USGS Mesozoic 23391, Fort Peck (Cretaceous of the United States)

Where: Montana (48.0° N, 106.3° W: paleocoordinates 54.6° N, 79.1° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Baculites grandis ammonoid zone, Bearpaw Formation, Early/Lower Maastrichtian (70.6 - 66.0 Ma)

• Unit 6, upper part. PJW: This is very top of formation, which is Baculites grandis zone.

• group of beds-level stratigraphic resolution

Environment/lithology: offshore; poorly lithified, concretionary shale

Size class: macrofossils

Reposited in the USNM

Primary reference: F. S. Jensen and H. D. Varnes. 1964. Geology of the Fort Peck area, Garfield, McCone and Valley counties, Montana. United States Geological Survey Professional Paper 414-F:1-49 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 213092: authorized by Matthew Clapham, entered by Matthew Clapham on 25.08.2020

Creative Commons license: CC BY (attribution)

Taxonomic list

Scaphopoda
 Dentaliida - Dentaliidae
Cephalopoda
 Ammonitida - Scaphitidae
Discoscaphites sp. Meek 1870 ammonite
 Ammonitida - Baculitidae
Baculites grandis Hall and Meek 1855 ammonite