Largest monkey family

The largest taxonomic family of monkeys is Cercopithecidae, which contains all 138 species of Old World monkey. These include the baboons and mandrill, colobuses, mangabeys, langurs, guenons, and macaques. It is in turn split into two subfamilies: Cercopithecinae, housing the baboons and mandrill, mangabeys, guenons, and macaques; and Colobinae, housing the colobuses (all African) and the langurs (all Asian).

In contrast, the 139 species of New World monkey currently known to science (several new ones have been discovered recently with others likely to be recognized in the future) are nowadays divided between no less than five separate taxonomic families (traditionally, they were split into two, the marmosets and tamarins being separated from the larger, "true" New World monkeys).