Postilla /Yale Peabody Museum of Natural History.

POSTILLA

PEABODY MUSEUM
YALE UNIVERSITY

NUMBER 168 15 APRIL 1976

A NEW SPECIES OF APTERODON (MAMMALIA,
CREODONTA) FROM THE UPPER EOCENE
QASR EL-SAGHA FORMATION OF EGYPT

ELWYN L. SIMONS

PHILIP D. GINGERICH

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A NEW SPECIES OF APTERODON (MAMMALIA, CREODONTA)
FROM THE UPPER EOCENE QASR EL-SAGHA FORMATION OF EGYPT

Elwyn L. Simons

Peabody Museum of Natural History and
Department of Geology and Geophysics
Yale University

New Haven, Connecticut 06520

Philip D. Gingerich

Museum of Paleontology
The University of Michigan
Ann Arbor, Michigan 48109

Received 6 January 1975

ABSTRACT

The mandible of a medium-sized carnivore discovered by a recent Yale
paleontological expedition to the Fayum Province of Egypt represents a new
species of the creodont Apterodon. The type and only specimen of this new
species, Apterodon saghensis, comes from the Upper Eocene Qasr el-Sagha
Formation and thus represents the earliest terrestrial carnivore yet described
from the African continent. Unfortunately the specimen contributes little to
our understanding of the origin and relationships of Apterodon.

POSTILLA 168; 9 p. 15 April 1976

POSTILLA 168

INTRODUCTION

From 1961 through 1967 a series of paleontological expeditions to the Fayum
Province of Egypt was undertaken by Yale University field parties, and these
expeditions have added considerably to our knowledge of the Paleogene
mammalian faunas of Africa. The Oligocene faunas of the Jebel el-Qatrani
Formation proved to be very rich and they have consequently received the
most attention. Recent publications on these faunas include description of a
new species of the primate Parapithecus (Simons, 1974), two new genera
and species of carnivores (Simons and Gingerich, 1974), and a new genus
and species of hyrax (Meyer, 1973). Detailed analysis of the sediments of
the Jebel el-Qatrani Formation indicates that they were deposited on a low,
featureless deltaic plain with gallery forests along the rivers and open savan-
nah between (Bowen and Vondra, 1974).

Some attention was devoted to the underlying Qasr el-Sagha Formation
by the Yale expedition. Study of the marine invertebrate fauna from this
formation indicates that it is probably of late Bartonian age [ca. 40 million
years (m.y.) B.P.] and correlative with the Mokattam and Maadi Formations
of the Cairo region (Said, 1962, p. 102-103). Of particular interest is a frag-
mentary mammalian mandible found by one of us in an interbedded clay-
stone, siltstone, and quartz sandstone facies of the Qasr el-Sagha Formation,
which detailed sedimentary and stratigraphic analysis has indicated represents
a prograding delta front (Vondra, 1974).

The new specimen, a very corroded mandibular ramus preserving the
crowns of three teeth and parts of two others, is important as the first good
record of a wholly terrestrial mammal from the Qasr el-Sagha Formation
and the earliest confirmed record of a terrestrial carnivore from the African
continent.

ABBREVIATIONS

CGM Cairo Geological Museum, Cairo, Egypt

MNHN Muséum National d’Histoire Naturelle, Paris, France

UCMP Museum of Paleontology, University of California, Berkeley,
California

UM Museum of Paleontology, The University of Michigan, Ann
Arbor, Michigan

YPM Peabody Museum of Natural History, Yale University, New

Haven, Connecticut

NEW SPECIES OF APTERODON 3

SYSTEMATICS

cLass MAMMALIA

ORDER CREODONTA
FAMILY HY AENODONTIDAE
GENUS A pterodon Fischer, 1880

Apterodon Fischer, 1880, p. 288. Type species: Aperodon gaudryi Fischer.

Dasyurodon Andreae, 1887, p. 126. Type species: Dasyurodon flonheimensis
Andreae.

Pterodon (in part), Andrews, 1904, p. 211.

INCLUDED SPECIES. Apterodon gaudryi Fischer, 1880; A. flonheimensis (An-
dreae, 1887); A. macrognathus (Andrews, 1904); A. altidens Schlosser,
1910; A. saghensis new species.

