A primate (pronounced /ˈprаɪmeɪt/, us: prī′·māt) is a member of the biological order Primates (/prаɪˈmeɪtiːz/ prī·mā′·tēz; Latin: “prime, first rank”[2]), the group that contains lemurs, the Aye-aye, lorids, galagos, tarsiers, monkeys, and apes, with the last category including humans.[3] With the exception of humans, who now inhabit every continent on Earth,[a] most primates live in tropical or subtropical regions of the Americas, Africa and Asia.[4] Primates range in size from the 30-gram (1 oz) Pygmy Mouse Lemur to the 200-kilogram (440 lb) Mountain Gorilla. According to fossil evidence, the primitive ancestors of primates may have existed in the late Cretaceous period around 65 mya (million years ago), and the oldest known primate is the Late Paleocene Plesiadapis, c. 55–58 mya. Molecular clock studies suggest that the primate branch may be even older, originating in the mid-Cretaceous period around 85 mya. (WIKIPEDIA)