| 1970. | Spisula (Oxyperas) sp. |
| Condition: | Present |
| Taxonomy: | Mollusca: Bivalvia: Mactridae: |
| Geologic Time: | Cenozoic: Miocene: |
| Horizon: | Higashi-Tanakura group: |
| Iwasaki, Y., 1970a: The Shiobara-type molluscan fauna. An ecological analysis of fossil molluscs. Journal of the Faculty of Science, University of Tokyo, Section 2, vol. 17, pt. 3, pp. 351–444, pls. 1–7. (Reference No. 0353) |
| Ichikawa, T., 1983, no. 9, p. 31. |
