Editing Avemetatarsalia

{{Short description|Clade of archosaur reptiles}}
{{Redirect-distinguish|Panaves|Paraves}}
{{Automatic taxobox
| name = Avemetatarsalians
| fossil_range = <br/>[[Middle Triassic]]&ndash;[[Holocene|Present]], {{fossil_range|earliest=249|247|0}} <small>(possible [[Early Triassic]] record if ''[[Prorotodactylus]]'' is part of the [[clade]]<ref name="BNB11">{{cite journal |last1=Brusatte |first1=S. L. |last2=Niedźwiedzki |first2=G. |last3=Butler |first3=R. J. |title=Footprints pull origin and diversification of dinosaur stem lineage deep into Early Triassic |journal=Proceedings of the Royal Society B: Biological Sciences |date=2011 |volume=278 |issue=1708 |pages=1107–1113 |doi=10.1098/rspb.2010.1746 |pmid=20926435 |pmc=3049033 }}</ref>)</small>
| image = Avemetatarsalia Infobox Panoply.png
| image_caption = Seven avemetatarsalians (top left to bottom right):  a [[Gentoo penguin]], ''[[Marasuchus]]'', ''[[Kentrosaurus]]'', ''[[Thalassodromeus]]'' (foreground) with ''[[Anhanguera (pterosaur)|Anhanguera]]'' (background), ''[[Diplodocus]]'', ''[[Rhamphorhynchus]]''
| image_upright = 1.3
| taxon = Avemetatarsalia
| authority = [[Michael J. Benton|Benton]], 1999
| display_parents = 2
| subdivision_ranks = Subgroups
| subdivision = 
*{{extinct}}''[[Incertovenator]]''?
*{{extinct}}''[[Mambachiton]]''
*{{extinct}}[[Aphanosauria]]
* '''Ornithodira''' <small>[[Jacques Gauthier|Gauthier]], 1986</small>
** {{extinct}}[[Pterosauromorpha]]
** [[Dinosauromorpha]]<br>(including [[Aves]])
| synonyms = *'''Dracones''' <small>[[Ernst Haeckel|Haeckel]], 1895</small>
* '''Ornithosuchia''' <small>[[Friedrich von Huene|Huene]], 1908</small>
* '''Ornithotarsi''' <small>Gauthier, 1986</small>
* '''Pan-Aves''' <small>Gauthier and de Queiroz 2001</small>
}}
'''Avemetatarsalia''' (meaning "bird [[metatarsal]]s") is a [[clade]] of [[diapsid]] [[Reptile|reptiles]] containing all [[archosaur]]s more closely related to [[bird]]s than to [[crocodilia]]ns.<ref name="Benton, 1999">{{cite journal | last1 = Benton | first1 = M.J. | year = 1999 | title = ''Scleromochlus taylori'' and the origin of dinosaurs and pterosaurs | journal = Philosophical Transactions of the Royal Society B: Biological Sciences | volume = 354 | issue = 1388| pages = 1423–1446 | doi=10.1098/rstb.1999.0489 | pmc=1692658}}</ref> The two most successful groups of avemetatarsalians were the dinosaurs and pterosaurs. [[Dinosaur|Dinosaurs]] were the largest terrestrial animals for much of the [[Mesozoic era|Mesozoic Era]], and one group of small feathered dinosaurs (Aves, i.e. birds) has survived up to the present day. [[Pterosaur|Pterosaurs]] were the first flying vertebrates and persisted through the Mesozoic before dying out at the [[Cretaceous–Paleogene extinction event|Cretaceous-Paleogene (K-Pg) extinction event]]. Both dinosaurs and pterosaurs appeared in the [[Triassic period|Triassic Period]], shortly after avemetatarsalians as a whole.<ref name="Benton, 1999" /><ref name="NSJ11" /> The name Avemetatarsalia was first established by British palaeontologist [[Michael J. Benton|Michael Benton]] in 1999. An alternate name is '''Pan-Aves''', or "all birds", in reference to its definition containing all animals, living or extinct, which are more closely related to birds than to crocodilians.<ref name ="2020lagerpetids">{{cite journal |last1=Ezcurra |first1=Martín D. |last2=Nesbitt |first2=Sterling J. |last3=Bronzati |first3=Mario |last4=Dalla Vecchia |first4=Fabio Marco |last5=Agnolin |first5=Federico L. |last6=Benson |first6=Roger B. J. |last7=Brissón Egli |first7=Federico |last8=Cabreira |first8=Sergio F. |last9=Evers |first9=Serjoscha W. |last10=Gentil |first10=Adriel R. |last11=Irmis |first11=Randall B. |last12=Martinelli |first12=Agustín G. |last13=Novas |first13=Fernando E. |last14=Roberto da Silva |first14=Lúcio |last15=Smith |first15=Nathan D. |last16=Stocker |first16=Michelle R. |last17=Turner |first17=Alan H. |last18=Langer |first18=Max C. |title=Enigmatic dinosaur precursors bridge the gap to the origin of Pterosauria |journal=Nature |date=2020 |volume=588 |issue=7838 |pages=445–449 |doi=10.1038/s41586-020-3011-4 |pmid=33299179 |s2cid=228077525 |url=https://www.nature.com/articles/s41586-020-3011-4 |language=en |issn=1476-4687}}</ref>

