For a long time, scientists believed the first humans to arrive in the Americas soon killed off these giant ground sloths through hunting ... crossing the Bering land bridge from Asia.

It is believed that this species of sloth came from the Pliocene Epoch (5.3 to 2.6 million years ago). The last genus of these giant land sloths eventually died out around 5,000 BC in Patagonia.

Some of the clues come from an archaeological site in central Brazil, Santa Elina, where bones of giant ground sloths show signs ... after crossing the Bering land bridge from Asia.

Giant ground sloths, described as "a hamster the size ... constructed an impressive network of 17 land tunnels and four subsea ones, including the world's only underwater roundabout, to prevent ...