Northern Montezuma Range, Campito Fm., Nevadella zone, section MS-S 14.7 (Cambrian of the United States)

Where: Esmeralda County, Nevada (37.7° N, 117.3° W: paleocoordinates 3.5° S, 96.9° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Nevadella zone, Montenegro Member (Campito Formation), Montezuman (530.0 - 516.0 Ma)

• At the base of the middle Montezuman Stage.

• member-level stratigraphic resolution

Environment/lithology: deep subtidal; siltstone and sandstone

• Montenegro Member is 349 m thick. The lower 144 m is light brown sericitic siltstone and fine sandstone. The next 21 m interval contains silstone with quartzite and sandstone beds, and lenses of bioclastic carbonate packstone and glauconitic arenaceous limestone. The upper 184 m is greenish gray shaly siltstone with occasional lenses of fine sandstone. Near the top of the member there are thin beds of sandstone and bioclastic limestone.

•Holmiid specimens comprise 60% of the trilobite fauna from 170 to 215 m in the composite Montezuma Range section (Fig. 5) increasing to 75% for the interval from 215 m to the top of the Montenegro, with nevadiids making up the rest of the trilobite fauna. This constitutes the holmiid-dominated biofacies which occurs in a relatively deep subtidal and dysaerobic mud bottom.

• siltstone and fine sandstone

Size classes: macrofossils, mesofossils

Primary reference: J. S. Hollingsworth. 2006. Holmiidae (Trilobita: Olenellina) of the Montezuman Stage (Early Cambrian) in Western Nevada. Journal of Paleontology 80(2):309-332 [W. Kiessling/M. Krause]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 140514: authorized by Wolfgang Kiessling, entered by Mihaela Krause on 11.03.2013

Creative Commons license: CC BY (attribution)

Taxonomic list

 Redlichiida - Holmiidae
Montezumaspis parallela Fritz 1995 trilobite