Mapinguari Giant Sloth
Could a surviving giant ground sloth explain the Amazon's mapinguari? One researcher thought so, but ground sloths died out on the mainland 12,000 years ago.
The question behind the mapinguari is whether a giant ground sloth could still be alive in the Amazon. The answer from the fossil record is almost certainly no, but the idea has a history worth setting out.
What ground sloths were
Ground sloths were a large group of mammals in the Americas. The biggest, such as Megatherium, weighed roughly 3,700 to 4,100 kilograms, close to a modern elephant. Others were far smaller. Wikipedia says they became extinct on the American mainland about 12,000 years ago, along with most other big animals there. Small Caribbean species lasted much longer, until about 4,800 years ago in Cuba by radiocarbon dating. Oren notes that Argentine paleontologist Florentino Ameghino argued in 1898 that sloths still lived in Patagonia, based partly on a piece of skin from a cave in Chile. That skin turned out to be thousands of years old.
How the mapinguari became a sloth
Folklore describes a hairy, smelly beast with backward feet. In 1993 David C. Oren of the Museu Paraense Emílio Goeldi suggested that this might be based on real contact with a ground sloth. In his 2001 follow-up he reported seven hunters who said they had killed one and more than 80 people who said they had met one. He said the witnesses described a creature about 2 metres tall with four large canine-like teeth. He admitted that the short tail the hunters described does not match a sloth, and he named no confirmed specimen.
Weighing the idea
Critics point out that no sloth remains younger than a few thousand years have been found on the mainland. Paul S. Martin called survival not credible in 2005. Features such as a single eye and a mouth on the belly match no sloth. The theory remains an unproven hypothesis.
Sources
- Mapinguari (Wikipedia) - folklore, name origin, indigenous names, Oren’s hypothesis and critics
- Does the Endangered Xenarthran Fauna of Amazonia Include Remnant Ground Sloths? (David C. Oren, Edentata, 2001) - Oren’s own account of his informants and the hunters’ claims
- Ground sloth (Wikipedia) - extinction dates and sizes of ground sloths