Microwear and isotopic analyses on cave bear remains from Toll Cave reveal both short-term and long-term dietary habits

Dietary habits of the extinct Ursus spelaeus have always been a controversial topic in paleontological studies. In this work, we investigate carbon and nitrogen values in the bone collagen and dental microwear of U. spelaeus specimens recovered in Level 4 from Toll Cave (Moia, Catalonia, NE Iberian Peninsula). These remains have been dated to > 49,000 C-14 BP. The ability of both proxies to provide data on the diet of U. spelaeus at different times in the life-history (isotopes: average diet of life; microwear: last days/weeks before death), allows us to generate high-resolution and complementary data. Our results show lower values (delta C-13 & delta N-15) in cave bears than in strict herbivores (i.e. Cervus elaphus) recovered from the same level of Toll Cave. On the other hand, 12 lower molars (ml) were analysed through low-magnification microwear technique. The cave bears from Toll Cave show a microwear pattern like that of extant bears with omnivorous and carnivorous diets. These data are discussed in the framework of all available data in Europe and add new information about the plasticity of the dietary habits of this species at the southern latitudes of Europe during Late Pleistocene periods.Isotopic samples were prepared at the Biomolecular laboratory of IPHES and measured at the Institute of Environmental Science and Technology (ICTA) with technical assistance by Dr. Pau Comes. Some samples were reanalysed at the University of Cape Town (UCT). Dr. C. Tornero acknowledges the Beatriu de Pinos Postdoctoral fellowship (BP-MSCA Cofound code 2016-00346) from the AGAUR, Goverment of Catalonia, Spain. The research at Toll Cave is supported by projects CLT009-18-00055 and 2017 SGR 836 from the Generalitat de Catalunya; and project HAR2016-76760-C3-1-P from the Ministerio de Ciencia, Innovacion y Universidades (Spain). Dr. J. Rosell and Dr. R. Blasco develop their work within the Spanish MINECO/FEDER projects CGL2015-65387-C3-1-P and CGL2015-68604-P