USGS D1987 [Pierre Shale]: Early/Lower Maastrichtian, Wyoming
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Cephalopoda
- Ammonitida
- Scaphitidae
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Discoscaphites sp.
Meek 1870
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sp. nov. | ||||||||||
Cephalopoda
- Ammonitida
- Baculitidae
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Baculites clinolobatus
Elias 1933
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Bivalvia
- Myalinida
- Inoceramidae
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Inoceramus subcircularis
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Inoceramus cf. incurvus
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originally entered as "Inoceramus cf. incurvus" | ||||||||||
? Inoceramus fibrosus
(Meek and Hayden 1857)
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originally entered as "? Inoceramus fibrosus" | ||||||||||
unclassified
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Bryozoa indet.
Ehrenberg 1831
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pyriporoid bryozoan | ||||||||||
see common names |
Geography
Country: | United States | State/province: | Wyoming | County: | Niobrara |
Coordinates: | 43.3° North, 104.3° West (view map) | ||||
Paleocoordinates: | 49.7° North, 79.1° West | ||||
Basis of coordinate: | estimated from map | ||||
Geographic resolution: | small collection |
Time
Period: | Cretaceous | Epoch: | Late/Upper Cretaceous |
Stage: | Maastrichtian | 10 m.y. bin: | Cretaceous 8 | *Epoch: | Senonian |
Key time interval: | Early/Lower Maastrichtian | Ammonoid zone: | Baculites clinolobatus |
Age range of interval: | 70.60000 - 66.00000 m.y. ago | ||
* legacy (obsolete) database fields |
Stratigraphy
Geological group: | Montana | Formation: | Pierre Shale | ||
Stratigraphic resolution: | bed | ||||
Stratigraphy comments: AGE: Early Maastrichtian, on the basis of ammonoid biostratigraphy; Baculites clinolobatus zone. |
Lithology and environment
Primary lithology: | gray lithified silty "shale" | ||
Secondary lithology: | "limestone" | ||
Environment: | offshore | Tectonic setting: | cratonic basin |
Geology comments: "Shale, silty; weathers light gray; contains many gray and brown weathering ls concretions, some having fossils." |
Taphonomy
Modes of preservation: | body |
Size of fossils: | macrofossils |
Collection methods and comments
Collection methods: | mechanical,field collection |
Reason for describing collection: | biostratigraphic analysis |
Museum repositories: | USGS |
Collection method comments: "[collected] from concretions" | |
Taxonomic list comments:"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." |
Metadata
Database number: | 1577 | ||
Authorizer: | J. Alroy | Enterer: | M. Sommers |
Modifier: | M. Carrano | Research group: | marine invertebrate |
Created: | 1999-05-17 15:57:32 | Last modified: | 2012-01-31 16:47:24 |
Access level: | the public | Released: | 1999-05-17 15:57:32 |
Creative Commons license: | CC BY |
Reference information
Primary reference:
45. | 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] |