Sexual Dimorphism in Diaphyseal Cross-sectional Shape in the Medieval Muslim Population of Écija, Spain, and Anglo-Saxon Great Chesterford, UK

Differences in adult male and female activity patterns may influence levels of sexual dimorphism in physical dimensions, including the cross-sectional shape of long bone diaphyses. Previous studies of archaeological populations have demonstrated significant differences in diaphyseal shape between males and females. In this study, dimorphism in external diaphyseal shape of upper and lower limb bones (reflected in indices of external diaphyseal diameters), and bilateral asymmetry in these indices, were examined in two medieval populations: Muslim Écija (Spain) and Anglo-Saxon Great Chesterford (UK). Attempts were made to relate observed patterns to documentary and other osteological evidence for differences in male and female activity patterns. While few significant differences in upper limb bone cross-sectional shape were observed in either population, significant differences in shape were found in the lower limb diaphyses at Écija at the femoral midshaft and tibial foramen and midshaft levels, and at the tibial midshaft for Great Chesterford. Comparison with published data suggests that these differences are marked for Écija, and perhaps fairly high for Great Chesterford compared with other populations with an agriculture-based economy. This is consistent with documentary and osteological evidence suggesting marked gender differences in behaviour in medieval Muslim Spain. No significant differences in bilateral asymmetry were found, but the effects of small sample size cannot be ruled out. Copyright 2008 John Wiley & Sons, Ltd.