Bulletin of the Mizunami Fossil Museum No. 2
Polyplacophora assemblage from the Mizunami group, central Japan (First report)
- BMFM02-004Itoigawa&Nishimoto, 1975（PDF 5.13MB）
Itoigawa and Nishimoto (1975) print-version
Published: 1975/12/25 Page: 35–50, pls. 9–11
About 1000 specimens of fossil Polyplacophora are collected from the Kujiri and Shukunohora facies of the Akeyo formation, and the Nataki conglomerate member of the Oidawara formation, both of the Miocene Mizunami group for the latest about ten years. Twelve species are recognized in them as shown in Table 1. Each member has the characteristic assemblage respectively as follows; Nataki member: Lepidozona-Chaetopleura?-Placiphorella Assemblage Shukunohora facies: Lepidozona-Acanthochitona-Rhyssoplax A. Kujiri facies: (Lepidozona A.) Many problems on paleoenvironments of sedimentation of the members are discussed referring various data on Mollusca, Elasmobranchus and Anthozoa etc. Occurrence, preservation and fragmentation of chitons are also argued on viewpoint of paleoecology.