PBDB Collection

Palaeoneilo fecunda-Plagioglypta iowaensis Community of the Dubuque (Ordovician of the United States)

Where: Dubuque County County, Iowa (42.5° N, 90.9° W: paleocoordinates 20.5° S, 61.6° W)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Scales Formation, Maysvillian (450.2 - 449.6 Ma)

• Scales Formation, basal 3 cm phosphorite just above the contact with the Dubuque Formation and below the Argo-Fay Bed of Kolata & Graese (1983).

• bed-level stratigraphic resolution

Environment/lithology: deep subtidal shelf; lithified phosphorite

• Richly fossiliferous. The lithology is a 1-100cm thick poorly sorted, poorly consolidated phosporite composed of concentrically laminated hydroxyapatite pellets less than 1 mm in diameter, irregularly shaped apatite clasts ranging up to pebble size, and phosphatized fossils. The Dubuque surface, most likely a submarine corrosion surface much like those typical of the underlying Galena Group, may have as much as 8 cm of relief (Witzke, 1985b) and is commonly phosphate and/or pyrite coated and bored. No epifauna has been observed attached to it. The phosphorite commonly contains quartz geodes with minor sulfide mineralization and more common calcite, fluorite, dolomite, and selenite crystals. The matrix may be more or less completely pyritized or limonized, but the unit is as often essentially unlithified.

Preservation: replaced with phosphate

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 13262: authorized by Michael Foote, entered by Kimberly Koverman on 04.02.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

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Scaphopoda
Dentaliida - Dentaliidae	Plagioglypta iowaensis Plagioglypta iowaensis tusk shell
unclassified
-	Scolecodonta indet. Scolecodonta indet.
Crinoidea
-	Crinoidea indet. Crinoidea indet. Miller 1821 Sea lily undetermined crinoid plates
Pterobranchia
Graptoloidea - Diplograptidae	"Orthograptus truncatus" = Rectograptus truncatus "Orthograptus truncatus" = Rectograptus truncatus Lapworth 1876 graptolite Orthograptus truncatus peosta
Conodonta
-	Conodonta indet. Conodonta indet. Pander 1856 conodont
Trilobita
-	Trilobita indet. Trilobita indet. Walch 1771 trilobite
Deuteropoda
-	Ostracoda indet. Ostracoda indet. Latreille 1802 ostracod
Bryozoa
-	Bryozoa indet. Bryozoa indet. Ehrenberg 1831
Rhynchonellata
Orthida - Platyorthidae	Diceromyonia sp. Diceromyonia sp. Wang 1949
Lingulata
Acrotretida - Acrotretidae	Conotreta sp. Conotreta sp. Walcott 1889
Lingulida - Obolidae	Leptobolus occidentalis Leptobolus occidentalis
Lingulida - Lingulasmatidae	"Lingula changi" = Lingulasma changi "Lingula changi" = Lingulasma changi Hussey 1928
Hyolitha
Hyolithida - Hyolithidae	Hyolithes parviusculus Hyolithes parviusculus
Polyplacophora
Paleoloricata -	Septemchiton iowaensis Septemchiton iowaensis chiton
Gastropoda
Bellerophontida - Bucanellidae	Bucanella (Bucanella) conradi Bucanella (Bucanella) conradi Hall 1862 snail
Bellerophontida - Bellerophontidae	"Bucanopsis patersoni" = Bellerophon patersoni, Bucanopsis lirata "Bucanopsis patersoni" = Bellerophon patersoni Hall 1862 snail Bucanopsis lirata Ladd 1925 snail
Murchisoniina - Eotomariidae	Liospira micula Liospira micula Hall and Whitney 1862 snail
Murchisoniina - Lophospiridae	"Loxoplocus (Lophospira) depauperata" = Lophospira depauperata "Loxoplocus (Lophospira) depauperata" = Lophospira depauperata Hall and Whitney 1862 snail
Euomphalina - Platyceratidae	"Cyclora minuta" = Cyclonema minuta "Cyclora minuta" = Cyclonema minuta Hall 1845 snail
Bivalvia
-	Bivalvia indet. Bivalvia indet. Linnaeus 1758 clam
Nuculida - Praenuculidae	Similodonta obliqua Similodonta obliqua clam
Solemyida - Ctenodontidae	Ctenodonta anatina Ctenodonta anatina clam
Nuculanida - Cucullellidae	Nuculites neglectus Nuculites neglectus Hall 1862 clam
Nuculanida - Malletiidae	Palaeoneilo fecunda Palaeoneilo fecunda Hall 1862 clam
Cephalopoda
Orthocerida - Proteoceratidae	Isorthoceras sociale Isorthoceras sociale Hall in Miller 1877
Scyphozoa
-	Climacoconus pumilus Climacoconus pumilus jellyfish
Demospongiae
Streptosclerophorida - Hindiidae	Hindia ? parva Hindia ? parva demosponge