Where: Illinois, Iowa (42.0° N, 90.5° W: paleocoordinates 21.3° S, 63.6° W)

• coordinate estimated from map

• basin-level geographic resolution

When: St. James Member (Ion Formation), Kirkfieldian (457.3 - 449.6 Ma)

• member-level stratigraphic resolution

Environment/lithology: shale

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 23798: authorized by Steven Holland, entered by Tori Hanson on 21.07.2002

Creative Commons license: CC BY (attribution)