PBDB Collection

Lower Decorah Shale Ostracodes in Minnesota (Ordovician to of the United States)

Where: Minnesota (44.0° N, 92.0° W: paleocoordinates 19.1° S, 62.9° W)

• coordinate estimated from map

• basin-level geographic resolution

When: Stictoporella angularis zone, Decorah Shale Formation, Rocklandian to Rocklandian (457.3 - 449.6 Ma)

• Equivalent of Spechts Ferry Shale Member in northeastern Iowa.

• formation-level stratigraphic resolution

Environment/lithology: gray shale and limestone

• Environmental call by T. Hanson

• "Interbedded greenish gray and bluish gray shale and thin 1-to-6 inch fossiliferous impure limestone layers and a somewhat localized 1-3 inch metabentonite (Milbrig) layer near the base."

Size class: microfossils

Collection methods: chemical,

Primary reference: F. M. Swain and J. R. Cornell. 1987. Ostracoda of the superfamilies Drepanellacea, Hollinacea, Leperditellacea, and Healdiacea from the Decorah Shale of Minnesota. In R. E. Sloan (ed.), Middle and Late Ordovician lithostratigraphy and biostratigraphy of the Upper Mississippi Valley: Minnesota Geological Survey Report of Investigations 35 102-130 [S. Holland/T. Hanson/S. Bruning]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 23123: authorized by Steven Holland, entered by Tori Hanson on 09.07.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names

Ostracoda
Beyrichicopida - Bolliidae	Bollia subaequata, Dicranella bicornis Bollia subaequata ostracod orig. Bollia subaequeata Dicranella bicornis ostracod
Hollinocopida - Tetradellidae	Thomasatia falcicosta, Bromidella depressa, Bromidella rhomboides, Tetradella ellipsilira, Bellornatia tricollis Thomasatia falcicosta ostracod Bromidella depressa ostracod Bromidella rhomboides ostracod Tetradella ellipsilira ostracod Bellornatia tricollis ostracod
Hollinocopida - Euprimitiidae	Primitiella plattevillensis, Primitiella constricta, Euprimitia sanctipauli Primitiella plattevillensis ostracod Primitiella constricta Ulrich 1894 ostracod Euprimitia sanctipauli ostracod
Hollinocopida - Eurychilinidae	Eurychilina subradiata, Eurychilina ventrosa, Eurychilina reticulata Eurychilina subradiata ostracod Eurychilina ventrosa ostracod Eurychilina reticulata ostracod
Palaeocopida - Hollinidae	Winchellatia lansingensis, Winchellatia minnesotensis, ? Winchellatia ceratopea n. sp. Winchellatia lansingensis ostracod Winchellatia minnesotensis ostracod ? Winchellatia ceratopea n. sp. ostracod
Podocopida - Bairdiidae	Krausella variata Krausella variata Kraft 1962 ostracod
Podocopida - Bairdiocyprididae	Elliptocyprites paracylindrica n. sp. Elliptocyprites paracylindrica n. sp. ostracod