Where: Niobrara County, Wyoming (43.3° N, 104.3° W: paleocoordinates 49.2° N, 71.6° W)
• coordinate estimated from map
• small collection-level geographic resolution
When: Red Bird Silty Member (Pierre Shale Formation), Campanian (83.6 - 72.1 Ma)
• bed-level stratigraphic resolution
Environment/lithology: offshore; lithified, concretionary, brown, gray, yellow, silty, calcareous shale
• "shale; silty; weathers light gray; contains persistent beds of ls concretions at base, 11, 26, and 51 ft above base; concretions weather yellowish gray, grayish orange, plae brown, moderate brown, or orange brown, and a few at 11 and 26 ft above base have veins of white to pale yellow calcite."
• "shale; silty; weathers light gray; contains persistent beds of ls concretions at base, 11, 26, and 51 ft above base; concretions weather yellowish gray, grayish orange, plae brown, moderate brown, or orange brown, and a few at 11 and 26 ft above base have veins of white to pale yellow calcite."
Reposited in the USGS
Collection methods: mechanical,
• "[collected] from concretions 1-10 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 1682: authorized by John Alroy, entered by Mike Sommers on 25.05.1999
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
| Cephalopoda |
| Ammonitida - Baculitidae |
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| Ammonitida - Scaphitidae |
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| Bivalvia |
| Cardiida - Mactridae |
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| Myalinida - Inoceramidae |
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| Bryozoa |
| - |
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