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.

Scientists discovered world's oldest known bone tools in Tanzania, revealing early human intelligence and innovation 1.5 million years ago.

Early humans were regularly using animal bones to make cutting tools 1.5 million years ago. A newly discovered cache of 27 carved and sharpened bones from elephants and hippos found in Tanzania's Olduvai Gorge site pushes back the date for ancient bone tool use by around 1 million years.