A new crocodile from New Guinea

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FIELD MUSEUM OF NATURAL HISTORY

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PUBLICATION 247
ZOOLOGICAL SERIES VOL. XII, No. 14

A NEW CROCODILE FROM
NEW GUINEA

BY

KARL P. SCHMIDT

Assistant Curator of Reptiles and Amphibians

WILFRED H. OSGOOD

Curator, Department of Zoology

EDITOR

\ NATURAL
HISTORY

Al'K 3 1928
CHICAGO, U. S. A.

February 23, 1928 UNIVtKSllY Of ,ui.lNOI!S

PRINTED IN THE UNITED STATES OF AMERICA
BT FIELD MUSEUM PRESS

A NEW CROCODILE FROM NEW GUINEA-

BY KARL P. SCHMIDT

In arranging the crocodilian material in the collections of Field
Museum of Natural History, I find two skulls which represent a
strikingly distinct new species of crocodile. These skulls were
received by the Department of Zoology as a transfer from the De-
partment of Anthropology, where they had long been stored with the
Museum's very extensive New Guinean collections. The skulls in
question were secured by Dr. George A. Dorsey in the course of his
expedition of 1908. I am indebted to Dr. A. B. Lewis for kindly aid
in searching for the second of the two skulls now before me.

Crocodilus novae-guineae sp. nov.

Type from Ibundo, lower Sepik River, northern New Guinea.
No. 13092, Field Museum of Natural History. A juvenile skull with-
out mandibles. Collected in 1908 by George A. Dorsey.

Range. — Known only from the Sepik River, Northern New
Guinea.

Diagnosis. — A crocodile with a moderately acute snout, inter-
mediate between C. porosus and C. johnstoni. Allied to porosus by
the presence of anteorbital ridges, to johnstoni by the sharper snout
and the form of the palatines. Length of snout slightly more than
twice its breadth. No bulbous swelling at the base of the palatines.

Description of type. — General form of skull acutely triangular,
much depressed, and without median ridge or swelling, lightly and
slenderly built throughout. Supratemporal fenestrae large. Orbits
about twice the diameter of the narial aperture. Palatine fenestrae
with a well-marked angulation in their posterior border. Internal
narial aperture rounded, longer than wide. Premaxillaries little ex-
panded, pierced by the anterior mandibular teeth, separated by the
entry of the nasals into the external narial aperture. Maxillary-pre-
maxillary suture produced backward to the second maxillary tooth.
Premaxillary foramen arrow-head shaped. An obtuse ridge from the
anteorbital border on each lacrymal. Cranial table flat. Palatines
with an acute anterior angle, (as in other sharp-snouted crocodiles),
nearly parallel sided, narrow. Pterygoids distinctly stalked, i. e.

177 THE L1BKABY \tt THE
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UNIVERSITY 01- ILLINOIS

1 78 FIELD MUSEUM OF NATURAL HISTORY — ZOOLOGY, VOL. XII.

palato-pterygoid suture anterior to the posterior border of the palatal
fenestrae. Upper teeth 18-19.

Notes on paratype. — A larger skull, Field Museum No. 2854, is
labeled "Probably from Lower Sepik River," and was received with
the same collection of anthropological material as the type. The
smaller specimen is made the type in order to fix the type locality
more definitely.

The paratype is an excellently preserved skull, with the man-
dibles, slightly charred in two places and with one pterygoid angle
broken away. Although nearly twice as large as the smaller skull,
there is remarkably little difference in proportions. It agrees very
satisfactorily with the type in all essential characters.

Comparing the proportionate length of snout with that of porosus
given by Mook (1921, p. 191), we have the following figures, (a) being
the ratio of the breadth of the snout at its base to the length, (b) that
of the breadth at the fifth maxillary tooth to the same length :

C, novae-guineae C. porosus

Museum Number F.M.N.H. 13092 2854 A.M.N.H* 7115 15179

Length of skull 150 mm. 271 mm. 305 mm. 642 mm.

Ratio (a) .46 .48 .55 .56

Ratio (b) .34 .34 .42 .47

Remarks. — It is highly remarkable to find a well characterized new
species of crocodile, even from New Guinea. It seems certain that
other material of the present species must exist in museums, and the
anthropological collections of the Berlin Museum, especially, should
be searched for additional specimens.

