Some thoughts regarding MIS3 marmots (Marmota marmota) of north-western Italy with particular reference to those from Caverna Generosa (Centro Valle Intelvi, Como)

This work focuses on fossil bones of the alpine marmot Marmota marmota (Rodentia, Sciuridae), a topic poorly studied in previous palaeontological work. In northern Italy the alpine marmot seems to be absent during the Lower Pleistocene and very poorly represented in the Middle Pleistocene. Only during the Upper Pleistocene is this rodent widespread. The fossil remains studied herein come from Upper Pleistocene deposits of the Caverna Generosa (Centro Valle Intelvi, CO; 1450 m a.s.l.), Buco del Frate (Prevalle, BS; 253 m a.s.l.) and Büs di Tri Fradei (Oltre il Colle, BG; 1200 m a.s.l.). Furthermore, the remains of the extant alpine marmot were analysed for comparison. The morphometric study revealed that the sexual dimorphism is negligible, and that fossil and extant specimens are dimensionally similar, although most of the extant marmots seem to be slightly larger than the fossil ones. The Caverna Generosa fossil specimens were divided into classes of dental eruption and wear, associated with different ontogenetic stages. This allowed us to highlight a peak of mortality among the juvenile specimens. Furthermore, the Caverna Generosa sample was compared with those from Grotte di Pradis (Friuli Venezia Giulia, Italy) and Grotte Colomb (France) where human exploitation of the marmot is attested. This comparison confirmed that the pattern of mortality at the Caverna Generosa is not related to human exploitation. Dating of two alpine marmot bones from two different levels of two different areas of the Caverna Generosa returned ages of 35,645-34,371 y cal BC and 32,540-32,032 y cal BC, respectively. These results suggest that the frequentation of the cave by M. marmota is more or less contemporary with that of Ursus spelaeus and other Upper Pleistocene species found at the site.