Roadcut near Turkey Creek on south side of county highway east of Fort Atkinson (Ordovician of the United States)

Also known as Porocrinus fayettensis-Pleurocystites beckeri-Sygcaulocrinus typus Community at

Where: Winneshiek County, Iowa (43.1° N, 91.9° W: paleocoordinates 19.1° S, 60.0° W)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Upper Member (Fort Atkinson Formation), Richmondian (449.6 - 445.5 Ma)

• upper Fort Atkinson Formation

• group of beds-level stratigraphic resolution

Environment/lithology: shallow subtidal; lithified, graded, cherty/siliceous grainstone

• Very fossiliferous, but whole fossils uncommon. The most common lithology is echinodermal grainstone and packstone in thin, somewhat rubbly beds to 3.7 cm in thickness. Locally there are interbedded chert lenses, some graded bedding, and winnowed debris piles.

Size class: macrofossils

Primary reference: T. J. Frest, C. E. Brett, and B. J. Witzke. 1999. Caradocian-Gedinnian echinoderm associations of Central and Eastern North America. Paleocommunities--a case study from the Silurian and Lower Devonian 638-783 [M. Foote/K. Koverman/P. Wagner]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 13200: authorized by Michael Foote, entered by Kimberly Koverman on 29.01.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
unclassified
  -
Maquoketacrinus ornatus
Cyclocystoidea
  - Cyclocystoididae
Cyclocystoides sp.
Cyclocystoides sp. Salter and Billings 1858
Edrioasteroidea
 Pentacystida - Steganoblastidae
Astrocystites aff. ottawaensis
Echinoidea
 Bothriocidaroida - Bothriocidaridae
Bothriocidaris maquoketensis
Asteroidea
 Hadrosida - Hudsonasteridae
Hudsonaster sp.
Hudsonaster sp. Stürtz 1899 sea star
Crinoidea
 Diplobathrida - Rhodocrinitidae
? Trichinocrinus sp., Archaeocrinus obconicus
? Trichinocrinus sp. Moore and Laudon 1943 Sea lily
 Flexibilia - Cupulocrinidae
Cupulocrinus aff. latibrachiatus
Cupulocrinus aff. latibrachiatus Billings 1857 Sea lily
 Taxocrinida - Taxocrinidae
Protaxocrinus sp.
Protaxocrinus sp. Springer 1906 Sea lily
 Dendrocrinida - Dendrocrinidae
? Dendrocrinus oswegoensis
 Porocrinida -
Carabocrinus slocomi, Porocrinus fayettensis
 Calceocrinida - Calceocrinidae
Calceocrinus levorsoni
 Homocrinida - Homocrinidae
Sygcaulocrinus typus, Ectenocrinus raymondi
Sygcaulocrinus typus Ulrich 1925 Sea lily
 Myelodactylida - Iocrinidae
Iocrinus sp.
Iocrinus sp. Hall 1866 Sea lily
 Rhombifera - Pleurocystitidae
Pleurocystites spp., Pleurocystites beckeri
Pleurocystites beckeri Foerste 1924
Soluta
 Syringocrinida - Iowacystidae
Iowacystis sagittaria