Chickasha Formation

Geologic formation in Oklahoma, United States

Chickasha Formation
Stratigraphic range: Roadian PreꞒ Ꞓ O S D C P T J K Pg N
Type	Formation
Location
Region	Oklahoma
Country	United States
Type section
Named for	Chickasha, Grady County, Oklahoma
Named by	Charles Newton Gould, 1924^[1]

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]

References

^ Gould, Charles N. (1924). "A new classification of the Permian redbeds of southwestern Oklahoma". American Association of Petroleum Geologists Bulletin. 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. doi:10.1051/bsgf/2022007. ISSN 1777-5817.
^ Gee, Bryan M.; Scott, Diane; Reisz, Robert R. (October 2018). "Reappraisal of the Permian dissorophid Fayella chickashaensis". Canadian Journal of Earth Sciences. 55 (10): 1103–1114. doi:10.1139/cjes-2018-0053.
^ Olson, Everett C. (1972). "Diplocaulus parvus n. sp. (Amphibia: Nectridea) from the Chickasha Formation (Permian: Guadalupian) of Oklahoma". Journal of Paleontology. 46 (5): 656–659. ISSN 0022-3360.
^ Olson, E. C. (1965). "New Permian Vertebrates from the Chickasha Formation in Oklahoma". New Permian Vertebrates from the Chickasha Formation in Oklahoma. 70: 1–70.
^ Smith, Gary E. (1974). "Depositional systems, San Angelo Formation (Permian), north Texas--facies control of red-bed copper mineralization". Report of Investigations, Bureau of economic geology. 80: 73. doi:10.26153/tsw/4807.
^ Olroyd, Savannah L.; Sidor, Christian A. (1 August 2017). "A review of the Guadalupian (middle Permian) global tetrapod fossil record". Earth-Science Reviews. 171: 583–597. doi:10.1016/j.earscirev.2017.07.001. ISSN 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 (1 April 2004). "A reevaluation of the enigmatic Permian synapsid Watongia and of its stratigraphic significance". Canadian Journal of Earth Sciences. 41 (4): 377–386. doi:10.1139/e04-016. ISSN 0008-4077.