Buccal striations on fossil human anterior teeth: evidence of handedness in the middle and early Upper Pleistocene

摘要

The presence of gross preferentially distributed striations on the buccal surfaces of permanent anterior teeth of Neandertal individuals from La Quina, Hortus and Angles-sur-l'Anglin (France), Saint Brais (Switzerland) and Shanidar (Iraq) has led some authors to hypothesize that Neandertals used stone tools to cut something held between the anterior teeth, inadvertently scratching the enamel at the same time. We also observe these striations on the anterior teeth of Middle Pleistocene hominids from Atapuerca/Ibeas, Spain, on the incisors of La Quina 5, and on one isolated I1 from Cova Negra, Spain. Macro- and microscopic studies of these striations, together with those striations produced in an experimental study suggest that scratching of these hominid anterior teeth was indeed the result of ante-mortem tool use, producing striations indicating right- (normally) or left-handedness (rarely). These results provide indirect evidence for lateralization of the brain of Middle and early Upper Pleistocene hominids