig, an active student of 
archosaur evolution. 



14 BREVIORA No. 379 

Gualosuchus is represented in the Harvard-La Plata collections 
only by the holotype, which includes the dermal bones of the 
right side of the skull roof, the pterygoids, right palatine, most 
of the right lower jaw and a number of postcranial elements. 
Further materials, including a second skull, are present in the 
Instituto Lillo collections. The length of the holotype skull (Figs. 
6, 7), measured to the quadrate, is about 325 mm; the Instituto 
Lillo skull, presumably that of a young individual, is much 
smaller. Quite probably the holotype represents a "mature" speci- 
men; it is nearly a quarter larger than the largest known skull of 
Chaiuiresuchus. The skull of the holotype is highly rugose, pre- 
sumably in correlation with large size; this feature has made 
identification of sutures difficult. 

In every major structural feature the Gualosuchus skull closely 
resembles that of Chanaresuchus. In consequence, detailed de- 
scription is unnecessary; mention need be made only of points 
in which the two genera differ. As in Chanaresuchus, the skull 
is long and low; the proportions of snout length to total skull 
length are much the same in the two genera, and both have the 
same anteroposterior elongation of the lateral temporal fenestra. 
The skull of Gualosuchus, however, is much less depressed pos- 
teriorly than that of Chanaresuchus, and less broad. In Cha- 
naresuchus, for example, the height of the skull at the orbit is 
little more than 15 per cent the skull length; in Gualosuchus 
about 22 per cent, and the comparable figures at midlength of 
the lateral temporal fenestra are 17 per cent and 24 per cent. 
In relation to greater depth at the orbit, this opening, which is 
subcircular in lateral view in Chanaresuchus, is taller and sub- 
quadrate in shape in Gualosuchus and is much less incised into 
the skull roof. Part of the contrast in depth is due to the greater 
depth of the maxilla and jugal beneath the antorbital vacuity, 
orbit, and the anterior part of the lateral fenestra. The differ- 
ences in breadth between the two genera relate mainly to differ- 
ences in width of the skuU table. In Chanaresuchus the width 
across the postorbital-squamosal bars bordering the skull table on 
either side, is nearly a third the measurement of skull length; in 
the Gualosuchus type this width is but a quarter the skull length. 
This difference in table proportions results in contrasts in the 
pattern of the posterior part of the skull roof. In Chanaresuchus 
the superior temporal fenestrae are relatively short and broad 



97: 



CHANARESUCHUS AND GUALOSUCHUS 



15 



and slant outward posteriorly; in Gualosuchus these openings are 
relatively long and narrow and lie on a direcdy anteroposterior 
line. In Chanaresuchus the two parietals are united on the skull 
table for only a short distance before they diverge sharply to 
extend outward and backward to meet the squamosals; in Gualo- 
suchus, in contrast, the parietals extend backward in contact 
with one another for a considerable distance before diverging, at 
a lesser angle, toward the squamosals. 




Figure 6. Gualosuchus reigi, holotype skull in dorsal view. X 1/3. 




Figure 7. Gualosuchus reigi, holotype skull in lateral view. X 1/3. 



16 BREVIORA No. 379 

The disarticulated pterygoids and right palatine are very simi- 
lar in construction to those of Chanaresuchus. Most of the right 
ramus of the lower jaw is preserved in the type. It had been 
somewhat weathered before recovery, but in all observable fea- 
tures it agrees well with the Chanaresuchus jaw. 

DISCUSSION 

Chanaresuchus and Gualosuchus are closely related; they ap- 
pear to be almost identical in all structural features and as far 
as known differ only in size and in skull proportions, the Gualo- 
suchus skull being relatively narrower and taller posteriorly. We 
need not search far to find relatives. It is obvious that Cerrito- 
saurus described by Price (1946) from the slightly later Santa 
Maria beds of Brazil is a close relative, as shown by similar 
skull proportions, slitlike dorsally-placed nostrils, loss of post- 
frontal element, absence of the parietal foramen, comparable 
shape of the lateral temporal fenestra, and posterior situation 
of the jaw articulation. Possibly some of the thecodont material 
from the Manda beds may pertain to a related type, but this 
material is too fragmentary to allow positive determination. 

