The first known ancestor of modern primates.
Fifty-five to fifty-eight million years ago this early tree dwelling mammal, resembling a modern squirrel, roamed North America and Europe. Plesiadapis had a broad flat skull with a rodent-like jaw and teeth. dental records indicate a functional shift toward grinding and crushing in the cheek teeth as an adaptation towards increasing omnivority and herbivority. This early mammal, first discovered in France, was known to have a bushy tail and sharped curved claws.