CONICET | Buscador de Institutos y Recursos Humanos

The record of South American Pleistocene Megalonychidae is scarce. Of the species described for intertropical Brazil, including Megalonyx sp., Ocnopus gracilis, Valgipes deformis, Xenocnus cearensis and Ahytherium aureum, only the latter, recently described, is valid. The new megalonychid species described here was recovered from the same locality as Ah. aureum. The latter is apparently more closely linked to the North American Pleistocene forms whereas Australonyx aquae may be more closely related to the Antillean sloths. The fossil remains of extant taxa recovered in association with the new sloth species suggest that the region, currently within the Caatinga biome, was a mosaic of the Atlantic Forest and Savannah biomes during the final stages of the Pleistocene.