Batillariid and potamidid gastropods from the Middle Miocene Kukinaga Group, Tanegashima Island, southwest Japan, and their paleobiogeographic implications

Abstract

ABSTRACT Two batillariid and four potamidid species from the middle to upper Middle Miocene Kukinaga Group, Tanegashima Island, southwest Japan are described systematically. Of these, the two batillariid species are new to science. Batillariids and potamidids from the Kukinaga Group are composed of three elements: (1) survivors from the late Early to early Middle Miocene, (2) species confined to the middle to late Middle Miocene, and (3) earliest records of living species. The occurrence of Vicarya japonica Yabe and Hatai from the Kukinaga Group marks the last appearance of the species in the Neogene of Japan, and the presence of Telescopium telescopium (Linne) and Cerithidea (Cerithideopsilla) cingulata (Gmelin) marks their first appearance in the Neogene in the Indo-Pacific region. The Kukinaga molluscan fauna, characterized by the occurrence of these gastropods, flourished during the Middle Miocene along the Pacific coast of southwestern Japan under the strong influence of a paleo-Kuroshio warm current...