Although dinosaurs and pterosaurs were the only avemetatarsalians to survive past the end of the Triassic, other groups flourished during the Triassic. The most [[Basal (phylogenetics)|basal]] (earliest-branching) and [[plesiomorphic]] ("primitive") known avemetatarsalians were the [[Aphanosauria|aphanosaurs]]. Aphanosaurs were rare, four-legged carnivores which were only properly distinguished as a group in 2017.<ref name=":02">{{cite journal|last1=Nesbitt|first1=Sterling J.|last2=Butler|first2=Richard J.|last3=Ezcurra|first3=Martín D.|last4=Barrett|first4=Paul M.|last5=Stocker|first5=Michelle R.|last6=Angielczyk|first6=Kenneth D.|last7=Smith|first7=Roger M. H.|last8=Sidor|first8=Christian A.|last9=Niedźwiedzki|first9=Grzegorz|last10=Sennikov|first10=Andrey G.|last11=Charig|first11=Alan J.|date=2017|title=The earliest bird-line archosaurs and the assembly of the dinosaur body plan|url=http://pure-oai.bham.ac.uk/ws/files/39495711/Nesbitt_et_al._in_press.pdf|journal=Nature|volume=544|issue=7651|pages=484–487|bibcode=2017Natur.544..484N|doi=10.1038/nature22037|pmid=28405026|s2cid=9095072 }}</ref> The split between dinosaurs and pterosaurs occurred just after aphanosaurs branched off the archosaur family tree. This split corresponds to the subgroup '''Ornithodira''' ([[Ancient Greek]] ''ὄρνις'' (''órnis'', “bird”) + ''δειρή'' (''deirḗ'', “throat”), defined as the [[Most recent common ancestor|last common ancestor]] of dinosaurs and pterosaurs, and all of its descendants. Until the discovery of aphanosaurs, Ornithodira and Avemetatarsalia were considered roughly equivalent concepts.<ref name="NSJ11" />

Pterosauromorpha includes all avemetatarsalians closer to pterosaurs than to dinosaurs. True non-pterosaur pterosauromorphs have been historically difficult to determine. Small, insectivorous archosaurs of the family [[Lagerpetidae]] may potentially be examples, alongside the similar genus ''[[Scleromochlus]]''.<ref name=":1" /> [[Dinosauromorpha]], on the other hand, includes all avemetatarsalians closer to dinosaurs than to pterosaurs. Probable non-dinosaur dinosauromorphs include the diverse and widespread [[Silesauridae|silesaurids]], as well as more controversial and fragmentary taxa such as ''[[Marasuchus]]'', ''[[Lagosuchus]]'', ''[[Nyasasaurus]]'', and ''[[Saltopus]]''. Lagerpetids were also traditionally considered dinosauromorphs,<ref name=":0">{{Cite book|last=Gauthier|first=Jacques|title=The Origin of Birds and the Evolution of Flight|publisher=California Academy of Sciences|year=1986|isbn=|editor-last=Padian|editor-first=Kevin|series=Memoirs of the California Academy of Sciences|volume=8|location=San Francisco|pages=1–55|chapter=Saurischian monophyly and the origin of birds|chapter-url=https://www.biodiversitylibrary.org/page/15651737#page/287/mode/1up}}</ref><ref name="NSJ11">{{cite journal|last=Nesbitt|first=S.J.|year=2011|title=The early evolution of archosaurs: relationships and the origin of major clades|journal=Bulletin of the American Museum of Natural History|volume=352|pages=1–292|doi=10.1206/352.1|hdl=2246/6112|s2cid=83493714|doi-access=free}}</ref> though this has been more recently debated.<ref name=":2" /><ref name=":1" /><ref>{{Cite journal|date=2021-08-20|title=The origin of Pterosaurs|url=https://www.sciencedirect.com/science/article/abs/pii/S0012825221002786|journal=Earth-Science Reviews|language=en|pages=103777|doi=10.1016/j.earscirev.2021.103777|issn=0012-8252|last1=Baron |first1=Matthew G. |volume=221 }}</ref>  

==Description==
[[File:AdvMesotarsal.png|left|thumb|The "advanced mesotarsal" ankle present in most avemetatarsalians.]]

