Bromide Formation, Lower Mountain Lake Member Conodonts (Ordovician of the United States)

Where: Oklahoma (34.0° N, 97.0° W: paleocoordinates 22.5° S, 73.8° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Mountain Lake Member (Bromide Formation), Blackriveran (457.3 - 449.6 Ma)

• Lower Mountain Lake Member.

• member-level stratigraphic resolution

Environment/lithology: marine; sandstone and gray shale

• Upper and lower shoreface; transition zone; shallow lagoonal; shallow shelf or carbonate ramp. Environments from M. W. Longman. 1982. Depositional environments. Echinoderm faunas from the Bromide Formation (Middle Ordovician) of Oklahoma: Lawrence, Kansas, University of Kansas Paleontological Institute Monograph 11 : 17-29.
• "[B]asal tan to greenish-gray fine-grained quartz arenite sandstone, with well-rounded and frosted grains, overlain by a sandstone and greenish-gray illitic-chloritic shale above. The sandstone sequence is thickest (more than 37 m) along Lick Creek in the northwestern Arbuckles and thinnest (less than 9 m) in the eastern Arbuckles, losing sand at the top of the section. The overlying shale and limestone is thickest (more than 60 m) along the axis of aulacogen and is mostly shale. In a comparable section in the northeastern Arbuckles, limestone predominates with some sand, and the section is 24 to 31 m thick." Lithology from R, O. Fay and A. A. Graffman. 1982. Stratigraphic studies. Echinoderm faunas from the Bromide Formation (Middle Ordovician) of Oklahoma: Lawrence, Kansas, University of Kansas Paleontological Institute Monograph 11 : 11-16. Edited by J. Sprinkle.

Size class: macrofossils

Collection methods: chemical,

Primary reference: R. O. Fay and A. A. Graffham. 1982. Biostratigraphic and paleontological studies. Echinoderm faunas from the Bromide Formation (Middle Ordovician) of Oklahoma: Lawrence, Kansas, University of Kansas Paleontological Institute Monograph 11 30-33 [S. Holland/T. Hanson/T. Hanson]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 23985: authorized by Steven Holland, entered by Tori Hanson on 25.07.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

• After Branson and Mehl, 1943; Bergstrom, 1971b; Sweet and Bergstrom, 1973; Sweet, Bergstrom, and Carnes, 1973.
Show authors, comments, and common names
unclassified
  -
Polycaulodus bidentatus, Polycaulodus tridentatus, Trucherognathus distorta, Trucherognathus irregularis
Conodonta
 Proconodontida - Cordylodontidae
Cordylodus sp.
Cordylodus sp. Pander 1856 conodont
 Prioniodontida -
Phragmodus sp. n. sp.
Phragmodus sp. n. sp. Branson and Mehl 1933 conodont
 Prioniodontida - Chirognathidae
"Curtognathus coronata" = Curtognathus, "Curtognathus limitaris" = Curtognathus, "Cardiodella arcuatus" = Curtognathus, "Cardiodella robustus" = Curtognathus
"Curtognathus coronata" = Curtognathus conodont
"Curtognathus limitaris" = Curtognathus conodont
"Cardiodella arcuatus" = Curtognathus conodont
"Cardiodella robustus" = Curtognathus conodont
 Prioniodontida - Polyplacognathidae
Polyplacognathus sp. n. sp., "Polyplacognathus sweeti" = Cahabagnathus sweeti
Polyplacognathus sp. n. sp. Stauffer 1935 conodont
"Polyplacognathus sweeti" = Cahabagnathus sweeti Bergström 1971 conodont
 Prioniodontida - Multioistodontidae
Leptochirognathus extensa, ? Leptochirognathus sp.
? Leptochirognathus sp. Branson and Mehl 1943 conodont
 Prioniodontida -
"Microcoelodus asymmetricus" = Erismodus asymmetricus, "Microcoelodus typus" = Erismodus asymmetricus, "Microcoelodus intermedius" = Erismodus, "Microcoelodus minutidentatus" = Erismodus, "? Microcoelodus sp." = Erismodus, "Microcoelodus inornatus" = Erismodus symmetricus
"Microcoelodus asymmetricus" = Erismodus asymmetricus Branson and Mehl 1933 conodont
"Microcoelodus typus" = Erismodus asymmetricus Branson and Mehl 1933 conodont
"Microcoelodus intermedius" = Erismodus conodont
"Microcoelodus minutidentatus" = Erismodus conodont
"? Microcoelodus sp." = Erismodus conodont
"Microcoelodus inornatus" = Erismodus symmetricus Branson and Mehl 1933 conodont