Where: Montana (48.2° N, 112.9° W: paleocoordinates 40.9° N, 52.1° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Upper Siltstone Member (Sawtooth Formation), Bathonian (168.3 - 166.1 Ma)

• from sandy limestone near top of Sawtooth formation; the Upper Siltstone member is probably of Bathonian age

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified, sandy limestone

Size class: macrofossils

Reposited in the USGS

• collection was made by R. W. Imlay in 1944

Primary reference: R. W. Imlay. 1962. Jurassic (Bathonian or Early Callovian) Ammonites from Alaska and Montana. Geological Survey Professional Paper 374-C:1-32 [M. Aberhan/S. Nurnberg]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 68840: authorized by Martin Aberhan, entered by Sabine Nürnberg on 10.02.2007

Creative Commons license: CC BY (attribution)