Morphometric analysis of <i>Mytilus edulis</i>: a tool for analysing shell middens and Patagonian Coastal archaeology

Abstract

Fragmentation is one of the most important taphonomic processes in archaeomalacological assemblages. The quantity of fragmented malacological material introduces biases that affect the interpretation of formation processes, shell midden preservation and human gathering strategies. In this paper we analyze the process of Mytilus edulis fragmentation at the PE 133 site, thereby presenting a methodology for studying archaeomalacological assemblages. The results show that no relationship could be established between shell size and the degree of fragmentation. This demonstrates that fragmentation depends on the mollusk characteristics. Therefore, shell thickness, shape and chemical composition, are more important that the size of the individual, the type of sediment, or site formation history. Finally, fragmentation introduces bias into shell length analysis, so that morphometric equations are a useful tool that permits us to to study fragmented individuals, resulting in a decrease in fragmentation bias.