Experimental Formation of Coffin Wear on Bone

Localized, eroded flat areas on bones recovered from former coffin burials are hypothesized to have been formed as “coffin wear,” caused by a combination of acidic groundwater pooling in a coffin that is slowly degrading over time, bones coming to rest against a flat surface, and overlying sediments applying pressure. Due to the time expected to be needed for this taphonomic effect to accrue, no experiments have tested this hypothesis. To shorten the timeframe, the authors exposed weighted and unweighted, already skeletonized pig (Sus scrofa) bones for a period of 20 two-week cycles and a sample of previously degraded, assorted nonhuman bones to acidic solutions for 12 two-week cycles. Flattened areas consistent with coffin wear were formed only on the previously degraded sample and were more prevalent and prominent on the subsample that had been weighted down during exposure. These findings may help clarify forensic investigations where bones are suspected to originate from a cemetery burial and not of a more recent origin or non-coffin burial. Additional testing under differing conditions is needed to explore this topic more fully, including long-term burial projects and examination of dated cemetery populations.