Chickasha Formation

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]