catarrhine

mammal

Also known as: Catarrhini

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Last updated

July 1, 2026

Quick Summary

Catarrhines are a division of primates that includes Old World monkeys, apes, and humans. They are characterized by nostrils that are close together and face downward. Unlike New World monkeys (platyrrhines), catarrhines typically have 32 teeth and, if they have a tail, it is never prehensile.12

Fossil evidence from Egypt's Fayum region indicates that catarrhines emerged during the Oligocene Epoch, between 33.9 and 23 million years ago. Early catarrhine genera found there include Aegyptopithecus, which is considered an ancestor to modern catarrhines. This period also saw the establishment of quadrupedalism as a common form of locomotion among these primates.3

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primate
Hands and feet
The hands of catarrhines show a greater range of precise manipulative activity than those of other primates. Lemurs, for example, lack the functional duality of the hands of most apes and Old World monkeys (catarrhines). Duality in hand function has been described in terms of precision and power…
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The hands of catarrhines show a greater range of precise manipulative activity than those of other primates. Lemurs, for example, lack the functional duality of the hands of most apes and Old World monkeys (catarrhines). Duality in hand function has been described in terms of precision and power…
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primate
Snouts, muzzles, and noses
…and Old World monkeys (the Catarrhini, meaning “downward nosed”), the nostrils are set close together, point forward or downward, and are separated by a very narrow septum.
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…and Old World monkeys (the Catarrhini, meaning “downward nosed”), the nostrils are set close together, point forward or downward, and are separated by a very narrow septum.
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Tertiary Period
Primates
…include the emergence of the catarrhines (Old World monkeys, apes, and humans) in Africa and the platyrrhines (New World monkeys) in South America. The catarrhines are the only group to possess truly opposable thumbs. (Some lower primates possess nominally opposable thumbs but lack the precision grip of catarrhines.)
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…include the emergence of the catarrhines (Old World monkeys, apes, and humans) in Africa and the platyrrhines (New World monkeys) in South America. The catarrhines are the only group to possess truly opposable thumbs. (Some lower primates possess nominally opposable thumbs but lack the precision grip of catarrhines.)
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