Aerosaurus (meaning "copper lizard") is an extinct genus within Varanopidae, a family of non-mammalian synapsids.

Cross-examination of the fragmentary holotype of A. greenleeorum Romer with the Camp Quarry skeleton with its expanded tooth-bearing parasphenoidal plate matches it to Aerosaurus taxa.

[2] The discovery of A. wellesi came from a team led in 1935 by Dr. Samuel P. Welles, who excavated blocks of red siltstone measuring thirty square feet in the Lower Permian Abo/Cutler Formation in near the Arroyo del Aqua settlement.

The blocks of siltstone contained two incomplete skulls of Oedaleops campi Langston, 1965, and the two nearly complete articulated skeletons of a varanopseid pelycosaur.

Overall varanopseid pelycosaurs measure about one meter long with fewer maxillary and dentary teeth compared to other Varanops.

Aerosaurus cranial morphology is distinguishable with its extremely long tooth row, recurved teeth, and triangular lateral temporal fenestra.

The teeth were so highly curved and compressed that they may have had difficulty penetrating flesh, and the tooth row extended far behind the orbit.

The dermal bones are shallow, irregular with pits and grooves and below the orbit we find a saw-like serration that hasn't been seen in other 'pelycosaurs'.

The maxilla contains specimens largest teeth and is extended posterior to the center of the triangular lateral temporal fenestra.

A foramen intermandibularis caudalis is on the medial surface of the mandible similar to the related Varannops and Ophiacodon species.

The left side of the limbs are well preserved with the humerus and femur in similar length to the lower legs.

[2] A. wellesi had a humerus and femur in similar length to the lower legs, which allowed it to have a high posture and long strides for a predaceous or carnivorous type of life.

The discovery of Pyozia mesenensis from the Middle Permian suggests there was an adaptation to ecological and climate changes that occurs into the late Paleozoic.

The P. mesenensis discovery is just an increasing trend of a “mammalness” trait during the introduction of herbivory prey that appears during the Permian.

Ectothermic animals like reptiles and 'pelycosaurs' needed to maintain a level of body temperature versus the external environment in order to survive.

This is backed up by the location of 'pelycosaur discoveries in the regions of warmer temperatures in the supercontinent of Pangea in now known localities in New Mexico, Texas and Oklahoma to name a few.

The northern and southern hemisphere during the Early Permian was hot and arid with evaporite deposits in North America and Europe.

The flora would change from the tropical forests of the Carboniferous to be replaced by seed-bearing plants like conifers during the Early Permian.

Discoveries of fossil tetrapods from the Middle and Late Permian were from South Africa and Russia creating a temporal gap.

Aerosaurus would be found in red siltstone in the Abo/Cutler Formation in New Mexico, so it existed within an open and arid environment.

[6] Lissamphibia Temnospondyl Eunotosaurus Mesosauridae Edaphosauridae Sphenacodontia Tetraceratops Eutherapsida Archaeothyris florensis Varanosaurus acutirostris Ophiacodon Stereophallodon ciscoensis Archaeovenator hamiltonensis Pyozia mesenensis Mycterosaurus longiceps Elliotsmithia longiceps Heleosaurus scholtzi Mesenosaurus romeri Varanops brevirostris Watongia meieri Varanodon agilis Ruthiromia elcobriensis Aerosaurus wellesi Aerosaurus greenleorum Media related to Aerosaurus at Wikimedia Commons