Strontium and stable isotope evidence of human mobility strategies across the Last Glacial Maximum in southern Italy

Understanding the reason(s) behind changes in human mobility strategies through space and time is a major challenge in palaeoanthropology. Most of the time this is due to the lack of suitable temporal sequences of human skeletal specimens during critical climatic or cultural shifts. Here, we present temporal variations in the Sr isotope composition of 14 human deciduous teeth and the N and C stable isotope ratios of four human remains from the Grotta Paglicci site (Apulia, southern Italy). The specimens were recovered from the Gravettian and Epigravettian layers, across the Last Glacial Maximum, and dated between 31210-33103 and 18334-19860 yr cal BP (2 sigma). The two groups of individuals exhibit different Sr-87/ Sr-86 ratios and, while the Gravettians are similar to the local macro-fauna in terms of Sr isotopic signal, the Epigravettians are shifted towards higher radiogenic Sr ratios. These data, together with stable isotopes, can be explained by the adoption of different mobility strategies between the two groups, with the Gravettians exploiting logistical mobility strategies and the Epigravettians applying residential mobility.