D1887 (Cretaceous of the United States)

Also known as Pierre Shale (USGS D1887, D1881)

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 gilberti ammonoid zone, Mitten Black Shale Member (Pierre Shale Formation), Campanian (83.6 - 72.1 Ma)

• Pierre shale, from ferro-calcareous Concretions 66' above uppermost conspicuous ridge of Mitten concretions. Was Bed 33.

• bed-level stratigraphic resolution

Environment/lithology: offshore; lithified, gray, yellow, silty shale and limestone

• "shale, dark gray, contains numerous pale yellowish brown weathering fossiliferous ls concretions and conspicuous beds of darker brown weathering ls concretions at base where they form ridges and top."

Size class: macrofossils

Reposited in the USGS

Collection methods: mechanical,

• "[collected] from 1-22 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 1720: 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
 Myalinida - Inoceramidae
"Inoceramus subcompressus" = Cataceramus subcompressus
"Inoceramus subcompressus" = Cataceramus subcompressus Meek and Hayden 1860 clam
Gastropoda
 Sorbeoconcha - Aporrhaidae
Aporrhais sp.
Aporrhais sp. da Costa 1778 snail
Cephalopoda
 Ammonitida - Scaphitidae
Hoploscaphites sp., Hoploscaphites gilli
Hoploscaphites sp. Nowak 1911 ammonite
sp. nov.
Hoploscaphites gilli Cobban and Jeletzky 1965 ammonite
 Ammonitida - Baculitidae
Baculites gilberti
Baculites gilberti Cobban 1962 ammonite
Bryozoa
  -
Bryozoa indet.
Bryozoa indet. Ehrenberg 1831
pyriporoid bryozoan