Unravelling the oxygen isotope signal (δ18O) of rodent teeth from northeastern Iberia, and implications for past climate reconstructions

Abstract

Small mammals, especially rodents, constitute valuable proxies for continental Quaternary environments at a regional and local scale. Recent studies have demonstrated the relation between the stable oxygen isotope composition of the biogenic phosphate from rodent teeth (d 18 Op), and the oxygen isotope composition of meteoric waters (d 18 O mw), which is related to air temperatures at mid and high latitudes. This work explores the d 18 Op of rodent tooth enamel (from Murinae and Arvicolinae subfamilies) to investigate the palaeoenvironmental conditions in northeastern Iberia during Marine Isotope Stage 3 (MIS 3; ca. 60-30 ka). Fourteen new d 18 Op analyses from modern samples in conjunction with forty-six d 18 Op analyses previously published are used to decipher the isotope record of present-day rodent teeth in this region. Two main factors should be considered in Iberian palaeoenvironmental reconstructions: the singular nature of Iberian

Combined palaeoecological methods using small-mammal assemblages to decipher environmental context of a long-term Neanderthal settlement in northeastern Iberia

“…Under geochemical perspective, homogenous sequence and low variability in MATs were also observed in a contemporaneous palaeontological site of northeastern Iberia, Xaragalls cave (Vimbodí-Poblet) (Ferna 'ndez-García et al, 2019;Lo 'pez-García et al, 2012a). Medium to small d 18 Op ranges, which are always associated with high means and relatively constant throughout these sequences, differ from a contemporaneous archaeological site in southern France, Les Pradelles (Royer et al, 2013b).…”

“…Four incisors from the subfamily Arvicolinae, belonging to a minimum of four individuals, were also included. Unbroken and well-preserved lower incisors from adult rodents were preferentially selected (Barham et al, 2017;Ferna 'ndez-García et al, 2019;Royer et al, 2014). The phosphate component constitutes the major source of oxygen in biogenic apatite and is less prone to mechanisms of geochemical and biological alteration (Clementz, 2012;Grimes et al, 2008;Le 'cuyer et al, 1999;Lindars et al, 2001), favouring the preservation of the original oxygen isotope composition at geological timescales.…”

“…The most parsimonious hypothesis is that analyzed rodent remains were introduced into the site during a preferential period of the year. Given the higher number of murid specimens and the observed oxygen isotope compositions of contemporaneous Iberian rodent tooth samples, spring-early summer months may have resulted in a higher probability of prey capture by owls (Ferna 'ndez-García et al, 2019;Lagos, 2019;Manzanares, 2012;Norrdahl and Korpima, 2002;Royer et al, 2013aRoyer et al, , 2013bSalamolard et al, 2000). (Fig.…”

New insights in Neanderthal palaeoecology using stable oxygen isotopes preserved in small mammals as palaeoclimatic tracers in Teixoneres Cave (Moià, northeastern Iberia)

“…Oxygen isotope analysis performed on presentday material coming from the Moià area is also included. The remains came from one pellet recovered at the end of August from a barn owl (Tyto alba) nest, located at 7.7 km from Teixoneres Cave at 1000 m a.s.l (Table 2; Fernández-García et al 2019). These remains consist of three lower incisors from M. (T.) duodecimcostatus and M. musculus.…”

“…This work complements previous reconstructions performed by using 40 oxygen isotope analysis (δ 18 O) of rodent incisors from subunits IIIb to IIa. The relationships between δ 18 O preserved in mammal body tissues with δ 18 O of meteoric waters and mean annual temperatures allowed us to quantify the magnitude of the climatic changes through the sequence (Royer et al 2013a(Royer et al , 2014Fernández-García et al 2019. Thus, considering all the recent research on the site, this work aims to reevaluate the ecological conditions during this sequence formation, unravelling the origins of the small-mammal remains and post-depositional processes.…”