Stonington Beds, Ogontz Creek (Ordovician of the United States)

Where: Delta County, Michigan (45.9° N, 87.0° W: paleocoordinates 19.3° S, 55.3° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Amorphognathus ordovicicus conodont zone, Ogontz Member (Stonington Formation), Richmondian (449.6 - 445.5 Ma)

• group of beds-level stratigraphic resolution

Environment/lithology: offshore; brown, gray, cherty/siliceous limestone

• Clear offshore water
• Massive, irregularly bedded limestone, soft and argillaceous to hard and cherty (the latter predominating), light grey to yellowish-brown to dark brown. Softer material in bands and lenses.

Size class: macrofossils

Primary reference: R. C. Hussey. 1926. The Richmond Formation of Michigan. In E. S. McCartney (ed.), Michigan University Contributions from the Museum of Geology 2:113-188 [S. Holland/T. Hanson/S. Bruning]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 26316: authorized by Steven Holland, entered by Tori Hanson on 12.10.2002, edited by Pete Wagner

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Modiomorphida - Modiomorphidae
"Whiteavesia pholadiformis" = Pholadomorpha pholadiformis
"Whiteavesia pholadiformis" = Pholadomorpha pholadiformis Hall 1851 clam
Rhynchonellata
 Atrypida - Anazygidae
"Zygospira recurvirostris" = Anazyga recurvirostra
"Zygospira recurvirostris" = Anazyga recurvirostra Hall 1847
Z. recurvirostris turgida
 Orthida - Platystrophiidae
Platystrophia acutilirata, "Platystrophia clarkesvillensis" = Platystrophia clarksvillensis
"Platystrophia clarkesvillensis" = Platystrophia clarksvillensis Foerste 1910
 Orthida - Plectorthidae
Hebertella alveata Foerste 1909
H. alveata and H. alveata richmondensis
 Orthida - Dalmanellidae
Dalmanella jugosa
Dalmanella jugosa subplicata
Strophomenata
 Strophomenida - Strophomenidae
"Strophomena neglecta" = Tetraphalerella neglecta James 1891
Strophomena parvula Foerste 1917
 Strophomenida - Rafinesquinidae
 Strophomenida - Sowerbyellidae
"Plectambonites rugosus" = Sowerbyella rugosa
"Plectambonites rugosus" = Sowerbyella rugosa Meek 1873
P. rugosus noquettensis (?)
Anthozoa
 Stauriida - Streptelasmatidae
"Streptelasma rusticum" = Helicelasma rusticum
"Streptelasma rusticum" = Helicelasma rusticum Billings 1858 horn coral