The extinct mammals were about five times larger than a grizzly bear–and filled caves with their poop.

A new fossil and DNA analysis traces how dozens of sloth species responded to climate shifts and humans. Just two small tree-dwelling sloths remain today.

Most of us are familiar with sloths, the bear-like animals that hang from trees, live life in the slow lane, take a month to ...

An analysis of the sloth family tree suggests three different groups of the animals evolved to gigantic sizes in response to ...

A gigantic woolly mountain rat has finally been captured on camera deep in New Guinea’s remote forests.

Gorillas are beautiful animals of enormous size! They are easy to recognize as they thump their chests with muscular arms and ...