Estimating osteological sex using predictive geometric morphometric analyses of the greater sciatic notch

• Features of the pelvis are widely used for estimating sex in both forensic and archaeological contexts. • Qualitative scales are unreliable in estimating sex. • Quantifying the shape of pelvic features using morphometrics provides greater accuracy in sex estimations. • Both the shape and angle of the greater sciatic notch are accurate predictors of biological sex. Accurately estimating the biological sex of human skeletal remains is crucial in both forensic and archaeological contexts for constructing biological profiles. Presently, one of the most commonly used methods involves an ordinal scale describing the shape of the greater sciatic notch (GSN). However, this approach is limited by variations influenced by temporal, geographic, and ancestral factors affecting pelvic morphology. Consequently, its reliable applicability is restricted to populations resembling the original reference group. Recent advancements in quantitative analyses offer a promising alternative by enabling detailed measurement of subtle morphological changes, thus enhancing the accuracy of sex estimation using skeletal pelvic remains. In this study, we employ 2D landmark-based geometric morphometrics (GMM) to develop a protocol for pelvic sex estimation by quantifying the curve and angle of the GSN. These techniques are applied to both a contemporary population of adult European-Americans of known biological sexes (33 females, 38 males) and an archaeological population (n = 73) from south-west England. Our analysis reveals that our GMM approach achieves a 90 % accuracy rate in modern populations. Results indicate that both GSN morphology and angle are highly indicative of biological sex, allowing confidence in sex estimations of archaeological remains using these features.