Thaerodonta-Cupulocrinus angustus-Cornulites Community of the Brainard (Ordovician of the United States)

Where: Dubuque County County, Iowa (42.9° N, 91.7° W: paleocoordinates 19.4° S, 60.0° W)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Brainard Member (Maquoketa Formation), Richmondian (449.6 - 445.5 Ma)

• top 2.5 m of Brainard from contact with the Silurian

Environment/lithology: offshore; lithified, bioturbated, dolomitic, silty, calcareous shale and lithified, dolomitic, ferruginous wackestone

• The variable lithology but generally intact fossil preservation in the carbonate intervals suggests a moderately offshore environment still subject, however, to at least occasional storm disturbances. A BA 3-4 position seems likely.
• The upper Brainard sections most likely to have this community consist of silty calcareous or dolomitic biotutbated shales with interbedded brachiopod-bryozoan-echinoderm ferruginous dolowackestones and some packstones... Occasional phosphatic or highly pyritic intervals with either phosphatized diminutive or normal-sized mollusc faunas occur sporadically throughout the outcrop area.

Size classes: macrofossils, mesofossils

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 13260: authorized by Michael Foote, entered by Kimberly Koverman on 04.02.2002, edited by Pete Wagner

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
unclassified
  -
Hypsitycha hybrida, Hysitycha neenah
Crinoidea
  -
Crinoidea indet.
Crinoidea indet. Miller 1821 Sea lily
unidentified crinoid stems
 Cladida - Plicodendrocrinidae
"Dendrocrinus casei" = Plicodendrocrinus casei
"Dendrocrinus casei" = Plicodendrocrinus casei Meek 1871 Sea lily
 Flexibilia - Cupulocrinidae
Cupulocrinus angustatus, Cupulocrinus cf. angustatus
Cupulocrinus cf. angustatus Sea lily
Cupulocrinus sp. nov. cf. angustatus
 Porocrinida -
Porocrinus crassus
Tentaculita
 Cornulitida - Cornulitidae
Cornulites sp.
Cornulites sp. Schlotheim 1820
Strophomenata
 Strophomenida - Sowerbyellidae
Thaerodonta recedens
Thaerodonta recedens Sardeson 1892
 Strophomenida - Furcitellidae
Megamyonia unicostata
Megamyonia unicostata Meek and Worthen 1868
 Strophomenida - Strophomenidae
Tetraphalerella planodorsata
Tetraphalerella planodorsata Winchell and Schuchert 1892
Rhynchonellata
 Atrypida - Anazygidae
Zygospira resupinata
 Rhynchonellida - Rhynchotrematidae
Lepidocyclus sp.
Lepidocyclus sp. Wang 1949
 Orthida - Dalmanellidae
"Onniella quadrata" = Paucicrura quadrata
"Onniella quadrata" = Paucicrura quadrata Wang 1949
Bryozoa
  -
Bryozoa indet.
Bryozoa indet. Ehrenberg 1831
Gastropoda
  -
Gastropoda indet.
Gastropoda indet. Cuvier 1795 snail
 Murchisoniina - Murchisoniidae
"Murchisonia (Hormotoma) sp." = Murchisonia2
"Murchisonia (Hormotoma) sp." = Murchisonia2 d'Archiac and de Verneuil 1841 snail
Murchisonia (Hormotoma) sp.
 Murchisoniina - Lophospiridae
Lophospiridae indet.1
Lophospiridae indet.1 Wenz 1938 snail
Loxoplocus (Lophospira) sp.
 Euomphalina - Platyceratidae
Cyclonema sp.
Cyclonema sp. Hall 1852 snail
Bivalvia
 Nuculanida - Malletiidae
Palaeoneilo fecunda
Palaeoneilo fecunda Hall 1862 clam
 Nuculanida - Cucullellidae
Nuculites sp., Nuculites neglectus
Nuculites sp. Conrad 1841 clam
Nuculites neglectus Hall 1862 clam
Trilobita
 Phacopida - Calymenidae
Gravicalymene sp.
Gravicalymene sp. Shirley 1936 trilobite
 Phacopida - Cheiruridae
Ceraurus sp.
Ceraurus sp. Green 1832 trilobite
unclassified
  -
Porifera indet.
Porifera indet. Grant 1836
Demospongiae
 Streptosclerophorida - Hindiidae
Hindia ? parva
Hindia ? parva demosponge
1Lenz 1977; 2Wagner 2023