USGS 11990 (Cretaceous of the United States)

Where: Chouteau County, Montana (47.9° N, 110.5° W: paleocoordinates 51.7° N, 72.4° W)

• coordinate based on political unit

• small collection-level geographic resolution

When: Scaphites ventricosus ammonoid zone, Marias River Shale Formation, Middle Coniacian (89.3 - 85.8 Ma)

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified shale

Size class: macrofossils

Preservation: cast, mold/impression

Primary reference: I. Walaszczyk and W. A. Cobban. 2006. Palaeontology and stratigraphy of the Middle-Upper Coniacian and Santonian inoceramids of the US Western Interior. Acta Geologica Polonica 56(3):241-348 [W. Kiessling/U. Merkel]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 100229: authorized by Wolfgang Kiessling, entered by Uta Merkel on 02.12.2010

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Myalinida - Inoceramidae
Volviceramus exogyroides Meek and Hayden 1862 clam
Volviceramus involutus Sowerby 1828 clam