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''Ocepeia'' is an extinct genus of afrotherian mammal that lived in present-day Morocco during the middle Paleocene epoch, approximately 60 million years ago. First named and described in 2001, the type species is ''O. daouiensis'' from the Selandian stage of Morocco's Ouled Abdoun Basin. A second, larger species, ''O. grandis'', is known from the Thanetian, a slightly younger stage in the same area. In life, the two species are estimated to have weighed about and , respectively, and are believed to have been specialized leaf-eaters. The fossil skulls of ''Ocepeia'' are both the oldest known afrotherian skulls, and the best-known of any Paleocene mammal in Africa. Loosely grouped with the archaic ungulates known as "condylarths", ''Ocepeia'' shares several features with primitive paenungulates (a group including elephants, hyraxes, and extinct relatives), but some analyses suggest it is more closely related to Afroinsectiphilia (a group containing aardvarks, golden moles, and tenrecs). As such, it may represent a transitional stage in the evolution of paenungulates from insectivore-like mammals. Unusual features of ''Ocepeia'' include skull bones with many air-spaces, and teeth and jaws reminiscent of those of simian primates. ''Ocepeia'' also has fewer teeth than other early ungulates. ''Ocepeia'' is distinct enough from other groups that it is placed in its own family, Ocepeiidae. ''Ocepeia'' lived at a time when northwest Africa was at the intersection of the Atlantic Ocean and the ancient Tethys Ocean, and much of the area was flooded by shallow, warm inland seas. ''Ocepeia'' fossils are associated with diverse sharks, birds, and marine reptiles, and a small number of early mammals, including other condylarths and early proboscideans. The early appearance and specialized features of ''Ocepeia'' suggest afrotherians originated and diversified within Africa, contrary to theories suggesting a more northern origin. ==Discovery and naming== All specimens of ''Ocepeia'' come from the Ouled Abdoun Basin of Morocco, a phosphate basin. Research on ''Ocepeia'' has been carried out by French and Moroccan researchers led by Dr. Emmanuel Gheerbrant of the National Museum of Natural History in Paris. ''Ocepeia'' fossils have been recovered from the Grand Daoui, Meraa El Arech, and Sidi Chennane quarries, with the latter bearing the most complete specimens. Some of the original material was collected on-site as early as 1997, while other material was obtained from fossil dealers.〔〔 ''Ocepeia'' was first described and named in 2001 based on two lower jaw fragments assigned to the new species ''O. daouiensis'': one (designated CPSGM-MA1), bearing a premolar and first molar, is the holotype for the species.〔 Additional material assigned to ''O. daouiensis'' was described in 2010, including a near-complete left lower jaw bone and additional dental fragments.〔 In 2014, new specimens of ''O. daouiensis'' were described including a partial skull, upper jaw, and additional teeth, allowing for a complete reconstruction of what the intact skull looked like. The diversity of specimens, combined with CT scans of the partial skull, allowed for a much more detailed and comprehensive description. Additionally, new lower jaw fragments with larger teeth led to the description of ''O. grandis'', whose holotype (designated MNHN.F PM37) bears a canine tooth and full set of cheek teeth.〔 As of 2014, the skull of ''Ocepeia'' is the only known mammal skull from the Paleocene of Africa, as well as the oldest known skull of any afrotherian.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ocepeia」の詳細全文を読む スポンサード リンク
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