Megalonychid Sloths from the Early Late Hemphillian (Late Miocene), Curré Formation, San Gerardo de Limoncito, Costa Rica

A reevaluation of the late Miocene (early late Hemphillian) megalonychid fossils found at San Gerardo de Limoncito, Coto Brus Valley, Costa Rica is presented. These specimens which had previously been referred to Pliometanastes cf. P. protistus, based on a partial mandible and associated teeth material are now considered to belong to the genus Zacatzontli, previously only known from the late Miocene of Mexico and here reported for the first time from Costa Rica. The material is considered to be a new species of Zacatzontli based on a comparison with the type and other members of the Megalonychidae from the Hemphillian of North America as Zacatzontli tecolotlanensis, Pliometanastes protistus and Megalonyx spp.