Late Pleistocene Neanderthal exploitation of stable and mosaic ecosystems in northern Iberia shown by multi-isotope evidence

Abstract

During the last glacial period, rapidly changing environments posed substantial challenges to Neanderthal populations in Europe. Southern continental regions, such as Iberia, have been proposed as important climatic “buffer” zones during glacial phases. Contextualising the climatic and ecological conditions Neanderthals faced is relevant to interpreting their resilience. However, records of the environments and ecosystems they exploited across Iberia exhibit temporal and spatial gaps in coverage. Here we provide new evidence for palaeotemperatures, vegetation structure, and prey herbivore ecology during the late Pleistocene (MIS 5–3) in northern Spain, by applying multiple stable isotope tracers (δ18O, δ13C, δ15N, δ34S) to herbivore skeletal remains associated with Neanderthal occupations at Axlor Cave, Bizkaia. The results show little change over time and indicate stable climatic conditions and ecosystems across different occupations. Large within-layer isotopic variability in nitrogen and sulphur suggests the presence of a mosaic environment and a variety of isotopic ecotones that were exploited by Neanderthals and their prey. We implement a combination of carbonate and phosphate δ18O measurements to estimate palaeotemperatures using a cost-effective workflow. We show that the targeted use of phosphate δ18O measurements to anchor summer peak and winter trough areas enables high-precision seasonal palaeoclimatic reconstructions.

Seasonal climate variations during Marine Isotope Stages 3 and 2 inferred from high‐resolution oxygen isotope ratios in horse tooth enamel from Lower Austria

“…Mammalian tooth enamel provides another powerful tool for palaeoclimatic reconstructions, as its oxygen isotope composition reflects seasonal climatic variations during tooth mineralisation (D'Angela and Longinelli, 1993;van Dam and Reichart, 2009;Drucker et al, 2011;Fabre et al, 2011;Zazzo et al, 2012). Isotopic variations in tooth enamel from different regions and time periods have been investigated, mainly from Marine Isotope Stage (MIS) 5 (130-70 ka;Helmens, 2014;Bernard et al, 2009;Fabre et al, 2011;Skrzypek et al, 2011;Scherler et al, 2014;Britton et al, 2019;Pederzani et al, 2021bPederzani et al, , 2023, or MIS 3 (59-29 ka Voelker et al, 2002;Pushkina et al,2014;Britton et al, 2023;Pederzani et al, 2021bPederzani et al, , 2023.…”

“…δ 18 O and δ 13 C isotopic variations of the phosphate and/or carbonate component of tooth enamel from various living and fossil mammals have been analysed in several studies to reconstruct the palaeoclimate, including equids (Daniel Bryant et al, 1994; Chillón et al, 1994; van Dam and Reichart, 2009; Kohn and McKay, 2012; de Winter et al, 2016; Britton et al, 2019; Pederzani et al, 2021a), bovids (Kohn et al, 1998; Hoppe, 2006; Kohn and McKay, 2012; Makarewicz and Pederzani, 2017; Pederzani et al, 2021a, 2021b, 2023), cervids (Genoni et al, 1998; Li et al, 2017; Szabó et al, 2020), proboscideans (Genoni et al, 1998; Tütken et al, 2007; Kovács et al, 2012; Wigda et al, 2020; Liu et al, 2022) and humans (Levinson et al, 1987; Iacumin et al, 2004; Daux et al, 2005). The oxygen isotope composition is usually better preserved in the phosphate than in the carbonate component because P–O bonds are more resistant to isotope exchange than C–O bonds and calcium phosphate is less soluble in aqueous solutions than calcium carbonate (Zazzo et al, 2004a, b; Demény et al, 2019).…”