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

摘要

The rodent faunas from nine sites on the Russian Plain and Taman Peninsula corresponding to the Early-Middle Pleistocene transition have been analyzed. These localities are situated in the Dnieper, Don, Dniester and Danube drainage basins and in the northern regions of the Black and Azov Seas. Seven of the sites are associated with the upper part of Matuyama reversed polarity Chron and located between the beginning of Jaramillo event and the Brunhes/Matuyama boundary. One of the sites was recovered from the Chauda marine deposits of the Black Sea and referred to the very beginning of Brunhes Epoch. The species composition of the rodent fauna sequence has been established. The faunas referred to the Jaramillo event (～1.1-1.0 Ma) contain the advanced Mimomys, steppe lemmings Prolagurus pannonicus and Lagurodon arankae, and Allophaiomys pliocaenicus. Faunas were recovered from Korotoyak (Ostrogozhsk suite), Roksolany, Zapadnye Kairy and Ushkalka localities. 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.