Cyclocrinites dactioloides-Dimerocrinites (Eudimerocrinites) sp. Assoc., E Iowa (Silurian of the United States)

Where: Iowa (42.5° N, 91.5° W: paleocoordinates 19.6° S, 56.6° W)

• coordinate based on political unit

• local area-level geographic resolution

When: Farmers Creek Member (Hopkinton Formation), Llandovery (443.4 - 433.4 Ma)

• middle and lower portions of F.C. Member. Late Llandovery (C4).

• member-level stratigraphic resolution

Environment/lithology: deep subtidal ramp; dolomitic, shelly/skeletal packstone and dolomitic, shelly/skeletal grainstone

• "whole cyclocrinitid thalli sometimes well size-sorted and tightly packed into distinct layers or thin units, but more random dense aggregations also observed, and sekeltal grains and whole fossils not well sorted. At type loc. interfingers locally with Stricklandia lens ultima Assoc. and Bolicrinus-Theleproktocrinus Assoc. below and with overlying Harpidium (isovella) maquoketa Assoc...Echinoderm debris common..occasional whole cups noted...This is most probably storm generated, as it is unlikely that fragile thecae or thalli would stand up to much transport or to regular disturbance...outer BA 3 to shallow BA 4 seems likely."
• "Abundantly fossiliferous. The lithology is a very porous, noncherty skeletal-moldic, dolopackstone to grainstone."

Collection methods: Echinoderm and Cyclocrinites (algae) abundances given in table 45.22.

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 26712: authorized by Michael Foote, entered by Michael Foote on 25.10.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

 Glyptosphaeritida - Gomphocystitidae
Crinoidea
 Camerata -
Camerata indet. Wachsmuth and Springer 1885 Sea lily
 Diplobathrida - Dimerocrinitidae
 Diplobathrida - Lampterocrinidae
Lampterocrinus sp. Roemer 1860 Sea lily
 Monobathrida - Patelliocrinidae
 Monobathrida - Hapalocrinidae
 Monobathrida - Carpocrinidae
Rhombifera
 Hemicosmitoida - Caryocrinitidae
Strophomenata
 Strophomenida - Leptostrophiidae
Chileata
 Dictyonellida - Eichwaldiidae
"Dictyonella sp." = Eodictyonella
"Dictyonella sp." = Eodictyonella Wright 1994
Rhynchonellata
 Pentamerida - Pentameridae
 Spiriferida - Cyrtiidae
Hedeina sp. Boucot 1957
Eospirifer sp. Schuchert 1913
 Athyridida - Meristellidae
Meristina sp. Hall 1867
 Atrypida - Atrypidae
Atrypa sp. Dalman 1828
 Rhynchonellida - Machaerariidae
Ferganella sp. Nikiforova 1937
 Orthida -
Orthida indet. Schuchert and Cooper 1932
Bryozoa
  -
Bryozoa indet. Ehrenberg 1831
Cephalopoda
 Nautiloidea -
Nautiloidea indet. Agassiz 1847 nautiloid
Gastropoda
  -
Gastropoda indet. Cuvier 1795 snail
Anthozoa
  -
Anthozoa indet. Ehrenberg 1834
Chlorophyceae
 Dasycladales - Dasycladaceae