Sheeprock Ridge SR-47 (Permian of the United States)

Where: Elko County, Nevada (40.4° N, 114.8° W: paleocoordinates 14.4° N, 36.7° 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 measured section.

•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, cherty/siliceous packstone

• cherty, 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 39761: authorized by David Bottjer, entered by Matthew Clapham on 05.06.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

Bryozoa
  -
Bryozoa indet. Ehrenberg 1831
"Ramose bryozoa"
Rhynchonellata
 Rhynchonellida - Wellerellidae
Phrenophoria "n. sp. A" Cooper and Grant 1969
 Terebratulida - Gillediidae
 Spiriferinida - Pennospiriferinidae
 Athyridida - Athyrididae
Composita mira Girty 1899
 Athyridida - Neoretziidae
Hustedia elongata Cooper 1953
Strophomenata
 Productida - Paucispiniferidae
"Liosotella delicatula" = Anemonaria delicatula
"Liosotella delicatula" = Anemonaria delicatula Dunbar 1955
 Productida - Productellidae
cf. Echinauris subhorrida Meek 1877
Written "Echinauris" subhorrida
Crinoidea
  -
Crinoidea indet. Miller 1821 Sea lily