Bibai Formation, Ishikari Group (Eocene of Japan)

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: Bibai Formation (Ishikari Group), Lutetian (47.8 - 41.3 Ma)

• STRATIGRAPHIC RELATIONS: From Bibai Fm, which overlies the Wakkanabi and underlies the Akabira 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 sandstone and lithified siltstone

• ENVIRONMENT: Marine and non-marine faunal assemblage.
• SPECIFIC LITHOLOGY: Sandstone and siltstone. LITHIFICATION: Assume to be lithified on the basis of age and photgraphic plates of Takano and Osamu (2003).

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 70902: authorized by Austin Hendy, entered by Austin Hendy on 11.04.2007, edited by Bethany Allen

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Exhaustive for bivalvia and gastropoda. NOMENCLATURE: Somewhat antiquated, but with species-level identifications.
Gastropoda
 Architaenioglossa - Viviparidae
Paludina sp. FĂ©russac 1812 snail
Bivalvia
 Mytilida - Mytilidae
"Modiola sp." = Modiolus Lamarck 1801 mussel
 Ostreida - Ostreidae
Ostrea eorivularis Oyama and Mizuno 1958 oyster
 Ostreida - Pteriidae
"Margaritifera perdahurica" = Pinctada
"Margaritifera perdahurica" = Pinctada pearl oyster
 Unionida - Unionidae
Unio sp. Philipsson 1788 freshwater mussel
 Cardiida - Corbiculidae
Reptilia
 Testudines - Testudinidae
Sinohadrianus ezoensis n. sp. Shikama 1953 turtle
Unnumbered specimen in Institute of Geology and Mineralogy, Hokkaido University (holotype), carapace. Collected from "incline No. 19" at the Utashinai Coal Mine.
Angiospermae
 Malpighiales - Salicaceae
Populus sp. Linnaeus 1753 poplar
 Laurales - Lauraceae
Cinnamomum sp. Schaeffer 1760 cinnamon
 Mesangiosperms - Arecaceae
 Coniferales - Cupressaceae
Taxodium distichum Linnaeus 1753 bald cypress
Glyptostrobus sp. Endlicher 1847 Chinese swamp cypress
Sequoia langsdorfii Heer 1877 coast redwood