Sardeson Collection, Decorah Shale (Ordovician to of the United States)

Where: Minnesota (45.0° N, 93.3° W: paleocoordinates 17.8° S, 62.8° W)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Decorah Shale Formation (Galena Group), Rocklandian to Rocklandian (460.9 - 449.5 Ma)

• Beds numbered by F. W. Sardeson.

• group of beds-level stratigraphic resolution

Environment/lithology: calcareous shale

• Environmental call by T. Hanson
• Shale and calcareous shale.

Size class: macrofossils

Primary reference: W. F. Rice and E. P. Hedblom. 1987. Brachiopods and trilobites of the Sardeson Beds in the Twin Cities. Middle and Late Ordovician lithostratigraphy and biostratigraphy of the Upper Mississippi Valley: Minnesota Geological Survey Report of Investigations 35 131-135 [S. Holland/T. Hanson/T. Hanson]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 23277: authorized by Steven Holland, entered by Tori Hanson on 11.07.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

 Corynexochida - Illaenidae
Thaleops sp. Conrad 1843 trilobite
Bumastoides sp. Whittington 1954 trilobite
 Phacopida - Pterygometopidae
Sceptaspis lincolnensis Branson 1909 trilobite
Eomonorachus intermedius Walcott 1879 trilobite
 Phacopida - Cheiruridae
 Asaphida - Asaphidae
Isotelus gigas Dekay 1824 trilobite
 Strophomenida - Sowerbyellidae
 Strophomenida - Rafinesquinidae
 Strophomenida - Strophomenidae
Strophomena septata Winchell and Schuchert 1892
"Bellimurina charlottae" = Bellimurina (Bellimurina) charlottae Winchell and Schuchert 1892
Oepikina minnesotensis Winchell 1881
 Pentamerida - Parastrophinidae
 Protorthida - Skenidiidae
 Atrypida - Protozygidae
"Protozyga nicolleti" = Manespira nicolleti
"Protozyga nicolleti" = Manespira nicolleti Winchell and Schuchert 1892
 Atrypida - Septatrypidae
 Atrypida - Anazygidae
"Zygospira recurvirostris" = Anazyga recurvirostra, Zygospira lebanonensis
"Zygospira recurvirostris" = Anazyga recurvirostra Hall 1847
 Rhynchonellida - Trigonirhynchiidae
 Rhynchonellida - Rhynchotrematidae
 Orthida - Draboviidae
 Orthida - Dalmanellidae
 Orthida - Glyptorthidae
 Orthida - Plaesiomyidae
"Plaesiomys meedsi" = Dinorthis meedsi
"Plaesiomys meedsi" = Dinorthis meedsi Winchell and Schuchert 1892
 Orthida - Hesperorthidae
 Orthida - Platystrophiidae
 Orthida - Plectorthidae
 Lingulida - Trematidae
 Lingulida - Pseudolingulidae
 Lingulida - Obolidae
 Craniida - Craniidae