Quite surely, however, a further South American relative is 
Proterochampsa (Reig, 1959; Sill, 1967). A number of points 
of resemblance to Chanaresuchus and Gualosuchus can be seen 
in the figures of Reig and Sill, and further unpublished observa- 
tions and study of the Proterochampsa specimens in the fight of 
our better knowledge of the Chanares forms strongly suggest that 
the relationship is close indeed. The Proterochampsa skufis are 
even more flattened than in Chanaresuchus (although this may 
be due in part to post-mortem crushing) . The skull is sculptured 
as regards its dermal roofing elements in very rugose fashion, 
presumably in correlation with the fact that its size is consider- 
ably greater than that of either of the Chanares forms. This 
rugose condition makes for difficulty and doubt in the determina- 
tion of sutures. The skull proportions, with a long slender snout 
and a broad posterior region, are identical with those in the 
earlier genera. The outlines of the external nares are imperfectly 
preserved, but the structure here is apparently the same as in 
Chanaresuchus and Gualosuchus. The antorbital fenestrae are 
smafi, as in those genera; the orbit, subcircular in shape as in 
Chanaresuchus, is strongly incised into the skull table; because 



1971 CHANARESUCHUS AND GUALOSUCHUS 17 

of the great flattening of the skull, these openings face nearly 
directly dorsally rather than laterally. The pattern of the posterior 
part of the skull table, with a pineal opening absent, and the 
posterolateral extensions of the parietals swinging broadly out- 
ward, closely resembles that of the Chafiares genera. As in those 
forms, the lateral temporal fenestra is large and long anteropos- 
teriorly; the jaw articulation is far back of the occiput, and, as 
in the earlier genera, there is but a slight projection of the 
squamosal above the incipient archosaur otic notch. The lower 
jaw structure, as far as can be made out, is similar to that of the 
forms here described. 

The palate is poorly seen, but recent study indicates that the 
posterior portion of it was quite similar to that of Chanaresuchus 
and Gualosiichus. As in those genera, the basal articulation was 
movable and an interpterygoid vacuity present, in which, as in 
the genera here described, there projected forward a slender 
parasphenoidal rostrum. A row of denticles was present, as in 
the Chanares forms, on the palatine as well as denticle rows on 
the pterygoid. 

Again, as in these forms, the anterior ends of the palatines 
were notched for the posterior margins of the choanae. Forward 
of this point little can be made out regarding palatal structure. 
Both Reig and Sill restore this area with a small choana and a 
long secondary palate. This is, however, uncertain and the 
situation here may well have been much the same as in the 
Chaiiares forms. 

In sum, Proterochampsa in all observable features appears to 
be very similar in cranial structure to Chanaresuchus, Gualo- 
suchus and Cerhtosaurus; the differences between them are cer- 
tainly not more than of generic value, and all four may be 
reasonably grouped within the single family Proterochampsidae, 
erected by Sill (1967) for the reception of Proterochampsa. 

The general structure of these four genera is strongly suggestive 
of amphibious habits, not improbably paralleling those of the 
later phytosaurs and crocodilians. The postcranial skeleton ap- 
pears to have the general proportions of crocodilians (although 
without diagnostic crocodihan characteristics). The slender 
snout, flattened skull, the trend for a dorsal facing of the orbits 
and the dorsal position of the nostrils are all suggestive of water- 
dwelling habits. 



18 BREVIORA No. 379 

What is the pedigree of these forms? Currently, as regards 
classification of thecodonts, one tends to sort out a few early and 
primitive genera as the Proterosuchia, separate off as advanced 
types the Phytosauria and (in some fashion or other) crocodilian 
ancestors, and, having done this, "lump" all remaining forms as 
members of the suborder Pseudosuchia. One's first inclination 
would be to include the Proterochampsidae in this last general 
category. Further consideration, however, suggests that the 
proterochampsids are too primitive structurally to be placed in 
the Pseudosuchia. In a few regards our forms are advanced or 
specialized — dorsal position of the nares, loss of the postfrontal 
and of the parietal foramen, structure of the anterior part of the 
palate, and an advanced jaw structure. But there are many 
primitive features — for example, small size of the antorbital 
opening, posterior position of the suspensorium, long antero- 
posterior extent of the lateral temporal fenestra, presence of a 
movable basal articulation, retention of an interpterygoid vacuity 
and retention of palatal teeth. Typical pseudosuchians are ad- 
vanced in all these characters. Euparkeria, recently well described 
by Ewer (1965), which is either reckoned as a primitive pseudo- 
suchian or as an advanced proterosuchian leading toward the 
pseudosuchians, is as primitive as the proterochampsids in most 
of the features listed. But even Euparkeria is more advanced in 
some features, such as the relatively large antorbital fenestra and, 
more significantly, shortening of the lateral temporal fenestra and 
forward movement of the suspensorial region. 

