Giant Sloth

Category: Dinosaur

Megatherium, also known as the ‘giant sloth’, was a large ground-dwelling relative of today's tree-dwelling sloths. The largest species was Megatherium americanum. It browsed for plants in South America, becoming extinct around ten thousand years ago during the Pleistocene era.

Giant Sloth

Giant Sloth

Genera and Species

Genus: Megatherium

Species: M. americanum

Common Name: Giant Sloth


Megatherium americanum was a large mammal with stubby legs and long arms. It was covered with yellow brown fur its blunt skull contained teeth specialized for grinding plant matter. Its large claws aided it in pulling down branches to feed on tree leaves, and it likely had a long tongue to further assist in this.


Length: 20 feet

Weight: 4.4 tons


Thanks to numerous skeletons and other remains, the biology of Megatherium is very well known. Hair samples show that its coloration was a yellowish brown, and also featured a mat of green aglae, similar to living sloths today. Samples of dung show which plants Megatherium preferred, and that its diet varied according to climate. During the dry season, it ate desert plants, while in the cooler wet months it preferred to feed from trees.

History of Discovery

Megatherium americanum was first named in 1796 by the eminent French anatomist Georges Cuvier, known to many as the ‘father of palaeontology’. He recognized it was a type of sloth, and dubbed it Megatherium, which means ‘large beast’.

The oldest fossils of the genus Megatherium are 5.4 million years old, but the species Megatherium americanum evolved later, in the Pleistocene era, around 1.8 million years ago. Humans lived alongside the giant sloth and may have contributed to its extinction ten thousand years ago by hunting it for food.