Big River banks 2.5 kilometers southwest of Irondale (Cambrian of the United States)

Where: Washington County, Missouri (37.8° N, 90.7° W: paleocoordinates 22.9° S, 86.5° W)

• outcrop-level geographic resolution

When: Bonneterre Formation, Dresbachian (501.0 - 485.4 Ma)

• Specimens collected from a 0.5m thick bed located in the studied upper 3 meters of the formation

• bed-level stratigraphic resolution

Environment/lithology: reef, buildup or bioherm; lithified dolomite

• The St. Francois Mountains igneous complex is an uplifted area of rhyolites, granits, and tuffs which were flooded by an epicontinental sea during the Cambrian.
• medium, crystalline, buff dolomite. (Digitate stromatolite bearing dolomite.)

Collection methods: bulk,

• the specimens represent organisms that lived between the fingers of a bioherm located around a small epicontinental sea island.

Primary reference: B. L. Stinchcomb. 1975. Paleoecology of two new species of Late Cambrian Hypseloconus (Monoplacophora) from Missouri. Journal of Paleontology 49(2):416-421 [M. Patzkowsky/P. Borkow]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 158316: authorized by Pete Wagner, entered by Pete Wagner on 18.07.2014

Creative Commons license: CC BY (attribution)

Taxonomic list

 Aulacopleurida - Tricrepicephalidae
Tricrepicephalus sp. Kobayashi 1935 trilobite
 Ptychopariida - Kingstoniidae
Blountia sp. Walcott 1916 trilobite
 Bellerophontida - Tropidodiscidae
Strepsodiscus major Knight 1948 snail
 Hypseloconida -
 Hypseloconida - Shelbyoceridae
Ulrichoconus bonneterrense n. gen. n. sp. Stinchcomb and Angeli 2002