Wheeler Amphitheater [Marjum Fm] (Cambrian of the United States)

Where: Millard County, Utah (39.4° N, 113.3° W: paleocoordinates 4.3° S, 91.7° W)

• outcrop-level geographic resolution

When: Ptychagnostus atavus trilobite zone, Marjum Formation, Middle Cambrian (509.0 - 497.0 Ma)

• STRATIGRAPHIC RELATIONS: From the Marjum Fm, which overlies the Wheeler Fm. AGE: Marjumian; Ptychagnostus atavus Zone. STRATIGRAPHIC POSITION: From beds in succession, below Nisusia beds, about 250 m above the base of the Marjum Fm.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified, burrowed, gray, calcareous wackestone

• SPECIFIC LITHOLOGY: Dark-grey, wavy bedded carbonate wackestone, abundantly burrowed. LITHIFICATION: Lithified, on the basis facies description and figures.

Size class: macrofossils

Preservation: replaced with silica

Collection methods: surface (in situ),

• COLLECTOR: Not stated in text. REPOSITORY: University of Kansas Museum of Invertebrate Paleontology.

Primary reference: A. J. Rowell and N. E. Caruso. 1985. The evolutionary significance of Nisusia sulcata, an early articulate brachiopod. Journal of Paleontology 59(5):1227-1242 [A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 86727: authorized by Austin Hendy, entered by Austin Hendy on 14.02.2009, edited by Pete Wagner

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Not exhaustive, but characteristic for range of groups. NOMENCLATURE: Not an authoritative publication, but with relatively modern nomenclature; lacking species-level identifications.
 Acrotretida - Acrotretidae
Prototreta sp. Bell 1941
 Corynexochida - Dorypygidae
Olenoides sp. Meek 1877 trilobite
 Ptychopariida - Marjumiidae
Modocia sp. Walcott 1924 trilobite
 Agnostida - Peronopsidae
Peronopsis sp. Corda 1847
 Hymenocarina - Pseudoarctolepidae
Pseudoarctolepis sharpi Brooks and Caster 1956
from either the Wheeler Amphitheatre area or the Swasey Spring area according to the colour of the fossil and surrounding matrix;