Choloepus Illiger, 1811 . Prodr. Syst. Mamm. Avium., p. 108.
TYPE SPECIES: Bradypus didactylus Linnaeus, 1758, by subsequent designation (Gray, 1827).
SYNONYMS: Unaues Rafinesque, 1815; Unaus Gray, 1821 .
COMMENTS: Reviewed by Wetzel (1985a).