The relationship between age and arachnoid depressions in humans

The human skeletal collection housed in the Department of Anthropolog y at the University of Alberta was used to determine the relationship between age and the occurrence of arachnoid depressions on the endocranial aspect of the skull. There were significant differences between the total number of arachnoid depressions found on the vaults of juveniles, adolescents, and adults. When mean ages were compared with total number of arachnoid depressions on the vault, a significant relationship did not emerge. When age was grouped into nine-year intervals to counteract the effect of idiosyncratic variation, the mean number of depressions increased with age, as did the maximum number of arachnoid depressions. The frequency of older individuals without arachnoid depressions waslow. Older individuals were more likely to have larger and deeper arachnoid depressions. There were no sex-based differences in the expression of arachnoid depressions. There were no significant differences between archaeological, historic, and modern samples or between pathological and healthy individuals. Although this study verifies the association between arachnoid depressions and senescence, the presence of arachnoid depressions is highly variable andcannot be used reliably as an indicator of chronological age or even as a sign of senescence.