definition of megatherium
Megatherium (/ m É É¡ É Ë Î¸ ÉªÉr i É m / meg-É-THEER-ee-Ém from the Greek mega [Î¼Î­Î³Î±Ï], meaning great, and therion [Î¸Î·ÏÎ¯Î¿Î½], beast) was a genus of elephant-sized ground sloths endemic to South America, sometimes called the giant ground sloth, that lived from the Early Pliocene through the end of the Pleistocene.