The oldest collection of prehistoric tools made out of bone reveals that humans were capable of advanced abstract reasoning about one million years earlier than previously thought, according to a study published by Nature. The study, conducted by researchers at UCL and CSIC—Spanish National Research Council—describes a collection of 27 now-fossilised bones that were shaped into tools about 1.5 million years ago.
This collection is the earliest group of bone tools ever found, showing that tools were produced one million years earlier than archaeologists once thought. Our early ancestors, known as hominins (human ancestors who could walk upright), already knew how to make tools out of stones for at least a million years, but there’s been limited evidence of toolmaking out of bones before about 500,000 years ago.
The hominins who shaped these bone tools used a technique similar to how they made tools out of stone by chipping away small flakes to create sharp edges—a process called ‘knapping.’ Using the same techniques in different materials shows that the hominins understood how to make tools and could adapt their techniques to different materials, which is a significant intellectual leap. This indicates that human ancestors at that time already possessed high cognitive skills.
“The tools show evidence that their creators carefully worked the bones, chipping off flakes to create useful shapes. We were excited to find these bone tools from such an early timeframe. It means that human ancestors could transfer skills from stone to bone, a level of complex cognition that we haven’t seen elsewhere for another million years,” said Dr Renata F. Peters from UCL Archaeology.
“This discovery leads us to assume that early humans significantly expanded their technological options, which until then were limited to the production of stone tools and now allowed new raw materials to be incorporated into the repertoire of potential artifacts,” added Dr Ignacio de la Torre of the CSIC-Spanish National Research Council. “At the same time, this expansion of technological potential indicates advances in the cognitive abilities and mental structures of these hominins, who knew how to incorporate technical innovations by adapting their knowledge of stonework to the manipulation of bone remains.”
The tools were originally discovered in Olduvai Gorge, Tanzania, renowned for its long history of critical archaeological discoveries revealing the origins of humans. The team found 27 bones that had been shaped into tools. The bones used are primarily from large mammals, including elephants and hippos. This collection’s tools are exclusively made from the animals’ limb bones, as these are the most dense and strong.
The tools originate from a prehistoric point where hominin cultures underwent one of the first technological transitions. The tools date back about 1.5 million years ago and include axes carefully shaped by knapping. This method allowed for the production of tools through more standardised means.
Before finding this collection, bone tools had only been identified a few times in isolated instances and never in a manner that implied that human ancestors were systematically producing them.
At this stage, it’s not clear what the tools were used for. The authors suggest that because of their overall shape, size, and sharp edges, it’s likely that they were used to process animal carcasses for food. It’s also unclear which species of human ancestor made the tools. No hominin remains were found alongside the bones, but researchers know that our human ancestors, Homo erectus and Paranthropus boisei lived in this region.
The team hopes their findings will prompt archaeologists to re-examine bone discoveries worldwide in case other evidence of bone tools has been missed.
de la Torre, I., Doyon, L., Benito-Calvo, A., et al. Systematic bone tool production at 1.5 million years ago. Nature (2025). https://doi.org/10.1038/s41586-025-08652-5