Where: Dawson County, Montana (47.0° N, 104.8° W: paleocoordinates 53.3° N, 77.9° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Baculites baculus ammonoid zone, Pierre Shale Formation, Early/Lower Maastrichtian (70.6 - 66.0 Ma)

• upper Pierre Shale (baculus zone according to Sohl 1961)

• bed-level stratigraphic resolution

Environment/lithology: marine; shale

Size class: macrofossils

Reposited in the USNM

Primary reference: C. W. Cooke. 1953. American Upper Cretaceous Echinoidea. United States Geological Survey Professional Paper 254-A:1-44 [W. Kiessling/U. Merkel/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 197464: authorized by Matthew Clapham, entered by Matthew Clapham on 12.11.2018

Creative Commons license: CC BY (attribution)