Stone tools found in Israel are at least 1.9 million years old, showing humans left Africa earlier than scientists once believed.

Sloths weren't always slow-moving, furry tree-dwellers. Their prehistoric ancestors were huge - up to 4 tons - and when startled, they brandished immense claws. For a long time, scientists believed ...

A newly uncovered trove of ancient stone tools in northwest Kenya suggests early humans didn't use them sporadically but routinely over hundreds of thousands of years, at the very emergence of ...