Brachiopods of Nora Mbr., Shell Rock Fm., North-Central Iowa (Devonian of the United States)

Where: Iowa (43.3° N, 92.8° W: paleocoordinates 29.0° S, 37.3° W)

• coordinate based on political unit

• basin-level geographic resolution

When: Nora Member (Shell Rock Formation), Frasnian (382.7 - 372.2 Ma)

• Within Strophodonta cicatricosa zone. Shell Rock as a whole is early-middle Frasnian.

• member-level stratigraphic resolution

Environment/lithology: marine; shelly/skeletal, argillaceous lime mudstone and reef rocks

• Witzke et al. (ref. 9582): mainly shallow subtidal.
• From Witzke et al. (PBDB ref. 9582): " the type area is characterized by prominent stromatoporoid biostromes separated by an intervening shale or argillaceous skeletal calcilutite....becomes more dolomitic, less shaly, and contains fewer stromatoporoids to the W and SW...locally includes 'birdseye' bearing and intraclastic beds."

Collection methods: Fauna of the Shell Rock not reported here include mollusks, corals, stromatoporoids, and echinoderms. These elements usually dominate the assemblages.

Primary reference: J. Day. 1988. The brachiopod succession of the Late Givetian-Frasnian of Iowa. In N. J. McMillan, A. F. Embry, and D. J. Glass (eds.), Devonian of the World, Volume III. Canadian Society of Petroleum Geologists. Calgary, Alberta, Canada 303-325 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 35495: authorized by Michael Foote, entered by Michael Foote on 17.12.2003

Creative Commons license: CC BY (attribution)

Taxonomic list

 Productida - Strophalosiidae
Strophalosia sp. King 1844
S. n. sp.
 Productida - Productellidae
 Orthotetida - Areostrophiidae
Floweria sp. Cooper and Dutro 1982
F. n. sp.
 Strophomenida - Douvillinidae
? Douvillina sp.
D.? n. sp.
 Strophomenida - Strophodontidae
 Athyridida - Athyrididae
 Spiriferinida - Cyrtinidae
Cyrtina sp. Davidson 1858
C. n. sp.
 Spiriferida - Cyrtospiriferidae
 Spiriferida - Spinocyrtiidae
 Spiriferida - Adolfiidae
 Pentamerida - Gypidulidae
 Atrypida - Atrypidae
Spinatrypina sp. Rzhonsnitskaya 1964
S. n. sp.
 Rhynchonellida - Hypothyridinidae
 Rhynchonellida - Stenoscismatidae
 Orthida - Schizophoriidae
 Craniida - Craniidae