Thalassocnus is an extinct genus of apparently semiaquatic (for the geologically oldest species) or fully aquatic (for the geologically most recent species) marine sloth from the Miocene and Pliocene of South America. Fossils found to date have been from the coast of Peru and Chile. Thalassocnine were (semi-) marine sloths that grew to be slightly larger than the average human. Order: Pilosa, Family: Megatheriidae, Subfamily: Thalassocninae, Genus: Thalassocnus de Muizon & McDonald, 1995
Species:
Thalassocnus antiquus
Thalassocnus natans
Thalassocnus littoralis
Thalassocnus carolomartini
Thalassocnus yaucensis
