West Fork Blacktail Creek, Unionites Bed, Beaverhead County (Triassic of the United States)

Where: Montana (44.8° N, 112.3° W: paleocoordinates 15.2° N, 33.9° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Dinwoody Formation, Griesbachian (251.9 - 250.5 Ma)

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified mixed carbonate-siliciclastic sediments

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 105393: authorized by Matthew Clapham, entered by Matthew Clapham on 20.02.2011

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Cardiida - Anthracosiidae
Unionites fassaensis2 Wissmann 1841 clam
 Pectinida - Aviculopectinidae
Eumorphotis amplicostata Ciriacks 1963 scallop
Lingulata
 Lingulida - Lingulidae
Lingularia sp.1 Biernat and Emig 1993