Where: Japan (43.5° N, 142.0° E: paleocoordinates 46.2° N, 137.6° E)
• coordinate based on nearby landmark
• local area-level geographic resolution
When: Hiragishi Formation (Ishikari Group), Bartonian (41.3 - 38.0 Ma)
• STRATIGRAPHIC RELATIONS: From Hiragishi Fm, which overlies the Ikushunbetsu and underlies the Ashibetsu Fm, all of the Ishikari Gp (Middle Eocene). THICKNESS: From unit which reaches a thickness of 120-700 m. AGE: late 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: fluvial; lithified sandstone and lithified siltstone
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 70905: authorized by Austin Hendy, entered by Austin Hendy on 11.04.2007
Creative Commons license: CC BY (attribution)
Taxonomic list
unclassified | |
Bivalvia | |
Corbicula sakakibarai, Corbicula sitakaraensis, Corbicula ? tokudai, "Geloina ? takaoi" = Polymesoda (Geloina)
Corbicula ? tokudai clam
"Geloina ? takaoi" = Polymesoda (Geloina) clam | |
Anodonta subjapanensis freshwater mussel
Hyriopsis mabutii freshwater mussel | |
Gastropoda | |
Bellamya mabutii snail | |
Melanoides otatumei snail |