Reinterpretation of the Holotype of Malerisaurus Langstoni, a Diapsid Reptile from the Upper Triassic Chinle Group of West Texas

The holotype of Malerisaurus langstoni from the Late Triassic (Otischalkian) Trilophosaurus quarry 2 of West Texas is a chimera. The holotype represents at least 6-7 individuals of four reptilian groups: Trilophosauridae, Rhynchosauridae, Parasuchidae and Aetosauria. The majority of the material, including all of the cranial fragments, are re-identified as Trilophosaurus buettneri. Based on the chimeric nature of the specimen, the holotype of M. langstoni is restricted to the skull fragments and considered a junior subjective synonym of T. buetterni. This reassessment of M. langstoni calls into question the validity of M. robinsonae from the Maleri Formation in India and suggests that at least some of the elements referred to this taxon may, in fact, be a record of Trilophosaurus. This would extend the paleogeographic range of Trilophosaurus from a taxon endemic to the American Southwest to a nearly Pangean distribution during the Late Triassic.