Paleoanthropological research of the neandertal fossils from El Sidron (Asturias, Spain)

The archaeological project in the Gallery of the Osario of the cave of El Sidron (Asturias, Spain) has recently concluded after 13 field seasons of detailed, methodical excavation. We present here a summary of the lines of research and the paleoanthropological studies carried out to date, as well as a brief perspective of the ongoing investigations. More than 2550 neandertal fossil remains have been recovered from this singular deposit, together with 400 pieces of Mousterian lithic industry, and less than 60 non-human remains. Sedimentological, taphonomic and structural analyses of the karst clarify that this fossil assemblage is in a secondary position and comes by mudflow from a gallery/shelter located in a superior level of the karst. All the skeletal parts are represented, and 13 individuals have been identified: 7 adults (3 males, 4 females), 3 adolescents (2 males, 1 female), 2 male juveniles and an infant. The El Sidron collection constitutes the most numerous and diverse neandertal sample of the Iberian Peninsula, allowing systemic studies on tempo and modo of appearance of the derived characters in the neandertal lineage. The wide undertaken paleobiological research program includes the study of the different levels of biological organization, from demographic and evolutionary dynamics to molecular aspects. With regard to the latter, the extraction of DNA sequences has played a central role, with the characterization of the mt-DNA haplotype of 12 individuals, and with the inclusion of samples from El Sidron in the Neandertal Genome and Exome projects. Results from the genetic and osteological studies define El Sidron neandertals as a homogenous group, with narrow kinship bonds between their individuals. Finally, the numerous evidences of human-induced treatment of the bones make of El Sidron a paradigmatic example of practices of cannibalism between the neandertals.