Differentiating trauma from taphonomic alterations

•Differentiating trauma in bone from taphonomic damage requires a systematic approach.•Perimortem trauma occurs while bone is biomechanically elastic and lacks signs of healing.•Taphonomic alterations occur in dry bone or exhibit scavenger or other postmortem signatures.•Analysis of fracture mechanics, taphonomic signatures and environmental context is critical. Differentiating traumatic injuries in bone from taphonomic damage in the postmortem period is a complex process requiring a systematic approach. Trauma by definition occurs while the individual is still living, but bone characteristics usually do not allow delineation of the moment of death. Thus, the anthropologist seeks characteristics that will associate a skeletal defect with the perimortem period, at or about the time of death. However, the anthropological designation of perimortem time period does not have precise boundaries. It refers to remains that lack any sign of remodeling or healing on the one hand, and which have not lost biomechanical elasticity and plasticity on the other hand, i.e., it refers to the condition of skeletal remains when they sustained the suspected injury. Fracture patterns that reflect biomechanical plasticity are lost gradually as the time since death increases, and this pace will depend on the environmental context. There are additional clues to identify postmortem status, including when the damaged feature fits a taphonomic pattern of scavenger modification or weathering, or physically overlies obvious postmortem modifications, or when the feature fits a known pattern of sharp force instruments or weapons. Damage due to recovery or the examination process must be ruled out. The timing of occurrence of a suspected perimortem injury can therefore extend for days or weeks into the time before the actual death, and it can extend for days to months after death. The anthropologist responds to the challenge of differentiating trauma and taphonomic modification by knowing the characteristics of healing bone, the features of biomechanical plasticity reflected in fracture morphology, the taphonomic patterns of scavenging and weathering, the environmental context of discovery and recovery, and the characteristics of the relevant regional taphonomy.