Soulier, M.-C. | bioRxiv Science

bioRxiv2025

Bone collagen hydrogen isotopes as tracers of local palaeoclimate: The Aurignacian from Isturitz cave (France) as a case study

Hydrogen stable isotopes ({delta}2H) preserved in bone collagen have been proposed as a promising proxy for palaeoclimatic reconstruction, though empirical applications remain limited. To evaluate the reliability and scope of this approach, we performed a multiisotopic analysis ({delta}13C, {delta}15N, {delta}34S, and {delta}2H) on 50 herbivore bone samples collected from three archaeostratigraphic layers spanning the Aurignacian sequence of Isturitz Cave (France). This archaeological well-preserved, dated and studied site provides a robust framework for testing isotopic proxies across temporal and taxonomic gradients. Our results reveal a progressive {delta}2H depletion over [~]3000-year interval, consistent with predicted increasing aridity. We also identified species-specific {delta}2H differences, underscoring the need for taxonomic resolution in future applications and in general palaeoclimatic interpretations. While these samples reflect faunal remains accumulated through human activity--introducing potential ecological and sampling biases--they nonetheless provide valuable records of past local conditions. Overall, our findings support the potential of bone collagen {delta}2H as a sensitive indicator of past hydrological conditions and a complementary tool for reconstructing both climatic trends and humanenvironment dynamics.

ecology↗

bioRxiv2024

Expanding the use of reindeer foetal bone measurements for zooarchaeological applications

When foetal bones are preserved in archaeological sites, they are often used to identify the seasonality of prey acquisition by past human populations and, subsequently, to discuss their lifestyle, their management of food resources, nomadic cycles, etc. To do so, zooarchaeologists use charts to estimate foetal age based on the growth of their bones. For reindeer (Rangifer tarandus), a species that was widely exploited since the Palaeolithic throughout Eurasia, existing reference data are limited and require the measurement of complete bones, a procedure that is rarely applicable to archaeological contexts in which bones are often fragmented. In this study we present a wide range of measurements (9-10 measurements per bone) taken on the humerus, radius, metacarpal, femur, tibia and metatarsal of 31 individuals housed at the Zoological Museum of the University of Oulu (Finland). With this large data set, a more accurate estimation of the time of death of reindeer foetus can be achieved using skeletal measurements, even in the case of fragmented bones. To facilitate the use of this referential, an open-access web interface (foetusmeteR) was designed in RShiny. This interface allows for the direct estimation of foetal age and season of death by entering a single skeletal measurement, as well as the possibility of estimating if two bones might correspond to the same individual using two different measurements. This new tool should help to discuss in more detail the condition of reindeer herds hunted in the past, the hunting techniques and strategies that may have been used by human groups, and allow for a more detailed reconstruction of the seasonal nomadic cycle of past societies that focused their subsistence on Rangifer populations.

zoology↗