Prepotherium is an extinct genus of Prepotheriina ground sloths that lived during the Miocene period. Fossils of them have been found in Argentina.Prepotherium differed from Megatherium by being smaller and having a less exaggeratedly convex inferior border of the lower jaw.An additional species from Venezuela, P. venezuelanum, was named by R. Collins in 1935. from fossils found in the Portuguesa state and additional remains from the Acre state in Brazil.