Where: Japan (44.6° N, 142.1° E: paleocoordinates 49.3° N, 130.4° E)

• coordinate stated in text

• small collection-level geographic resolution

When: Osousyunai Formation (Yezo Group), Early/Lower Campanian (83.5 - 70.6 Ma)

• The nodule in which the Nakagawa specimen was found is rich in the bivalve Sphenoceramus naumanni (Yokoyama, 1890) and the heteromorph ammonite Polyptychoceras sp. These fossils, as well as the silty mudstone lithology, suggest that the nodule came from the Campanian Osousyunai Formation of the Upper Yezo Group.

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified, nodular, silty mudstone

Size class: macrofossils

Collection methods: Repository: Nakagawa Museum of Natural History (NMA)

Primary reference: K. Tanabe, Y. Hikida, and Y. Iba. 2006. Two coleoid jaws from the Upper Cretaceous of Hokkaido, Japan. Journal of Paleontology 80:138-145 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 212860: authorized by Matthew Clapham, entered by Matthew Clapham on 21.08.2020

Creative Commons license: CC BY (attribution)