Most individuals of Aetosauroides measured around 1.3 metres (4 ft 3 in) in length, with one large individual reaching 2.4 metres (7 ft 10 in) (with histology suggesting an age of 23 years). Sexual maturity was probably reached at 1 metre (3 ft 3 in) in length, although these individuals were not yet fully grown.[2]Sexual dimorphism has been suggested for Aetosauroides, with males reaching the 2-metre (6 ft 7 in) size range.[3]
Skeletal diagram of the holotype of Polesinesuchus aureloi, a possible synonym of Aetosauroides scagliai
Aetosauroides was proposed to be synonymous with the genus Stagonolepis in 1996 and 2002.[4][5] Smaller specimens of both species were placed with Stagonolepis robertsoni, and larger specimens were considered to be S. wellesi. This synonymy is not accepted,[1][6][7][8] 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.[8] Additionally, a contemporary aetosaur named from a juvenile specimen in 2014, Polesinesuchus aurelioi, was found to be similar in its vertebrae and the basioccipital of its braincase to juvenile specimens of Aetosauroides in two 2021 studies, and it was proposed as a junior synonym of the latter.[2][9]
Classification
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.[1]
Palaeobiology
A pathological specimen of A. scagliai has been found, consisting of a distal fragment of a fibula containing radial fibrolamellar bone indicative of periostitis. This palaeopathology is believed to have been caused by some sort of non-traumatic stress followed by a pyogenic infection.[10]
^ abPaes-Neto, V.D.; Desojo, J.B.; Brust, A.C.B.; Schultz, C.L.; Da-Rosa, A.A.S.; Soares, M.B. (2021). "Intraspecific variation in the axial skeleton of Aetosauroides scagliai (Archosauria: Aetosauria) and its implications for the aetosaur diversity of the Late Triassic of Brazil". Annals of the Brazilian Academy of Sciences. 93 (supp. 2): e20201239. doi:10.1590/0001-3765202120201239. hdl:11336/150258. PMID34468486. S2CID237372648.{{cite journal}}: CS1 maint: article number as page number (link)
^Tabora, J.R.A.; Heckert, A.B.; Desojo, J.B. (2015). "Intraspecific variation in Aetosauroides Casamiquela (Archosauria: Aetosauria) from the Upper Triassic of Argentina and Brazil: an example of sexual dimorphism?". Ameghiniana. 52 (2): 173–187. doi:10.5710/AMGH.05.01.2015.2824. S2CID11498039.
^Heckert, A.B.; Lucas, S.G. (2002). "South American occurrences of the Adamanian (Late Triassic: latest Carnian) index taxon Stagonolepis (Archosauria: Aetosauria) and their biochronological significance". Journal of Paleontology. 76 (5): 852–863. doi:10.1666/0022-3360(2002)076<0852:SAOOTA>2.0.CO;2. S2CID128610620.
^Parker, W. G.; Stocker, M. R.; Irmis, R. B. (2008). "A new desmatosuchine aetosaur (Archosauria; Suchia) from the Upper Triassic Tecovas Formation (Dockum Group) of Texas". Journal of Vertebrate Paleontology. 28 (2): 692–701. doi:10.1671/0272-4634(2008)28[692:ANDAAS]2.0.CO;2. ISSN0272-4634. S2CID84455880.
^ abDesojo, J.B.; Ezcurra, M.D. (2011). "A reappraisal of the taxonomic status of Aetosauroides (Archosauria, Aetosauria) specimens from the Late Triassic of South America and their proposed synonymy with Stagonolepis". Journal of Vertebrate Paleontology. 31 (3): 596–609. Bibcode:2011JVPal..31..596D. doi:10.1080/02724634.2011.572936. S2CID85418778.
^Paes-Neto, V.D.; Desojo, J.B.; Brust, A.C.B.; Ribeiro, A.M.; Schultz, C.L.; Soares, M.B. (2021). "The first braincase of the basal aetosaur Aetosauroides scagliai (Archosauria: Pseudosuchia) from the Upper Triassic of Brazil". Journal of Vertebrate Paleontology. 41 (2): e1928681. Bibcode:2021JVPal..41E8681P. doi:10.1080/02724634.2021.1928681. S2CID237518035.{{cite journal}}: CS1 maint: article number as page number (link)
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