Smallest Old World monkey

The Old World monkeys all belong to the taxonomic family Cercopithecidae, and are therefore wholly distinct taxonomically from the New World monkeys. The smallest Old World monkeys or cercopithecids are the two very closely related species of talapoin, formerly classed together as a single species but lately split into the Angolan or southern talapoin Miopithecus talapoin and the Gabon or northern talapoin M. ogouensis. Talapoins have a total length not normally exceeding 45 cm, and weigh about 0.8 kg in females, but are slightly heavier in males.

Although the Gabon talapoin was deemed to be a separate species as far back as 1969, it did not receive a formal binomial (Latin) name until 1997, and even today there is controversy as to whether its Latin name is zoologically valid. It derives from the Ogoue River in Gabon. The name "talapoin" derives from an old French word for a Buddhist monk, as it was once joked that these monkeys resemble such monks.