USGS Mesozoic loc. 27037, Sun River area, Western Montana (Jurassic of the United States)

Where: Montana (47.6° N, 112.7° W: paleocoordinates 39.7° N, 51.4° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Lower Sandstone Member (Sawtooth Formation), Bajocian (170.3 - 168.3 Ma)

• from lower sandstone member of Sawtooth formation; the Lower Sandstone member is probably of Bajocian age

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified sandstone

• The lower member of the Sawtooth formation consists of siliceous sandstone and sandy limestone.

Size class: macrofossils

Reposited in the USGS

• collection was made by R. W. Imlay in 1958

Primary reference: R. W. Imlay. 1962. Jurassic (Bathonian or Early Callovian) Ammonites from Alaska and Montana. Geological Survey Professional Paper 374-C:1-32 [M. Aberhan/S. Nurnberg]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 68828: authorized by Martin Aberhan, entered by Sabine Nürnberg on 09.02.2007

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Trigoniida - Trigoniidae
 Pholadida - Pleuromyidae
 Ostreida - Ostreidae
Ostrea sp. Linnaeus 1758 oyster
 Pectinida - Oxytomidae
Meleagrinella curta Hall 1852 scallop
 Pectinida - Pectinoidae
Camptonectes stygius White 1874 scallop
Echinoidea
  -
Echinoidea indet. Leske 1778 sea urchin
Echinoid spines