Quaternary rodent and insect faunas of the Urals and Western Siberia: Connection between Europe and Asia

摘要

The biogeographic groups of rodent (arvicoline) and beetle species in the modern fauna of the Urals and Western Siberia based on the longitudinal patterns of their present-day distribution are established. Occurrence of species of the Transpalearctic, West Palearctic (European), East-Palearctic, and Central-Palearctic faunal groups is estimated at different stages of the Late Quaternary development of the present-day fauna of the region. The border between the European and East-Palearctic faunal groups represents a vast territory where the ranges of the species included in those groups intersect. The border territory includes the Ural Mountains and the lowlands lying west and east of it (the East-European Plain and the West Siberian Plain). The biomes of those territories represent the North-Eurasian corridors providing migrations of species from the different faunal complexes in the west-east, east-west, and north-south directions. The importance of the study area for faunal correlations throughout the continent is determined by presence of the key arvicoline taxa traditionally used for correlation purposes (taxa Dicrostonyx, Lagurus, Microtus gregalis), and by the gradual change in faunal composition along the latitudinal gradient of environment at any given stage of the Quaternary. Transzonal faunal correlations within the Urals and Western Siberia integrating the evolutionary morphological studies of the key taxa and assessment of the faunal successions may serve as a basis for Trans-Eurasian correlation.