DISTRIBUTION, The type and only specimen of Apterodon gaudryi comes from
the French Quercy Phosphorites of early or middle Oligocene age (ca. 32-37
m.y.) and A. flonheimensis, a possible synonym of A. gaudryi, comes from
the middle Oligocene (ca. 32-34 m.y.) of Flonheim in the German Mainz
Basin. Apterodon macrognathus and A. altidens both come from the lower
fossil wood zone of the Jebel el-Qatrani Formation in Egypt (early to middle
Oligocene, ca. 32-37 m.y.). Apterodon saghensis, described below, comes
from the Egyptian Qasr el-Sagha Formation and extends the range of the
genus into the late Eocene (ca. 40 m.y.) These approximate ages are based
on Romer (1966, p. 335) and Berggren (1972, p. 198).

Apterodon saghensis, new species
Proures 1) 2, 35€
?A pterodon sp. nov., Simons, 1968, p. 15.
TYPE. CGM 40006, a left mandible with the root of the lower canine,
the crowns of Ps—4, and the damaged crown of M4. Sharp casts of the type
Specimen are deposited at Yale (YPM 30241) and the University of Michi-
gan (UM 63389).

HYPODIGM. Type specimen only.

TYPE LOCALITY. The type specimen was collected in 1963 by E. L. Simons
from a locality in the Fayum depression of Egypt some twenty feet above the

POSTILLA 168

base of the deltaic sandstone facies of the Qasr el-Sagha Formation and
approximately one-half mile north or northwest of the Qasr el-Sagha temple,
near the road up the escarpment leading to the overlying lower fossil wood
zone of the Jebel el-Qatrani Formation.

ETYMOLOGY. Named with reference to the specimen’s provenance, from the
Qasr el-Sagha Formation near the temple Qasr el-Sagha.

DIAGNOSIS. A pterodon saghensis differs from the species previously described
in being significantly smaller (see Table 1), and in having a higher, straighter,
and less robust fourth lower premolar (see Fig. 3).

TABLE 1. Tooth measurements of the type specimen of Apterodon saghensis
and a comparison with the Fayum species A. macrognathus and A. altidens
from the lower fossil wood zone. All measurements in millimeters. Mandi-
bular depth measured beneath My.

Apterodon Apterodon Apterodon
saghensis macrognathus altidens
CGM 40006 UCMP 62218 YPM 18160
Bae ee 14.8 Oo
WwW 4.2 8.3 On
Beek LO. 15.8 -
WwW 4.7 CE) -
Pale 12,0 18.7 vel
WwW 5.9 8.9 GE Al
M, L oS 13.4* N27
WwW Sep) dade 6.4
Mandibular
Depth ie 372)(0) 26.6

*estimated

DESCRIPTION. The type and only specimen of Apterodon saghensis is a left
mandible fragment six centimeters in length. The bone is highly corroded,
but a portion of the symphyseal surface remains on the medial side of the
mandible. The front of the jaw is missing, and no trace remains of the in-
cisors or their alveoli.

The crown of the lower canine is also missing, but its root is preserved
and measures 9.7 mm by 7.1 mm in cross section. The mandible is damaged
above and lateral to the canine root and the first premolar is missing, though
it was undoubtedly retained in this species.

The crowns of three premolors, P:—4, are well preserved. Py. has a single
blunt protoconid cusp, with cristids extending anteriorly and posteriorly from

NEW SPECIES OF APTERODON 5

Fic. 1. Lateral view of type specimen of Apterodon saghensis, CGM 40006, show-
ing the root of the lower canine, and Pz—~Mj. Note the badly corroded mandibular
bone.

the protoconid. A very weak cingulid is present on the buccal side of the
crown, and a slightly more prominent cristid is developed at the anterolingual
corner. The posterior portion is damaged slightly, but the crown length was
approximately 8.5 mm. The width of the crown of Py is 4.2 mm. Ps is slightly
larger, but is otherwise very simliar in morphology to Py. Ps measures 10.7
mm in length, and 4.7 mm in width. A portion of the lingual cingulid is miss-
ing, but this shelf broadens posteriorly making a very shallowly basined heel
medial to the posterior cristid from the protoconid. Py and P3 both lack any
accessory cusps.

