Palaeodiet during the pre-dormancy period of MIS 3 Romanian cave bears as inferred from dental microwear analysis

Abstract

Cave bears (Ursus spelaeus) have been recognized as being predominantly herbivorous. However, Romanian Carpathian cave bears have displayed a flexible diet based on a wide range of δ15N values. In this work, we analyse 97 lower first molars of Ursus spelaeus and contemporaneous Ursus arctos from different sites in this region, using dental microwear analysis to reconstruct their pre-dormancy diets during MIS 3. Newly obtained radiocarbon dates of the individuals are also reported. The short-term diet of all populations studied is identified as omnivorous, with a preference for the consumption of hard objects. For the first time, the widespread presence of puncture pits on U. spelaeus populations has been observed, which could be linked to the intake of seeded and hard-shelled fruits from temperate broadleaf trees. Hence, the dietary patterns of Carpathian cave bears exhibit similarities to those of present-day brown bears inhabiting the same region and suggests that the Carpathians served as an ecological refuge for cave bear specimens. This is reinforced by an early 27.1 cal kyr B.P. date from an individual from Urşilor Cave, which sheds light on the potential dietary continuity of Romanian Carpathian cave bear populations even during the final phases leading up to their extinction.