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: Buckhorn Member (Ion Formation), Kirkfieldian (457.3 - 449.6 Ma)

• member-level stratigraphic resolution

Environment/lithology: limestone

Size class: macrofossils

Primary reference: D. R. Kolata, J. C. Brower, and T. J. Frest. 1987. Upper Mississippi Valley Champlainian and Cincinnatian echinoderms. Middle and Late Ordovician lithostratigraphy and biostratigraphy of the Upper Mississippi Valley: Minnesota Geological Survey Report of Investigations 35 179-181 [S. Holland/T. Hanson/T. Hanson]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 23460: authorized by Steven Holland, entered by Tori Hanson on 15.07.2002

Creative Commons license: CC BY (attribution)