The oldest human-crafted bone tools on record are 1.5 million years old, a finding that suggests our ancestors were much smarter than previously thought, a new study reports. The tools, made from hippo and elephant leg bones, were discovered at Olduvai Gorge in Tanzania and are a million years older than any previously found shaped bone tools.

A recent discovery in Tanzania’s Olduvai Gorge has revealed that early humans were crafting bone tools 1.5 million years ago, pushing back previous estimates by a million years. Researchers found 27 well-preserved bone tools,