History of rodent fauna in the Northern Urals during the late Pleistocene (data of paleontological research in Studyony locality)

Assemblages of rodent remains obtained from sediments of Studyony locality in the western slope of the Northern Urals were studied. In the result, two stages of microtheriofauna history are described: the Byzovaya interstadial and the Last Glacial Maximum. Fauna of the termination of Byzovaya (Middle Valday) interstadial is described on the basis of studying materials from the lower assemblage. This fossil complex is the oldest assemblage of cave taphonomic type in the Fore-Uralian Subarctic. Byzovaya fauna existed when moss tundra with the some forest vegetation was widely distributed. The community is dominated by the Siberian lemming, and considerable portion of forest and intrazonal species. The composition and ecological structure of communities of the Last Glacial Maximum indicates extremely cold and dry conditions. In this fauna the collared lemming sharply dominates with significant share of narrow-headed vole remains. Collared lemmings of the Last Glacial Maximum from Studyony locality are at the evolutionary level of teeth development corresponding to morph 3 Dicrostonyx gulielmi , characteristic for animals that lived in the northeastern part of European Russia, approximately from 30 to 11 cal. ka, from the end of Byzovaya interstadial till the beginning of the Holocene. Narrow-headed voles of this interval demonstrate the size and morphotypic features of the first lower molar, characteristic for the Late Quaternary voles of northeastern Europe.