The foundational characteristic is the "advanced mesotarsal" ankles, which are characterized by a large [[Talus bone|astragalus]] and a small [[Calcaneus|calcaneum]]. This ankle orientation operated on a single hinge, allowing for better mobility. Probably as a result of this change, the common ancestor of the avemetatarsalians had an upright, bipedal posture, with their legs extending vertically, similar to that of mammals.

[[Feather]]s and other filamentary structures are known across the avemetatarsalians, from the downy pycnofibers of pterosaurs, to quill-like structures present in [[ornithischia]]n dinosaurs, such as ''[[Psittacosaurus]]'' and ''[[Tianyulong]]'', to feathers in theropod dinosaurs and their descendants, birds.

Two clades of avemetatarsalians, pterosaurs and birds, independently evolved flight. Pterosaurs are the earliest [[vertebrate]]s known to have evolved powered flight. Their wings are formed by a membrane of skin, muscle, and other [[tissue (biology)|tissues]] stretching from the ankles to a dramatically lengthened fourth finger.<ref name=Elgin2011>{{cite journal |vauthors=Elgin RA, Hone DW, Frey E |title=The Extent of the Pterosaur Flight Membrane |journal=Acta Palaeontologica Polonica |volume=56 |issue=1 |pages=99–111 |year=2011 | doi=10.4202/app.2009.0145 |doi-access=free }}</ref> Birds evolved flight much later. Their wings formed from elongated fingers and their arms, all covered with [[flight feathers]].

Avemetatarsalians were generally more lightly built than [[pseudosuchia|crocodile-line archosaurs]]. They had smaller heads and usually a complete lack of [[osteoderm]]s.

==Origin==
{{see|Origin of birds}}
Bird-line archosaurs appear in the fossil record by the [[Anisian]] stage of the [[Middle Triassic]] about 245 million years ago, represented by the [[dinosauriform]] ''[[Asilisaurus]]''. However, [[Early Triassic]] [[Ichnite|fossil footprints]] reported in 2010 from the [[Świętokrzyskie Mountains|Świętokrzyskie (Holy Cross) Mountains]] of [[Poland]] may belong to a more primitive [[dinosauromorph]].<ref name="BNB11" /> If so, the origin of avemetatarsalians would be pushed back into the early [[Olenekian]] age, around 249 Ma. The oldest Polish footprints are classified in the [[ichnogenus]] ''[[Prorotodactylus]]'' and were made by an unknown small quadrupedal animal, but footprints called ''[[Sphingopus]]'', found from Early Anisian strata, show that moderately large bipedal dinosauromorphs had appeared by 246 Ma. The tracks show that the dinosaur lineage appeared soon after the [[Permian–Triassic extinction event]]. Their age suggests that the [[evolution of dinosaurs|rise of dinosaurs]] was slow and drawn out across much of the Triassic.<ref name="BNB11" /> The primitive traits found in the [[Quadrupedalism|quadrupedal]] aphanosaur ''[[Teleocrater]]'' shows that the earliest avemetatarsalians had many pseudosuchian-like features, and that the traits typical for the group evolved later.<ref>[http://www.ibtimes.com/dinosaur-evolution-crocodile-ancient-cousin-teleocrater-rhadinus-confuses-scientists-2524858 Dinosaur Evolution: Crocodile-Like Ancient Cousin, Teleocrater Rhadinus, Confuses Scientists]</ref>

