An approach to the study of post-depositional processes affecting inter-proximal wear facets and buccal enamel surfaces in hominid teeth

Abstract

The reconstruction the diet and dietary related habits of our ancestors is very informative about their evolutionary behaviour and adaptability. One method to infer diet from skeletal remains is to study the dental microwear pattern of teeth, since these constitute the most abundant remains in the fossil record. By using dental enamel microwear as a direct evidence for food consumption, we can obtain direct evidence of hominid ecology and adaptation to fluctuating environments. During mastication, food repeatedly contacts with dental enamel and abrasive particles, such as phytoliths present in plant tissues, are bound to scratch and rub the enamel surface of teeth. Many fossil teeth generally show poor enamel preservation caused by post-mortem damage, not informative of diet. Therefore, knowledge of ante-mortem buccal microwear variability as well as post-mortem enamel damage is required to make dietary inferences on fossil human populations. The absence of striation-like features on the inter-proximal facets, as opposed to the fine microstriations generally present on the buccal tooth surfaces, may be considered as indicative of lack of post-depositional processes affecting fossil teeth. However, experimental studies on enamel damage have shown that taphonomic processes rarely produce micro-striations on the enamel. Since taphonomic processes are expected to affect in the same manner to all enamel surfaces in the isolated teeth, a clear microwear distinction between buccal and interdental surfaces would be indicative of no post-mortem damage. Thereby, the comparison of occlusal-to-buccal and interproximal-tobuccal enamel surfaces stands as the best method to discriminate post-mortem damage on tooth enamel surfaces for dietary analysis in ancient primate populations.