... Nipponocythere bicarinata is a typical middle bay species in Japan (Irizuki et al., 2006) abundant in muddy substrates at a water depth of deeper than 10 m Yasuhara and Seto, 2006). Since its original description based on specimens collected from the Seto Inland Sea of Japan (Brady, 1880), N. bicarinata has been routinely reported in sediments from several studies of Japan's Pliocene (Iwatani and Irizuki, 2008;Tanaka and Nomura, 2009; Ozawa and Tanaka, : Brady, 1880;van den Bold, 1966van den Bold, , 1985Ishizaki, 1971Ishizaki, , 1981Ishizaki and Gunther, 1976;Ishizaki and Kato, 1976;Hanai et al., 1977;Guan et al., 1978;Hu, 1978Hu, , 1982Hu, , 1984Osario, 1978;Colalongo and Pasini, 1980;Ishizaki, 1981;Malz, 1981;Frydl, 1982;Hou et al., 1982;Gou et al., 1983;Ř íha, 1983;Ciampo, 1986;Tabuki, 1986;Bodergat and Ikeya, 1988;Paik and Lee, 1988;Ruan and Hao, 1988;Wang et al., 1988;Zhao and Wang, 1988;Liu, 1989;Yajima and Lord, 1990;Ikeya et al., 1992;Ayress and Corrège, 1993;Drapala and Ayress, 1993;Barra, 1995;Zhou, 1995;Cao, 1998;Bonaduce et al., 1994;Yamane, 1998;Lee et al., 2000;Yasuhara and Irizuki, 2001;Bodergat et al., 2002;Szczechura and Aiello, 2003;Yasuhara and Yamazaki, 2005;Irizuki et al., 2006Irizuki et al., , 2018Yasuhara and Seto, 2006;Hu and Tao, 2008;Tanaka, 2008;Ozawa, 2009;Hou and Gou, 2007;Tanaka and Nomura, 2009;Iwatani et al., 2011;Irizuki et al., 2018;Tanaka et al., 2012Tanaka et al., , 2019Hong et al., 2019;Ozawa and Tanaka, 2019. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.) ...