Thaerodonta recedens-Iowacystis sagittaria Comm., Elgin Member, Maquoketa Fm.: Maysvillian, Iowa

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Trilobita - Phacopida - Cheiruridae
Ceraurus sp. Green 1832
Trilobita - Phacopida - Calymenidae
Flexicalymene sp. Shirley 1936
Trilobita - Asaphida - Asaphidae
Isotelus sp. Dekay 1824
Anataphrus sp. Whittington 1954
Cephalopoda
Nautiloidea indet. Agassiz 1847
Bivalvia
Pelecypoda indet. Goldfuss 1820
synonym of Bivalvia
Rhynchonellata - Orthida - Plaesiomyidae
Plaesiomys subquadrata (Hall 1847)
recombined as Plaesiomys subquadratus
Rhynchonellata - Orthida - Dalmanellidae
Paucicrura corpulenta (Sardeson 1892)
Strophomenata - Strophomenida - Furcitellidae
Megamyonia unicostata (Meek and Worthen 1868)
Strophomenata - Strophomenida - Sowerbyellidae
Thaerodonta recedens (Sardeson 1892)
unclassified
Bryozoa indet. Ehrenberg 1831
Soluta - Syringocrinida - Iowacystidae
Iowacystis sagittaria
Myeinocystites sp.
Crinoidea - Cupulocrinidae
Cupulocrinus sp. d'Orbigny 1849
Crinoidea - Porocrinida
Porocrinus fayettensis
Carabocrinus slocomi
Rhombifera - Pleurocystitidae
Pleurocystites sp.
Anthozoa - Stauriida - Streptelasmatidae
Grewingkia sp. Dybowski 1873
see common names

Geography
Country:United States State/province:Iowa
Coordinates: 43.1° North, 91.8° West (view map)
Paleocoordinates:19.6° South, 61.8° West
Basis of coordinate:based on political unit
Geographic resolution:local area
Time
Period:Ordovician Epoch:Late/Upper Ordovician
Stage:Katian 10 m.y. bin:Ordovician 5
*Epoch:Ashgill
*Local age/stage:Maysvillian
Key time interval:Maysvillian Graptolite zone: Amplexograptus manitoulinensis
Age range of interval:450.40000 - 449.80000 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Geological group:Maquoketa Formation:Scales Shale Member:Elgin
Stratigraphic resolution:member
Stratigraphy comments: "Late Ordovician (Edenian, Upper Caradocian) according to Sloan, 1987: but more likely Maysvillian (Ashgillian) because of the occurrence of Amorphognathus ordovicius."
Lithology and environment
Primary lithology: argillaceous wackestone
Includes fossils?Y
Includes fossils?Y
Lithology description: "The dominant lithology is moderately fossiliferous thin, wavy-bedded shaley limestones (wackestones to rare grainstone textures) with thin, fossiliferous shale interbeds."
Environment:deep subtidal ramp Tectonic setting:cratonic basin
Geology comments: Interpreted by authors as shoal margin, BA 4, subject to episodic, strong disturbance (based on numerous compositional and taphonomic features).
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:paleoecologic analysis
Collection method comments: Some overlap with PBDB collections 23409 and 23521, but not a duplicate entry.
Metadata
Database number:26683
Authorizer:M. Foote Enterer:M. Foote
Modifier:P. Wagner Research group:marine invertebrate
Created:2002-10-24 04:44:57 Last modified:2018-03-08 17:15:38
Access level:the public Released:2002-10-24 04:44:57
Creative Commons license:CC BY
Reference information

Primary reference:
4379. 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]