The lower fourth premolar is very well preserved, apart from an antero-
posterior split in the enamel of the protoconid predating mineralization of
the specimen. The protoconid is the dominant cusp on the tooth, and it is
relatively high and straight (see Figure 3). A cristid runs down the anterior
surface of the protoconid, connecting with a small but distinct anterior basal
cusp or paraconid. The posterior cristid of the protoconid joins the posterior
basal cusp (which is apparently serially homologous with the hypoconid of
a typical molar) in a distinct notch toward the back of the crown. A strong
lingual cingulid connects the anterior and posterior basal cusps, and a very
weak cingulid is developed on the buccal margin of the tooth. The crown of
P, measures 12.0 mm in length and 5.9 mm in width. Just as on Py_3, the
enamel on this crown appears to be very slightly crenulated.

The protoconid of M; appears possibly to have had a straighter posterior
margin than is typical in Apterodon, which suggests that perhaps a small

POSTILLA 168

FIG. 2. Type specimen of Apterodon saghensis in lateral (A) and occlusal (B)
view, showing the root of the lower canine (C), lower premolars (P2—4), and the
first lower molar (M1).

metaconid was retained, but the crown of this tooth is too damaged to offer
any positive evidence of this. A distinct constriction separating the trigonid
of the tooth from the talonid is apparent, and a buccal cingulid is weakly
developed. The tooth is too poorly preserved to show any other details. My;
measures approximately 9.5 mm in length and 5.5 mm in width. The man-
dible is broken behind M,, and no trace of Me or Mz remains.

DISCUSSION

Species of Apterodon are the most common carnivores found in the Oligo-
cene Jebel el-Qatrani Formation of the Fayum, and the specimen described
here indicates that species of this genus were probably common in the Late
Eocene as well. The abundance of Apterodon in Egyptian deposits and its

NEW SPECIES OF APTERODON if

FNe
aie
s
4
gx
\
\

A ‘B

(0) lom

. be | C oe | D

FIG. 3. Comparison of the lower fourth premolar of four species of Apterodon.
A, Apterodon altidens from the Fayum lower fossil wood zone, Jebel el-Qatrani
Formation (YPM 18160). B, Apterodon macrognathus from the Fayum lower
fossil wood zone, Jebel el-Qatrani Formation (YPM 18165, reversed). C, Aptero-
don saghensis from the Fayum, Qasr el-Sagha Formation (CGM 40006). D,

Apterodon gaudryi from the French Quercy Phosphorites (from a cast of the
type, MNHN).

rarity elsewhere (the two European species are known from a single speci-
men each) suggests that Apterodon probably evolved in isolation in Africa,
with the exception of a limited migration around the Tethyan Sea resulting
in a minor invasion of Europe in the early Oligocene.

Unfortunately, only one other carnivore specimen possibly equal in age
to Apterodon saghensis is known from Africa, a fragmentary specimen of

a “hyaenodont” mentioned by Savage (1969) from Dor el Talha in southern
Libya. Neither specimen contributes significantly to understanding the origin

POSTILLA 168

and relationships of Apterodon. In his original description of Apterodon,
Fischer (1880) recognized its similarities to Pterodon. Andrews (1904) at
first placed Apterodon macrognathus in Pterodon. In describing the first
skulls of the genus, Osborn (1909) retained Apterodon in the Hyaenodon-
tidae. However, the long-supported relationship of Apterodon to Pterodon
and the Hyaenodontidae was questioned by Van Valen (1966, p. 85), who
proposed transferring Apterodon to the condylarth family Mesonychidae,
a suggestion followed by Romer (1966, p. 385). Szalay (1967) disputed
many of the points raised by Van Valen. Szalay concluded that as a result
of his discussion “the undoubted hyaenodontid affinity of Apterodon is con-
firmed.” In the absence of an adequate Eocene fossil record, we follow
Lange (1967) in regarding any definitive phylogenetic or systematic place-
ment of Apterodon as premature. It seems preferable to retain provisionally
for Apterodon the place it has long occupied among the creodont Hyaenodon-
tidae; however, if and when true mesonychids are discovered in Africa the
question might be reopened.