==Classification==
In 1986, [[Jacques Gauthier]] defined the name '''Ornithosuchia''' (previously coined by [[Friedrich von Huene|Huene]]) for a branch-based clade including all archosaurs more closely related to birds than to crocodiles.<ref name=":0" /> In the same year, Gauthier also coined and defined a slightly more restrictive node-based clade, Ornithodira, containing the last common ancestor of the [[dinosaur]]s and the [[pterosaurs]] and all of its descendants. [[Paul Sereno]] in 1991 gave a different definition of Ornithodira, one in which ''[[Scleromochlus]]'' was explicitly added.<ref name="Sereno, 1991">Sereno, P. C. 1991. Basal archosaurs: phylogenetic relationships and functional implications. ''Journal of Vertebrate Paleontology'' ''Memoir 2'', 11(4, Supplement):1–53.</ref> It was thus a potentially larger group than the Ornithodira of Gauthier. In 1999 [[Michael J. Benton|Michael Benton]] concluded that ''Scleromochlus'' was indeed outside Gauthier's original conception of Ornithodira, so he named a new [[Phylogenetic nomenclature#Phylogenetic definitions|branch-based]] clade for this purpose: Avemetatarsalia, named after the birds ([[Aves]]), the last surviving members of the clade, and the metatarsal [[ankle joint]] that was a typical character of the group. Avemetatarsalia was defined as all Avesuchia closer to Dinosauria than to [[Crocodylia]]. In 2005, Sereno stated the opinion that Ornithodira was not a useful concept, whereas Avemetatarsalia was. In 2001, the same clade was given the name "Panaves" ({{lit|all birds}}, from Greek {{wikt-lang|grc-Latn|παν-|pan-}} + Latin {{wikt-lang|la|aves}}), coined by Jacques Gauthier. He defined it as the largest and most inclusive clade of archosaurs containing Aves (birds, anchored on ''Vultur gryphus'') but not Crocodylia (anchored on ''Crocodylus niloticus''). Gauthier referred Aves, all other Dinosauria, all Pterosauria, and a variety of [[Triassic]] archosaurs, including ''[[Lagosuchus]]'' and ''Scleromochlus'', to this group.<ref name="gauthier&dequeiroz2001">Gauthier, J. and de Queiroz, K. (2001). "Feathered dinosaurs, flying dinosaurs, crown dinosaurs, and the name "Aves"". pp. 7–41 in Gauthier, J. and L. F. Gall (eds.), ''New Perspectives on the Origin and Early Evolution of Birds: Proceedings of the International Symposium in Honor of John H. Ostrom''. New Haven: Peabody Museum of Natural History, Yale University. {{ISBN|0-912532-57-2}}.</ref>

In a 2005 review of archosaur classification, Phil Senter attempted to resolve this conflicting set of terminology by applying strict priority to names based on when and how they were first defined.<ref>{{cite journal |last1=Senter |first1=P. |year=2005 |title=Phylogenetic taxonomy and the names of the major archosaurian (Reptilia) clades. |journal=PaleoBios |volume=25 |issue=3 |pages=1–7}}</ref> Senter noted that Ornithosuchia, the earliest name used for the total group of archosaurs closer to birds than to crocodiles, should be the valid name for that group, and have precedence over later names with identical definitions, such as Avemetatarsalia and Pan-Aves. While this has been followed by some researchers, others have either continued to use Avemetatarsalia or Ornithodira, or have followed Senter only reluctantly. Mike Taylor (2007) for example noted that, while Senter is correct in stating that Ornithosuchia has priority, this is "undesirable" because it probably excludes the eponymous family [[Ornithosuchidae]], and questioned the utility of using priority before the [[PhyloCode]] is implemented to govern it.<ref name=taylor2007>{{cite journal | last1 = Taylor | year = 2007 | title = Phylogenetic definitions in the pre-PhyloCode era; implications for naming clades under the PhyloCode | url =http://www.miketaylor.org.uk/dino/pubs/taylor2007/Taylor2007-pre-phylocode-pn.pdf | journal = PaleoBios | volume = 27 | issue = 1| pages = 1–6 }}</ref> In fact, the name Ornithosuchia may be "illegal" under the PhyloCode because it does not include its eponymous taxon as part of its definition.<ref name=taylor2007/>

