Milligan Creek, locality no. 25c (Devonian of the United States)

Also known as USGS D39(SD)

Where: Jefferson County, Montana (45.9° N, 111.6° W: paleocoordinates 14.2° S, 46.4° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Three Forks Shale Formation, Famennian (372.2 - 358.9 Ma)

• 30-40 feet below Lodgepole Limestone, 5-15 feet above base of upper siltstone unit.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified, gray limestone

• gray limestone

Reposited in the USGS

Primary reference: G. D. Robinson. 1963. Geology of the Three Forks Quadrangle, Montana. United States Geological Survey Professional Paper 370:1-143 [J. Alroy/M. Sommers/J. Ju]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 7302: authorized by John Alroy, entered by Mike Sommers on 23.05.2000

Creative Commons license: CC BY (attribution)

Taxonomic list

• only brachs and cephalopods listed.
unclassified
  -
Strophomenata
 Strophomenida - Chonetidae
Chonetes sp. Fischer de Waldheim 1830
 Orthotetida - Schuchertellidae
 Productida - Productidae
"Avonia cf. arcuata" = Dictyoclostus arcuatus
"Avonia cf. arcuata" = Dictyoclostus arcuatus Hall 1858
Rhynchonellata
 Rhynchonellida - Camarotoechiidae
 Spiriferinida - Syringothyrididae
 Spiriferida - Cyrtospiriferidae
Cyrtospirifer sp. Nalivkin 1924
 Spiriferida - Ambocoeliidae
? Crurithyris sp. George 1931
 Spiriferida - Spiriferidae
Spirifer sp. Sowerby 1818
"large" type