One is thus tempted to consider a direct origin of the protero- 
champsids from a proterosuchian ancestor. Charig and Reig 
(1970) list some 27 structural features that are characteristic of 
proterosuchians, 16 of which (2-17) pertain to the cranium. In 
the greater part of these characters, the Proterochampsidae are 
in agreement with the Proterosuchia. They differ in a few points: 
(2, part) absence of a postfrontal and of a parietal foramen; 
(5, part) nonterminal position of external nares; (9) a slight 
projection of the squamosal back beyond the head of the quadrate 
(present, however, in Chasmatosaiirus); (13) formation of an 
incipient secondary palate; (14) the presence or absence of an 
epipterygoid is unknown. In all other points the Proterochamp- 
sidae are in full agreement with the Proterosuchia: (2, part) a 
median postparietal present; (3) well-developed and projecting 



1971 CHANARESUCHUS AND GUALOSUCHUS 19 

prefrontal; (4) short and broad parietal; (5, part) exclusion of 
maxilla from naris by premaxilla; (6) moderate size of antorbital 
vacuity; (7) superior temporal fenestra facing dorsally; (8) no 
V-shaped lateral temporal fenestra; (10) Uttle development of 
otic notch; (11) jaw^ articulation well behind condyle; (12) 
interpterygoid vacuity present; (15) marginal teeth more or less 
isodont; and, (16) tooth insertion subthecodont. To this long 
list of primitive characters may be added the presence of a mov- 
able basipterygoid articulation, and retention of palatal teeth. 
It seems clear that the Proterochampsidae are of direct protero- 
suchian derivation and, despite a few advances, may best be 
classified as a family of the Proterosuchia. 

Further, one's attention can be immediately directed to Pro- 
terosuchus [Champsosaurus] as a proterosuchian probably not 
far removed from the near ancestry of the Proterochampsidae. 
Reig (1959), Sill (1967), and Walker (1968) have each in 
turn commented on the similarity of Proterochampsa to ''Clias- 
matosaurus.'' Apart from the nasal apparatus, little change is 
needed to transform "Chasmatosaurus" into a proterochampsid 
— reduction of the downward curvature of the snout, loss of the 
postfrontal bone, and modification of the posterior part of the 
lower jaw. Two changes anteriorly are needed — an upward and 
backward shift of the external nares and, with further elongation 
of the already slitlike choanae of ''Chasmatosaurus,"" initiation 
of a secondary palate. The proterochampsids can be reasonably 
considered to be direct and relatively unmodified descendants of 
a proterosuchian of "chasmatosaurid" type. 

Were the Proterochampsidae a sterile line or could they have 
given rise to more advanced archosaurs of any sort? The two 
possibilities are the Phytosauria and Crocodilia. Reig and Sill 
believe Proterochampsa to be an ancestral crocodile; Walker 
(1968, 1970) denies the crocodilian affinities of Proterochampsa 
but suggests relationships to phytosaurs, while, on the other 
hand, he suggests that Cerritosaurus is a crocodile relative. 

I see little positive evidence to support relationship of any 
member of the Proterochampsidae to the Crocodilia. As far as I 
am aware, the postcranial skeleton of Clianaresuchus shows none 
of the significantly crocodihan features of coracoid, pubis, etc., 
that are characteristic of Triassic "pre-crocodilians." As regards 
the skull, Reig calls attention, in addition to the beginning of a 



20 BREVIORA No. 379 

secondary palate, to the rather crocodihan skull proportions, 
particularly those of the table. Sill gives a careful and detailed 
analysis of skull structure, but, apart from the secondary palate, 
cannot point out any feature in which Proterochampsa approaches 
crocodilian conditions; at best, it exhibits features that may have 
been present in the remote ancestors of the Crocodiha, and that 
are, essentially, those present in generahzed ancestral thecodonts. 
The posterior portion of the palate, for example, is of an ex- 
tremely primitive pattern, markedly modified in all nonprotero- 
suchian thecodonts. Notably primitive is the suspensorial region, 
with the jaw articulation far to the rear of the occiput and the 
lateral temporal opening greatly elongated. To attain the croco- 
dilian condition it seems structurally necessary for this region to 
pass through the pseudosuchian stage of a short lateral temporal 
region with a V-shaped posterior boundary, followed by closure 
of the upper part of the lateral vacuity, a forward shift of the 
upper end of the quadrate and, finally, downward closure of the 
squamosal back of the otic notch. There is not, in protero- 
champsids, the slightest trace of the beginning of this highly 
important series of structural changes; these forms are not a 
whit more advanced than the archaic thecodont "'Chasmato- 
saurusy The posterior part of the proterochampsid jaw, again, 
is specialized in a noncrocodilian fashion. Finally, the movement 
of the external nares upward and backward along the skull roof 
is a structural feature that is not primitive or merely "neutral" 
in nature, but is in direct contrast to the situation expected in an 
ancestor of the Crocodilia, in which the nostrils are persistently 
terminal in position in almost every case. 

