ammonites
Mud Spring, locality no. 260b (Devonian of the United States)

Also known as USGS D48(SD)

Where: Broadwater County, Montana (45.9° N, 111.6° W: paleocoordinates 15.0° S, 46.4° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Three Forks Shale Formation, Famennian (376.1 - 360.7 Ma)

• 60 feet below Lodgepole Limestone, 1 feet below base of upper siltstone unit.

• group of beds-level stratigraphic resolution

Environment/lithology: offshore; lithified, yellow siltstone

• orange or yellow siltstone

Reposited in the USGS

Primary reference: G. D. Robinson. 1963. Geology of the Three Forks Quadrangle, Montana. United States Geological Survey Professional Paper 370:1-143 [J. Alroy/M. Sommers] more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 7225: authorized by John Alroy, entered by Mike Sommers on 19.05.2000, edited by Alycia Stigall

Creative Commons license: CC BY-NC-ND (attribution-noncommercial-no derivatives)