Where: Japan (43.5° N, 142.0° E: paleocoordinates 46.7° N, 136.4° E)
• coordinate based on nearby landmark
• local area-level geographic resolution
When: Wakkanabi Formation (Ishikari Group), Lutetian (47.8 - 41.3 Ma)
• STRATIGRAPHIC RELATIONS: From Wakkanabi Fm, which overlies the Yubari and underlies the Bibai Fm, all of the Ishikari Gp (Middle Eocene). THICKNESS: From unit which reaches a thickness of 100-250 m. AGE: early Middle Eocene according to Takano and Waseda (2003). Referred only to Eocene in Mizuno (1964). STRATIGRAPHIC POSITION: Composite checklist for formation from local area.
• formation-level stratigraphic resolution
Environment/lithology: marginal marine; lithified siltstone and sandstone
Size class: macrofossils
Preservation: cast, mold/impression
Collection methods: COLLECTOR: T. Mizuno (c. 1960's). REPOSITORY: Unknown, not stated in text.
Primary reference: A. Mizuno. 1964. Summary of the Paleogene molluscan faunas in North Japan. Geological Survey of Japan Report 207 [A. Hendy/A. Hendy/A. Hendy]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 70900: authorized by Austin Hendy, entered by Austin Hendy on 11.04.2007
Creative Commons license: CC BY (attribution)
Taxonomic list
unclassified | |
Bivalvia | |
Brachidontes ogasawarai mussel
Brachidontes sakakurai mussel | |
Ostrea eorivularis Oyama and Mizuno 1958 oyster | |
Venericardia otatsumei Uozumi 1955 clam | |
"Crassatellites yessoensis" = Crassatella
"Crassatellites yessoensis" = Crassatella clam | |
Soletellina shimogawarai sunset shell
Soletellina otatsumei sunset shell | |
Spisula sorachiensis Otatsume 1933 clam | |
"Microcallista munroei" = Callista (Microcallista), Cyclina shirokiana, Pitar sannosawaensis, Pitar sorachiensis
"Microcallista munroei" = Callista (Microcallista) venus clam
Cyclina shirokiana venus clam
Pitar sannosawaensis venus clam
Pitar sorachiensis Oyama and Mizuno 1958 venus clam | |
"Geloina takaoi" = Polymesoda (Geloina), "Geloina hokkaidoensis" = Polymesoda (Geloina), Corbicula tokudai
"Geloina takaoi" = Polymesoda (Geloina) clam
"Geloina hokkaidoensis" = Polymesoda (Geloina) clam
Corbicula tokudai clam | |
"Mya ezoensis" = Mya (Arenomya) ezoensis
"Mya ezoensis" = Mya (Arenomya) ezoensis Nagao and Inoue 1941 softshell clam | |
Claibornites quinquangulus Uozumi 1955 clam | |
Gastropoda | |
Calyptraea sorachiensis Oyama and Mizuno 1958 slipper shell | |
Bellamya mabutii snail | |
"Siphonalia" ishikariensis true whelk
"Siphonalia" sakakurai Mizuno 1954 true whelk | |
Polinices nagahamai moon snail | |
Pyrazus miyajimai snail |