Eastern European rodent (Rodentia, mammalia) faunas from the Early-Middle Pleistocene transition

The more advanced rodent faunas of the Morozovian assemblage (Port-Katon site) include also the first representatives of Terricola. Karai-Dubina and Shamin localities have been found below the Brunhes/Matuyama boundary (0.85 Ma), including the first representatives of Microtus (Microtus ex gr. oeconomus and Microtus arvalinus). The “Pitymys” like voles-Microtus (Stenocranius) hintoni, steppe lemming P. pannonicus and yellow steppe lemming Eolagurus argyropuloi compose the core of these faunas. The Litvin locality, located in the deposits of the Chauda transgression of the Black Sea and corresponding to the very beginning of the Middle Pleistocene, contains a rodent fauna closely resembling the Shamin one. It yielded the remains of Mimomys savini, advanced A. pliocaenicus, P. pannonicus, Microtus (Stenocranius) hintoni, Microtus ex gr. oeconomus and Mcirotus arvalinus. Thus, numerous data permit elucidation of the history of rodent faunas of the Russian Plain during Early-Middle Pleistocene transitions and reveal the definitive stages in their evolution.