Where: Montana (45.0° N, 112.7° W: paleocoordinates 17.1° N, 32.9° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Retort Member (Phosphoria Formation), Lopingian (259.9 - 252.2 Ma)

• 23.9 foot thick interval, 27.3 feet above base of member. Davydov et al. 2017 dated an ash bed in the upper Meade Peak Member at 260.57 ± 0.07 / 0.14 / 0.31 Ma, indicating that the Meade Peak is as young as uppermost Capitanian.

• group of beds-level stratigraphic resolution

Environment/lithology: offshore; lithified, phosphatic mudstone

Size class: macrofossils

Primary reference: M. Gordon. 1966. Permian coleoid cephalopods from the Phosphoria Formation in Idaho and Montana. United States Geological Survey Professional Paper 550-B:B28-B35 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 107757: authorized by Matthew Clapham, entered by Matthew Clapham on 14.04.2011

Creative Commons license: CC BY (attribution)