Advanced computing techniques to revolutionize cranial fracture analysis in archeology

A scientific advance opens new possibilities for analyzing fragmented bone remains in the archaeological record.

A multidisciplinary team has developed a new methodology to analyze past human skull fractures. This research has focused on the use of advanced computing techniques to determine whether these fractures are the result of natural processes or human interventions. The study has been applied to the case of the Txispiri skull, a cranial fragment discovered in Gipuzkoa, Basque Country, with the aim of resolving a historical debate about its origin and offering new tools for archaeological analysis.

The work has been led by Francesc Marginedas, a predoctoral researcher at the Catalan Institute of Human Paleoecology and Social Evolution (IPHES), which is one of the CLOSE institutions of the Generalitat of Catalonia. Palmira Saladié, from IPHES, Antonio Rodríguez-Hidalgo, from the Institute of Archeology of Mérida (joint center of the Higher Council for Scientific Research (CSIC) and the Government of Extremadura) and researcher associated with IPHES, Asier Gómez-Olivencia, from the University of the Basque Country, as well as Abel Moclán and Miriam Cubas, from the University of Alcalá, in Spain.

A paradigmatic case: the Txispiri shell

The research has focused on the Txispiri skull, a cranial fragment discovered in the Txispiri-Gaztelu funerary cave (Gipuzkoa, Basque Country), which was initially considered a cranial cup used in funerary rites or religious ceremonies. The results of this research have shown that the fractures present in the fragment were caused by natural postmortem processes and have no link with human manipulations, as had been proposed for decades.

“Our study highlights the great potential of digital tools to provide precision to the analysis of archaeological human remains,” explains Francesc Marginedas, lead author of the work. “This approach opens the door to applying similar techniques in other archaeological contexts with similar problems,” he adds.

Shell of the Txispiri site. (Images: IPHES / CERCA)

The research team compared the characteristics of the skull fractures with samples of fresh and dry fractures from other sites such as the El Mirador cave (Sierra de Atapuerca, Burgos) and the remains of the 19th century historical cemetery of Abric Romaní (Capellades, Barcelona). Using advanced computing techniques, variables such as texture, angle and trajectory of the fractures were analyzed. The precision of the models used reached 100% in the classification of fractures, evidencing the reliability of these techniques.

The results confirm that Txispiri skull fractures are typical of natural processes, highlighting that shapes similar to crown skulls can arise spontaneously without human intervention. It is a clearly opposite case to the set of six skulls from the Bronze Age in the El Mirador cave. These last elements were made and possibly used in ceremonies related to the cannibalism practiced by these populations.

In summary, this new technological approach not only provides a more precise perspective on the Txispiri shell, but also offers a revolutionary tool to analyze other fragmented remains in complex archaeological contexts.

Marginedas and his colleagues present the technical details of their new methodology in the academic journal Archaeological and Anthropological Sciences, under the title “Alteration by natural processes or anthropogenic manipulation? Assessing human skull breakage through machine learning algorithms.” (Source: IPHES)