R6302 - Obira (Saku Formation) (Cretaceous of Japan)

Where: Japan (44.1° N, 142.0° E: paleocoordinates 52.1° N, 134.4° E)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Saku Formation, Turonian (93.9 - 89.8 Ma)

• STRATIGRAPHIC RELATIONS: Presumably from the Saku Formation of Turonian age, which overlies pre-Cenomaniann Cretaceous deposits. THICKNESS: Total unit has thickness of 1200 m. AGE: Turonian, based on ammonite biostratigraphy.

• bed-level stratigraphic resolution

Environment/lithology: coastal; lithified, concretionary, silty, sandy mudstone and lithified, conglomeratic sandstone

• ENVIRONMENT: Inshore to nearshore and nearshore to offshore or deeper waters.
• GENERAL LITHOLOGY: Mudstone, sandy siltstone, tuffite, and intercalated sandstone and conglomerate; specimens occur in calcite concretions. LITHIFICATION: Lithified, assumed as from concretions.

Size class: macrofossils

Preservation: concretion

Collection methods: COLLECTOR: Tanable et al. (1977). REPOSITORY: Unknown repository.

Primary reference: K. Tanabe. 1979. Paleoecological analysis of ammonoid assemblages in the Turonian Scaphites facies of Hokkaido, Japan. Palaeontology 22(3):609-630 [A. Hendy/A. Hendy]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 69170: authorized by Austin Hendy, entered by Austin Hendy on 20.02.2007

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Not exhaustive, only including ammonites, other taxa no listed, but mentioned (i.e. ostreids, trigonians, Glycymeris, drifted plant remains). NOMENCLATURE: Not authoritative publication, but apparently precise nomenclature.
Cephalopoda
 Ammonitida - Nostoceratidae
Eubostrychoceras sp. Matsumoto 1967 ammonite
 Ammonitida - Scaphitidae
"Otoscaphites puerculus" = Yezoites puerculus, "Scaphites planus" = Yezoites puerculus
"Otoscaphites puerculus" = Yezoites puerculus Jimbo 1894 ammonite
"Scaphites planus" = Yezoites puerculus Jimbo 1894 ammonite
 Ammonitida - Desmoceratidae
Damesites ainuanus Matsumoto 1957 ammonite