The genus name Ateles derives from the ancient greek word ἀτέλεια ( atéleia), meaning 'incomplete, imperfect', in reference to the reduced or non-existent thumbs of spider monkeys. More recent molecular evidence suggests the Atelinae split in the middle to late Miocene (13 Ma), separating spider monkeys from the woolly spider monkeys and the woolly monkeys. Other theories include Brachyteles, Lagothrix and Ateles in an unresolved trichotomy, and two clades, one composed of Ateles and Lagothrix and the other of Alouatta and Brachyteles. This theory is not supported by fossil evidence. Theories abound about the evolution of the atelines one theory is they are most closely related to the woolly spider monkeys ( Brachyteles), and most likely split from woolly monkeys ( Lagothrix) in the South American lowland forest, to evolve their unique locomotory system. The population trend for spider monkeys is decreasing the IUCN Red List lists one species as vulnerable, five species as endangered and one species as critically endangered. Spider monkeys are susceptible to malaria and are used in laboratory studies of the disease. They are an important food source due to their large size, so are widely hunted by local human populations they are also threatened by habitat destruction due to logging and land clearing. They can produce a wide range of sounds and will 'bark' when threatened other vocalisations include a whinny similar to a horse and prolonged screams. Recent meta-analyses on primate cognition studies indicated spider monkeys are the most intelligent New World monkeys. They are social animals and live in bands of up to 35 individuals, but will split up to forage during the day. Due to their large size, spider monkeys require large tracts of moist evergreen forests, and prefer undisturbed primary rainforest. They primarily eat fruits, but will also occasionally consume leaves, flowers, and insects. Spider monkeys live in the upper layers of the rainforest, and forage in the high canopy, from 25 to 30 m (82 to 98 ft). They are also notable for their ability to be easily bred in captivity.ĭisproportionately long limbs and long prehensile tails make them one of the largest New World monkeys and give rise to their common name. The genus consists of seven species, all of which are under threat the brown spider monkey is critically endangered. Like other atelines, they are found in tropical forests of Central and South America, from southern Mexico to Brazil. Spider monkeys are New World monkeys belonging to the genus Ateles, part of the subfamily Atelinae, family Atelidae.

Monkey type