V-9: V(B) Frenchman Mts. (Triassic of the United States)

Where: Nevada (36.0° N, 114.0° W: paleocoordinates 7.2° N, 40.2° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Virgin Limestone Member (Moenkopi Formation), Spathian (251.3 - 247.2 Ma)

• The Moenkopi Formation in southwestern Utah contains three limestone members. The lower limestone member, the Timpoweap is only very sparsely fossiliferous and is primarily a marginal marine deposit. The middle limestone, the Virgin Member, contains limestone units deposited under normal marine conditions during the Spathian trangression. The upper limestone, the Schnabkaib Limestone, is unfossiliferous and mainly evaporitic. These limestone members are separated by red members, informally distinguished as lower, middle, and upper.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified packstone

• Wave-influenced bioclastic packestones, distinguished by very abundant large crinoid ossicles and large biavalves.

Size class: macrofossils

Primary reference: J. K. Schubert and D. J. Bottjer. 1995. Aftermath of the Permian-Triassic mass extinction event: Paleoecology of Lower Triassic carbonates in the western USA. Palaeogeography, Palaeoclimatology, Palaeoecology 116:1-39 [D. Bottjer/N. Bonuso/N. Bonuso]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 32945: authorized by David Bottjer, entered by Nicole Bonuso on 21.07.2003

Creative Commons license: CC BY (attribution)

Taxonomic list

Crinoidea
 Holocrinida - Holocrinidae
Holocrinus sp. Wachsmuth and Springer 1886 Sea lily
Echinoidea
 Cidaroida - Miocidaridae
Miocidaris sp. Döderlein 1887 pencil urchin
Bivalvia
 Pectinida - Hunanopectinidae
Leptochondria sp. Bittner 1891 scallop