Mechanisms of tooth damage and Paranthropus dietary reconstruction

Abstract

According to the current fossil record, the extinct hominin genus Paranthropus and the genus Homo both first appeared ∼2.7 million years ago. Despite this similarity in geological age, Paranthropus evolved enormous postcanine teeth with very thick enamel while Homo evolved smaller teeth. Results from contact mechanics models derived from multiple scales of tooth damage (microwear, macrowear, and fracture) are reviewed to examine this evolutionary divergence and the role that diet may have played in it. Each scale of investigation reveals different kinds of evidence that can be combined into a more complete picture of hominin diet and feeding behaviour. Microwear reveals information about recent feeding events, while macrowear and fracture record longer-term trends. The synthesis of all three levels of evidence exposes significant dietary diversity, not only between these two hominin genera but within them as well. Within Paranthropus, the eastern and southern African species (P. boisei and P. robustus, respectively) were morphologically similar but appear to have been functionally different. Whereas P. boisei apparently used its teeth to consume large quantities of low quality vegetation, P. robustus had a more varied diet that included harder objects, possibly items such as seeds, nuts, or underground storage organs.