El Reno Group

El Reno Group
Stratigraphic range: Permian
Type	Group
Location
Region	Oklahoma
Country	United States

The El Reno Group is a geologic group in Oklahoma. It preserves fossils dating back to the Permian period. The Chickasha Formation, which is part of this group, contains the geologically most recent Permian continental vertebrates (Roadian) known from North America.^[1] These include one of the most recent lepospondyls,^[2] a dissorophoid,^[3] and some fragmentary fossils of Steppesaurus that Everett C. Olson interpreted as one of the oldest known therapsids,^[4] an interpretation that has not been widely accepted.

References

^ 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.
^ 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, Everett C. (1972). "Fayella chickashaensis, the Dissorophoidea and the Permian Terrestrial Radiations". Journal of Paleontology. 46 (1): 104–114. ISSN 0022-3360.
^ Olson, Everett C. (1962). "Late Permian Terrestrial Vertebrates, U. S. A. and U. S. S. R." Transactions of the American Philosophical Society. 52 (2): 1–224. doi:10.2307/1005904. ISSN 0065-9746.