Megatherium

Megatherium ( ; from Greek () 'great' + () 'beast') is an extinct genus of large ground sloths endemic to South America that lived from the Early Pliocene through the end of the Late Pleistocene. It is best known for the elephant-sized, type species Megatherium americanum, primarily known from the Pampas, but ranging southwards to northernmost Patagonia and northwards to southern Bolivia during the late Middle Pleistocene and Late Pleistocene. Various other species have been described, including those belonging to the Andean subgenus Pseudomegatherium, which range in size from comparable to M. americanum down to approximately .

The first (holotype) specimen of Megatherium americanum was discovered in 1787 on the bank of the Luján River in what is now northern Argentina. The specimen was then shipped to Spain the following year wherein it caught the attention of the pioneering French paleontologist Georges Cuvier, who named the animal in 1796, making it one of the first prehistoric animals to be scientifically named, and was the first to determine, by means of comparative anatomy, that Megatherium was a giant sloth.