The oldest known record of a ground sloth (Mammalia, Xenarthra, Folivora) from Hispaniola: evolutionary and paleobiogeographical implications

Abstract Sloths were among the most diverse groups of land vertebrates that inhabited Greater Antilles until their extinction in middle-late Holocene following arrival humans to islands. Although fossil record group is well known from Quaternary deposits Cuba, Hispaniola, and Puerto Rico, remains older units are scarce, limiting our understanding evolution biogeographic history. Here we report oldest ground sloth represented by an unassociated partial tibia scapula recognized as a single taxon late Miocene-early Pliocene Dominican Republic. The combination characters observed on suggests close relationship with Megalocnus , otherwise only Pleistocene–Holocene Cuba. These fossils fill temporal gap between those previously early Miocene Cuba region provide additional support for continuous presence since Oligocene.