6533b82bfe1ef96bd128d503

RESEARCH PRODUCT

Miocene fossil cercopithecoids from Kenya

subject

description

Fossil cercopithecoid material from Ngeringerowa, Ngorora, and Nakali, dated at between 8.5 and 10.5 m.y., is described. The specimens are the only cercopithecoid remains dated between 15 and 6 m.y. from sub-Saharan Africa. The mandible of asmall colobine from Ngeringerowa (similar in size to Colobus verus) is assigned to a new genus and species, Microcolobus tugenensis. Unlike other colobine genera, the symphysis of Microcolobus lacks an inferior transverse torus. A colobine lower M1 or 2 from Nakali is longer and narrower than molars of M. tugenensis, indicating that it may belong to a distinct taxon. A P4 from Ngorora cannot be assigned confidently to subfamily, due to its unique metaconid morphology. The relationship between the new genus and other Miocene monkeys is considered.