Loc. Y5091 - River Hakkinzawa [Yezo Gp] (Cretaceous of Japan)

Where: Japan (43.0° N, 142.0° E: paleocoordinates 53.0° N, 137.7° E)

• coordinate stated in text

• outcrop-level geographic resolution

When: Yezo Group, Late/Upper Albian (105.3 - 99.6 Ma)

• STRATIGRAPHIC RELATIONS: From unnamed lithostratigraphic unit within the middle Yezo Gp, which unconformably overliesthe late Mesozoic Sorachi Gp, and is overlain by Cenozoic strata. AGE: Late Albian, on the basis of ammonite and inoceramid biostratigraphy. STRATIGRAPHIC POSITION: From base of regional section.

• bed-level stratigraphic resolution

Environment/lithology: coastal; lithified, tuffaceous mudstone and lithified sandstone

• ENVIRONMENT: Marine siliciclastic setting.
• SPECIFIC LITHOLOGY: Mudstone with thin but frequent intercalates of fine sandstone and acid bentonite tuff. LITHIFICATION:

Size class: macrofossils

Preservation: cast, mold/impression

Collection methods: COLLECTOR: H. Hirano, T. Matsumoto, and K. Tanabe, 1970's. REPOSITORY: Dept. of Geology, Kyushu University.

Primary reference: H. Hirano, T. Matsumoto, and K. Tanabe. 1977. Mid-Cretaceous stratigraphy of the Oyubari area, central Hokkaido. Palaeontological Society of Japan Special Papers 21:1-10 [A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 86982: authorized by Austin Hendy, entered by Austin Hendy on 26.02.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Limited to representative ammonoids and inoceramids. NOMENCLATURE: Not an authoritative publication, but with fairly modern nomenclature and species-resolution identifications.
Cephalopoda
 Ammonitida - Lyelliceratidae
"Stoliczkaia sp." = Stoliczkaiella
"Stoliczkaia sp." = Stoliczkaiella Cooper 2012 ammonite
 Ammonitida - Kossmaticeratidae