Distal portions of humeri from two Miocene Colombian primates were recovered during field work in 1986. The larger IGM 183420 is very similar in size and morphology to the humerus included in the type specimen of Cebupithecia sarmientoi, recovered from La Venta in 1945 (Stirton and Savage: Serv. Geol. Nac. Bogata 7:345–356, 1951) and is assigned to this taxon. IGM 183420 presents a number of features of the humerus associated with clinging postural behaviors in living platyrrhines, including a medial epicondyle with very little dorsal angulation, a cylindrical trochlea, and a contact facet for the coronoid process of the ulna. In these and other features Cebupithecia most closely resembles the extant genus Pithecia.
IGM 183512 is approximately the size of Saimiri sciureus and is very similar in morphology to the humerus of this small arboreal quadruped. The medial epicondyle is more dorsally angled, the medial lip of the trochlea is more pronounced and the capitulum is less spherical as compared to Cebupithecia. This fossil is assigned to the taxon Neosaimiri fieldsi.