Aetosauroides

{{Short description|Extinct genus of reptiles}} {{Automatic taxobox | fossil_range = [[Late Triassic]]<br />~{{fossil range|231.4|225.9}} | image = Aetosauroides skull.PNG | image_caption = Skull of ''A. scagliai'' | taxon = Aetosauroides | authority = Casamiquela, [[1960 in paleontology|1960]] | type_species = {{extinct}}'''''Aetosauroides scagliai''''' | type_species_authority = Casamiquela, 1960 | synonyms = * ''A. subsulcatus'' {{small|Zacarias, 1982}} * ''A. inhamandensis'' {{small|Barberena ''et al.'', 1985}} * ''[[Polesinesuchus|Polesinesuchus aurelioi]]''? {{small|Roberto-da-Silva ''et al.'', 2014}} }}

'''''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''. [[Fossil|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.<ref name=Aetobarbakinoides/>

== Description == [[File:Aetosauroides scagliai life restoration.jpg|thumb|left|Restoration of ''A. scagliai'']] Most individuals of ''Aetosauroides'' measured around {{convert|1.3|m}} in length, with one large individual reaching {{convert|2.4|m}} (with [[histology]] suggesting an age of 23 years). [[Sexual maturity]] was probably reached at {{convert|1|m}} in length, although these individuals were not yet fully grown.<ref name="paesneto2021axial"/> [[Sexual dimorphism]] has been suggested for ''Aetosauroides'', with males reaching the {{convert|2|m|adj=on}} size range.<ref name="taborta2015">{{cite journal |last1=Tabora |first1=J.R.A. |last2=Heckert |first2=A.B. |last3=Desojo |first3=J.B. |year=2015 |title=Intraspecific variation in ''Aetosauroides'' Casamiquela (Archosauria: Aetosauria) from the Upper Triassic of Argentina and Brazil: an example of sexual dimorphism? |journal=Ameghiniana |volume=52 |issue=2 |pages=173–187 |doi=10.5710/AMGH.05.01.2015.2824|s2cid=11498039 }}</ref> The [[Premaxilla|premaxilla's]] shovel-shaped tip in ''A. scagliai'' lacked the same prominence as the lateral expansion found in desmatosuchines.<ref>{{Cite journal |last1=Biacchi Brust |first1=Ana Carolina |last2=Desojo |first2=Julia Brenda |last3=Schultz |first3=Cesar Leandro |last4=Paes-Neto |first4=Voltaire Dutra |last5=Da-Rosa |first5=Átila Augusto Stock |date=15 August 2018 |editor-last=Smith |editor-first=Thierry |title=Osteology of the first skull of Aetosauroides scagliai Casamiquela 1960 (Archosauria: Aetosauria) from the Upper Triassic of southern Brazil (Hyperodapedon Assemblage Zone) and its phylogenetic importance |journal=[[PLOS ONE]] |language=en |volume=13 |issue=8 |article-number=e0201450 |doi=10.1371/journal.pone.0201450 |doi-access=free |issn=1932-6203 |pmc=6093665 |pmid=30110362 |bibcode=2018PLoSO..1301450B }}</ref> [[File:Polesinesuchus skeletal (possible synonym with Aetosauroides).png|left|thumb|Skeletal diagram of the holotype of ''Polesinesuchus aureloi'', a possible synonym of ''Aetosauroides scagliai'']] ''Aetosauroides'' was proposed to be [[Synonym (taxonomy)|synonymous]] with the genus ''[[Stagonolepis]]'' in 1996 and 2002.<ref name=LH96>{{cite journal |last=Lucas |first=S.G. |author2=Heckert, A.B. |year=1996 |title=Late Triassic aetosaur biochronology |journal=Albertiana |volume=17 |pages=57–64 |url=http://work.geobiology.cn/ebook/ALBERTIANA%20NO.17/12%20Late%20Triassic%20aetosaur%20biochronology.pdf |access-date=2011-05-11 |archive-url=https://web.archive.org/web/20131113115918/http://work.geobiology.cn/ebook/ALBERTIANA%20NO.17/12%20Late%20Triassic%20aetosaur%20biochronology.pdf |archive-date=13 November 2013 }}</ref><ref name=HL02>{{cite journal |last=Heckert |first=A.B. |author2=Lucas, S.G. |year=2002 |title=South American occurrences of the Adamanian (Late Triassic: latest Carnian) index taxon ''Stagonolepis'' (Archosauria: Aetosauria) and their biochronological significance |journal=[[Journal of Paleontology]] |volume=76 |issue=5 |pages=852–863 |doi=10.1666/0022-3360(2002)076<0852:SAOOTA>2.0.CO;2|s2cid=128610620 }}</ref> Smaller [[Biological specimen|specimens]] of both species were placed with ''Stagonolepis robertsoni'', and larger specimens were considered to be ''S. wellesi''. This synonymy is not accepted,<ref name=Aetobarbakinoides>{{cite journal |author=Julia B. Desojo, Martin D. Ezcurra and Edio E. Kischlat |year=2012 |title=A new aetosaur genus (Archosauria: Pseudosuchia) from the early Late Triassic of southern Brazil |journal=Zootaxa |volume=3166 |pages=1–33 |doi=10.11646/zootaxa.3166.1.1 |issn=1175-5326|url=http://www.mapress.com/zootaxa/2012/f/z03166p033f.pdf }}</ref><ref name=Heliocanthus>{{cite journal |last=Parker |first=William G. |year=2007 |title=Reassessment of the Aetosaur ''"Desmatosuchus" chamaensis'' with a reanalysis of the phylogeny of the Aetosauria (Archosauria:Pseudosuchia) |journal=[[Journal of Systematic Palaeontology]] |volume=5 |issue=1 |pages=41–68 |doi=10.1017/S1477201906001994 |bibcode=2007JSPal...5...41P |s2cid=85826683 |url=http://www.miketaylor.org.uk/dino/nm/Parker2007-Heliocanthus.pdf }}</ref><ref name=PSI08>{{cite journal |last=Parker |first=W. G. |author2=Stocker, M. R.|author3= Irmis, R. B. |year=2008 |title=A new desmatosuchine aetosaur (Archosauria; Suchia) from the Upper Triassic Tecovas Formation (Dockum Group) of Texas |journal=[[Journal of Vertebrate Paleontology]] |volume=28 |issue=2 |pages=692–701 |doi=10.1671/0272-4634(2008)28[692:ANDAAS]2.0.CO;2 |s2cid=84455880 |issn=0272-4634}}</ref><ref name=DE11/> with several studies identifying unique features that distinguish ''Aetosauroides'' from ''Stagonolepis''. Among these are [[maxilla]]e that do not touch the nostrils, oval-shaped holes on the [[Body of vertebra|centra]] of the [[vertebra]]e, 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''.<ref name="DE11">{{cite journal |last=Desojo |first=J.B. |author2=Ezcurra, M.D. |year=2011 |title=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=[[Journal of Vertebrate Paleontology]] |volume=31 |issue=3 |pages=596–609 |bibcode=2011JVPal..31..596D |doi=10.1080/02724634.2011.572936 |s2cid=85418778}}</ref> Additionally, a contemporary aetosaur named from a juvenile specimen in 2014, ''[[Polesinesuchus|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.<ref name="paesneto2021axial">{{cite journal |last1=Paes-Neto |first1=V.D. |last2=Desojo |first2=J.B. |last3=Brust |first3=A.C.B. |last4=Schultz |first4=C.L. |last5=Da-Rosa |first5=A.A.S. |last6=Soares |first6=M.B. |year=2021 |title=Intraspecific variation in the axial skeleton of ''Aetosauroides scagliai'' (Archosauria: Aetosauria) and its implications for the aetosaur diversity of the Late Triassic of Brazil |journal=[[Annals of the Brazilian Academy of Sciences]] |volume=93 |issue=supp. 2 |article-number=e20201239 |doi=10.1590/0001-3765202120201239|pmid=34468486 |s2cid=237372648 |hdl=11336/150258 |hdl-access=free }}</ref><ref name="paesneto2021bc">{{cite journal |last1=Paes-Neto |first1=V.D. |last2=Desojo |first2=J.B. |last3=Brust |first3=A.C.B. |last4=Ribeiro |first4=A.M. |last5=Schultz |first5=C.L. |last6=Soares |first6=M.B. |year=2021 |title=The first braincase of the basal aetosaur ''Aetosauroides scagliai'' (Archosauria: Pseudosuchia) from the Upper Triassic of Brazil |journal=[[Journal of Vertebrate Paleontology]] |volume=41 |issue=2 |article-number=e1928681 |doi=10.1080/02724634.2021.1928681|bibcode=2021JVPal..41E8681P |s2cid=237518035 }}</ref>

