Inter-tooth comparison of δ13C and δ18O in ungulate tooth enamel from south-western Africa

Abstract

This study explores variation in δ13C and δ18O in tooth enamel carbonate along the tooth-row of wild African ungulate fauna from southwestern Africa. The study includes seven species (six bovids and a suid), all indigenous wild mammals from game parks and nature reserves, i.e. relatively undisturbed natural environments. Three to six teeth from each of a total of 23 individuals were analysed. δ13C and δ18O in different teeth from the same individual showed ranges of up to 4.4 (excluding one outlier) and 6.2‰ respectively, with median values of 2.7 and 2.0‰. In three of the seven species studied, first molars tended to be depleted in δ13C compared with second and third molars (although not all individuals showed this pattern), while in the remaining species they did not. First molars were not enriched in 18O, as reported by some previous researchers. We conclude that there is no universal patterning in δ13C and δ18O along the tooth row. The amount of isotopic variation between teeth depends on the species’ life history and on the environment in which the animals lived. This is important in archaeological and palaeontological studies, which frequently and unavoidably rely on only small numbers of samples.