[[Cladogram]] after Nesbitt ''et al.'' (2017),<ref name=teleocrater>{{cite journal|last1=Nesbitt|first1=Sterling J.|last2=Butler|first2=Richard J.|last3=Ezcurra|first3=Martín D.|last4=Barrett|first4=Paul M.|last5=Stocker|first5=Michelle R.|last6=Angielczyk|first6=Kenneth D.|last7=Smith|first7=Roger M. H.|last8=Sidor|first8=Christian A.|last9=Niedźwiedzki|first9=Grzegorz|last10=Sennikov|first10=Andrey G.|last11=Charig|first11=Alan J.|title=The earliest bird-line archosaurs and the assembly of the dinosaur body plan|journal=Nature|volume=544|issue=7651|pages=484–487|date=2017|doi=10.1038/nature22037|pmid=28405026|s2cid=9095072 |url=http://pure-oai.bham.ac.uk/ws/files/39495711/Nesbitt_et_al._in_press.pdf}}</ref> with clade names from Cau (2018).<ref name=cau2018>{{Cite journal|author=Andrea Cau |year=2018 |title=The assembly of the avian body plan: a 160-million-year long process |journal=Bollettino della Società Paleontologica Italiana |volume=57 |issue=1 |pages=1–25 |doi=10.4435/BSPI.2018.01 |url=http://paleoitalia.org/media/u/archives/01_Cau_2018_BSPI_571.pdf }}</ref>
{{Clade| style=font-size:90%;line-height:85%
|label1=[[Archosauria]]
|1={{clade
  |1=[[Pseudosuchia]] (crocodile-line archosaurs) <span style="{{MirrorH}}">[[File:Deinosuchus riograndensis.png|80px]]</span>
  |label2='''Avemetatarsalia'''
  |2={{Clade
  |1=†[[Aphanosauria]] [[File:Teleocrater v1.png|80 px]]
    |label2='''Ornithodira'''&nbsp;
    |2={{Clade
   |label1=†Pterosauromorpha 
   |1=†[[Pterosauria]] [[File:Aerodactylus MCZ 1505.png|80 px]]
   |label2=&nbsp;[[Dinosauromorpha]]&nbsp;
   |2={{Clade
      |1=†[[Lagerpetidae]] [[File:Dromomeron BW (flipped).jpg|80 px]]
      |label2=&nbsp;[[Dinosauriformes]]&nbsp;
      |2={{Clade
         |1=†''[[Marasuchus]]'' [[File:Marasuchus flipped.jpg|80 px]]
         |label2=&nbsp;[[Dracohors]]&nbsp;
         |2={{Clade
            |1=†[[Silesauridae]] [[File:Silesaurus opolensis flipped.jpg|80 px]]
            |label2=&nbsp;[[Dinosauria]]&nbsp;
            |2={{Clade
               |1=†[[Ornithischia]] [[File:Stegosaurus stenops sophie wiki martyniuk flipped.png|80px]]
               |label2=&nbsp;[[Saurischia]]&nbsp;
               |2={{Clade
                  |2=[[Theropoda]] [[File:Meyers grosses Konversations-Lexikon - ein Nachschlagewerk des allgemeinen Wissens (1908) (Antwerpener Breiftaube).jpg|30 px]]
                  |1=†[[Sauropodomorpha]] [[File:Barapasaurus DB.jpg|80 px]]
}} }} }} }} }} }} }} }} }}

Kammerer ''et al''. (2020) and Ezcurra ''et al''. (2020) supported an alternative hypothesis regarding the relationships of lagerpetids. They were interpreted as non-pterosaur pterosauromorphs. This phylogeny would shorten the morphological and chronological gap perceived between pterosaurs and other stem-birds, and explain the origin of this group.<ref name=":2">{{Cite journal|last1=Kammerer|first1=Christian F.|last2=Nesbitt|first2=Sterling J.|last3=Flynn|first3=John J.|last4=Ranivoharimanana|first4=Lovasoa|last5=Wyss|first5=André R.|date=2020-07-28|title=A tiny ornithodiran archosaur from the Triassic of Madagascar and the role of miniaturization in dinosaur and pterosaur ancestry|journal=Proceedings of the National Academy of Sciences|language=en|volume=117|issue=30|pages=17932–17936|doi=10.1073/pnas.1916631117|issn=0027-8424|pmc=7395432|pmid=32631980|doi-access=free }}</ref><ref name=":1">{{Cite journal|last1=Ezcurra|first1=Martín D.|last2=Nesbitt|first2=Sterling J.|last3=Bronzati|first3=Mario|last4=Dalla Vecchia|first4=Fabio Marco|last5=Agnolin|first5=Federico L.|last6=Benson|first6=Roger B. J.|last7=Brissón Egli|first7=Federico|last8=Cabreira|first8=Sergio F.|last9=Evers|first9=Serjoscha W.|last10=Gentil|first10=Adriel R.|last11=Irmis|first11=Randall B.|date=2020-12-17|title=Enigmatic dinosaur precursors bridge the gap to the origin of Pterosauria|url=http://www.nature.com/articles/s41586-020-3011-4|journal=Nature|language=en|volume=588|issue=7838|pages=445–449|doi=10.1038/s41586-020-3011-4|pmid=33299179|s2cid=228077525|issn=0028-0836}}</ref> Bennett (2020) argued that ''Scleromochlus'', a genus historically considered a relative of ornithodirans or even a basal pterosauromorph, was instead a non-archosaur archosauriform (possibly a [[Doswelliidae|doswelliid]]).<ref>{{Cite journal|last=Bennett|first=S. Christopher|date=2020-02-19|title=Reassessment of the Triassic archosauriform Scleromochlus taylori: neither runner nor biped, but hopper|journal=PeerJ|language=en|volume=8|pages=e8418|doi=10.7717/peerj.8418|pmid=32117608|pmc=7035874|issn=2167-8359|doi-access=free}}</ref>

