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 POSTILLA Published by the Peabody Museum of Natural History, Yale University Postilla includes results of original research on systematic, evolution- ary, morphological, and ecological biology, including paleontology. Syntheses and other theoretical papers based on research are also welcomed. Postilla is intended primarily for papers by the staff of the Peabody Museum or on research using material in this Museum. Editor: John H. Ostrom Managing Editor: Zelda Edelson Postilla is published at frequent but irregular intervals. 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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, REVIEW STYLE FORM TITLE ABSTRACT NOMENCLATURE ILLUSTRATIONS FOOTNOTES TABLES REFERENCES AUTHOR’S COPIES PROOF COPYRIGHT INFORMATION FOR AUTHORS The Publications Committee of the Peabody Museum of Natural History reviews and approves manuscripts for publication. Papers will be published in approximately the order in which they are accepted; delays may result if manuscript or illustrations are not in proper form. To facilitate review, the original and one carbon or xerox copy of the typescript and figures should be submitted. The author should keep a copy. Authors of biological papers should follow the CBE Style Manual Third Edition (Amer. Inst. Biol. Sci.). Authors of paleontological manuscripts may choose to follow the Suggestions to Authors of the Reports of the U.S. Geological Survey, Fifth Edition (U.S. Govt. Printing Office). 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