Giant ground sloth

Megatherium Temporal range: Early Pliocene to Early Holocene, 5–0.010 Ma PreЄ Є O S D C P T J K Pg N ↓ Possible later date of 0.008 Ma
M. americanum skeleton, Natural History Museum, London
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Pilosa
Family:	†Megatheriidae
Subtribe:	†Megatheriina
Genus:	†Megatherium
Type species
†Megatherium americanum Cuvier, 1796
Species
†M. altiplanicum Saint-André & de Iuliis, 2001 †M. medinae Philippi, 1893 †M. istilarti Kraglievich, 1925 †M. parodii Hoffstetter, 1949 †M. sundti Philippi, 1893 †M. gallardoi Ameghino & Kraglievich, 1921
Synonyms
Essonodontherium Ameghino, 1884 Hebetotherium Ameghino, 1895

Megatherium (/mɛɡəˈθɪəriəm/ meg-ə-THEER-ee-əm from the Greek mega [μέγας], meaning "great", and [θηρίον], "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 . 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 to Museo 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. 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. In his 1796 paper, Cuvier assigned the fossil the scientific name Megatherium americanum.