Where: Montana (48.2° N, 112.9° W: paleocoordinates 40.2° N, 51.4° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Lower Sandstone Member (Sawtooth Formation), Bajocian (170.3 - 168.3 Ma)

• from 3 ft of siliceous limestone about 6.5 ft above base of Sawtooth formation in the lower member; the Lower Sandstone member is probably of Bajocian age

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified, cherty/siliceous 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 68824: authorized by Martin Aberhan, entered by Sabine Nürnberg on 09.02.2007

Creative Commons license: CC BY (attribution)