Behavioral traces on dental wear in Pleistocene fossil humans

Abstract

Following the emergence of the Hominini, the biological evolution of the tribe has been always accompanied by cultural changes, and behavioral patterns were underlying the relationships among individuals. These behavioral patterns allowed and helped the first humans to adapt, spread, and evolve into who we are today. This study aims to analyze non-masticatory dental wear patterns in fossil Homo in order to trace the expression of some behavioral patterns and cultural habits among these species. The sample studied includes early Homo, Middle Pleistocene Homo (Atapuerca-SH) and H. neanderthalensis (Sidrón, Cova Foradà, Valdegoba, Krapina, Vindija among other). Original teeth and high-resolution replicas were analyzed using Scanning Electron Microscopy. The recorded non-masticatory dental wear features indicate an increase of the use of the mouth in non-masticatory tasks from early Homo (cultural striations 1.8 Mya, and toothpicking) during the Pleistocene, with the highest incidence and variety of dental wear features detected (cultural striations, toothpicking, dental chipping, parafacets) in Homo neanderthalensis, as well of some evidence of sex-related differences. The increase in the use of the dentition in non-masticatory activities could be related to the development of the behavioral complexity during the Pleistocene. In this sense, the increasing number of cultural striations could be interpreted as the diversification of the activities that use the mouth as a third hand such as skins and vegetable fibers preparation for clothing and other crafts. On the other hand, the generalization of toothpicking and dental chipping could be associated with the spread of oral hygiene or therapeutic habits.