Golden-bellied mangabeys are medium-sized monkeys and are closely related to the baboons. Their head and body length ranges from 17 to 33 inches. Males weigh up to 22.5 pounds, and females up to 12 pounds. The brownish species, C. galeritus and C. torquatus, are considered to be closely related to each other, and widely separated from the blackish species, C. albigena and C. aterrimus. All have tails longer than their bodies. Females are smaller than males. Their large, strong incisor teeth allow mangabeys to exploit hard seeds which are not accessible to guenons, with which they share habitats. General coloration is a dull yellowish-brown. The hair on top of the head forms a crest, similar to that of the langurs.