ACKNOWLEDGMENTS

We thank Mr. D. Alfar of the Cairo Geological Museum, Dr. R. Hamilton
of the British Museum (Natural History), Dr. M. C. McKenna, the Ameri-
can Museum of Natural History, and Dr. D. E. Savage, University of Cali-
fornia, Berkeley, for access to comparative material in their care. Mr. Grant
Meyer of the Yale Peabody Museum assisted in preparing the manuscript.
We also thank Mrs. Krystyna Butterfield, Mr. Karoly Kutasi, and Mrs.
Gladys Newton of the University of Michigan Museum of Paleontology for,
respectively, their drawing, photography, and typing skills.

LITERATURE CITED

Andreae, Achilles. 1887. Ein neues Raubtier aus dem mitteloligociinen Meeressand
des Mainzer Beckens. Ber. Senckenberg. naturforsch. Ges., Frankfurt a. M.
1887: 125—133.

Andrews, Charles W. 1904. Further notes on the mammals of the Eocene of Egypt.
Geol. Mag. 1: 211—215.

Berggren, William A. 1972. A Cenozoic time-scale—some implications for
regional geology and paleobiogeography. Lethaia 4: 195—215.

Bowen, Bruce E. and Carl F. Vondra. 1974. Paleoenvironmental interpretations
of the Oligocene Gabal el Qatrani Formation, Fayum depression, Egypt. Ann.
Geol. Surv. Egypt 4: 115—138.

Fischer, Paul. 1880. Note sur un nouveau genre de mammifére fossile (Apterodon
gaudryi) des Phosphorites de Quercy. Bull. Soc. Géol. France 8: 288—290.
Lange, Brigitte. 1967. Créodontes des phosphorites du Quercy Apterodon gaudryi.
Ann. Paléontologie 53: 79—90.

NEW SPECIES OF APTERODON 9

Meyer, Grant E. 1973. A new Oligocene hyrax from the Jebel el Qatrani Forma-
tion, Fayum, Egypt. Postilla (Peabody Mus. Natur. Hist., Yale Univ.) no.
163: 1-11.

Osborn, Henry F. 1909. New carnivorous mammals from the Fayum Oligocene,
Egypt. Bull. Amer. Mus. Natur. Hist. 26: 415—424.,

Romer, Alfred S. 1966. Vertebrate paleontology. 3rd ed. Univ. Chicago Press,
Chicago. 468 p.

Said, Rushdi. 1962. The geology of Egypt. Amer. Elsevier Pub. Co., New York.
S)IPIE joy.

Savage, Robert J. G. 1969. Early Tertiary mammal locality in southern Libya.
Proc. Geol. Soc. London. 1969: 167—171.

Schlosser, Max. 1910. Uber einige fossile Saugetiere aus dem Oligociin von
Agypten. Zool. Anz. 35: 500—508.

Simons, Elwyn L. 1968. African Oligocene mammals: Introduction, history of
study, and faunal succession. Bull. Peabody Mus. Natur. Hist. (Yale Univ.)
28: 1-21.

1974. Parapithecus grangeri (Parapithecidae, Old World Higher Pri-
mates): New species from the Oligocene of Egypt and the initial differentiation
of Cercopithecoidea. Postilla (Peabody Mus. Natur, Hist., Yale Univ.) no.
166: 1—12.

Simons, Elwyn L. and Philip D. Gingerich. 1974, New carnivorous mammals from
the Oligocene of Egypt. Ann. Geol. Surv. Egypt 4: 157—166.

Szalay, Frederick S. 1967. The affinities of Apterodon (Mammalia, Deltatheridia,
Hyaenodontidae). Amer. Mus. Natur. Hist. Novitates, no. 2293: 1—17.

Van Valen, Leigh. 1966. Deltatheridia, a new order of mammals. Bull. Amer.
Mus. Natur. Hist. 132: 1-126.

Vondra, Carl F. 1974. Upper Eocene transitional and near-shore marine Qasr
el Sagha Formation, Fayum depression, Egypt. Ann. Geol. Surv. Egypt 4:
79—94,

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