Photo: Ring-tailed Lemur

A primate (pronounced /ˈprаɪmeɪt/, us: prī′·māt) is a member of the biological order Primates (/prаɪˈmeɪtiːz/ prī·mā′·tēz; Latin: "prime, first rank"), the group that contains lemurs, the Aye-aye, lorids, galagos, tarsiers, monkeys, and apes, with the last category including humans. With the exception of humans, who now inhabit every continent on Earth, most primates live in tropical or subtropical regions of the Americas, Africa and Asia. 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.

The Primates order has traditionally been divided into two main groupings: prosimians and simians. Prosimians have characteristics most like those of the earliest primates, and included the lemurs of Madagascar, lorisiforms, Aye-aye and tarsiers. Simians included the monkeys and apes. More recently, taxonomists have created the suborder Strepsirrhini, or "wet-nosed" primates, to include non-tarsier prosimians and the suborder Haplorrhini, or "dry-nosed" primates, to include tarsiers and the simians. Simians are divided into two groups: the platyrrhines ("flat nosed") or New World monkeys of South and Central America and the catarrhine ("narrow nosed") monkeys of Africa and southeastern Asia. The New World monkeys include the capuchin, howler and squirrel monkeys, and the catarrhines include the Old World monkeys (such as baboons and macaques) and the apes. Humans are the only catarrhines that have spread outside of Africa and southeastern Asia, although fossil evidence shows many species once existed in Europe as well.

Photo: Ring-tailed Lemur

A primate (pronounced /ˈprаɪmeɪt/, us: prī′·māt) is a member of the biological order Primates (/prаɪˈmeɪtiːz/ prī·mā′·tēz; Latin: "prime, first rank"), the group that contains lemurs, the Aye-aye, lorids, galagos, tarsiers, monkeys, and apes, with the last category including humans. With the exception of humans, who now inhabit every continent on Earth, most primates live in tropical or subtropical regions of the Americas, Africa and Asia. 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.

The Primates order has traditionally been divided into two main groupings: prosimians and simians. Prosimians have characteristics most like those of the earliest primates, and included the lemurs of Madagascar, lorisiforms, Aye-aye and tarsiers. Simians included the monkeys and apes. More recently, taxonomists have created the suborder Strepsirrhini, or "wet-nosed" primates, to include non-tarsier prosimians and the suborder Haplorrhini, or "dry-nosed" primates, to include tarsiers and the simians. Simians are divided into two groups: the platyrrhines ("flat nosed") or New World monkeys of South and Central America and the catarrhine ("narrow nosed") monkeys of Africa and southeastern Asia. The New World monkeys include the capuchin, howler and squirrel monkeys, and the catarrhines include the Old World monkeys (such as baboons and macaques) and the apes. Humans are the only catarrhines that have spread outside of Africa and southeastern Asia, although fossil evidence shows many species once existed in Europe as well.