The 89th Annual Meeting of the American Association of Physical Anthropologists (2020)

Detection of early postmortem changes in burnt bones through histotaphonomical analysis


1Research Laboratory for Archaeology and the History of Art, School of Archaeology, University of Oxford, 2Cranfield Forensic Institute, Cranfield University, Defence Academy of the United Kingdom

April 18, 2020 2:45PM, Diamond 8-9 Add to calendar

Recent histotaphonomic studies have focused on the presence of features thought to be caused either by bacteria (microscopic focal destruction/MFDs and cyanobacterial tunnelling) or fungal (Wedl tunnelling types 1 and 2) attack on unburnt, mostly archaeological bones. Identifying these diagnostic characteristics on burnt bones could reflect some degree of decomposition before cremation, with important repercussions for both forensic and archaeological contexts. Thus, this study aims to establish the utility of diagenetic features as a proxy for the body’s condition prior to incineration.

Fleshed pig (Sus scrofa, N=20) tibiae were left exposed on a field, then collected at 2 weeks, 1, 3, and 6 months intervals before being cremated in an outdoor fire (≤750 °C bone temperatures). Fresh (fleshed) legs (N=10) acted as unburnt and burnt controls. The fresh, decayed, and post-burnt bone thin sections (~50-70μm) were examined under transmitted light microscopy and backscatter scanning electron microscopy (BSEM). Diagenetic traits were quantitatively assessed by a data labelling application built in Python and Javascript programming languages. Statistical analysis showed no significant correlation between the time of decay and the presence of diagenetic features on either unburnt or burnt bones. Tunnelling is more pronounced in the cremated bones than in the pre-burnt ones in all postmortem intervals.

Histotaphonomic features survived cremation. However, their presence in freshly burnt bones and absence in the unburnt controls suggest that the presence of many, if not all of these features is, in fact, not due to bacterial bioerosion or fungal attack.

Meyerstein fund and Wolfson College (University of Oxford)

Slides/Poster (pdf)