Okinoshima Fm (lower part) - Okinoshima (Eocene of Japan)

Where: Japan (32.7° N, 132.6° E: paleocoordinates 39.8° N, 127.9° E)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Okinoshima Formation, Late/Upper Eocene (37.2 - 33.9 Ma)

• STRATIGRAPHIC RELATIONS: From Okinoshima Fm, which regionally overlies the Middle Eocene Hashima Fm, and underlying the Lower Iojima Fm (Late Eocene). THICKNESS: From portion of formation that attains a thickness of ~200 m. AGE: Late Eocene, based on molluscan biostratigraphy. STRATIGRAPHIC POSITION: From lower part of formation.

• member-level stratigraphic resolution

Environment/lithology: coastal; lithified, fine-grained, medium, glauconitic, green sandstone

• ENVIRONMENT: Shallow sea, soft-bottom siliciclastic bottom.
• SPECIFIC LITHOLOGY: Green-colored, glauconite-bearing, fine-medium grained sandstone. LITHIFICATION: Presumed lithified on the basis of age.

Size class: macrofossils

Collection methods: surface (float),

• COLLECTOR: A. Mizuno (c. 1964). REPOSITORY: Not stated in text, unknown.

Primary reference: A. Mizuno. 1964. Paleogene and Early Neogene molluscan faunae in West Japan. Geological Survey of Japan Report 204 [A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 70919: authorized by Austin Hendy, entered by Austin Hendy on 11.04.2007

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Exhaustive for gastropoda and bivalvia. NOMENCLATURE: Farly modern nomenclature, and species-level assignments.
Bivalvia
 Arcida - Glycymerididae
 Ostreida - Gryphaeidae
"Pycnodonta cassis" = Pycnodonte
"Pycnodonta cassis" = Pycnodonte oyster
 Carditida - Carditidae
"Venericardia nipponica" = Venericardia (Venericor) nipponica
"Venericardia nipponica" = Venericardia (Venericor) nipponica Yokoyama 1911 clam
 Cardiida - Psammobiidae
"Psammotaea equideclivis" = Sanguinolaria (Psammotaea)
"Psammotaea equideclivis" = Sanguinolaria (Psammotaea) clam
Gastropoda
 Neogastropoda - Volutidae
Volutospina ? nishimurai Nagao 1928 volute
 Stromboidea - Thersiteidae
"Orthaulax" japonicus Nagao 1924 snail
 Naticoidea - Naticidae
"Polinices nomii" = Pliconacca nomii
"Polinices nomii" = Pliconacca nomii Nagao 1928 moon snail