Press office

NewsNext Previous

An Israeli and Catalan team is trying to solve the mysteries surrounding the presence of 1.5 million-year-old stone balls at some sites

This collaboration is led by the IPHES and is funded by the Gerda Henkel Foundation

It is presently unknown how these tools were developed or what they were used for and high-tech 3D artifact analysis will be used for this research


Stone balls are present in some Oldowan and Acheulian stone-tool assemblages, the oldest human cultural complexes known to humankind, dating to around 1.5 million years old. Their presence has puzzled researchers for more than half a century and still, little is known about how and why they acquired this shape, or what their uses might have been. Although some in the scientific community believe that these tools, known as spheroids, were intentionally manufactured, others claim that their form was obtained accidentally through percussion activities. In addition, some researchers have proposed that their morphology must reflect a specific function, or perhaps even some kind of social or symbolic norm.

Scanned 3D image of a limestone spheroid from the ‘Ubeidiya archeo-paleontological site (Israel) with associated dimensional data.

Now, a team of Catalan and Israeli specialists will try to find answers to the questions surrounding spheroids, by analyzing more than 200 spheroidal morphotypes found in the ‘Ubeidiya site (Israel). They want to find out if these objects were intentionally manufactured using a specific operating sequence, whether they are the result of heavy use for pounding, or if they were used as hammerstones. Different experiments are planned to obtain results helping to determine whether or not spheroids are the result of a complex cultural scheme involving mental planning.

Doctoral students Antoine Muller (HUJI) and Stefania Titton (URV) at Computational Archeology Laboratory of The Hebrew University of Jerusalem analyzing digital images obtained from ‘Ubeidiya spheroids (Photos D. Barsky).

This is the aim of the Lower Paleolithic Spheroids Project (LPSP), directed by IPHES researcher Deborah Barsky (Institut Català de Paleoecologia Humana i Evolució Social) and associate professor at the URV (Rovira i Virgili University of Tarragona), in collaboration with the Computational Archeology Laboratory of the Hebrew University of Jerusalem (CAL-HUJI, Israel) and Tel Hai College (Upper Galilee); funded by the Gerda Henkel Foundation (Germany).

Robert Sala, Josep Maria Vergès and Stefania Titton are among participating members from the IPHES and the URV (Rovira i Virgili University of Tarragona), with Leore Grosman and Antoine Muller from CAL-HUJI, and Gonen Sharon from THC.

This international team aims to apply the new analytical methodologies offered by the Computational Archeology Laboratory (CAL) of the Hebrew University of Jerusalem (Israel) to study a set of over 200 spheroidal limestone tools from the Early Acheulian site of ‘Ubeidiya (Israel), dating to around 1.5 million years ago, with the purpose of developing a methodological holotype for future interpretations.

Conference by Stefania Titton: “The Barranco León site (Orce, Spain) and the European Oldowan” was attended by students and professors of the Department of archeology of the HUJI.

In the first phase of this project, Deborah Barsky, lead project researcher, and Stefania Titton (a URV doctoral student), recently traveled to Jerusalem to work with experts from the CAL (HUJI) to create high precision 3D digitized artifact models for the geometric morphometry study using the associated computer software, developed and provided by this institute. Also during this visit, Stefania Titton delivered a conference about European Oldowan technology, attended by members of the Department of Archeology of the HUJI.

The next phase of the project will be to experimentally reproduce spheroid morphologies using the same limestone as that of the ‘Ubeidiya site. This investigation will allow the researchers to compile computer data obtained from digital reproduction of both the archeological and experimental spheroids. This data will be stored and shared among researchers working on similar topics.

Contributions from this project are expected to provide an operative multidisciplinary methodology to define and analyze spheroids more objectively, broadening our understanding of their presence during the Oldowan to Acheulian transition in the global archeological record.