Reaching new heights: Testing the performance of metric approaches to estimate stature from burned skeletal remains.

Bone heat-induced changes complicate osteometric stature estimation of human remains from forensic settings. The validity of current methods has not been tested to a great extent. Our aim was to determine how precise are stature estimations obtained from three different approaches, namely by using (i) Rösing's method (Rösing 1977), (ii) a 10% shrinkage correction factor (Strzalko et al. 1972) and (iii) chemosteometry (Gonçalves et al. 2020). For this purpose, pre- and post-burned head measurements from the humerus, radius and femur were used. The sample comprised 46 human skeletons of known sex and age-at-death. These were experimentally burnt to maximum temperatures ranging from 700 to 1100°C (attained after 90-188 min) for other research purposes. Stature estimations were performed through measurements in both pre-burned and burned bones using the three approaches and based on the method of Olivier and Tissier (1975). Mean absolute differences and the relative technical errors of measurements (TEM%) between the pre-burned and the estimations were calculated. Absolute mean differences indicated that the chemosteometric approach allowed for potentially more precise stature estimations than the other two procedures. However, the TEM% was very low for all approaches (smaller or close to 1%), and stature estimations were thus well within the error margin reported by Olivier and Tissier (1975). Results suggest that the chemosteometric approach enables more accurate predictions of the actual heat-induced shrinkage of each bone thus rendering more precise stature estimations. Nonetheless, the other procedures also provided quite reliable estimations although they require confirmation that the bone is calcined.

Preliminary results of an investigation on postmortem variations in human skeletal mass of buried bones.

Extreme fragmentation can complicate the inventory of human skeletal remains. In such cases, skeletal mass can provide information regarding skeleton completeness and the minimum number of individuals. For that purpose, several references for skeletal mass can be used to establish comparisons and draw inferences regarding those parameters. However, little is known about the feasibility of establishing comparisons between inherently different materials, as is the case of curated reference skeletal collections and human remains recovered from forensic and archaeological settings. The objective of this paper was to investigate the effect of inhumation, weather and heat exposure on the skeletal mass of two different bone types. This was investigated on a sample of 30 human bone fragments (14 trabecular bones and 16 compact bones) that was experimentally buried for two years after being submitted to one of four different heat treatments (left unburned; 500 °C; 900 °C; 1000 °C). Bones were exhumed periodically to assess time-related mass variation. Skeletal mass varied substantially, decreasing and increasing in accordance to the interchanging dry and wet seasons. However, trends were not the same for the two bone types and the four temperature thresholds. The reason for this appears to be related to water absorption and to the differential heat-induced changes in bone microporosity, volume, and composition. Our results suggest that mass comparisons against published references should be performed only after the skeletal remains have been preemptively dried from exogenous water.