A new species of Megalonychidae (Mammalia, Xenarthra) from the Quaternary of Poço Azul (Bahia, Brazil)

Cástor CARTELLE, Gerardo DE IULIIS & François PUJOS

en Comptes Rendus Palevol 7 (6) - Pages 335-346

Published on 31 August 2008

The new genus and species Ahytherium aureum (Mammalia, Xenarthra, Megalonychidae) from the Quaternary of Poço Azul (Bahia, Brazil) is described. It is the first Brazilian megalonychid known from reasonably complete and well-preserved remains. Purported Brazilian megalonychids described in the past, such as Ocnopus gracilis and Xenocnus cearesis, are noted as belonging to other sloth clades, and the acceptance by past paleontologists of the existence of ‘strange’ megalonychids in Brazil is shown to be erroneous. Ahytherium aureum, in fact, exhibits typical megalonychid morphology. It differs from other known members of Megalonychidae in several characters, including a markedly shortened, but high rostral region, with dorsally inflated frontals, wide zygomatic processes of the frontal, narrow, blade-like and anterolaterally oriented lacrimals, curved, slender and oval caniniforms, gracile humerus with less developed deltopectoral shelf, and relatively distal position of the greater trochanter of the femur. A second specimen from São Paolo state is tentatively assigned to the new genus and species.


Xenarthra, Megalonychidae, Ahytherium aureum, Quaternary, Brazil

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