Paleoecological insights into the giant deer (Megaloceros giganteus): the Italian Peninsula as a glacial refuge

The Irish elk (Megaloceros giganteus) is an iconic cervid of the Eurasian Pleistocene megafauna. In the Italian Peninsula, its earliest occurrence is recorded at Torre in Pietra (RM; MIS 9), while the last occurrence is dated back to 17 ka cal BP at Ex Cava a Filo in the Bolognese gypsum outcrops. The Italian Peninsula is recognized as a key glacial refugium for several mammal species during the Last Glacial Maximum (LGM), highlighting its importance for Late Pleistocene megafauna. Notably, this period corresponds to a gap in the European fossil record of the Irish elk, whereas evidence from Ex Cava a Filo and Cava I.E.C.M.E. (BO) indicates its persistence in Italy, supporting the hypothesis of a refugial role prior to the regional extinction of the species. Despite a relatively rich fossil record, particularly during the Late Pleistocene of Northern Italy, the Italian Irish elk remains poorly studied. In this work, we characterize its paleoecology by investigating paleodiet at different temporal scales through dental mesowear and microwear analyses. Dental remains from several institutions, such as the Museo Civico di Storia Naturale di Milano, the Kosmos – Museo di Storia Naturale dell’Università di Pavia and the Museo della Preistoria L. Donini provide a robust dataset to infer dietary adaptations. We assess how Pleistocene paleoclimatic and paleoenvironmental changes influenced dietary variations in Italian populations and evaluate interspecific competition with other cervid species that co-occurred within the same herbivore paleocommunities. Furthermore, specimens dated to the LGM are particularly relevant to identify the main drivers of its regional extinction. Overall, this study aims to clarify the paleoecology of the Irish elk across Italian Late Pleistocene fossil assemblages.