Where: Alaska (59.8° N, 153.3° W: paleocoordinates 30.1° N, 85.9° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Bowser Member (Tuxedni Formation), Bathonian (168.3 - 166.1 Ma)

• from 25-50 ft above lowermost conglomerate in greenish-gray siltsone and silty shale, about 1750 ft below base of Chinitna formation; Middle part of Bowser member, Tuxedni formation;

•Cranocephalites beds, 'the beds could be of late Bathonian or very early Callovian age... the Arctocephalites (Cranocephalites) beds in Alaska or Montana are herein tentatively correlated with the Bathonian rather than the Callovian stage'

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified, gray, green siltstone and lithified, silty shale

Size class: macrofossils

Reposited in the USGS

• collection was made by R. L. Detterman in 1958

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 68800: authorized by Martin Aberhan, entered by Sabine Nürnberg on 07.02.2007

Creative Commons license: CC BY (attribution)