MORPHOLOGY OF THE FIRST MANDIBULAR TOOTH MICROTUS GREGALIS (RODENTIA, ARVICOLINAE) FROM THE MIDDLE PLEISTOCENE OF THE PRE-ALTAI PLAIN

In this paper morphological structure of the first lower molar m1 tooth of the narrow-skulled vole from alluvial deposits of the Pre-Altai Plain Middle Neo-Pleistocene is described. Morphological study of the vole remains showed that they belong to the modern species Microtus gregalis. At the same time, the study sample showed significant differences, both in morphological structure and in the size of the first lower molar, in comparison with the recent representatives of the same territory. The set of morphological and morphometric data shows that the studied voles occupy an intermediate position between M. gregaloides of the Early and M. gregalis of the Late Neo-Pleistocene. The ratio of m1 morphotypes also showed the relative primitiveness of the M. gregalis sampling. Morphological study of remains of the narrow-skulled vole from the Solonovka, Petropavlovskoe and Malinovka-4 locations confirmed the previously determined age for sediments containing the remains of microtheriofauna.