SW Richey Field-Williston Basin, Zone A, Deadwood Fm. ( of the United States)

Where: Montana (47.4° N, 105.6° W: paleocoordinates 10.3° S, 75.5° W)

• coordinate based on political unit

When: Deadwood Formation, Tremadoc (486.5 - 477.7 Ma)

• "lower Tremadoc"

Environment/lithology: lagoonal; shale

• "sh, ls and congl. muddy shelf lagoon. BA2. cratonic shelf."

Size class: macrofossils

Primary reference: C. Lochman-Balk and J. L. Wilson. 1967. Stratigraphy of Upper Cambrian-Lower Ordovician Subsurface Sequence in Williston Basin. AAPG Bulletin 51(6):883-917 [M. Uhen/J. Ju]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 270: authorized by Jack Sepkoski, entered by Mike Sommers on 20.11.1998

Creative Commons license: CC BY (attribution)

Taxonomic list

• "Lochman-Balk and Wilson, 1967. biostratigraphic lists"
Show authors, comments, and common names
Pterobranchia
 Dendroidea - Dendrograptidae
Dendrograptus sp.
Dendrograptus sp. Hall 1858 graptolite
 Graptoloidea - Lasiograptidae
Hallograptus sp.
Hallograptus sp. Lapworth 1876 lasiograptid
Artiopoda
 Agnostida - Metagnostidae
Geragnostus sp.
Geragnostus sp. Howell 1935
Trilobita
 Olenida - Eulomidae
Euloma sp.
Euloma sp. Angelin 1854 trilobite
 Asaphida - Nileidae
Symphysurina sp.
Symphysurina sp. Ulrich 1924 trilobite
Rhynchonellata
 Orthida - Eoorthidae
Apheoorthis sp.
Apheoorthis sp. Ulrich and Cooper 1936
Lingulata
 Siphonotretida - Siphonotretidae
Schizambon sp.
Schizambon sp. Walcott 1884
 Lingulida - Obolidae
Lingulella sp.
Lingulella sp. Salter 1866