Bank vole Myodes (=Clethrionomys) glareolus (Schreber, 1780): Rare species in the Late Pleistocene fauna of Croatia

摘要

In comparison to other vole species, bank vole Myodes (=Clethrionomys) glareolus (Schreber, 1780) is a very rare fossil element in the Late Pleistocene fauna in Croatia. So far, it has been found in several Croatian localities, from which four are presented here. In the Vindija Cave (NW Croatia), 33 molars were found in the faunal assemblages from layers/complexes I to B (MIS 5 to MIS 1; dated at approximately 88 ka to Holocene). A very small sample (16 molars) has been discovered from the Romualdova Cave (W Istria; layer B? (Postglacial). Only one fragment of a mandible with M_(1and2) has been found in the fossil material from the Marlera I site (S Istria; MIS 3-2), and one molar originates from the Ljubiceva Cave (S Istria; MIS 2-1). This small sample of 52 teeth (M_1s, M_2s, M_3s, and M~3s) was determined as M. glareolus, a very good indicator of forest habitats. These molars have been morphometrically analysed, and the results have been compared to those of the contemporaneous fossil material from other European localities. Increase of the length values has been observed for the Vindija sample, in concordance to the Berg-mann's rule. A/L indices show higher values for the Holocene sample (layer B) than for the specimens which originated from the G and E + F complexes dated at ＞42-18.5 ka BP. The most frequent mor-photype is B in the Vindija and Romualdova Caves, respectively. Morphometric data for the present-day bank voles of Croatia have been also given. M. glareolus is for the first time determined from the Romualdova and Ljubiceva Caves. Both sites have been recently systematically excavated. It is expected that future investigations of the small mammal remains will yield new findings of the bank vole from the Late Pleistocene layers of these Croatian sites.