 Bunje (2005) hypothetized that the ancestral range of "Theodoxus fluviatilis" was the Ponto-Pannonian region (southern Ukraine, Romania and Hungary).Bunje suggested that the species first colonized northern Italy, Greece and Turkey; in the second phase it colonized Spain, France and Germany; and finally in the Holocene it colonized the British Isles, Sweden and the Baltic Sea.In 2002, German malacologist Peter Glöer summarized the distribution of this species during the Pleistocene and Holocene epochs.