Primates

A primate (from Latin primat-, from primus: "prime, first rank") is a n constituting the   Primates. Primates arose 85–55 million years ago first as from small  mammals, which adapted to living in the trees of s: many primate characteristics represent adaptations to life in this challenging environment, including large brains, , , altered , and dexterous hands. Primates range in size from, which weighs 30 g, to the , weighing over 200 kg. There are 190–448 of living primates, depending on which classification is used. New primate species continue to be discovered: over 25 species were described in the first decade of the 2000s, and eleven since 2010.

Primates are divided into two distinct s (see diagram under History of terminology). The first suborder is called (from Greek 'wet-nosed'), which contains, , and s. These primates can be found throughout Africa, Madagascar, India, and Southeast Asia. The colloquial names of species ending in -nosed refer to the of the primate. The second suborder is called, which contains "dry-nosed" primates (from Greek 'simple-nosed') in the , , and clades. The last of these groups includes s. s (the infraorder called from the Greek word simos, meaning 'flat-nosed') refer to monkeys and apes, which can be classified as Old World monkeys and apes under the infraorder of s (from Latin 'narrow nosed') or as New World monkeys under the infraorder of  (from Latin 'flat-nosed'). Forty million years ago, simians from Africa migrated to South America by drifting on debris (presumably), which gave rise to the New World monkeys. The remaining simians (catarrhines) split into apes and Old World monkeys  approximately twenty-five million years ago. Common species that are simians include the s, s, s, and s; and the  s, s and s.

Primates have large brains (relative to body size) compared to other mammals, as well as an increased reliance on visual acuity at the expense of the sense of, which is the dominant sensory system in most mammals. These features are more developed in monkeys and apes, and noticeably less so in lorises and lemurs. Some primates are, with three independent channels for conveying color information. Except for s and s, primates have tails. Most primates also have. Many species are ; differences may include mass,  distribution,  width, canine tooth size, hair distribution, and coloration. Primates have slower rates of development than other similarly sized mammals, reach maturity later, and have longer lifespans. Depending on the species, adults may live in solitude, in mated pairs, or in groups of up to hundreds of members. Some primates, including s, humans and baboons, are primarily rather than, but all species have adaptations for climbing trees. Arboreal techniques used include leaping from tree to tree and swinging between branches of trees ; terrestrial locomotion techniques include walking on two limbs (ism) and modified walking on four limbs.

Primates are among the most social of animals, forming pairs or family groups, uni-male harems, and multi-male/multi-female groups. Non-human primates have at least four types of, many defined by the amount of movement by adolescent females between groups. Most primate species remain at least partly arboreal: the exceptions are some great apes, baboons, and humans, who left the trees for the ground and now inhabit every continent.

Close interactions between humans and non-human primates (NHPs) can create opportunities for the transmission of, especially virus diseases, including , , , , and. Thousands of non-human primates are used in research around the world because of their psychological and physiological similarity to humans. About 60% of primate species are threatened with extinction. Common threats include, , s, and primate hunting for use in medicines, as pets, and for food. Large-scale tropical forest clearing for agriculture most threatens primates.