Also known as Pierre Shale (USGS D1866)
Where: Niobrara County, Wyoming (43.3° N, 104.3° W: paleocoordinates 49.2° N, 71.7° W)
• coordinate estimated from map
• small collection-level geographic resolution
When: Baculites perplexus ammonoid zone, Mitten Black Shale Member (Pierre Shale Formation), Campanian (83.6 - 72.1 Ma)
• Was Bed 29. Pierre shale, 695 - 714' above top of Mitten Member
• bed-level stratigraphic resolution
Environment/lithology: offshore; lithified, concretionary, brown, gray, yellow, calcareous shale and concretionary limestone
• "shale, dark gray, contains ls concretions that weather light brown, yellowish gray, moderate brown, yellowish brown and dark yellowish orange. Persistent beds of concretions are present at base and at top and at 19, 50, and 74 ft above base; concretions in upper 4 ft may be septarian with yellow calcite."
• "shale, dark gray, contains ls concretions that weather light brown, yellowish gray, moderate brown, yellowish brown and dark yellowish orange. Persistent beds of concretions are present at base and at top and at 19, 50, and 74 ft above base; concretions in upper 4 ft may be septarian with yellow calcite."
Size class: macrofossils
Reposited in the USGS
Collection methods: mechanical,
• "[collected] from 1-19 ft above base"
Primary reference: J. R. Gill, W. A. Cobban, and P. M. Kier. 1966. The Red Bird Section of the Upper Cretaceous Pierre Shale in Wyoming. United States Geological Survey Professional Paper 393-A:1-73 [J. Alroy/M. Sommers/A. Clement]more details
Purpose of describing collection: biostratigraphic analysis
PaleoDB collection 1731: authorized by John Alroy, entered by Mike Sommers on 03.06.1999
Creative Commons license: CC BY (attribution)
Taxonomic list
• "The fossils are ordinarily well-preserved. Most of the cephalopod shells and the inner nacreous layer of Inoceramus are aragonitic, especially specimens from above the Red Bird Silty Member. Shell material and specimens from the Red Bird member and the upper 50' of the underlying Mitten Member is partially transformed to calcite...Ammonites...of the [mid-upper third] of the Mitten Member are...entirely aragonite whereas shell material [of underlying material] is completely transformed to calcite."
Show authors, comments, and common names
| Bivalvia |
| Lucinida - Thyasiridae |
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| Cephalopoda |
| Ammonitida - Baculitidae |
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| Ammonitida - Scaphitidae |
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