Plant processing experiments and use-wear analysis of Tabon Cave artefacts question the intentional character of denticulates in prehistoric Southeast Asia

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The presence of notches on European Palaeolithic flaked stone tools termed ‘denticulates’ has been variously ascribed to cultural, functional and taphonomic factors. In Southeast Asia prehistoric stone tool assemblages are dominated by unretouched flakes, so the rare retouched lithics, including denticulates, can be considered unique testimonies of the intention of the tool makers to control the shape and properties of tool edges. Here we report the results of plant processing experiments with modern unretouched flakes made of red jasper. Splitting plants with the help of a specific hand and arm movement (“twist-of-the-wrist”) resulted in a series of use-wear traces that included large crescent-break micro-scars. These are very similar in shape and appearance to the notches of prehistoric denticulated tools. These results suggest that some denticulated pieces in prehistoric Southeast Asia could be less intentional than previously thought, being instead the result of plant processing activities. We also report here the analysis of 41 denticulates from Tabon Cave, Philippines. While some are clearly intentionally retouch, others exhibit use-wear and nocth micro-morphology characteristic of plant splitting. The notches of others result from utilisation and taphonomy or trampling. Altogether, our observations raise the following question: should the term denticulates be restricted to the tools intentionally retouched or encompass all the tools with adjacent notches whatever the origin of the latter is?