It seems probable that this species is a fresh- water crocodile, with
the same mutual exclusiveness of range with that of the salt-water
crocodile, C. porosus, as exists between the north Australian fresh-
water species and the wide-ranging porosus. The Sepik River, (Kai-
serin Augusta on German maps), is the largest river of northern New
Guinea, and in view of the existence of C. johnstoni in Australia, it is
less surprising to find a fresh-water species in New Guinea. In many
respects the new form is intermediate between porosus and johnstoni,
being allied to johnstoni in the depressed snout and narrow pointed
palatines. However, it seems certain, from comparison with other
species, that these characters are parallel modifications accompany-
ing elongation of the snout, and that novae-guineae is not especially
available as a form ancestral to johnstoni, though it illustrates well
enough how johnstoni may have been developed.

NEW CROCODILE FROM NEW GUINEA — SCHMIDT 179

In view of the detailed account of the skull characters of recent
crocodilia on a uniform plan drawn up by Dr. Charles C. Mook,
(Mook, 1921, 1923; Longman, 1925; supplemented by Schmidt,
1924), I have prepared an account of the single paratype (the more
complete skull) with the same headings, comparing the respective
bones with those of Crocodilus porosus, employing Mook's description
and a large skull, Field Museum No. 13219, for comparison.

General form. — The skull of Crocodilus novae-guineae has the gen-
eral proportions of the skull of Crocodilus acutus, from which it
differs in being flat and depressed from the orbits forward. The
skull is more acute than in porosus, with much lower pre-orbital
ridges, and is much less massive in almost every bone. The lateral
constrictions and the vertical festooning are slight.

Cavities of skull. — The supratemporal fenestrae are large and
rounded. The infratemporal fenestrae are proportioned as in acutus.
The orbits are relatively large, their length twice the width of the
interorbital space. The external narial aperture is an elongated oval,
with a re-entrant angle in front and at the rear, its length nearly one
and a half times its breadth. The premaxillary foramen has the shape
of a blunt arrow-head. The palatine fenestrae differ from those of
porosus in the rather sharp angulation of their ectopterygoid border.
They are slightly longer than the maxillary suture, nearly as wide as
the base of the palatines, and wider than the palatines at the middle.
The internal narial aperture is broken away anteriorly, but is evi-
dently round, and not expanded from side to side as in porosus.

Premaxillaries. — The premaxillaries are much narrower than in
porosus, and barely meet behind the narial aperture, over the nasal
process. Their posterior extensions are acute. On the palate their
greatest length is once and a half their combined width. The maxil-
lary-premaxillary suture is weakly produced backward, not reaching
the second maxillary tooth.

Maxillaries. — The maxillaries are elongate and their ectoptery-
goid suture does not reach the tenth maxillary tooth. They are very
little expanded at the fifth tooth. There is only a trace of the ridge
on the dorsal surface along their suture with the nasals, so character-
istic of porosus.

Nasals. — The nasals are more elongate than in porosus, and their
sutures with the lacrymals even shorter. They are separated posteri-
orly by a very acute process of the frontal.

i8o FIELD MUSEUM OF NATURAL HISTORY — ZOOLOGY, VOL. XII.

Lacrymals. — These bones are proportionately shorter and wider
than in porosus, in contrast with the form of other bones. They bear
a prominent obtuse ridge, below which is a deep pit. Their nasal
suture is extremely short.

Pref rentals. — The prefrontals are also less elongate than in poro-
sus. Their share of the orbital border is about equal to that of the
lacrymals.

Frontal. — The frontal differs in outline from that of porosus in its
angularity. Mook describes the acuminate forward process as pre-
sent in one of his specimens of porosus. The suture with the pre-
frontals falls much in advance of the center of the orbits.

Postorbitals. — The postorbitals are smaller than those of porosus,
and their suture with the frontal falls farther back on the orbits.

Squamosals. — Similar to those of porosus.

Parietal. — Similar to that of- porosus, but the width at the con-
striction exceeds the width of the lateral part of the squamosal on
the cranial table.

