Middle paleocene euprimate from Southern China and the distribution of primates in the paleogene

Abstract

A re-examination of the Paleogene small mammals in the collection of the IVPP in 1985 revealed that the type specimens of Diacronus anhuiensis Xu, 1976 , and Decoredon elongatus Xu, 1977 are conspecific. These specimens, previously allocated to the Anagalidae and Hyopsodontidae, respectively, represent the oldest recognized member of the primate semiorder Euprimates, either an omomyid or the representative of the common stock which gave rise to the Adapidae and Omomyidae. The presence of a euprimate in Asia during the middle Paleocene (and therefore possibly a whole radiation of this group) might help explain the sudden appearance of euprimates in the beginning of the Eocene in Euroamerica as a northern dispersal event rather than a northern migration of hitherto unknown Paleocene African primates.