Where: Blaine County, Montana (48.4° N, 109.3° W: paleocoordinates 55.4° N, 75.1° W)

• coordinate stated in text

• outcrop-level geographic resolution

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

• Possibly 45-60 m below top

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified shale

Size class: macrofossils

Collected by R.G. Schmidt in 1957; 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 178317: authorized by Matthew Clapham, entered by Matthew Clapham on 30.04.2016

Creative Commons license: CC BY (attribution)