Supraoccipital. — The supraogipital occupies a very small tri-
angular space on the cranial table.

Quadrates, Basioccipitals, Exoccipitals,and Basis phenoid. — These
bones are more slender in novae-guineae than in porosus.

Quadratojugals. — The quadratojugals are parallel sided, not nar-
rowed anteriorly. The spine is close to the jugal.

Jugals. — The jugals are notably slender in proportion when com-
pared with those of porosus.

Palatines. — These bones present the most striking characteristics
of the new species. They are narrow, little wider at the pterygoid
suture than at the middle, sharp pointed in front. Their suture with
the pterygoids is anterior to the posterior extension of the palatine
fenestrae. There is no trace of the bulbous posterior expansion shown
by the palatines in porosus.

Pterygoids. — The lack of the superior expansion of porosus is the
most notable difference, together with the broad entry into the pala-
tine fenestrae, and minor differences in outline.

Ectopterygoids. — These bones present an obtusely angular inner
border. They do not extend as far forward as the tenth maxillary
tooth.

NEW CROCODILE FROM NEW GUINEA — SCHMIDT 181

Mandibles. — The mandible of novae-guineae is slender in com-
parison with that of porosus. The symphysis between the two rami
extends to a point midway between the fifth and sixth teeth.

No. 13092 No. 2854

Tip of snout to supraoccipital I5omm 271 mm

Tip of snout to ends of quadrates 160 303

Tip of snout to anterior border of orbits 94.4 183

Width of snout at base 43.7 89.4

Width of snout at 5th maxillary tooth 32.1 63.0

Greatest width of premaxillaries 21.2 45.7

Width of skull across quadratojugals 68.2 133.7
Least width of frontal between orbits 8.2 19.0

Length of orbit 26.6 41.3

Width of orbit at middle 22.2 33.0

Width of cranial table behind 44.0 82.8

Width of cranial table in front 37.3 65.3

Length of premaxillary suture on palate 31.8 55.5

Length of maxillary suture 30.0 60.3

Length of palatine suture 55-O 95-6
Length of pterygoid suture 43.9

Width of palatines at base 12.6 25.7
Least width of palatines 9.7 18.8

Width of palatine fenestrae 11.9 24.0

Length of palatine fenestrae 34.7 63.5

Length of mandibles 335

Length of mandibular symphysis 53.7

REFERENCES

BOULENGER, GEORGE ALBERT

1889. "Catalogue of the Chelonians, Rhynchocephalians, and Crocodiles in the
British Museum (Natural History)." London: Printed by order of the
Trustees. 8vo., pp. X, 311, 6 pis., 72 textfigs.

LONGMAN, HEBER A.

1925. "Crocodilus johnsoni Krefft." Mem. Queensland Mus., 8, p. 95-102, pis.
23-24.

MOOK, CHARLES C.

1921. "Skull Characters of Recent Crocodilia with Notes on the Affinities of the
Recent Genera." Bull. Amer. Mus. Nat. Hist., 44, p. 123-268, 14 textfigs.

1923. "Skull Characters of Alligator sinensis Fauvel." idem, 48, p. 553-562,
2 textfigs.

ROOIJ, NELLY de

1915. "The Reptiles of the Indo-Australian Archipelago I Lacertilia, Chelonia,
Emydosauria." Leiden: E. J. Brill, Ltd. 8vo. p. XIV, 384, 132 textfigs.

SCHMIDT, KARL P.

1924. "Notes on Central American Crocodiles." Field Mus. Nat. Hist. Publ.,
Zool. Series, 12, p. 77-92, pi. 5-9.

3 19$

FIELD MUSEUM OF NATURAL HISTORY. ZOOLOGY, VOL. XII, PLATE XIII.

DORSAL VIEW OF SKULL OF Crocodilus novae-guineae, F. M.N.H. NO. 2854, X 1/3.

THE UBRAHY

OF IHE
UNIVERSITY OF ILLINOIS

FIELD MUSEUM OF NATURAL HISTORY.

ZOOLOGY, VOL. XII, PLATE XIV.

PALATAL VIEW OF SKULL OF Crocodilus novae-guineae, F. M.N.H. NO. 2854, X 1/3.

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