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

Sloths once came in a variety of sizes and lived in multiple settings in many parts of the world. A study in the journal Science examined sloth evolution over the past 35 million years, investigated ...

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 ...

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 ...

Ancient sloths lived in trees, on mountains, in deserts, boreal forests and open savannahs. These differences in habitat are primarily what drove the wide difference in size between sloth species.