^ abMichel Laurin (1991). "The osteology of a Lower Permian eosuchian from Texas and a review of diapsid phylogeny". Zoological Journal of the Linnean Society. 101 (1): 59–95. doi:10.1111/j.1096-3642.1991.tb00886.x.
^ abRobert R. Reisz, Michel Laurin and David Marjanović (2010). "Apsisaurus witteri from the Lower Permian of Texas: yet another small varanopid synapsid, not a diapsid". Journal of Vertebrate Paleontology. 30 (5): 1628–1631. doi:10.1080/02724634.2010.501441.