An experimental study of the patterned nature of anthropogenic bone breakage and its impact on bone surface modification frequencies

Abstract

The analysis of bone breakage is one of the most relevant issues of current taphonomic studies. Available experimental analogies aim at differentiating agencies in the production of fractured bones. Possible equifinality presented by different agents can hinder the characterisation of bone breakage at archaeological sites. Equally important is the potential distortion that bone-breaking processes introduce in bone surface modification (BSM) frequencies. This study presents an experimental approach to the problem of identifying signatures for anthropogenic bone breaking as a product of direct hammerstone percussion. This study also contributes to improving the existing analogical framework on processes related to bone breakage of medium-sized animals (80–200 kg), since most previous experimentation has focused on smaller (10–80 kg) and larger (200–800 kg) carcasses. It has been possible to verify the existence of non-random and non-intentional breakage patterns on long bones due to their shape and structural properties. Thus, this introduces the possibility of correctly identifying anthropogenic fracture patterns in the archaeological record. Additionally, it also opens up the possibility of finding different cultural patterns. It has frequently been argued that the frequency of bone surface modifications correlates with fragmentation intensity. However, this assertion remained untested until now. Here, we test the frequency and occurrence of percussion and cut marks in faunal assemblages according to the intensity of green bone fragmentation. The results also improve the current referential framework in reference to interpretation of notches produced by dynamic loading.