The Mechanical Properties of Marine and Terrestrial Skeletal Materials

Abstract

The innate, mechanical properties of tool raw materials place ultimate limits on how the materials can be worked and used, thus affecting most facets of tool use-lives. Prehistoric forager groups such as the Alutiiq of Alaska's Kodiak archipelago constructed tools not only from stone, but also from a range of skeletal materials whose mechanical properties are not well understood. Laboratory tests were carried out to determine the material stiffness, strength, and toughness (fracture resistance) of sea lion and cervid limb bone as they relate to better-studied antler. Sea lions are a semi-marine adapted species but their limb bone properties overlap those of elk and white-tailed deer. Elk bone is particularly strong and stiff; while antler's remarkable degree of toughness makes it the ideal choice for tools that require maximum fracture resistance, a pattern that is evident in protohistoric Alutiiq toolkits. Further tests are needed to refine our understanding of how the mechanical properties of osseous tissues vary within and between taxa and skeletal elements.