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

• coordinate based on nearby landmark

• small collection-level geographic resolution

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

• Limestone lens. 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: marine; lithified limestone

Size class: macrofossils

Preservation: mold/impression

Primary reference: K.W. Ciriacks. 1963. Permian and Eotriassic bivalves of the middle Rockies. Bulletin of the American Museum of Natural History 125(1):1-100 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 105349: authorized by Matthew Clapham, entered by Matthew Clapham on 19.02.2011

Creative Commons license: CC BY (attribution)