Spechts Ferry Formation Cephalopods, Illinois, Iowa, Wisconsin (Ordovician to of the United States)

Where: Illinois, Iowa, Wisconsin (43.0° N, 91.0° W: paleocoordinates 20.4° S, 63.1° W)

• coordinate estimated from map

• basin-level geographic resolution

When: Spechts Ferry Formation, Blackriveran to Blackriveran (457.3 - 449.6 Ma)

• formation-level stratigraphic resolution

Environment/lithology: pyritic, green shale

• Environmental call by T. Hanson.
• "[D]ark-green to green-gray, thin-bedded, soft, locally pyritic shale interbedded with fine- to medium-grained argillaceous limestone." Lithology from O. L. Karklins. 1987. Bryozoa from Rocklandian (Middle Ordovician) rocks of the Upper Mississippi Valley region. Middle and Late Ordovician lithostratigraphy and biostratigraphy of the Upper Mississippi Valley: Minnesota Geological Survey Report of Investigations 35 :173-176. R. E. Sloan, ed.

Size class: macrofossils

Primary reference: J. A. Catalani. 1987. Biostratigraphy of the Middle and Late Ordovician cephalopods of the Upper Mississippi Valley area. In R. E. Sloan (ed.), Middle and Late Ordovician lithostratigraphy and biostratigraphy of the Upper Mississippi Valley: Minnesota Geological Survey Report of Investigations 35 187-189 [S. Holland/T. Hanson/S. Bruning]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 23761: authorized by Steven Holland, entered by Tori Hanson on 19.07.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

• Faunal list compiled from: 1. Whitfield's (1882) report in volume 4 of Chamberlin's Geology of Wisconsin 2. Clarke's (1897) report in volume III part 2 of Winchell's Final Reports of the Minnesota Geological and Natural History Survey 3. Bassler's Index 4. Individual articles (Foerste, Flower, etc.) 5. Treatise, Part K 6. Author's personal field data
Show authors, comments, and common names
Cephalopoda
 Orthocerida - Dawsonoceratidae
Metaspyroceras minneapolis
 Orthocerida - Orthoceratidae
Michelinoceras multicameratum, Michelinoceras sp.
Michelinoceras sp. Foerste 1932
 Endocerida - Endoceratidae
Endoceras proteiforme
 Pseudorthocerida - Spyroceratidae
Spyroceras lesueuri, Spyroceras scofieldi
Spyroceras lesueuri
"Spyroceras" lesueri
Spyroceras scofieldi
"Spyroceras" scofieldi
 Oncocerida - Oncoceratidae
Kentlandoceras husseyi
 Oncocerida - Valcouroceratidae
? Fayettoceras beloitense