Abstract:
Remains of the rodent Prosomys insuliferus (Kowalski 1958) (Arvicolidae) from the Pliocene of Podlesice in Poland and from Antipovka and Chugunovka in the European part of U.S.S.R. are described. The faunal lists of these fossil localities are given. Prosomys insuliferus is also known from the Pliocene of Vendargues in France and another species of this genus P. mimus Shotwell 1956 from the western part of the U.S.A. The systematic position of other primitive forms of Arvicolidae is discussed. Prosomys Shotwell 1956, primitive in many of its characteristics, nevertheless belongs to the family Arvicolidae and is its oldest well known member.