Identifying sword marks on bone: criteria for distinguishing between cut marks made by different classes of bladed weapons

Swords have been one of the major weapons used in violent conflicts for much of human history. Certain archaeological situations, especially those dealing with the recovery and analysis of battle casualties, may raise questions about what type(s) of bladed weapon was used in a particular conflict (e.g., the battle of Kamakura, Japan, AD 1333; the battle of Wisby, Sweden, AD 1361; the battle of Towton, England, AD 1461). Little work has been done, however, on developing criteria to differentiate sword cut marks from other types of cut marks, or to distinguish between marks created by different sword types. To develop such criteria, bovine tibiae (n = 7) were struck using six different types of bladed weapon and the resulting marks (n = 92) were analyzed. Eight traits describing the morphology of the cut mark – such as shape, the presence and unilateral/bilateral state of flaking and feathering, the presence of bone shards, associated breaks, etc. – are defined and related to blade type used. Sword marks were found to be easily distinguishable from knife marks. The variation in marks made by different sword types is significantly correlated with differences in blade weight (p < 0.0001), grip (p < 0.0113), and sharpness (p ≤ 0.0179). The criteria and analyses developed and implemented in this study will be of use to researchers in forensics and osteoarchaeology who want to infer bladed weapon type from marks on bones.