The first Asian plesiadapoids (Mammalia: Primatomorpha)

Abstract

Two new genera and species of carpolestid plesiadapoids are described from early Eocene coal beds of the Wutu Formation, Wutu Basin, Shandong Province, China. Chronolestes simul, n. gen. and sp., possesses a reduced P3 and hypertrophied P4 as do all carpolestids, but contrasts with other members of this family in lacking a bladelike, polycuspidate P4. P3-4 of Chronolestes are structurally simpler, and almost certainly more primitive, than those of any other plesiadapoid. Chronolestes is interpreted as the sister group of all other carpolestids and forms the basis for the new, monotypic subfamily Chronolestinae. Carpocristes oriens, n. gen. and sp., is a dentally derived carpolestine characterized by triple median crests on P3-4 and an S-shaped blade on P4. The closely related North American species "Carpodaptes' hobackensis and "Carpodaptes' cygneus are transferred here to the new genus Carpocristes. Relationships among species of Carpocristes are reconstructed as (C. cygneus (C. hobackensis, C. oriens). The fossil record of North American and Asian Carpolestidae suggests at least two episodes of trans-Beringian dispersal for members of this clade during the Paleocene. -from Authors