The extinct giant ground sloth that lived in South America and weighed up to about 4 tons was Megatherium.
Megatherium was an enormous member of the sloth family Megatheriidae. Its best-known species, Megatherium americanum, reached roughly 6 meters in total length and had a mass estimated at approximately 3.5–4 metric tons—comparable to a modern Asian elephant. It lived mainly in South America during the Pleistocene.
Despite its size, Megatherium was generally reconstructed as a plant-eating browser. Its powerful limbs allowed it to rear up while braced against its tail and hind limbs, giving it access to higher leaves and branches. Its large claws may also have served as defensive weapons, although older ideas about it digging extensively are disputed.
The first known M. americanum specimen was discovered near Argentina’s Luján River in 1787. Georges Cuvier named the genus in 1796; the name comes from Greek words meaning “great beast.” Megatherium disappeared around 12,000 years ago, near the end of the Pleistocene, alongside many other American megafauna. Eremotherium was a similarly giant relative, while Glyptodon and Doedicurus were armored mammals rather than sloths.