Mifflin Formation Bryozoa of the Upper Mississippi Valley (Ordovician of the United States)

Where: Iowa, Wisconsin, Illinois (42.5° N, 91.3° W)

• Paleocoordinates: 11.0° S, 115.3° W (Wright 2013)

• coordinate estimated from map

• basin-level geographic resolution

When: Mifflin Formation, Rocklandian (457.3 - 449.6 Ma)

• formation-level stratigraphic resolution

Environment/lithology: argillaceous limestone

• Environmental call by T. Hanson.
• "Thinly bedded argillaceous and shaly fossiliferous limestone."

Size class: macrofossils

Primary reference: 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 [S. Holland/T. Hanson/T. Hanson]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 23304: authorized by Steven Holland, entered by Tori Hanson on 11.07.2002

Creative Commons license: CC0 (CC0)

Taxonomic list

Show authors, comments, and common names
Stenolaemata
 Trepostomata - Aisenvergiidae
Eridotrypa subtilis
 Trepostomata - Heterotrypidae
Heterotrypa sp.
Heterotrypa sp. Nicholson 1879
 Trepostomata - Halloporidae
Diplotrypa catenulata
Diplotrypa catenulata Coryell 1921
 Trepostomida - Amplexoporidae
Amplexopora winchelli
 Trepostomida - Monticuliporidae
Orbignyella sublamellosa, Homotrypa sp.
Orbignyella sublamellosa Ulrich and Bassler 1904
Homotrypa sp. Ulrich 1882