Map showing hypothesized paleodistribution of clade I, that includes genus Blanfordia (Blanfordia simplex, Blanfordia japonica, Blanfordia bensoni) and "Fukuia" ooyagii in Middle Pliocene to Late Pliocene (3.5-2 Ma). There are Japanese archipelago, Sea of Japan and surrounding part of continental East Asia on the map.
Kameda Y. &amp; Kato M. (2011). "Terrestrial invasion of pomatiopsid gastropods in the heavy-snow region of the Japanese Archipelago". BMC Evolutionary Biology 11: 118. doi:10.1186/1471-2148-11-118. Figure 5C. Modified: added color of ocean.
Yuichi Kameda &amp; Makoto Kato