Aetosaur
Over 20 genera of aetosaurs have been described. Two distinct subdivisions of aetosaurs are currently recognized, Desmatosuchia and Aetosaurinae, based primarily on broad differences in skull morphology. Osteoderms structure is generally one of the most useful traits for classification. Among other archosaurs, aetosaurs are most closely related to Revueltosaurus, a small reptile whose teeth were once mistaken for those of a herbivorous dinosaur.