Aetosauroides

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Aetosauroides
Temporal range: Late Triassic, 231.4–225.9Ma
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Aetosauria
Genus: Aetosauroides
Casamiquela, 1960
Type species
Aetosauroides scaglia
Casamiquela, 1960
Synonyms

A. subsulcatus Zacarias, 1982
A. inhamandensis Barberena et al., 1985

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. scaglia, A. subsulcatus and A. inhamandensis. Fossils have been found from the Ischigualasto Formation and the Santa Maria Supersequence of the late Carnian and early Norian stages, making Aetosauroides one of the oldest aetosaurs.[1]

Aetosauroides was proposed to be synonymous with the genus Stagonolepis in 1996 and 2002.[2][3] 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][4][5][6] 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. scaglia.[6] 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]

References[edit]

  1. ^ a b c Julia B. Desojo, Martin D. Ezcurra and Edio E. Kischlat (2012). "A new aetosaur genus (Archosauria: Pseudosuchia) from the early Late Triassic of southern Brazil". Zootaxa 3166: 1–33. ISSN 1175-5326. 
  2. ^ Lucas, S.G.; Heckert, A.B. (1996). "Late Triassic aetosaur biochronology". Albertiana 17: 57–64. 
  3. ^ 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. 
  4. ^ Parker, William G. (2007). "Reassessment of the Aetosaur "Desmatosuchus" chamaensis with a reanalysis of the phylogeny of the Aetosauria (Archosauria:Pseudosuchia)". Journal of Systematic Palaeontology 5: 41–68. doi:10.1017/S1477201906001994. 
  5. ^ 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. ISSN 0272-4634. 
  6. ^ a b Desojo, 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. doi:10.1080/02724634.2011.572936.