Catarrhini

Catarrhini is a parvorder of primates, established in 1812 by Etienne Geoffroy Saint-Hilaire, comprising the Old World monkeys and apes, native exclusively to Africa and Asia. It sits within the infraorder Simiiformes and contains two superfamilies, Cercopithecoidea, the Old World monkeys, and Hominoidea, the apes, the sister group of the New World monkeys, Platyrrhini. Its name, from Greek for downward-facing nose, reflects the group distinguishing feature: nostrils that face downward rather than to the side, along with flat fingernails and toenails, an absence of prehensile tails, and a dental formula with eight rather than twelve premolars. Most catarrhine species show pronounced sexual dimorphism, live in social groups, and are active during the day.