Olduvai Gorge, located in northern Tanzania, is renowned for its rich archaeological significance, with sediment layers that date back approximately 1.8 million years. These layers have previously yielded some of the earliest evidence of stone tools, marking a pivotal moment in the history of human technology. Recently, however, researchers have made a groundbreaking discovery in this region: a substantial cache of prehistoric bone tools dating back about 1.5 million years, representing the oldest known collection of mass-produced bone tools.
The findings were detailed in a recent paper published in the journal Nature, highlighting the implications of this discovery for our understanding of early human cognition. While the exact hominin species responsible for crafting these tools remains unidentified, the evidence suggests that our early ancestors possessed advanced reasoning skills much earlier than previously believed. Co-author Renata F. Peters, an archaeologist at University College London, emphasized the significance of the evidence: “The tools show evidence that their creators carefully worked the bones, chipping off flakes to create useful shapes,” she noted. “We were excited to find these bone tools from such an early timeframe, indicating that human ancestors were capable of transferring skills from stone to bone.”
The history of tool-making within the hominin family tree is extensive, with species utilizing stone tools for around 2.6 million years. Early members of our genus, such as Homo habilis, exhibited a blend of human and ape-like features and were among the first to walk upright. By approximately 1.2 million years ago, the species known as Homo erectus began to create more advanced tools, such as hand axes. The previously dominant Oldowan tools, primarily sharp flakes used for basic tasks like chopping and scraping, were soon outmatched by the more refined tools crafted by later hominins like the Neanderthals.
Using geochemical analysis, researchers at Ewass Oldupa discovered that hominins sourced some of their quartzite locally while traveling up to 12 kilometers (7.5 miles) for other materials. This indicates a selective approach to raw material choice, with hominins favoring different types of quartzite based on the specific requirements of their tools. Previous studies have suggested that early toolmakers possessed a keen understanding of material properties, recognizing which resources produced sharper blades and which offered a better balance of durability and sharpness.
The recent findings reveal a prehistoric bone tool factory within the T69 Complex at Olduvai Gorge. Excavations conducted between 2015 and 2022 uncovered over 10,000 stone tools alongside remains of various animals, including fish, crocodiles, hippopotamuses, elephants, and rhinoceroses. Among these fossils, researchers identified 27 bone tools, demonstrating distinct signs of intentional modification, such as flake removal and shaping to create elongated forms. Although other factors like carnivore gnawing could account for some flaking, the evidence suggests that these tools were purposefully crafted.
The analysis reveals that the hominins selectively used bones from large mammals, particularly elephants and hippopotamuses. This selection indicates a sophisticated understanding of bone morphology and anatomy, as evidenced by their preference for thick limb bones and the application of specific flaking techniques. Co-author Ignacio de la Torre from the CSIC-Spanish National Research Council remarked, “This discovery leads us to assume that early humans significantly expanded their technological options, which until then were limited to stone tools.”
Ultimately, this expansion signifies not only a broadening of technological capabilities but also a notable advancement in the cognitive abilities of these early hominins. Their ability to innovate and adapt their knowledge of stone tool-making to include bone manipulation marks a significant milestone in our understanding of human evolution.
For more on this fascinating discovery and its implications for understanding human evolution, refer to the article published in Nature (2025). DOI: 10.1038/s41586-025-08652-5.
