Sexual dimorphism in the human dental sample from the SH site (Sierra de Atapuerca, Spain): a statistical approach

Abstract

Abstract The human dental sample from the site Sima de los Huesos (SH) (Sierra de Atapuerca, Burgos, Spain) exhibits a size distribution pattern defined by most of the specimens of the same tooth class to cluster in two distinct sets. This fact led us to hypothetize that the Atapuerca hominids had a tooth size sexual dimorphism greater than that of modern humans. A statistical procedure to deal with small size samples and non-sexed specimens was designed to test this hypothesis. The Krapina dental sample was also analysed, and both Atapuerca and Krapina were compared with each other and with a sample of modern humans, used as the population of reference in this analysis. Significant differences were found between Atapuerca and the modern human sample for all the tooth classes analysed (lower lateral incisors, canines, premolars and first molars). In contrast, all the comparisons between Krapina and Atapuerca were not statistically significant. However, Krapina differs significantly from the modern humans only for the lower premolars and first molars, thus giving some indication that the Krapina hominids showed a decrease in the magnitude of dental sexual dimorphism in relation to late Middle Pleistocene populations. These results are discussed and interpreted in the light of the known European Pleistocene hominid fossil record.