Aurignacian groups at Isturitz (France) adapted to a shifting environment upon their arrival in Western Europe ∼42,000 years ago

The Marine Isotope Stage 3 is a context of considerable climatic instability. Establishing the link between global climate changes and their impact on the local ecological contexts and prey exploited by human populations is challenging. Still, it is necessary to understand better the local conditions where humans lived to unravel how they adapted to fluctuating environmental conditions. Here, we address this question by studying 250 osteodental elements from animals hunted and consumed by human groups at Isturitz, a rich and well-documented French archaeological site and one of the earliest in Western Europe where the Aurignacian technoculture has been attested. To do so, we set up a multiproxy approach (archaeozoology, three-dimensional dental microwear texture analyses, and stable isotopic analyses of δ¹⁸O and δ¹³C in enamel bioapatite and δ¹³C, δ¹⁵N, and δ³⁴S in bone collagen) that informs us on a timeline from the first years to the last few days of an animal's life. We reconstructed their ecologies and paleoenvironments during the different Aurignacian phases at Isturitz. Our findings indicate that the first human occupations at Isturitz occurred under cold and arid conditions, rapidly becoming even cooler and drier. Limited changes are observed in the human-environment-prey relationship despite this unstable climatic context where significant changes in rainfall, temperature, and a gradual opening of environments and some changes in the faunal assemblage occurred. Our findings suggest that human groups hunted in similar territories and utilized comparable strategies throughout the temporal sequence. Our multiproxy approach, combining complementary analyses, provides a better understanding of the adaptation strategies when the first phases of the Upper Paleolithic were emerging in Western Europe.