Ancient sloths ranged in size from tiny climbers to ground-dwelling giants. Now, researchers report this body size diversity was largely shaped by sloths’ habitats, and that these animals’ precipitous ...

At first glance, this mammal looks like a horse gone terribly wrong. But, in reality, Chalicotherium is far from a botched ...

Pleistocene ground sloths constitute a remarkable and diverse group of xenarthran mammals that thrived across South America during a period of significant climatic and environmental flux. Their fossil ...

Giant sloths with razor-sharp claws and as large as Asian bull elephants once roamed the Earth, snacking on leaves at the tops of trees with a prehensile tongue. Now, scientists have figured out why ...

Recent excavations in South America have unearthed a fascinating glimpse into the prehistoric world, revealing the existence of giant, elephant-sized sloths that once carved massive, 2000-foot-long ...

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American Everybody loves sloths, and whenever we talk ...