Before this discovery in Tanzania’s Olduvai Gorge, in which CENIEH participated, researchers believed that hominins only occasionally made bone tools. This finding suggests that toolmaking may have played a role in shaping more advanced cognitive patterns and establishing a standardized set of behaviors among early humans.
Alfonso Benito Calvo, a researcher at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), is part of an international team led by the Consejo Superior de Investigaciones Científicas (CSIC) that has published a study in Nature on the Olduvai Gorge in Tanzania. The research reveals that early humans systematically and methodically produced bone tools 1.5 million years ago.
This discovery marks a significant breakthrough in the study of human origins. Before uncovering this set of bone tools at the T69 Complex excavation site in Olduvai, researchers believed that such tool-making techniques were virtually unknown among our earliest ancestors.
“This discovery leads us to believe that early humans expanded significantly their technological choices, which until this moment was constrained to the production of stone artifacts, and now enabled incorporating new raw materials to the repertoire of potential tools,” states Ignacio de la Torre, a scientist at the CSIC- Instituto de Historia and co-director of the OGAP project. “Additionally, this enhancement of the technological potential hints at advances in the cognitive capacities and mental templates of these hominins (i.e., hominids with a bipedal locomotion), who understood how to transfer technical innovations from stone flaking to bone tool production.”
Evolutionary keys
Eastern Africa contains the earliest evidence of tool use and production among the first Genus Homo ancestors. The best known is the Oldowan culture, named after the stone artifacts first discovered at Olduvai Gorge. The Oldowan spanned between 2.6 and 1.5 million years ago, and is characterized by the production of stone sharp flakes through striking two rocks against each other.
This relatively simple technology led to a new culture emerging 1.7 million years ago, i.e., the Acheulean, that lasted until 150,000 years ago.
The Acheulean technology is well known by the conspicuous presence of handaxes, which are large, robust, often pointed and almond-shaped stone artifacts, and whose production requires remarkable technical ability. “Prior to our discovery, the technological transition from the Oldowan to the Acheulean was limited to the study of stone tools,” de la Torre points out.
A New Perspective on Early Human-Animal Interaction
For hundreds of thousands of years, early humans had seen the animals they co-existed with at the African savannahs either as a hazard, for there is evidence that often humans were prey to felids and large birds–; as competitors, for our ancestors rivaled with hyenas and vultures to access carcasses hunted by large felids; or as a source of proteins, which our ancestors obtained mostly from bone marrow in prey leftovers abandoned by carnivores.
“Our discovery indicates that, from the Acheulean–period in which the T69 Complex site was formed and where humans already had primary access to meaty resources–no longer were animals only dangerous, competitors or just foodstuff, but also a source of raw materials for producing tools,” says de la Torre.
Our results demonstrate that at the transition between the Oldowan and the early Acheulean, East African hominins developed an original cultural innovation that entailed a transfer and adaptation of knapping skills from stone to bone.
“By producing technologically and morphologically standardized bone tools, early Acheulean toolmakers unraveled technological repertoires that were previously thought to have appeared routinely more than 1 million years later,” states de la Torre. “This innovation may have had a significant impact on the complexification of behavioral repertoires among our ancestors, including enhancements in cognition and mental templates, artifact curation, and raw material procurement,” he concludes.
Reference: “Systematic bone tool production at 1.5 million years ago” by Ignacio de la Torre, Luc Doyon, Alfonso Benito-Calvo, Rafael Mora, Ipyana Mwakyoma, Jackson K. Njau, Renata F. Peters, Angeliki Theodoropoulou and Francesco d’Errico, 5 March 2025, Nature.
DOI: 10.1038/s41586-025-08652-5
The Olduvai Gorge Archaeology Project (OGAP) is led by Ignacio de la Torre (scientist at the Instituto de Historia, CSIC-Spanish National Research Council and head of the Pleistocene Archaeology Lab) and Jackson Njau (Indiana University, US), and includes collaborators from several institutions in Spain (CENIEH, UAB, ICREA) and abroad (UK, France, Germany, US, Canada and Tanzania, among others).
Fieldwork at Olduvai by OGAP has been primarily funded by two European Research Council grants (ORACEAF (Starting Grants, 2012-2016) and BICAEHFID (Advanced Grants, 2019-2026). Research at Olduvai has been possible thanks to the support of the Tanzanian Authorities (Tanzanian Commission of Science and Technology, the Department of Antiquities, the National Museum of Tanzania, and the Ngorongoro Conservation Area Authority) and local collaborators, particularly Maasai communities living around the Olduvai area (which is cataloged by UNESCO as a World Heritage Site).
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