The burning maze: The potential value of the human bony labyrinth in estimating sex of calcined remains

Abstract

Estimating sex from burnt human remains is a challenging task in bioanthropology, mainly due to their high level of alteration and fragmentation. Protected within the petrous part of the temporal bone, the bony labyrinth may be particularly valuable for assessing the sex of burnt remains. This prospective study aims at testing predictive models, already found reliable on unburnt bony labyrinths, to burnt specimens. Six discriminant functions were applied on six bony labyrinths of donated adult cadavers of known sex, before and after outdoor burning experiments. Comparisons between unburnt and burnt measurements were executed using Mann-Whitney U tests while shape and size differences induced by fire exposure were examined through a geometric morphometrics (GM) analysis. Predicted sex on unburnt bony labyrinths was consistent with known sex in five cases while a systematic misclassification for males was highlighted on burnt specimens. Higher values of shrinkage were found in males for two measurements included in the equations. GM analysis revealed significant differences in centroid size among males after calcination. Visualization of mean consensus of both female and male bony labyrinths evidenced a reduction in cochlear size and variations in the width and length of semicircular canals of burnt specimens. This exploratory study seems to confirm that designing sex estimation standards specifically for burnt bony labyrinth may be advisable. Understanding how the burning process could impact its morphology is highly recommended through further experiments on larger samples and in controlled environments.

Lateral angle: A landmark‐based method for the sex estimation in human cremated remains and application to an Austrian prehistoric sample

“…Due to its robustness, density and position in the cranial base, the pars petrosa frequently survives the cremation process in good condition and can also be easily identified because of its distinct shape (Kontopoulos et al, 2019; Lynnerup et al, 2006; Masotti et al, 2013; Masotti et al, 2019; Norén et al, 2005; Wahl, 1981b, 1982; Wahl & Graw, 2001; Wahl & Henke, 1980). Various anatomical structures have been found to be sexual dimorphic in unburnt (Akansel et al, 2008; Graw et al, 2005; Lynnerup et al, 2006; Norén et al, 2005; Wahl & Graw, 2001) and in burnt petrous portions (Boucherie et al, 2022; Masotti et al, 2019; Schutkowski & Herrmann, 1983; Wahl, 1981b), for example, the so‐called lateral angle (Graw et al, 2005; Hałuszko & Guziński, 2022; Kozerska et al, 2020; Norén et al, 2005; Wahl, 1981b), or the diameter of the internal acoustic meatus (Lynnerup et al, 2006; Pezo‐Lanfranco & Haetinger, 2021).…”