{{Short description|Extinct genus of reptiles}} {{Automatic taxobox | fossil_range = [[Late Triassic]], {{fossil_range|231.4|225.9}} | authority = Desojo ''et al.'', [[2012 in paleontology|2012]] | type_species = {{extinct}}'''''Aetobarbakinoides brasiliensis''''' | type_species_authority = Desojo ''et al.'', 2012 | taxon = Aetobarbakinoides }}

'''''Aetobarbakinoides''''' is an [[extinct]] [[genus]] of [[stagonolepidid]] [[aetosaur]] known from the [[Late Triassic]] of [[Rio Grande do Sul]] state, southern [[Brazil]]. Fossils have been found from the [[Santa Maria Formation|Santa Maria Supersequence]] of the late [[Carnian]] and early [[Norian]] stages, making ''Aetobarbakinoides'' one of the oldest aetosaurs. The type species, ''A. brasiliensis'', was named in 2012, and is notable for being described primarily by features of the vertebrae; most other aetosaurs are diagnosed by features in bony plates called [[osteoderm]]s, which are by far the most common material. Although placed in a [[basal (phylogenetics)|basal]] [[phylogenetic]] position among aetosaurs, ''Aetobarbakinoides'' is closely related to both [[desmatosuchine]]s and [[typothoracisine]]s, two derived clades of aetosaurs.<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=1175-5334 |url=http://www.mapress.com/zootaxa/2012/f/z03166p033f.pdf }}</ref>

==Discovery== ''Aetobarbakinoides'' is known only from the [[holotype]] specimen CPE2&nbsp;168, a partially articulated partial [[postcrania]]l [[skeleton]] which is housed at the Coleção Municipal in [[São Pedro do Sul, Rio Grande do Sul|São Pedro do Sul]]. It was found near the city of São Pedro do Sul, in the center of [[Rio Grande do Sul]], Brazil. It was collected in the Inhamandá locality, from the ''[[Hyperodapedon]]'' Assemblage Zone, Sequence 2 of the [[Santa Maria Supersequence]] (formerly known as [[Santa Maria Formation]]) which dates back to the late [[Carnian]] and earliest [[Norian]] stages of the [[Late Triassic]]. CPE2&nbsp;168 was assigned by Lucas & Heckert (2001) to ''[[Stagonolepis robertsoni]]''. It is the first aetosaur to be diagnosed in its original description without [[osteoderm]]s, the most common material associated with these reptiles. Along with the genus ''[[Aetosauroides]]'' from Argentina and Brazil and ''Stagonolepis robertsoni'' from Scotland, ''Aetobarbakinoides'' is among the oldest aetosaurs. Its presence in South America indicates that aetosaurs had a wide geographic distribution early in their history. ''Aetobarbakinoides'' is most closely related to ''Aetosauroides'' and ''[[Neoaetosauroides]]''. Features of its osteoderms suggest a close relationship with [[aetosaurine]]s, but its vertebrae are more similar to [[desmatosuchine]]s.<ref name=Aetobarbakinoides/>

==Description== ''Aetobarbakinoides'' is known from neck and back vertebrae, ribs, and several limb bones including the [[scapula]], [[humerus]], [[tibia]], and foot bones. Paramedian [[osteoderm]]s overlying the midline of the back and neck are also known. Most of the distinguishing features of ''Aetobarbakinoides'' are found in its vertebrae. Laterally-oriented projections on the neck vertebrae called prezygapophyses are longer and wider than those of many other aetosaurs. In contrast, the prezygapophyses of the vertebrae at the base of the tail are very thin. The humerus and tibia are large relative to the [[axial skeleton]]. The vertebrae of ''Aetobarbakinoides'' are more similar to those of ''[[Desmatosuchus]]'' than they are to its closest relatives, ''Aetosauroides'' and ''Neoaetosaurioides''. ''Aetobarbakinoides'' is a medium-sized aetosaur, it has been estimated to have been about {{convert|2|m|ft|abbr=on}} in total length.<ref name=Aetobarbakinoides/>

==Classification== A [[phylogenetic]] analysis was conducted in the first description of ''Aetobarbakinoides''. Close relatives included ''Aetosauroides'' and ''Neoaetosauroides'', both of which are from South America. ''Aetobarbakinoides'' was found to be most closely related to a [[clade]] including [[Desmatosuchinae]] and [[Typothoracisinae]]. In most studies, Typothoracisinae is placed in the subfamily [[Aetosaurinae]], while Desmatosuchinae makes up its own subfamily of aetosaurs. This study suggests that Aetosaurinae is paraphyletic, and that aetosaurines represent a [[evolutionary grade|grade]] of early aetosaurs that developed into desmatosuchines and typothoracisines later in the Triassic. The following [[cladogram]] simplified after an analysis presented by Julia B. Desojo, Martin D. Ezcurra and Edio E. Kischlat (2012).<ref name=Aetobarbakinoides/>

{{clade| style=font-size:100%;line-height:85% |label1=[[Aetosauria]] |1={{clade |1=''[[Aetosauroides]]'' |label2=[[Stagonolepididae]] |2={{clade |1=''[[Aetosaurus]]'' |2=''[[Coahomasuchus]]'' |3={{clade |1=''[[Neoaetosauroides]]'' |2={{clade |1=''[[Calyptosuchus]]'' |2=''[[Stagonolepis]]'' |3={{clade |1='''''Aetobarbakinoides''''' |2={{clade |1=[[Desmatosuchinae]] |2=[[Typothoracisinae]] }} }} }} }} }} }} }}

==Etymology== ''Aetobarbakinoides'' was first named by [[Julia B. Desojo]], [[Martin Ezcurra|Martin D. Ezcurra]] and [[Edio E. Kischlat]] in [[2012 in paleontology|2012]] and the [[type species]] is ''Aetobarbakinoides brasiliensis''. The [[name of a biological genus|generic name]] is derived from [[Greek language|Greek]] ''aetobarbakina'' meaning "long-legged buzzard" (the common name of ''[[Buteo rufinus]]'') and from [[Latin]] ''oides'' meaning "form". It refers to its elongated humerus and tibia and the close relation to the "eagle reptile", ''[[Aetosaurus]]''. The [[specific name (zoology)|specific name]] refers to Brazil, the country in which the holotype was found.<ref name=Aetobarbakinoides/>

== References == {{Reflist}}

{{Aetosauria}} {{Taxonbar|from=Q4688761}}

[[Category:Aetosauria]] [[Category:Late Triassic reptiles of South America]] [[Category:Triassic Brazil]] [[Category:Fossils of Brazil]] [[Category:Santa Maria Formation]] [[Category:Fossil taxa described in 2012]] [[Category:Prehistoric pseudosuchian genera]]