SW Richey Field-Williston Basin, Deadwood Fm., zone b (upper Tremadoc) (Ordovician 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 (485.4 - 477.7 Ma)

• "Lower Ord., upper Tremadoc, Zone B"

Environment/lithology: lagoonal; lithology not reported

• "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 275: 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. biostrat. lists"
Trilobita
 Aulacopleurida - Hystricuridae
Hystricurus sp. Raymond 1913 trilobite
 Asaphida - Asaphidae
Xenostegium sp. Walcott 1924 trilobite
Bellefontia sp. Walcott 1924 trilobite
 Asaphida - Remopleurididae
Praepatokephalus sp. Lochman 1964 trilobite
 Asaphida - Nileidae
Symphysurina sp. Ulrich 1924 trilobite
 Ptychopariida - Kingstoniidae
Clelandia sp. Cossman 1902 trilobite
Xiphosura
  -
"Merostomata indet." = Xiphosura
"Merostomata indet." = Xiphosura Latreille 1802
Strophomenata
 Strophomenida - Taffiidae
Aporthophyla sp. Ulrich and Cooper 1938
Rhynchonellata
 Pentamerida - Tetralobulidae
Tetralobula sp. Ulrich and Cooper 1936
 Pentamerida - Clarkellidae
Lingulata
 Lingulida - Obolidae
 Siphonotretida - Siphonotretidae
Schizambon sp. Walcott 1884
Gastropoda
 Murchisoniina - Hormotomidae
Plethospira sp. Ulrich and Scofield 1897 snail
Conodonta
 Conodontophorida -
Drepanodus sp. Pander 1856 conodont
Graptolithina
 Dendroidea - Dendrograptidae
Dictyonema sp. Hall 1851 graptolite