Co-evolution of the upper limbs of early hominids and the origins of stonecraft

This article discusses the subject of manipulative skills of early hominids in the context of stone toolmaking capabilities. A juxtaposition of morphological characteristics of fossilised bones with precise technological analyses, in particular studies on operational sequences (chaine operatoire) and debitage reassembly, allows us to determine which movement sequences were necessary to make tools. Analyses of the upper extremities of hominini are based on the comparison with well-studied principles which govern the functioning of the upper limb of Homo sapiens. Detailing the biomechanics of lithic reduction (stone knapping) by Homo sapiens enabled us to establish the required sequence of movements. This was compared with technological analyses of Lower Paleolithic materials. Based on biomechanical and technological studies we arrived at a number of characteristics in the morphological structure of upper limbs which could make it easier to specify which species had been capable of making tools. The set of characteristics was compared with data from analyses of fossilised bones of early hominids.