An international team involving researchers from Adelaide and Griffith Universities have discovered a peculiar archaeological site (Porto Maior) in Spain, which records an exceptionally high density of “giant” handaxes that had previously only been found in Africa. This discovery may suggest the coexistence of at least two different human groups in the Iberian Peninsula about 200-300 thousands years ago.
The open-access journal Scientific Reports publishes a detailed study of a new archaeological site (Porto Maior) located in Galicia, Northwest Spain, which document an exceptionally high density of large cutting tools that had previously only been found in Africa. This work raises new questions regarding the origin and mobility of prehistoric populations that occupied the European continent during the Middle Pleistocene (between 773000 and 125000 years ago). The research is led by E. Méndez-Quintas from the National Research Centre for Human Evolution (CENIEH) in Spain, and involves researchers from two Australian institutions; Dr Martina Demuro and Dr Lee Arnold from the University of Adelaide and Dr Mathieu Duval from Griffith University.
The significance of Porto Maior (Galicia, Spain)
The site of Porto Maior (As Neves, Pontevedra) is located in the Miño River basin of Northwest Spain. Archaeological excavations of the fluvial sediments have unearthed a total of about 3700 lithic artefacts; 290 of these make up the studied assemblage. The lithic assemblage is dominated by the presence of Large Cutting Tools, and in particular handaxes that are characteristic of the so-called Acheulean technology. Laboratory analyses suggest that the tools were not configured on site, but were brought from elsewhere for specific usage, including the processing of hard materials like wood or bone or the breaking up of carcasses. The high density of giant 18 cm-long handaxes at Porto Maior parallels trends identified at Acheulean sites located on the African continent and in the Near East. This discovery reinforces the possibility of an African origin for the Acheulean tradition of Southwest Europe.
The age of the Acheulean lithic assemblage at Porto Maior
The Australian research team determined the age of the Porto Maior site by combining two different dating techniques on the fluvial sediment associated to the lithic tools. Their results indicate that the lithic tool-bearing deposits date back to 293-205 thousand years ago. Luminescence dating was performed by Dr’s Demuro and Arnold at the University of Adelaide’s Prescott Environmental Luminescence Laboratory, while Electron Spin Resonance (ESR) was carried out at the CENIEH by Dr Duval, who is a member of the Australian Research Centre for Human Evolution (ARCHE) at Griffith University. “We applied the two dating techniques in an entirely independent way” says the Griffith researcher, “and we were quite pleased to realise that we obtained highly consistent results. This gave us good confidence in our dating work and enabled us to produce a robust chronology for Porto Maior“.
The increasing complexity of prehistoric settlements in Europe
The age of the site is consistent with previous findings from the Iberian Peninsula, which document the expansion of the Acheulean tradition in the region between 400 and 200 ka. However, there is also evidence of completely different stone tool assemblages (the so-called as Early Middle Palaeolithic) being used at other archaeological sites across Spain during this same time range. These overlapping technological patterns suggest the co-existence of culturally distinct human populations of different geographical origins; a trend that seems to be increasingly evident from the ancient human fossil record of Europe. “These chronological findings have important implications for understanding the complex human occupation history of the continent” says Dr Demuro. “The African affinities of the LCT assemblage at Porto Maior may be consistent with a technology brought in by an “intrusive” population, which differed from the core and flake industries of established human groups in SW Europe” adds Dr Arnold.