PBDB Collection

Threeforks Shale, Jefferson Island Co., Montana (measured section 3 of author): Middle Famennian, Montana

List of taxa

Where & when

Geology

Taphonomy & methods

Metadata & references

Taxonomic list

unclassified

	Nickelsopora sp. n. sp.
	Nickelsopora n. sp. A

	Hunanospirifer monticola

	Hunanospirifer ? gallatinensis

	Hunanospirifer animasensis
Stenolaemata - Trepostomida - Atactotoechidae

	Leptotrypella sp. n. sp. Vinassa de Regny 1921
	Leptotrypella n. sp. A
Stenolaemata - Rhabdomesida - Rhomboporidae

	Rhombopora sp. n. sp. Meek 1872
	Rhombopora n. sp.A
Stenolaemata - Rhabdomesida - Rhabdomesidae

	Rhabdomeson sp. n. sp.
	Rhabdomeson n. sp. A and Rhabdomeson n. sp. B
Strophomenata - Productida - Productidae

	Leioproductus coloradensis

	Leioproductus montanensis n. sp.

	Leioproductus plicatus (Kindle 1909)
Strophomenata - Productida - Sentosiidae

	Echinoconchus ? laminatus (Kindle 1909)
Strophomenata - Orthotetida - Areostrophiidae

	Schuchertella cf. arctostriata (Hall 1843)
Strophomenata - Orthotetida - Schuchertellidae

	Schuchertella cf. extensus

	Schuchertella sp. Girty 1904
Rhynchonellata - Rhynchonellida - Petasmariidae

	Shumardella dunbarensis
Rhynchonellata - Rhynchonellida - Leiorhynchidae

	Basilicorhynchus ventricosum
Rhynchonellata - Rhynchonellida - Trigonirhynchiidae

	Camarotoechia sobrina Stainbrook 1947
Rhynchonellata - Rhynchonellida - Rhynchotetradidae

	Paraphorhynchus jeffersonense

	Paraphorhynchus madisonense

	Paraphorhynchus threeforksense
Rhynchonellata - Spiriferida - Mucrospiriferidae

	Eleutherokomma raymondi
Rhynchonellata - Spiriferida - Ambocoeliidae

	Echinocoelia youngstownensis
Rhynchonellata - Spiriferida - Cyrtospiriferidae

	? Cyrtospirifer perryi n. sp.

	? Cyrtospirifer bertrandi n. sp.

	Syringospira prima
Rhynchonellata - Orthida - Schizophoriidae

	Schizophoria australis (Kindle 1909)
Rhynchonellata - Athyridida - Athyrididae

	Cleiothyridina devonica
Cephalopoda - Ammonoida - Platyclymeniidae

	Platyclymenia sp. Hyatt 1884

	Platyclymenia sp. n. sp. Hyatt 1884
	Platyclymenia n. sp. A and Platyclymenia n. sp. B
Cephalopoda - Ammonoida - Tornoceratidae

	Tornoceras crebiseptum
Cephalopoda - Ammonoida - Prolobitidae

	Raymondiceras simplex (Raymond 1909)
see common names

Country:	United States	State/province:	Montana	County:	Jefferson Island
Coordinates:	45.9° North, 112.0° West (view map)
Paleocoordinates:	10.3° South, 61.2° West (Wright 2013)
Basis of coordinate:	based on nearby landmark
Geographic resolution:	outcrop

Period:	Devonian	Epoch:	Late Devonian
Stage:	Famennian	10 m.y. bin:	Devonian 5
*Period:	Late/Upper Devonian
Key time interval:	Middle Famennian	Zone:	Platyclymenia
Age range of interval:	368.5 - 365.3 m.y. ago
* legacy (obsolete) database fields

Formation:	Three Forks Shale
Stratigraphic resolution:	formation
Stratigraphy comments: 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]

Primary lithology:	planar lamination,gray,red or brown,yellow "shale"
Secondary lithology:	"limestone"
Lithology description: 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 variegated in color (reds, yellow, brown) and finely laminated and the middle limestone, which is grey and nodular.
Environment:	marine indet.

Collection methods:	surface (in situ),field collection
Reason for describing collection:	biostratigraphic analysis

Database number:	6975
Authorizer:	A. Miller	Enterer:	K. Layou
Modifier:	J. Alroy	Research group:	marine invertebrate
Created:	2000-04-18 12:08:27	Last modified:	2025-02-22 15:12:02
Access level:	the public	Released:	2000-11-20 13:53:33
Creative Commons license:	CC0