In 2023, Nesbitt ''et al''. described ''[[Mambachiton]]'' as the earliest diverging avemetatarsalian, outside of the minimally inclusive clade containing [[aphanosaurs]] and ornithodirans. Preliminary analyses had considered ''Mambachiton'' to be a [[Basal (phylogenetics)|basal]] [[poposauroid]] (a clade of [[pseudosuchia]]ns), though the later recognition of aphanosaurs as basal avemetatarsalians corrected this view. The results of the [[phylogenetic analyses]] of Nesbit ''et al''. (2023) are shown in the cladogram below:<ref name="Mambachiton">{{Cite journal |last1=Nesbitt |first1=Sterling J. |last2=Patellos |first2=Emily |last3=Kammerer |first3=Christian F. |last4=Ranivoharimanana |first4=Lovasoa |last5=Wyss |first5=Andre´ R. |last6=Flynn |first6=John J. |date=2023-07-25 |title=The earliest-diverging avemetatarsalian: a new osteoderm-bearing taxon from the Triassic (?Earliest Late Triassic) of Madagascar and the composition of avemetatarsalian assemblages prior to the radiation of dinosaurs |url= |journal=Zoological Journal of the Linnean Society |volume=199 |issue=2 |language=en |pages=327–353 |doi=10.1093/zoolinnean/zlad038 |issn=0024-4082|doi-access=free }}</ref>

{{clade
|1={{clade
 |1=[[Pseudosuchia]] <span style="{{MirrorH}}">[[File:Deinosuchus riograndensis.png|70px]]</span>
 |label2='''Avemetatarsalia'''
 |2={{clade
  |1=''[[Mambachiton]]''
  |2={{clade
   |1=[[Aphanosauria]] <span style="{{MirrorH}}">[[File:Teleocrater v1.png|70px]]</span>
   |label2='''Ornithodira'''
   |2={{clade
   |1={{clade
    |1=[[Lagerpetidae]] <span style="{{MirrorH}}">[[File:Lagerpeton NT small.jpg|55px]]</span>
    |2=[[Pterosauria]] [[File:Quetzalcoatlus07.jpg|50px]] }}
    |3={{clade
   |1=''[[Lagosuchus]]'' <span style="{{MirrorH}}">[[File:Lagosuchus Talampayensis white background.png|60px]]</span>
   |2={{clade
    |1=[[Silesauridae]] <div style="{{MirrorH}}">[[File:Diodorus restoration.jpg|75px]]</div>
    |2=[[Dinosauria]] [[File:Meyers grosses Konversations-Lexikon - ein Nachschlagewerk des allgemeinen Wissens (1908) (Antwerpener Breiftaube).jpg|35px]]
}} }} }} }} }} }}|label1=[[Archosauria]]}}

==References==
{{Reflist}}

==Sources==
* {{cite book |author=Michael J. Benton |chapter=Origin and relationships of Dinosauria |editor=David B. Weishampel |editor2=Peter Dodson |editor3=Halszka Osmólska (Hrsg.) |title=The Dinosauria |url=https://archive.org/details/dinosauriandedit00weis |url-access=limited |publisher=Zweite Auflage, University of California Press |location=Berkeley |year=2004 |pages=[https://archive.org/details/dinosauriandedit00weis/page/n25 7]–19 |isbn=0-520-24209-2|author-link=Michael J. Benton }}

{{Portal|Dinosaurs}}
{{Archosauromorpha|B.}}
{{Avemetatarsalia}}
{{Taxonbar|from=Q133187}}

[[Category:Avemetatarsalians| ]]
[[Category:Anisian first appearances]]
[[Category:Extant Middle Triassic first appearances]]
[[Category:Taxa named by Michael Benton]]