ammonites
Dubuque Formation Cephalopods, Illinois, Iowa, Wisconsin (Ordovician 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: Dubuque Formation (Galena Group), Edenian (460.9 - 449.5 Ma)

• formation-level stratigraphic resolution

Environment/lithology: argillaceous wackestone

• Environmental call by T. Hanson.
• Lithology from  F. M. Swain. 1987. Middle and Upper Ordovician Ostracoda of Minnesota and Iowa. Middle and Late Ordovician lithostratigraphy and biostratigraphy of the Upper Mississippi Valley: Minnesota Geological Survey Report of Investigations 35 :99-101. Edited by R. E. Sloan.

Size class: macrofossils

Primary reference: J. A. Catalani. 1987. Biostratigraphy of the Middle and Late Ordovician cephalopods of the Upper Mississippi Valley area. 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/T. Hanson] more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 23780: authorized by Steven Holland, entered by Tori Hanson on 19.07.2002