First reported actinopterygian from the Navajo Sandstone (Lower Jurassic, Glen Canyon Group) of southern Utah, USA

Abstract

AbstractWe report the first occurrence of an actinopterygian fish from the Lower Jurassic Navajo Sandstone, discovered in the Grand Staircase-Escalante National Monument in southern Utah, U.S.A. The site contains multiple individuals, preserved within an interdune deposit, possessing the elongate modified dorsal scales usually characterizing semionotiform fishes. The presence of moderately sized fish provides further evidence that interdune oases were occasionally persistent environmental habitats within the greater Navajo dune system, and that the paleobiota is still woefully undersampled. Additionally, this site could help fill a gap in the actinopterygian fossil record between the patchy Lower Jurassic and better-known Middle Jurassic documentation of western North America.