The Centro Nacional de Investigación sobre la Evolución Humana (CENIEH) has participated in a study led by Daniel García Martínez, a researcher at the Complutense University of Madrid (UCM), and published in the Journal of Human Evolution. The research analyzes a cranial fragment attributed to the genus Homo that was recovered at the Ruidera site in Ciudad Real.

Dating of the fossil, designated RVH-1, has established a minimum age of 200,000 years, placing it at a pivotal moment in European human evolution during the Middle Pleistocene. The discovery is particularly significant because human fossils from this period are exceptionally scarce in the interior of the Iberian Peninsula, a region traditionally underrepresented in the paleoanthropological record.

Establishing the chronology of RVH-1 was one of the principal challenges of the study. To address it, CENIEH geochronologists combined uranium-series dating, optically stimulated luminescence (OSL), and electron spin resonance (ESR).

The results have not only made it possible to determine the minimum age of the cranial fragment, but also to interpret its anatomical characteristics accurately, compare it with other European human fossils from the same period, and better understand the diversity of the populations that inhabited the continent during the Middle Pleistocene.

A combination of archaic traits
The anatomical analysis shows that the Ruidera parietal bone displays a combination of traits rarely observed among European fossils from this period. Its morphology and thickness are particularly noteworthy because they retain characteristics considered archaic, also known as plesiomorphic.

“This is a thick cranial structure, similar to the morphology seen in other crania also regarded as archaic, such as the Ceprano specimen in Italy and the fossils from Caune de l’Arago in the French Pyrenees,” explains Daniel García Martínez.

This unusual anatomy indicates that hominin populations—the group of primates that includes modern humans and their closest fossil relatives—with unexpected characteristics were still living in the Iberian Peninsula at that time. These traits had been inherited from ancestral lineages and persisted until relatively late in the Middle Pleistocene.

“This finding reinforces the idea that human evolution in Europe was not a linear process, but rather a complex scenario in which different populations with distinct evolutionary histories coexisted,” says Carlos Palancar, a researcher at the National Museum of Natural Sciences (MNCN-CSIC).

A site with considerable potential
RVH-1 is the first cranial remain recovered from the Ruidera site, and its discovery confirms the site’s potential for investigating human evolution in the interior of the Iberian Peninsula. As Daniel García Martínez notes, it “provides information about the populations that inhabited the interior of the Iberian Peninsula during this period and places Ruidera in a privileged position on the European map for the study of human evolution during the Middle Pleistocene.”

The fossil was recovered by the team from the First Settlers of the Upper Guadiana project—Primeros Pobladores del Alto Guadiana (PPAG)—which aims to reconstruct the biological, cultural, and environmental history of the human populations that occupied the Upper Guadiana basin during the Pleistocene.

More specifically, it was discovered by Mario Modesto-Mata, a paleoanthropologist at CENIEH and lecturer at the International University of La Rioja (UNIR), who recalls: “It was an incredible and fortunate surprise. We went through a range of emotions, from initial skepticism and disbelief to immense joy once it was confirmed that it could only be human.”
Animal fossils, a rich assemblage of lithic artifacts, and numerous human remains have been recovered at Ruidera to date. Together, these finds could establish the site as a key locality for understanding human evolution in the Iberian Peninsula.

“This fossil is only the tip of the iceberg. Ruidera still has much to reveal about human evolution in Europe, and we are convinced that it will continue to yield discoveries of major scientific importance,” concludes Sara Díaz Pérez of the University of Wrocław in Poland.

The study was conducted by researchers from the Complutense University of Madrid and the National Museum of Natural Sciences (MNCN-CSIC), with the participation of CENIEH, the Catalan Institute of Human Paleoecology and Social Evolution (IPHES-CERCA), the Autonomous University of Madrid (UAM), the PATRICIA research group at the University of Córdoba, and other national and international institutions.