Goeldi's monkey
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Mammalia
Order:Primates
Family:Callitrichidae
Genus:Callimico
species:goeldii
Binomial name
Callimico goeldii
Goeldi's monkey (Callimico goeldii) is a small, South American monkey that lives in the upper Amazon Basin region of Bolivia, Brazil, Colombia, Ecuador, and Peru. It is the only species classified in the genus Callimico.

Goeldi's monkeys are blackish or blackish-brown in color. Their bodies are around 8 to 9 inches long (about 22 cm), and their tails are 10-12 inches long (25-30 cm).

Goeldi's monkey was first described in 1904, making it one of the last monkey genera to be described. Its features are intermediate between those of Callitrichidae and Cebidae. It is sometimes placed in its own family Callimiconidae and sometimes in Callitrichidae, the family containing marmosets and tamarins.

Females reach sexual maturity at 8.5 months, males at 16.5 months. The gestation period lasts from 140 to 180 days. The mother carries a single baby monkey per pregnancy. The infant is weaned after about 65 days.

Goeldi's monkeys prefer to forage in dense scrubby undergrowth; perhaps because of this, they are rare, with groups living in separate patches of suitable habitat, separated by miles of unsuitable flora. Their diet consists of fruit, insects, spiders, lizards, frogs, and snakes. They live in small social groups (approximately six individuals) that stay within a few feet of one another most of the time, staying in contact via high-pitched calls.

The life expectancy in captivity is about 10 years.