USNM 41968, Split Mountain, Clayton Ridge (Cambrian of the United States)

Where: Esmeralda County, Nevada (37.7° N, 117.5° W: paleocoordinates 1.0° S, 93.5° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Amecephalus arrojosensis trilobite zone, Emigrant Formation, Delamaran (511.2 - 506.5 Ma)

• 9.5 to 15m above base of Emigrant Formation; Amecephalus arrojosensis Biozone of lower Middle Cambrian

• group of beds-level stratigraphic resolution

Environment/lithology: offshore shelf; lithified, silty lime mudstone and lithified, concretionary lime mudstone

• interval from 9.85 to 15m above base of Emigrant Formation within a mudstone, beginning with silty limestone, ending with concretionary, bioclastic limestone

Size class: macrofossils

Preservation: mold/impression

Reposited in the USNM

Primary reference: F. A. Sundberg and L.B. McCollum. 2003. Early and Mid Cambrian Trilobites from the Outer-shelf Deposits of Nevada and California, USA. Palaeontology 46(5):945-986 [W. Kiessling/B. Brenneis]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 69413: authorized by Wolfgang Kiessling, entered by Benjamin Brenneis on 26.02.2007

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Trilobita
 Ptychopariida - Ptychopariidae
Onchocephalites claytonensis, Syspacephalus variosus
Onchocephalites claytonensis Sundberg and McCollum 2003 trilobite
a couple of hundred specimens (incl. holo- and paratypes) from 11 USNM Split Mountain loc.
Syspacephalus variosus Sundberg and McCollum 2003 trilobite
numerous specimens (including holo- and paratypes) from 7 USNM Split Mt. loc.