Continuity and individuality in Medieval Hereford, England: A stable isotope approach to bulk bone and incremental dentine

In this study, bulk bone collagen carbon (δ13C) and nitrogen (δ15N) isotope data from 49 individuals, recovered from two Medieval burial grounds in Hereford, England, are coupled with incremental dentine data from five individuals with high δ15N bone values who survived into old age, to see whether the high δ15N values were consistent throughout their childhood and adolescence. There are statistically insignificant differences between mean bone δ13C and δ15N values from the two Hereford populations, exhumed at Cathedral Close and St. Guthlac's Priory, despite temporal and demographic differences (St Guthlac's mean: δ13C −19.4 ± 0.5‰ and δ15N 10.9 ± 1.2‰; Hereford Cathedral mean: δ13C −19.6 ± 0.4‰ and δ15N 10.4 ± 0.9‰, 1σ). In comparison to other contemporary urban populations, the Hereford individuals present significantly lower but more variable δ15N values, suggesting a diet low in protein from high trophic level foods such as meat and milk, possibly the result of differing social status or geographic factors. The approximately 23-year long incremental dentine profiles all show considerable fluctuation in stable isotope values during childhood and adolescence for all individuals until around age 20, suggesting possible influence by physiological processes related to growth and development.