marmoset

Any of a group of small tree-dwelling monkeys found in South and Central America; some reach a body length of only 15 cm/6 in. Most species have characteristic tufted ears, clawlike nails, and a handsome tail, which is not prehensile (it cannot be used to grip branches in the same way as the arms and legs). Some marmosets are known as tamarins. (Genus Callithrix and related genera, family Callithricidae.)

Best-known is the common marmoset C. jacchus of Brazil, often kept there as a pet. The discovery of a new species of Brazilian marmoset, C. saterei, was announced in 1996. The black-capped dwarf marmoset was discovered in Brazil in 1997. Another new species was discovered in Brazil in 1998. It is the world's second smallest monkey and weighs 160 g/5.6 oz with a body length of 15 cm/6 in (excluding tail) and has been named dwarf marmoset Callithrix humilis. Two new species of marmoset were discovered in northwestern Brazil in 2000: the Manicore marmoset Callithrix manicorensis and the Acari marmoset C. acariensis.