Named By: Michel Laurin - 1991.
Classification: Chordata, Synapsida, Eupelycosauria, Varanopidae.
Species: A. witteri (type).
Known locations: USA, Texas - Archer City Formation.
Time period: Early/Mid Permian.
Fossil representation: Partial post cranial skeleton as well as a partial skull and jaws.
Initially thought to be a diapsid, Apsisaurus was later realised to a Eupelycosaurian varnopisd. As a Varanopid, Apsisaurus was related to the more famous Varanops which also lived in Texas at the same approximate time as Apsisaurus.
- 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. - Michel Laurin - 1991.
- Apsisaurus witteri from the Lower Permian of Texas: yet another small varanopid synapsid, not a diapsid. - Journal of Vertebrate Paleontology 30 (5): 1628–1631. - Robert R. Reisz, Michel Laurin and David Marjanović - 2010.