Deadline Ridge, Retort Mb, Sublette County (Permian of the United States)

Where: Wyoming (42.3° N, 110.4° W: paleocoordinates 13.9° N, 33.0° W)

• coordinate stated in text

• outcrop-level geographic resolution

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

• 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 shale

Size class: macrofossils

Preservation: replaced with silica

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 95799: authorized by Matthew Clapham, entered by Matthew Clapham on 28.04.2010

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Nuculida - Nuculidae
Nuculopsis poposiensis Branson 1930 nut clam
 Trigoniida - Schizodidae
Schizodus bifidus Ciriacks 1963 clam
 Pectinida - Aviculopectinidae
Aviculopecten cf. basilicus Newell 1938 scallop
 Pectinida - Pseudomonotidae
Pseudomonotis sp. von Beyrich 1862 scallop