Where: Garfield County, Montana (47.0° N, 107.8° W: paleocoordinates 53.7° N, 74.2° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Bearpaw Shale Formation (Montana Group), Late/Upper Campanian (83.5 - 70.6 Ma)

• Bearpaw Shale, from brown-weathering, ferruginous limestone concretions just below a bentonitic unit and about 204 m above base of formation.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified, concretionary, ferruginous shale

Size class: macrofossils

Collected by R.E. Burkholder in 1966; reposited in the USNM

Primary reference: W. A. Cobban. 1987. The Upper Cretaceous ammonite Rhaeboceras Meek in the western interior of the United States. United States Geological Survey Professional Paper 1477:1-15 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 177980: authorized by Matthew Clapham, entered by Matthew Clapham on 12.04.2016

Creative Commons license: CC BY (attribution)