In short, for positive signs of crocodilian relationships of the 
proterochampsids, we are reduced to the presence of a short 
secondary palate. It is possible, but difficult, to imagine this 
structure being expanded and modified to form the elongate 
secondary palatal structure seen in true crocodilians. It seems 
more probable, at present, to believe that the development of this 
structure plus the backward movement of the external nares, 
represent an attempt, parallel to that of crocodilian ancestors, 
to improve respiration in a long-snouted amphibious reptile. 

If we turn from the proterochampsids to a series of later 
Triassic archosaurs, such as Notochampsa, Erythrochampsa, 
Protosuchus, and the recently described Orthosuchiis (Nash, 



1971 CHANARESUCHUS AND GUALOSUCHUS 21 

1968; cf. Walker, 1970), we find a series of forms in which 
there is little development of a secondary palate, but in which 
there are numerous positive indications of crocodilian relation- 
ship, such as the series of crocodilian postcranial characters that 
arc absent in proterochampsids, progress in the development of 
the crocodilian type of suspensorial and otic regions, presence 
of supraorbital bones, fusion of braincase and palate ventrally. 
There is little indication that these forms are directly derived 
from such archaic and essentially proterosuchian forms as the 
proterochampsids; rather, it would seem, the crocodile ancestors 
advanced from the proterosuchian to the pseudosuchian stage 
of thecodont development, and then began to specialize in the 
direction of the Crocodilia. 

Although Walker (1968), as noted above, suggested that 
Cerritosaiinis might be related to crocodilian ancestry, he denies 
this for its relative Proterochampsa, and suggests, in contrast, 
that this genus might have been ancestral to the phytosaurs. Most 
of the items listed by him as phytosaurian similarities appear to 
be of little weight and could be countered by other features 
wherein Proterochampsa differs from possible "proto-parasuch- 
ians" (as, for example, in loss of postfrontals in proterochamp- 
sids). The one seemingly important and suggestive feature is the 
movement of the nares, as slitlike structures, well back onto the 
dorsal skull surface. This could well be an initiation of the strong 
posterior narial trend seen in phytosaurs. But in default of 
intermediate forms, the gap between such a proterochampsid as 
Chanaresiichus and a typical phytosaur is so great as to make 
an assumption of relationship, in the present state of our knowl- 
edge of thecodonts, little more than an interesting possibility. 

LITERATURE CITED 

Charig, a. J., AND O. A. Reig. 1970. The classification of the Protero- 

suchia. Biol. J. Linn Soc, 2: 125-171. 
Ewer, R. F. 1965. The anatomy of the thecodont reptile Eiiparkeiia 

capensis Broom. Phil. Trans. Roy. Soc. London, ser. B, 248: 379- 

435. 
Nash, D. 1968. A crocodile from the Upper Triassic of Lesotho. 

J. Zool. London, 156: 163-179. 
Price, L. L 1946. Sobre um novo pseudosuquio do Triassico superior 

do Rio Grande do Sul. Bol. Serv. Geol. Min. Brasil, 120: 7-38. 



22 BREVIORA No. 379 

Reig, O. a. 1959. Primeros datos descriptivos sobre nuevos reptiles 
arcosaurios del Triasico de Ischigualasto (San Juan, Argentina). 
Rev. Asoc. Geol. Argentina, 13: 257-270. 

Sill, W. D. 1967. Prolerochampsa barrionuevoi and the early evolution 

of the Crocodilia. Bull. Mus. Comp. Zool., 135: 415-446. 
Walker, A. D. 1968. Protosuchus, Proterochampsa, and the origin of 

phytosaurs and crocodiles. Geol. Mag., 105: 1-14. 
1970. A revision of the Jurassic reptile Hallopiis victor 

(Marsh), with remarks on the classification of crocodiles. Phil. Trans. 

Roy. Soc. London, ser. B, 257: 323-372. 



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