The molecular techniques are the standard tool for the study of taxonomic position and phylogenetic affinities of the lymnaeid genus Radix Montfort, 1810, and the majority of the European representatives of this taxon have been studied in this respect. However, a plethora of nominal species of Radix described from Northern Asia (Siberia and the Russian Far East) are still characterized only morphologically raising some doubts concerning their validity. In this paper, we present the triple (morphological, molecular, and zoogeographical) evidence that there are at least one endemic species of Radix, R. dolgini (Gundrizer et Starobogatov, 1979) widely distributed in Siberia and Western Mongolia. Phylogenetically, it is a sister species to the European Radix labiata (Rossmaessler, 1835) [= R. peregra auct.], and their common ancestor most probably lived in the Pliocene, nearly 3.25 myr. Our results assumes the existence of an extended dispersal barrier for freshwater hydrobionts between Europe and Siberia in the