Flake scar density and handaxe reduction intensity

We applied the SDI to two archaeological assemblages of Acheulean bifaces from East Africa: Kariandusi and Isenya; and two archaeological assemblages from India: Patpara and Bhimbetka. Exotic materials were more reduced at Kariandusi and Isenya. A relationship between SDI and volume, such that smaller handaxes have higher scar densities, and are thus likely small because they have been reduced more, suggests resharpening. Conversely, the lack of such a relationship may be taken as evidence that bifaces were not resharpened. Our results show that exotic handaxes from Kariandusi, local handaxes from Isenya, and bifaces in general from Patpara were resharpened. On the other hand neither local handaxes from Kariandusi, cleavers from Isenya, nor cleavers from Bhimbetka, were resharpened. The unretouched bit formed by the termination of the original flake blank on the Isenya and Bhimbetka cleavers provides independent evidence for the lack of resharpening.