Diamphidiocystis-Bucanopsis Community Of the Brainard Formation (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 Formation (Maquoketa Group), Richmondian (449.6 - 445.5 Ma)

• middle Brainard Formation

• group of beds-level stratigraphic resolution

Environment/lithology: offshore; lithified, pyritic, gray, green, silty shale and lithified, dolomitic wackestone

• The soft bottom and intact preservation of most echinoderms suggests very infrequent storm or wave disturbance and deposittion in a relatively offshore position.
• Generally only sparsely fossiliferous, but some beds moderately so. The middle Brainard is a greenish gray to brownish silty shale with occasional dolomitic wackestone interbeds. Pyrite nodules are common, and the fauna is typically completely pyritezed. Crystal clusters and fibrous spherules of pyrite and rare selenite crystals are scattered through the unit. Biogenic reworking is evident in may beds, and bedding in general is indistinct.

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 13204: authorized by Michael Foote, entered by Kimberly Koverman on 29.01.2002, edited by Pete Wagner

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
unclassified
  -
Simulodonta cf. obliqua
Edrioasteroidea
  - Pyrgocystidae
Pyrgocystis sp.
Pyrgocystis sp. Bather 1915
 Rhombifera - Callocystitidae
Anartiocystis sp.
Anartiocystis sp. Ausich and Schumacher 1984
Crinoidea
 Flexibilia - Cupulocrinidae
Cupulocrinus sp.
Cupulocrinus sp. d'Orbigny 1849 Sea lily
Cupulocrinus sp. B, Kolata et al., 1987
 Dendrocrinida - Dendrocrinidae
Dendrocrinus sp., Dendrocrinus aff. curvijunctus
Dendrocrinus sp. Hall 1852 Sea lily
 Cladida - Plicodendrocrinidae
"Dendrocrinus casei" = Plicodendrocrinus casei
"Dendrocrinus casei" = Plicodendrocrinus casei Meek 1871 Sea lily
 Monobathrida - Tanaocrinidae
Compsocrinus sp.
Compsocrinus sp. Wachsmuth and Springer 1885 Sea lily
 Diplobathrida - Rhodocrinitidae
Trichinocrinus sp.
Trichinocrinus sp. Moore and Laudon 1943 Sea lily
Stylophora
 Mitrata -
Diamphidiocystis sp.
 Mitrata - Anomalocystitidae
"Enoploura wetherbyi" = Enoploura balanoides
"Enoploura wetherbyi" = Enoploura balanoides Meek 1872
Bryozoa
  -
Bryozoa indet.
Bryozoa indet. Ehrenberg 1831
Brachiopoda
  -
Brachiopoda indet.
Brachiopoda indet. Cuvier 1805
Rhynchonellata
 Orthida - Glyptorthidae
Glyptorthis sp.
Glyptorthis sp. Foerste 1914
 Atrypida - Anazygidae
Zygospira cf. resupinata
Lingulata
 Lingulida - Discinidae
Orbiculoidea sp.
Orbiculoidea sp. d'Orbigny 1847
Tentaculita
 Cornulitida - Cornulitidae
Cornulites sp.
Cornulites sp. Schlotheim 1820
Cephalopoda
 Oncocerida - Oncoceratidae
? Beloitoceras discrepana
 Orthocerida - Proteoceratidae
Isorthoceras sp.
Isorthoceras sp. Flower 1962
Bivalvia
  -
Bivalvia indet.
Bivalvia indet. Linnaeus 1758 clam
 Nuculanida - Cucullellidae
Nuculites cf. neglectus
 Nuculanida - Malletiidae
Arisaigia sp., Palaeoneilo fecunda, Palaeoneilo cf. fecunda
Arisaigia sp. McLearn 1918 clam
Palaeoneilo fecunda Hall 1862 clam
Palaeoneilo cf. fecunda Hall 1862 clam
 Solemyida - Ctenodontidae
Ctenodonta anatina, Ctenodonta sp.
Ctenodonta sp. Salter 1852 clam
Gastropoda
 Murchisoniina - Lophospiridae
Lophospiridae indet.1
Lophospiridae indet.1 Wenz 1938 snail
Loxoplocus (Lophospira) sp.
 Murchisoniina - Eotomariidae
Liospira cf. spicula
 Murchisoniina - Murchisoniidae
"Murchisonia (Hormotoma) sp." = Murchisonia2
"Murchisonia (Hormotoma) sp." = Murchisonia2 d'Archiac and de Verneuil 1841 snail
Muchisonia (Hormotoma) sp.
 Bellerophontida - Bellerophontidae
Bucanopsis sp.
Bucanopsis sp. Ulrich and Scofield 1897 snail
Tergomya
 Cyrtonellida - Cyrtolitidae
Cyrtolites sp.
Cyrtolites sp. Conrad 1838
Demospongiae
 Streptosclerophorida - Hindiidae
Hindia cf. parva
Hindia cf. parva demosponge
1Lenz 1977; 2Wagner 2023