Medicine Range MR-47 (Permian of the United States)

Where: Elko County, Nevada (40.3° N, 115.2° W: paleocoordinates 14.4° N, 37.0° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Gerster Formation (Park City Group), Wuchiapingian (259.9 - 254.2 Ma)

• 47 feet above base of Gerster Formation.

•Gerster Formation is correlated with the upper Phosphoria Formation (Rex Chert, Retort, Tosi) and other upper units in the Park City Group (Franson, Ervay). Those units are now Lopingian in age, following a latest Capitanian U/Pb age of 260.57 Ma in the upper Meade Peak Member. The upper age of the Gerster is unclear, and it may span much of the Lopingian, although the top is unconformable (overlying units are Smithian) so some or all of the Changhsingian may be missing. For now, all collections are assigned a Wuchiapingian age.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; shelly/skeletal, silty packstone

• silty, crinoid, skeletal packstone

Size class: macrofossils

Preservation: replaced with silica

Collection methods: bulk, chemical,

Primary reference: B. R. Wardlaw. 1977. The biostratigraphy and paleoecology of the Gerster Limestone (Upper Permian) in Nevada and Utah. U.S.G.S. Open File Report 77(470):1-125 [D. Bottjer/M. Clapham/M. Clapham]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 39767: authorized by David Bottjer, entered by Matthew Clapham on 06.06.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Pectinida - Deltopectinidae
Cyrtorostra sp. Branson 1930 scallop
 Pectinida -
Pectinoidea indet. Rafinesque 1815 scallop
Strophomenata
 Orthotetida - Derbyiidae
Derbyia sulca Branson 1930
 Productida - Echinoconchidae
 Productida - Productellidae
cf. Echinauris subhorrida Meek 1877
Written "Echinauris" subhorrida
 Productida - Linoproductidae
cf. Grandaurispina "n. sp. A" Muir-Wood and Cooper 1960
Written "Grandaurispina" n. sp. A
 Productida - Aulostegidae
Ctenalosia fixata Cooper and Stehli 1955
Rhynchonellata
 Spiriferinida - Pennospiriferinidae
 Athyridida - Athyrididae
Composita mira Girty 1899
Bryozoa
  -
Bryozoa indet. Ehrenberg 1831
"Ramose bryozoa"
Crinoidea
  -
Crinoidea indet. Miller 1821 Sea lily