Implicaticystis-Acolocrinus-Pleurocystites Association of the Dunleith Formation (Ordovician of the United States)

Where: Scott County, Missouri (37.1° N, 89.6° W: paleocoordinates 25.2° S, 67.0° W)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Moredock Member (Dunleith Formation), Trentonian (457.3 - 449.6 Ma)

• member-level stratigraphic resolution

Environment/lithology: shallow subtidal; lithified, graded packstone

• Generally a pure echinodermal crystalline limestone (calcarenite); textures range from packstone to grainstone. Typically bedding appears massive, but on weathered outcrops units ranging from a few cm to as much as 20 cm in thickness are distinguishable. Often the unit is noncherty and crossbedded, with common graded bedding and winnowed debris piles. Locally, mottled textures characterize some beds.

Size class: macrofossils

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 13157: authorized by Michael Foote, entered by Kimberly Koverman on 24.01.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
Edrioasteroidea
 Cyathocystida - Cyathocystidae
Cyathocystis sp. Schmidt 1879
 Pentacystida - Steganoblastidae
Astrocystites sp. Whiteaves 1897
Paracrinoidea
 Comarocystitida - Comarocystitidae
Implicaticystis symmetricus Frest and Strimple 1982
Implicaticystis shumardi Meek and Worthen 1865
 Comarocystitida - Amygdalocystitidae
 Platycystitida - Malocystitidae
 Rhombifera - Pleurocystitidae
 Rhombifera - Glyptocystitidae
 Rhombifera - Echinosphaeritidae
Crinoidea
 Calceocrinida - Calceocrinidae
Cremacrinus sp. Ulrich 1886 Sea lily
 Eustenocrinida - Acolocrinidae
Acolocrinus sp. Kesling and Paul 1971 Sea lily
 Hybocrinida - Hybocrinidae
Hybocrinus conicus Billings 1857 Sea lily
 Porocrinida -
Carabocrinus sp. Billings 1857 Sea lily
 Diplobathrida - Rhodocrinitidae
Archaeocrinus sp. Wachsmuth and Springer 1881 Sea lily
Paradiabolocrinus sp. Brower and Veinus 1974 Sea lily
 Monobathrida - Glyptocrinidae
Abludoglyptocrinus sp. Kolata 1982 Sea lily
Cyclocystoidea
  - Cyclocystoididae
Polytryphocycloides sp. Smith and Paul 1982