1205-M-middle (Jurassic to of the United States)

Where: Bonneville, Madison, Teton County, Idaho (43.7° N, 111.3° W: paleocoordinates 38.6° N, 54.7° W)

When: F Member (Twin Creek Limestone Formation), Middle Jurassic to Middle Jurassic (174.1 - 145.0 Ma)

Environment/lithology: marine; lithified, fine-grained, gray, white, silty limestone

• Member F consists of a fine-grained gray silty limestone that weathers light gray to white. This member is almost entirely thin bedded and weathers into elongate pencil-shaped splinters.

Size classes: macrofossils, mesofossils

Primary reference: M. H. Staatz and H. F. Albee. 1966. Geology of the Garns Mountain Quadrangle Bonneville, Madison, and Teton Counties, Idaho. United States Geological Survey Bulletin (1205) [A. Zaffos/E. Ito]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 184619: authorized by Andrew Zaffos, entered by Erika Ito on 14.03.2017

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Pectinida - Pectinoidae
Camptonectes sp. Meek 1864 scallop
 Ostreida - Gryphaeidae
 Ostreida - Ostreidae
Ostrea sp. Linnaeus 1758 oyster
 Carditida - Astartidae
Astarte sp. Sowerby 1816 clam
 Cardiida - Arcticidae
? Pronoella sp. Fischer 1887 clam
 Cardiida - Cardiidae
Protocardia sp. Beyrich 1845 cockle
 Trigoniida - Trigoniidae
Trigonia sp. Bruguière 1789 clam
Gastropoda
  -
Gastropoda indet. Cuvier 1797 snail
Crinoidea
  -