View source for Chickasha Formation

{{Short description|Geologic formation in Oklahoma, United States}}
{{Infobox rockunit
| name           = Chickasha Formation
| image          =
| caption        =
| type           = [[Formation (stratigraphy)|Formation]]
| age            =  {{fossilrange|Roadian}}
| prilithology   =
| otherlithology =
| namedfor       = [[Chickasha, Oklahoma|Chickasha]], [[Grady County, Oklahoma|Grady County]], [[Oklahoma]]
| namedby        = Charles Newton Gould, 1924<ref>{{cite journal |last1=Gould |first1=Charles N. |title=A new classification of the Permian redbeds of southwestern Oklahoma |journal=American Association of Petroleum Geologists Bulletin |date=1924 |volume=8 |issue=3 |pages=322–341}}</ref>
| region         = [[Oklahoma]]
| country        = [[United States]]
| coordinates    =
| unitof         =
| subunits       =
| underlies      =
| overlies       =
| thickness      =
| extent         =
| area           =
| map            =
| map_caption    =
|period=Roadian}}

The '''Chickasha Formation''', which is part of the [[El Reno Group]], is a [[Formation (geology)|geologic formation]] in [[Oklahoma]]. It preserves [[fossils]] dating back to the [[Roadian]] stage of the [[Middle Permian]].<ref>{{Cite journal |last=Laurin |first=Michel |last2=Hook |first2=Robert W. |date=2022 |title=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 |url=https://www.bsgf.fr/10.1051/bsgf/2022007 |journal=BSGF - Earth Sciences Bulletin |volume=193 |pages=10 |doi=10.1051/bsgf/2022007 |issn=1777-5817|doi-access=free }}</ref> These include, among others, the [[Dissorophoidea|dissorophoid]] [[Temnospondyli|temnospondyl]] ''[[Nooxobeia]] gracilis'',<ref name="Gee et al. 2018">{{cite journal |last1=Gee |first1=Bryan M. |last2=Scott |first2=Diane |last3=Reisz |first3=Robert R. |title=Reappraisal of the Permian dissorophid Fayella chickashaensis |journal=Canadian Journal of Earth Sciences |date=October 2018 |volume=55 |issue=10 |pages=1103–1114 |doi=10.1139/cjes-2018-0053}}</ref> the [[lepospondyl]] ''[[Diplocaulus]] parvus'' ([[Amphibian|Amphibia]]: [[Nectridea]]),<ref name="Olson 1972">{{cite journal |last1=Olson |first1=Everett C. |title=Diplocaulus parvus n. sp. (Amphibia: Nectridea) from the Chickasha Formation (Permian: Guadalupian) of Oklahoma |journal=Journal of Paleontology |date=1972 |volume=46 |issue=5 |pages=656–659 |url=https://www.jstor.org/stable/1303021 |issn=0022-3360}}</ref> and the [[Captorhinidae|captorhinid]] ''Rothianiscus robusta'', initially called ''Rothia robusta'' by [[Everett C. Olson]].<ref name="Olson 1965">{{cite journal |last1=Olson |first1=E. C. |title=New Permian Vertebrates from the Chickasha Formation in Oklahoma |journal=New Permian Vertebrates from the Chickasha Formation in Oklahoma |date=1965 |volume=70 |pages=1-70}}</ref> 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.<ref name="Smith 1974">{{cite journal |last1=Smith |first1=Gary E. |title=Depositional systems, San Angelo Formation (Permian), north Texas--facies control of red-bed copper mineralization |journal=Report of Investigations, Bureau of economic geology |date=1974 |volume=80 |pages=73 |doi=10.26153/tsw/4807 |url=http://dx.doi.org/10.26153/tsw/4807 |language=en}}</ref> 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.<ref name="Olroyd & Sidor 2017">{{cite journal |last1=Olroyd |first1=Savannah L. |last2=Sidor |first2=Christian A. |title=A review of the Guadalupian (middle Permian) global tetrapod fossil record |journal=Earth-Science Reviews |date=1 August 2017 |volume=171 |pages=583–597 |doi=10.1016/j.earscirev.2017.07.001 |url=http://dx.doi.org/10.1016/j.earscirev.2017.07.001 |issn=0012-8252}}</ref> Worse, one of them, ''[[Watongia]]'',<ref name="olson1974">{{cite journal |last1=Olson |first1=E.C. |year=1974 |title=On the Source of Therapsids |journal=Annals of the South African Museum |volume=64 |pages=27–46 |url=https://www.biodiversitylibrary.org/page/40912017}}</ref> was later shown to be a [[Varanopidae|varanopid]].<ref name="Reisz & Laurin 2004">{{cite journal |last1=Reisz |first1=Robert R |last2=Laurin |first2=Michel |title=A reevaluation of the enigmatic Permian synapsid Watongia and of its stratigraphic significance |journal=Canadian Journal of Earth Sciences |date=1 April 2004 |volume=41 |issue=4 |pages=377–386 |doi=10.1139/e04-016 |url=https://doi.org/10.1139/e04-016 |language=en |issn=0008-4077}}</ref>

==See also==
{{Portal|Earth sciences|Oklahoma|Paleontology}}
* [[List of fossiliferous stratigraphic units in Oklahoma]]
* [[Paleontology in Oklahoma]]

==References==
{{reflist}}
* {{cite web|title= Fossilworks: Gateway to the Paleobiology Database|author= ((Various Contributors to the Paleobiology Database))|url= http://www.fossilworks.org/cgi-bin/bridge.pl?action=home|access-date= 17 December 2021}}

[[Category:Permian geology of Oklahoma]]


{{Oklahoma-geologic-formation-stub}}
{{Permian-stub}}