Analyse morphométrique comparée des dents humaines de Gran Dolina (TD6) et de Sima de los Huesos d'Atapuerca

Abstract

Comparative Morphometric Analysis of the Human Dental Samples of Gran Dolina (TD6) and Sima de los Huesos caves sites at Atapuerca. We present a comparative morphometric study of the human dental samples yielded by the Lower Pleistocene site of Gran Dolina (TD6 Aurora Stratum) and the Middle Pleistocene site of Sima de los Huesos (SH) from the Sierra de Atapuerca (Burgos, Spain). The remarkable size and shape differences between the TD6 and SH sample concern, especially, to the anterior vs. posterior size relationship. In the SH hominids, the strong size reduction of the posterior teeth, which reached a degree similar to that of the modern populations, implied the appearance of a set of derived traits, such as the crown and root simplification of the lower premolars, the absence of cingulum, the relative greater size reduction of the lower second premolar and second molar, or the reduction and absence of cusps of the upper and lower molars (hypocone and hypoconulid). The TD6 hominids, in contrast, exhibit a size balance between the anterior dentition and the posterior one, together with the retention of most plesiomorphies for the genus Homo. These observations imply important differences for certain dental development parameters of the two hominid populations, which justifies their taxonomical distinction. On the other hand, the SH hominids and the Neandertalians exhibit a similarity of most dental traits examined, which supports the hypothesis of a reproductive continuity (phyletic evolution) in Europe during the Middle and early Upper Pleistocene.