Differential skeletal preservation between sexes: a diachronic study in Milan over 2000 years

A recurring observation in the literature is that females tend to be less represented than males in osteological collections. How can we explain such observations? Do female skeletons preserve less well than their male counterparts? In this study, 200 skeletons from the Collezione Antropologica LABANOF (CAL), equally divided between sexes, were selected from four archaeological sites of Milan, representing a continuum of about 2000 years. The state of preservation was analyzed according to three criteria: quantity, quality, and integrity. Linear model and ANOVA statistical analyses were performed using R software. As a result, females tend to be less complete than males, regardless of age-at-death or post-mortem interval (PMI). Preservation also showed lower values as PMI increased, except for the medieval sample, which may be explained by soil taphonomy and/or general poor bone health. This is one of the few studies to demonstrate a differential skeletal preservation between sexes, supporting bone mineral density as a major factor of bone survival. Further studies may strengthen our results and confirm the trends observed in this paper.