==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.<ref name=Aetobarbakinoides/>

== Palaeobiology ==

=== Palaeoecology === Although ''A. scagliai'' had recurved ziphodont [[Tooth|teeth]] typical of [[Carnivore|carnivores]], its shovel-shaped [[snout]] and its edentulous anterior [[premaxilla]] and [[Mandible|dentary]] suggest that it was [[Omnivore|omnivorous]].<ref>{{Cite journal |last1=Paes Neto |first1=Voltaire Dutra |last2=Desojo |first2=Julia Brenda |last3=Brust |first3=Ana Carolina Biacchi |last4=Ribeiro |first4=Ana Maria |last5=Schultz |first5=Cesar Leandro |last6=Soares |first6=Marina Bento |date=2021 |title=Skull osteology of Aetosauroides scagliai Casamiquela, 1960 (Archosauria: Aetosauria) from the Late Triassic of Brazil: New insights into the paleobiology of aetosaurs |url=https://palaeo-electronica.org/content/2021/3463-aetosauroides-skull |journal=[[Palaeontologia Electronica]] |doi=10.26879/1120 |access-date=21 October 2025 |doi-access=free }}</ref>

=== Palaeopathology === A [[Paleopathology|palaeopathological]] [[Biological specimen|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 [[Pus|pyogenic infection]].<ref>{{Cite journal |last1=Ponce |first1=Denis |last2=Cerda |first2=Ignacio |last3=Desojo |first3=Julia |date=2024 |title=First record of palaeopathologies on appendicular bones of the Triassic pseudosuchians Erpetosuchidae and Aetosauria based on microstructural approaches |url=https://www.app.pan.pl/article/item/app011412024.html |journal=[[Acta Palaeontologica Polonica]] |volume=69 |doi=10.4202/app.01141.2024 |access-date=12 April 2025|doi-access=free |hdl=11336/249317 |hdl-access=free }}</ref>

== References == {{Reflist}}

[[Category:Aetosauria]] [[Category:Prehistoric pseudosuchian genera]] [[Category:Carnian genera]] [[Category:Norian genera]] [[Category:Late Triassic reptiles of South America]] [[Category:Triassic Argentina]] [[Category:Fossils of Argentina]] [[Category:Ischigualasto Formation]] [[Category:Triassic Brazil]] [[Category:Fossils of Brazil]] [[Category:Santa Maria Formation]] [[Category:Fossil taxa described in 1960]]