Megatherium (/mɛɡəˈθɪəriəm/ meg-ə-theer-ee-əm from the Greek mega [μέγας], meaning “great”, and therion[θηρίον], “beast”) was a genus of elephant-sized ground sloths endemic to South America that lived from the late Pliocene through the end of the Pleistocene.^[1] Its size was exceeded by only a few other land mammals, including mammoths and Paraceratherium.

The first fossil specimen of Megatherium was discovered in 1788 by Manuel Torres, on the bank of the Luján River in Argentina. The fossil was shipped toMuseo Nacional de Ciencias Naturales in Madrid the following year, where it remains. It was reassembled by museum employee Juan Bautista Bru, who also drew the skeleton and some individual bones.^[2] Based on Bru’s illustrations, comparative anatomist Georges Cuvier determined the relationships and appearance of Megatherium. He published his first paper on the subject in 1796, a transcript of a previous lecture at the French Academy of Sciences. He published on the subject again in 1804; this paper was republished in his book Recherches sur les ossemens fossiles de quadrupèdes.^[3] In his 1796 paper, Cuvier assigned the fossil the scientific name Megatherium americanum.

Cuvier determined that Megatherium was a sloth, and at first believed that it used its large claws for climbing trees, like modern sloths, although he later changed his hypothesis to support a subterranean lifestyle, with the claws used to dig tunnels.^[3]

Fossils of Megatherium and other western megafauna proved popular with the Georgian era public until the discovery of the dinosaurs some decades later. Since the original discovery, numerous other fossilMegatherium skeletons have been discovered across South America, in Chile, Argentina, Bolivia, Peru, Brazil,Paraguay and Uruguay.^[1]

(From Wikipedia, June 2015)