Stiptocrinus-Laurelocrinus Assoc., Laurel Limestone Unit 4, SE Indiana (Silurian of the United States)

Where: Indiana (39.4° N, 85.6° W: paleocoordinates 27.6° S, 51.7° W)

• coordinate based on political unit

• local area-level geographic resolution

When: Laurel Limestone Formation, Wenlock (433.4 - 427.4 Ma)

• "Early Wenlockian: upper third of unit 4 of the Laurel Limestone (= Laurel Member, Salamonie Dolomite of Pinsak and Shaver, 1964) of Frest (1975). The Tennesee equivalent, a part of the upper Maddox Member, Wayne Formation, is within the Kockelella ranuliformis and amsdeni conodont zones...the Indiana section's age is probably comparable."

• member-level stratigraphic resolution

Environment/lithology: deep subtidal; shelly/skeletal, argillaceous, cherty/siliceous wackestone and shelly/skeletal grainstone

• "...holdfasts common...occasional in dense...aggregations: thickets are present but rare...In some intervals echinoderm debris is micritized and whole megafossils are rare..Most likely outer BA 3 to 3-4 boundary, i.e. at or slightly below effectiv e normal wave base. No bioherms or carbonate buildups occur in association with this community, but ... it is the most diverse single Wenlockian echinoderm assemblage yet reported in North America."

•SEP environmental call based on given information and knowledge of regional geology

• "The dominant lithology is an argillaceous cherty echinodermal wackestone with occasional more pure carbonate grainstone and packstone intervals. In some units very little siliciclastic mud is present, but there may be as much as 30% locally. Bedding is thin (1-5 cm), and winnowed debris layers are common. Echinoderms usually found as appendageless calices, cups, or thecae, but occasional crons are present in some of the more muddy units..."

Collection methods: Echinoderms listed (with abundant, common, uncommon, rare ranking) in table 45.32, which includes several collections from Adams Quarry locality in St. Paul. I have also included other taxa mentioned in text. Echinoderms said to be similar to those of the Caryocrinites sphaeroidalis Association (PBDB coll. 26700, which comes from units 2 and 3 of the Laurel.

Primary reference: T. J. Frest, C. E. Brett, and B. J. Witzke. 1999. Caradocian-Gedinnian echinoderm associations of Central and Eastern North America. Paleocommunities--a case study from the Silurian and Lower Devonian 638-783 [M. Foote/K. Koverman/P. Wagner]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 26771: authorized by Michael Foote, entered by Michael Foote on 31.10.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

 Phacopida - Calymenidae
Calymenidae indet. Milne-Edwards 1840 trilobite
 Athyridida - Meristidae
Merista sp. Suess 1851
 Athyridida - Meristellidae
? Whitfieldella sp., "? Cryptothyrella sp." = Hindella
? Whitfieldella sp. Hall and Clarke 1893
"?Cryptothyrella or Whitfieldella"
"? Cryptothyrella sp." = Hindella Davidson 1882
"?Cryptothyrella or Whitfieldella"
 Rhynchonellida - Machaerariidae
Ferganella sp. Nikiforova 1937
Bryozoa indet. Ehrenberg 1831
 Coronata -
Coronata indet. Jaekel 1918
coronoid gen. nov.
 Spiraculata -
 Rhombifera - Caryocrinitidae
 Disparida -
 Pisocrinida - Pisocrinidae
Pisocrinus campana Miller 1891 Sea lily
 Calceocrinida - Calceocrinidae
Calceocrinus sp. Hall 1852 Sea lily
 Flexibilia -
Icthyocrinus sp. Conrad 1842 Sea lily
 Sagenocrinida -
 Sagenocrinida - Anisocrinidae
 Sagenocrinida - Lecanocrinidae
 Cyathocrinida - Thalamocrinidae
Thalamocrinus sp. Miller and Gurley 1895 Sea lily
 Cyathocrinida - Cyathocrinitidae
 Cyathocrinida - Euspirocrinidae
 Monobathrida -
 Monobathrida - Carpocrinidae
 Monobathrida -
 Monobathrida - Marsupiocrinidae
 Monobathrida -
 Monobathrida - Eucalyptocrinitidae
Eucalyptocrinites sp. Goldfuss 1831 Sea lily
 Monobathrida - Hirneacrinidae
Hirneacrinidae indet. Frest and Strimple 1977 Sea lily
hirneacrinid gen. nov.
 Monobathrida -
 Monobathrida - Patelliocrinidae
Patelliocrinidae "indet. 1" Angelin 1878 Sea lily
patelliocrinid gen. nov. sp. 1
Patelliocrinidae "indet. 2" Angelin 1878 Sea lily
patelliocrinid gen. nov. sp. 2
 Diplobathrida -
 Diplobathrida - Dimerocrinitidae
Dimerocrinites sp. Phillips 1839 Sea lily
 Diplobathrida - Anthemocrinidae
 Diplobathrida -
 Heliolitida - Plasmoporidae
Plasmopora sp. Milne-Edwards and Haime 1849 tabulate coral