A way to break bones? The weight of intuitiveness

The essential relationship to fat in the Middle Paleolithic, and especially to the yellow marrow, explains the importance of addressing this issue of butchery cultural practices through the study of bone fracturing gestures and techniques. In view of the quasi-systematization of bone marrow extraction in many anthropized archaeological levels, this butchery activity had to be recurrent, standardized and counter-intuitive. Thus, the highlighting of butcher traditions made possible by the analysis of the distribution of percussion marks within fossil assemblages, in particular by opposition at patterns resulting from an intuitive practice. With this in mind, we carried out an experiment that focus on the intuitive way of fracturing bones to extract marrow, involving volunteers with no previous experience in this butchery activity. The objective of this experiment was to highlight the presence or absence of a distribution pattern for percussion marks in an intuitive context by comparing several long bones and individuals. Thus, we wanted to evaluate the influence of the morphological specificity of the element and the specific characteristics of volunteers on the distribution of percussion marks during marrow extraction. Indeed, a previous study was able to show the possible existence of intuitive patterns of distribution of these traces according to the elements (Stavrova et al. 2019). In addition, the comparison of the different behaviours of volunteers during bone fracturing with the production of remains and marks on bone surfaces highlighted the variables that most influence the creation of an intuitive model. We selected twelve from a larger experiment that resulted in the fracturing of more than 360 long bones. Each of the experimenters broke a series of ten long bones, always the same element. Subsequently, we compared the data collected during the experiment with the data from the laboratory study of the remains. Then, we applied an innovative GIS (Geographic Information System) method to analyze the distribution of percussion marks to highlight recurrent patterns. One of the most significant results of our article shows the existence of significant concentrations of percussion marks, regardless of the volunteers’ behaviour during bone fracturing. The predominance of two factors explains the distribution patterns that emerge from our analysis: for humerus, radio ulnas and tibias, the morphology of each element seems to constrain the location of percussion marks, while for femurs, individual choices have more weight in this distribution. In addition, we have observed that at different levels of our analyses, the bone response to fracturing may be totally opposite (quantity of bone marrow, marrow quality, number of blows, difficulty felt, number of fragments produced, type of marks registered), particularly regarding the results for radio-ulnas and tibias. Subsequently, it would be most interesting to compare the intuitive models that we were able to highlight through spatial analysis with the distributions of percussion marks registered in fossil assemblages. It would thus be possible to propose new hypotheses on butchering practices based on the results presented in this work.