Two new megalonychid sloths (Mammalia: Xenarthra) from the Urumaco Formation (late Miocene), and their phylogenetic affinities

Here we describe two new megalonychid sloths from the late Miocene of the Urumaco Formation (Falcon State, Venezuela), Urumacocnus urbanii gen. et. sp. nov. and Pattersonocnus diazgameroi gen. et sp. nov. The recovery of these distinct taxa greatly improves our understanding of sloth diversity in the late Miocene of northern South America. A phylogenetic analysis based on the combination of cranial and postcranial elements (particularly the femur) partially supports previous interpretations of the relationships of genera within the Megalonychidae, but also suggests the existence of a more complex set of subclades within the family in South America, North America and the Antilles.