Where: Gumma, Japan (36.8° N, 139.0° E: paleocoordinates 46.2° N, 146.7° E)

• coordinate estimated from map

• local area-level geographic resolution

When: Iwamuro Formation, Toarcian (182.7 - 174.1 Ma)

• formation-level stratigraphic resolution

Environment/lithology: marine

Size class: macrofossils

Preservation: cast, mold/impression

Primary reference: I. Hayami. 1975. A systematic survey of the Mesozoic Bivalvia from Japan. The University Museum, The University of Tokyo, Bulletin (10) [M. Aberhan/S. Nurnberg/S. Nurnberg]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 39970: authorized by Martin Aberhan, entered by Sabine Nürnberg on 13.06.2004

Creative Commons license: CC BY (attribution)