Aetosauroides

Aetosauroides (meaning ""Aetosaurus"-like") is an extinct genus of aetosaur from the Late Triassic of South America. It is one of four aetosaurs known from South America, the others being "Neoaetosauroides", "Chilenosuchus" and "Aetobarbakinoides". Three species have been named: the type species "A. scagliai", "A. subsulcatus" and "A. inhamandensis". Fossils have been found in the Cancha de Bochas Member of the Ischigualasto Formation in the Ischigualasto-Villa Unión Basin in northwestern Argentina and the Santa Maria Formation in the Paraná Basin in southeastern Brazil. The strata date to the late Carnian and early Norian stages, making "Aetosauroides" one of the oldest aetosaurs.
Description.
"Aetosauroides" was proposed to be synonymous with the genus "Stagonolepis" in 1996 and 2002. Smaller specimens of both species were placed with "Stagonolepis robertsoni", and larger specimens were considered to be "S. wellesi". This synonymy is not accepted, with several studies identifying unique features that distinguish "Aetosauroides" from "Stagonolepis". Among these are maxillae that do not touch the nostrils, oval-shaped holes on the centra of the vertebrae, and a convex margin of the lower jaw. In a 2011 study, "A. subsulcatus" and "A. inhamandensis" were proposed to be synonymous with "A. scagliai". A phylogenetic analysis presented by Julia B. Desojo, Martin D. Ezcurra and Edio E. Kischlat in 2012 found that "Aetosauroides" lies outside Stagonolepididae. If this phylogeny is correct, Stagonolepididae and Aetosauria would not be equivalent groupings, and "Aetosauroides" would be the first non-stagonolepidid aetosaur.