Eocene plesiadapiform shows affinities with flying lemurs not primates

Abstract

PLESIADAPIFORMES, of the North American and European Paleogene, is often identified as a sister group of primates. This hypothesis is based on several proposed anatomical synapo-morphies linking the best-known plesiadapiform families, Plesiadapidae, and Paromomyidae with Eocene primates^1–5. The first well-preserved skull of Ignacius graybullianus, an early Eocene paromomyid plesiadapiform, clarifies and corrects previous cranial reconstruction based on more fragmentary material^3,6,7. The new material indicates Plesiadapiformes are not Primates. Rather, several synapomorphies argue for a closer phylogenetic relationship between Plesiadapiformes and Cynocephalus, the extant flying lemur (order Dermoptera). In view of the finding that "archaic" primates are not cladistic Primates, the recently coined taxon "Euprimates" should be discarded. No support is lent by cranial anatomy to the hypothesis that Primates, tree shrews, bats and dermopterans form a clade Archonta.