Family Cardiidae Lamarck, 1809

Remarks. This family is not well represented in the seep fossil record, with the only reliable report being of indeterminate cardiids from a “ Calyptogena Association ” in the Pliocene Nadachi Formation, central Japan (Amano & Kanno 1991). Hirayama (1973) also reported the occurrence of Clinocardium asagaiense (Makiyama 1934) and Papyridea cf. nipponica Yokoyama, 1924, from the middle Miocene Hiranita Formation, central Japan, which may be seep-related.