; suborder Simiiformes, superfamily Ceboidea)
A family of very small, squirrel-like, insectivorous and fruit-eating, New World monkeys that have thick fur, non-prehensile tails, claws on all but the first hind digits, and a quadrupedal gait. There are only two molar teeth, except in the genus Callimico, and no cheek pouches. The nostrils are platyrrhine. The thumb is not opposable. Litters commonly consist of two or three young, and the placental yolk sac grows larger than in most higher primates. The Callitrichidae live in family groups of three to eight individuals, but sometimes in larger groups. Fully arboreal, they inhabit the forests of tropical S. America. There are five genera, with some 25–30 species.
Subjects: Zoology and Animal Sciences.