Threeforks Shale, Gallatin Co., Montana (measured section 6 of author) (Devonian of the United States)

Where: Gallatin County, Montana (45.9° N, 111.4° W: paleocoordinates 15.1° S, 46.4° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Platyclymenia zone, Three Forks Shale Formation, Middle Famennian (370.6 - 364.7 Ma)

• species of ammonoid found by the author correspond to the Oberdevon III, the lower Platyclymenia horizon in the European stratigraphic column [JA: originally entered as late Devonian, but the lower Platyclymenia horizon corresponds to the Pa. trachytera conodont zone and is middle Famennian]

• formation-level stratigraphic resolution

Environment/lithology: marine; gray, yellow shale

• author gives no detailed description of lithology where she collected; however, through historic descriptions included in the text, the formation is divided into two shale units divided by limestone. this collection came from the lower shale, which is described as finely laminated and variegated in color (red, yellow, and brown) and the upper shale which is described as purple gray shale.

Collection methods: surface (in situ),

Primary reference: P. J. Renzetti. 1961. Fauna of the Threeforks Shale (Devonian) of Southwestern Montana. 1-342 [A. Miller/K. Layou/M. Uhen]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 6985: authorized by Arnold Miller, entered by Karen Layou on 18.04.2000

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
unclassified
  -
Hunanospirifer monticola, Hunanospirifer ? gallatinensis
Stenolaemata
 Rhabdomesida - Rhomboporidae
Rhombopora sp. n. sp.
Rhombopora sp. n. sp. Meek 1872
Rhombopora n. sp. A
Rhynchonellata
 Spiriferinida - Syringothyrididae
Syringothyris cf. typus
 Rhynchonellida - Rhynchotetradidae
Paraphorhynchus jeffersonense, Paraphorhynchus madisonense
 Rhynchonellida - Leiorhynchidae
Basilicorhynchus ventricosum
 Orthida - Rhipidomellidae
Rhipidomella cf. newalbanensis
Rhipidomella cf. newalbanensis
Rhipidomella cf. vanuxemi newalbanensis
 Spiriferida - Cyrtospiriferidae
Syringospira prima
 Spiriferida - Ambocoeliidae
Echinocoelia youngstownensis
 Spiriferida - Mucrospiriferidae
Eleutherokomma raymondi
Strophomenata
 Orthotetida - Schuchertellidae
Schuchertella sp.
Schuchertella sp. Girty 1904