6 (Silurian to of the United States)

Where: Illinois (37.3° N, 89.4° W: paleocoordinates 25.7° S, 57.7° W)

• coordinate estimated from map

When: St. Clair Formation, Llandovery to Llandovery (443.4 - 427.4 Ma)

• 6,7 meters above base.

Environment/lithology: lithified limestone

• The St. Clair Formation at Lindsey Cemetery is a pink fossiliferous limestone with medium to thick bedding. The formation unconformably overlies the Sexton Creek Limestone, which is the Brassfield Limestone equivalent in southern Illinois. A single sample from the top of the Sexton Creek yielded an undiagnostic conodont collection with representatives of Decoriconus, Panderodus, and Walliserodus. The St. Clair grades upwards into a poorly exposed sequence of thin bedded siltstones which is referred to the Moccasin Springs Formation. At Lindsey Cemetery, the St. Clair is about 7 m (23 feet) thick.

Size class: microfossils

Primary reference: B. J. Cooper. 1976. Multielement Conodonts from the St. Clair Limestone (Silurian) of Southern Illinois. Journal of Paleontology 50(2):205-217 [W. Kiessling/E. Jarochowska]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 188083: authorized by Emilia Jarochowska, entered by Sarah Haegele on 22.08.2017

Creative Commons license: CC BY (attribution)

Taxonomic list

 Belodellida - Dapsilodontidae
Dapsilodus obliquicostatus Branson and Mehl 1933 conodont
 Belodellida - Belodellidae
Walliserodus sancticlairi Cooper 1976 conodont
 Panderodontida - Panderodontidae
Panderodus unicostatus Branson and Mehl 1933 conodont
 Ozarkodinida - Spathognathodontodae
"Ozarkodina excavata" = Wurmiella excavata
"Ozarkodina excavata" = Wurmiella excavata Branson and Mehl 1933 conodont
  - Strachanognathidae
Decoriconus fragilis Branson and Mehl 1933 conodont