Chickasha Formation Explained
The Chickasha Formation, which is part of the El Reno Group, is a geologic formation in Oklahoma. It preserves fossils dating back to the Roadian stage of the Middle Permian.[2] These include, among others, the dissorophoid temnospondyl Nooxobeia gracilis,[3] the lepospondyl Diplocaulus parvus (Amphibia: Nectridea),[4] and the captorhinid Rothianiscus robusta, initially called Rothia robusta by Everett C. Olson.[5] Many of these fossils were indicated to have come from the Flowerpot Shale, but these actually come from the Chickasha Formation, according to the current nomenclature.[6] The age of the formation was long debated because Olson based part of his argument on fragmentary fossils that he interpreted as therapsids, an interpretation that was not widely accepted.[7] Worse, one of them, Watongia,[8] was later shown to be a varanopid.[9]
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References
Notes and References
- Gould . Charles N. . A new classification of the Permian redbeds of southwestern Oklahoma . American Association of Petroleum Geologists Bulletin . 1924 . 8 . 3 . 322–341.
- Laurin . Michel . Hook . Robert W. . 2022 . The age of North America’s youngest Paleozoic continental vertebrates: a review of data from the Middle Permian Pease River (Texas) and El Reno (Oklahoma) Groups . BSGF - Earth Sciences Bulletin . 193 . 10 . 10.1051/bsgf/2022007 . 1777-5817. free .
- Gee . Bryan M. . Scott . Diane . Reisz . Robert R. . Reappraisal of the Permian dissorophid Fayella chickashaensis . Canadian Journal of Earth Sciences . October 2018 . 55 . 10 . 1103–1114 . 10.1139/cjes-2018-0053.
- Olson . Everett C. . Diplocaulus parvus n. sp. (Amphibia: Nectridea) from the Chickasha Formation (Permian: Guadalupian) of Oklahoma . Journal of Paleontology . 1972 . 46 . 5 . 656–659 . 0022-3360.
- Olson . E. C. . New Permian Vertebrates from the Chickasha Formation in Oklahoma . New Permian Vertebrates from the Chickasha Formation in Oklahoma . 1965 . 70 . 1-70.
- Smith . Gary E. . Depositional systems, San Angelo Formation (Permian), north Texas--facies control of red-bed copper mineralization . Report of Investigations, Bureau of economic geology . 1974 . 80 . 73 . 10.26153/tsw/4807 . en.
- Olroyd . Savannah L. . Sidor . Christian A. . A review of the Guadalupian (middle Permian) global tetrapod fossil record . Earth-Science Reviews . 1 August 2017 . 171 . 583–597 . 10.1016/j.earscirev.2017.07.001 . 0012-8252.
- Olson . E.C. . 1974 . On the Source of Therapsids . Annals of the South African Museum . 64 . 27–46 .
- Reisz . Robert R . Laurin . Michel . A reevaluation of the enigmatic Permian synapsid Watongia and of its stratigraphic significance . Canadian Journal of Earth Sciences . 1 April 2004 . 41 . 4 . 377–386 . 10.1139/e04-016 . en . 0008-4077.