OLIGOCENE ANTHRACOTHERIIDAE (ARTIODACTYLA) FROM THE USFAN AND SHUMAYSI FORMATIONS, WESTERN SAUDI ARABIA

The (?Cretaceous-Oligocene) Usfan and overlying (Oligocene) Shumaysi formations are composed of pre- and synrift shallow marine to clastic sediments. These are exposed along the eastern coast of the Red Sea near Jeddah and Makkah, western Saudi Arabia. Both formations produced Oligocene terrestrial mammals including hyraxes, embrithopods, proboscideans, artiodactyls, and primates. Artiodactyl fossils found in both formations and are represented by cranial and postcranial elements. These specimens belong to the family Anthracotheriidae, an extinct group that lived in the Asia, Europe, Africa, and North America from the middle Eocene through the late Miocene. The Saudi anthracothere specimens represent Bothriogenys, a small to medium-sized taxon, with elongate skull and lower jaw with a shallow mandible, a complete dental formula (3.1.4.3), and modest diastemata between p1-c1 and c1-i3. The upper beds of the Usfan Formation yielded several specimens of Bothriogenys including a complete cranium with teeth, a lower jaw bearing complete set of teeth on left and right dentaries, and several typically artiodactyl astragali showing clear articulation facets. The middle part of the Shumaysi Fm. produced dental and postcranial elements of adult and juvenile individuals of Bothriogenys. Prior to this report, Bothriogenys was only known from the Paleogene of East and southeast Asia and the Fayum province of Egypt. The new material from western Saudi Arabia shows strong affinities with Fayumian species, in particular, the early Oligocene Bothriogenys andrewsi from the upper part of the Jebel Qatrani Formation. The Saudi specimens extend the record of Bothriogenys into the late Oligocene and fill a paleogeographic gap in the distribution of this group in the later Paleogene.