Aetosaurs (aetosaur /eɪˌɛtoʊˈsɔːr/; order name Aetosauria /eɪˌɛtoʊˈsɔːriə/; from Greek, ἀετός (aetos, "eagle") and σαυρος (sauros, "lizard")) are an extinct order of heavily armoured, medium- to large-sized herbivorous archosaurian reptiles, known from the Late Triassic. They have small heads, upturned snouts, erect limbs, and a body covered by plate-like scutes. All aetosaurs belong to the family Stagonolepididae. Two distinct subdivisions of aetosaurs are currently recognized, Desmatosuchinae and Aetosaurinae, based primarily on differences in the morphology of the bony scutes of the two groups. Over 20 genera of aetosaurs have been described, and recently there has been controversy regarding the description of some of these genera. Aetosaurs belong to the clade Suchia within Archosauria