A study led by the CSIC with involvement of the UAB reveals that the production of bone tools 1.5 million years ago was methodical and systematic. Before this discovery, it was considered that early humans only made bone tools occasionally. This practice could have had an effect on the development of more complex cognitive patterns, and the standardisation of a new set of behaviours among early humans.
The discovery, published in the journal Nature, was made at the Olduvai Gorge in Tanzania, considered to be the cradle of humankind. It is a milestone in the archaeology of human origins, since prior to the discovery of this bone tool assemblage it was thought that bone technology was barely known among our earliest ancestors.
"This discovery leads us to believe that early humans significantly expanded their technological choices, which until that moment were constrained to the production of stone artefacts but then enabled incorporating new raw materials to the repertoire of potential tools", states Ignacio de la Torre, scientist at the CSIC-Institut d'Història and co-director of the OGAP project. "Additionally, this enhancement of the technological potential hints at advances in 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", he adds.
The research also included the outstanding involvement of Rafael Mora Torcal, professor in the Department of Prehistory at the UAB.
"The possible use of bone tools had been proposed in several occasions, in which the technological practices seen in the stone remains had been transferred to bone fragments to create the artefacts. This controversial hypothesis has not enjoyed consensus in the palaeoanthropological discussion. In this article we make an important contribution to the characterisation of the cognitive capacities of the first representatives of the Homo genus, with new arguments that support the validity of the hypothesis that the use of bone tools is anchored to the origins of the first technological manifestations", Rafael Mora points out.
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 artefacts first discovered at Olduvai Gorge. The Oldowan spanned between 2.6 and 1.5 million years ago and is characterised by the production of sharp-edged stone flakes through the striking of two rocks against each other. This relatively simple technology led to a new culture emerging 1.7 million years ago, the Acheulean, that lasted until 150,000 years ago.
The Acheulean technology is well known in archaeological registries thanks to the presence of handaxes, large, robust, often pointed and almond-shaped stone artefacts, and whose production required 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.
For hundreds of thousands of years, early humans had considered the animals they co-existed with in the African savannahs either as a hazard, for there is evidence that often humans were preys to felids and large birds; as competitors, for these ancestors rivalled with hyenas and vultures to access carcasses hunted by large felids; or as a source of proteins, which these 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, found in the Frida Leakey Korongo West (FLK West) area of the Olduvai Gorge, and where humans already had a primary access to meaty resources, no longer were animals only dangerous, competitors or simply foodstuff, but also a source of raw materials for producing tools", says de la Torre.
The results of the study demonstrate that at the transition from Oldowan to 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 standardised bone tools, early Acheulean toolmakers unravelled technological repertoires that were previously thought to have appeared routinely more than one million years later", states de la Torre. "This innovation may have had a significant impact on the complexification of behavioural repertoires among our ancestors, including enhancements in cognition and mental templates, artefact curation and raw material procurement", he concludes.
The OGAP project
Per a dur a terme l'estudi ha estat necessària l'exhaustiva documentació del registre arqueològic excepcional que desenvolupa el Projecte OGAP (Olduvai Gorge Archaeology Project) To conduct the study it was necessary to access the exhaustive documentation of the exceptional archaeological record developed by the Olduvai Gorge Archaeology Project (OGAP). This multidisciplinary project is led by Ignacio de la Torre (CSIC) and Jackson Njau (Indiana University, US), and includes an international group of researchers, of which UAB researcher Rafael Mora Torcal plays a prominent role in the coordination of fieldworks and the study of the artefacts. The OGAP project includes collaborators from several institutions in Spain, such as CENIEH and ICREA, and from other countries such as the UK, France, Germany, US, Canada and Tanzania. Since 2010, the OGAP has organised 19 excavation campaigns in Olduvai, many of them to study the transition from the Oldovan to the Acheulean culture, closely linked to the study of Homo habilis and its evolutionary successor, Homo erectus.
Original article: 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
