
Organism · Placental mammals
Megatherium americanum
Source time context (not species duration) · ≈ 2.58–0.0117 Ma
Inferred life reconstruction
Megatherium americanum
Overview
Megatherium americanum was a gigantic ground-dwelling relative of sloths. Large claws and a robust skeleton on its enormous body attract attention. It illustrates a life unlike that of small modern sloths hanging from branches.[1]
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Key facts
The scientific name Megatherium americanum means “great beast of America.” There is also a story of the two halves of a skull collected by Charles Darwin being held in different institutions. Separated collections connect the story of one animal.[1]
Time and place
It is known from Pleistocene fossils of South America. The Pleistocene spans approximately 2.6 million to 12,000 years ago. It also appears in fossil assemblage lists from Chuí Creek in present-day southern Brazil. Records from several localities reveal the giant sloth’s former distribution.[1][3]
The time range describes source context, not the complete duration of this species.
Size, form and skeleton
Museums explain that large individuals could reach about 4 tonnes in body mass. Large claws and thick supporting bones are characteristic. Its ground-supported body can be compared with structures allowing it to rise on its hind limbs.[1]
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Habitat and reproduction
It was a sloth that lived on the ground rather than in trees. The interpretation that it could rear onto its hind limbs relates to how the skeleton supported its body. Consider how its height changed between standing on four legs and raising its body.[1]
Fossil discovery
The two halves of a skull collected by Darwin remained in different institutions. Modern research and museum accounts follow collection records to reconnect the specimen’s story. Its history of transport and storage, as well as its discovery locality, contributes to understanding the animal.[1]
References
Research questions
Which bones supported an enormous body standing on two legs? Researchers compare the skeleton, large claws, and body proportions together. Comparisons with other South American ground sloths reveal the group’s diverse bodies.[1]
Observation
Move your gaze from the large claws to the arms, trunk, and hind limbs. Alternating between a ground-supported posture and a raised stance brings the giant sloth’s body to life.[1]
Related organisms
Different bodies of Ice Age mammals
Place Megatherium’s large body and claws alongside Smilodon’s canines and forelimbs. Compare the bodies and ways of life of different Pleistocene mammals.
Two ground sloths known from Chuí Creek
Megatherium and Eremotherium appear in fossil lists from Chuí Creek in present-day southern Brazil. Together they allow exploration of a regional record in which fossils from several times accumulated and were reworked.