Burned Fleshed or Dry? The Potential of Bioerosion to Determine the Pre-Burning Condition of Human Remains

The practice of cremation is often interpreted as an alternative to inhumation, taking place shortly after an individual’s death. However, cremation could be a final stage in complex mortuary practices, with previous steps that are obscured due to the heating process. This project reports on experimental scoping research on a set of experimentally heated femoral fragments from modern and archaeological collections of the University of Coimbra. Sixteen recent femur samples from eight individuals, as well as five femur samples from an archaeological skeleton from the medieval-modern cemetery found at the Hospital de Santo António (Porto), were included in this research. Samples presented five different conditions: unburnt, and burnt at maximum temperatures of 300 °C, 500 °C, 700 °C and 900 °C. Each sample was prepared to allow observation using binocular transmitted light microscopes with ×10, ×25 and ×40 magnifications. Results indicated that, if burial led to bioerosion, this will remain visible despite burning, as could be in cases where cremation was used as a funerary practice following inhumation. From this, we conclude that the observation of bioerosion lesions in histological thin sections of cremated bone can be used to interpret potential pre-cremation treatment of the body, with application possibilities for both archaeological and forensic contexts. However, the effect on bioerosion of substances such as bacterial- or enzymatic-based products often used to accelerate decomposition should be investigated.