USGS D2118: Early/Lower Maastrichtian, Wyoming
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Anthozoa
- Scleractinia
- Caryophylliidae
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? Trochocyathus sp.
Milne-Edwards and Haime 1848
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originally entered as "? Trochocyathus sp." | ||||||||||
Cephalopoda
- Nautilida
- Nautilidae
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Eutrephoceras montanaense
(Meek 1876)
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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 grandis
Hall and Meek 1854
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Bivalvia
- Arcida
- Cucullaeidae
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Idonearca shumardi
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spelled with current rank as Cucullaea (Idonearca) | ||||||||||
Bivalvia
- Myalinida
- Inoceramidae
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Inoceramus sp.
Sowerby 1814
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? Inoceramus fibrosus
(Meek and Hayden 1857)
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originally entered as "? Inoceramus fibrosus" | ||||||||||
Bivalvia
- Pectinida
- Anomiidae
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Anomia sp.
Linnaeus 1758
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Bivalvia
- Pectinida
- Pectinidae
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Pecten nebrascensis
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(Chlamys) | ||||||||||
Bivalvia
- Ostreida
- Bakevelliidae
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Gervillia sp.
Defrance 1820
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Bivalvia
- Ostreida
- Pteriidae
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Pteria sp.
Scopoli 1777
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Bivalvia
- Poromyida
- Cuspidariidae
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Cuspidaria sp.
Dall 1886
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Bivalvia
- Nuculida
- Nuculidae
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Nucula cancellata
Meek and Hayden 1857
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(Pectinucula) | ||||||||||
Bivalvia
- Nuculanida
- Nuculanidae
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Nuculana evansi
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Polychaeta
- Serpulimorpha
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? Diploconcha sp.
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originally entered as "? Diploconcha sp." | ||||||||||
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 grandis |
Age range of interval: | 70.60000 - 66.00000 m.y. ago | ||
* legacy (obsolete) database fields |
Stratigraphy
Formation: | Pierre Shale | Member: | upper unnamed shale | ||
Regional section: | formation | Regional bed: | 427 - 451 ft | ||
Regional order: | top to bottom | ||||
Stratigraphic resolution: | bed | ||||
Stratigraphy comments: Pierre shale, from grown limestone concretions 427 - 451' below top; was bed 96 |
Lithology and environment
Primary lithology: | gray lithified silty "shale" | ||
Secondary lithology: | "limestone" | ||
Environment: | offshore | Tectonic setting: | cratonic basin |
Geology comments: "Shale. dark gray; basal 2-3 ft. very bentonitic, forming a gray bare gumbo surface; rest of unit silty, containing a few small very fossiliferous brown weathering limestone concretions." |
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 |
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
Also known as: | Pierre Shale (USGS D2118) | ||
Database number: | 1582 | ||
Authorizer: | J. Alroy | Enterer: | M. Sommers |
Modifier: | P. Wagner | Research group: | marine invertebrate |
Created: | 1999-05-17 16:26:58 | Last modified: | 2024-03-17 14:38:16 |
Access level: | the public | Released: | 1999-05-17 16:26:58 |
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] |