Editing Salamander (section)

==Phylogeny and evolution==
The origins and evolutionary relationships between the three main groups of amphibians ([[Caecilian|gymnophionan]]s, urodeles and [[anuran]]s) is a matter of debate. A 2005 molecular phylogeny, based on [[Ribosomal DNA|rDNA]] analysis, suggested that the first divergence between these three groups took place soon after they had branched from the [[lobe-finned fish]] in the [[Devonian]] (around 360 million years ago), and before the breakup of the supercontinent [[Pangaea]]. The briefness of this period, and the speed at which radiation took place, may help to account for the relative scarcity of amphibian fossils that appear to be closely related to [[lissamphibia]]ns.<ref>{{cite journal |author1=San Mauro, Diego |author2=Vences, Miguel |author3=Alcobendas, Marina |author4=Zardoya, Rafael |author5=Meyer, Axel |year=2005 |title=Initial diversification of living amphibians predated the breakup of Pangaea |journal=The American Naturalist |volume=165 |issue=5 |pages=590–599 |doi=10.1086/429523 |pmid=15795855 |s2cid=17021360 |url=https://pure.uva.nl/ws/files/3880726/39160_170248y.pdf }}</ref> More recent studies generally find more recent (Late [[Carboniferous]]<ref name=SM10>{{cite journal | last1 = San Mauro | first1 = D. | year = 2010 | title = A multilocus timescale for the origin of extant amphibians | journal = Molecular Phylogenetics and Evolution | volume = 56 | issue = 3| pages = 554–561 | doi = 10.1016/j.ympev.2010.04.019 | pmid=20399871| bibcode = 2010MolPE..56..554S }}</ref> to [[Permian]]<ref name=M&L07>{{cite journal | last1 = Marjanović | first1 = D. | last2 = Laurin | first2 = M. |name-list-style=vanc| year = 2007 | title = Fossils, molecules, divergence times, and the origin of lissamphibians | journal = Systematic Biology | volume = 56 | issue = 3| pages = 369–388 | doi = 10.1080/10635150701397635 | pmid=17520502| doi-access = free }}</ref>) age for the basalmost divergence among lissamphibians.
[[File:Karaurus sharovi skeleton 34.JPG|thumb|''[[Karaurus|Karaurus sharovi]]'']]
The earliest known salamander-line lissamphibian is ''[[Triassurus]]'' from the Middle-Late Triassic of Kyrgyzstan.<ref>{{Cite journal|last1=Schoch|first1=Rainer R.|last2=Werneburg|first2=Ralf|last3=Voigt|first3=Sebastian|date=2020-05-26|title=A Triassic stem-salamander from Kyrgyzstan and the origin of salamanders|journal=Proceedings of the National Academy of Sciences|language=en|volume=117|issue=21|pages=11584–11588|doi=10.1073/pnas.2001424117|issn=0027-8424|pmid=32393623|pmc=7261083|bibcode=2020PNAS..11711584S |doi-access=free}}</ref> Other fossil salamanders are known from the Middle-Late Jurassic of Eurasia, including ''[[Kokartus honorarius]]'' from the [[Middle Jurassic]] of Kyrgyzstan, two species of the apparently neotenic, aquatic ''[[Marmorerpeton]]'' from the Middle Jurassic of England and Scotland,<ref>{{cite journal | last1 = de Buffrénil | first1 = V. | last2 = Canoville | first2 = A. | last3 = Evans | first3 = S. E. | last4 = Laurin | first4 = M. |name-list-style=vanc| year = 2014 | title = Histological study of karaurids, the oldest known (stem) urodeles | journal = Historical Biology |volume=27 |issue=1 |pages=109–114 | doi = 10.1080/08912963.2013.869800| s2cid = 83557507 }}</ref><ref name="Jonesetal2022">{{Cite journal |last1=Jones |first1=Marc E. H. |last2=Benson |first2=Roger B. J. |last3=Skutschas |first3=Pavel |last4=Hill |first4=Lucy |last5=Panciroli |first5=Elsa |last6=Schmitt |first6=Armin D. |last7=Walsh |first7=Stig A. |last8=Evans |first8=Susan E. |date=2022-07-11 |title=Middle Jurassic fossils document an early stage in salamander evolution |journal=Proceedings of the National Academy of Sciences |volume=119 |issue=30 |pages=e2114100119 |doi=10.1073/pnas.2114100119 |issn=0027-8424|doi-access=free |pmid=35858401 |pmc=9335269 |bibcode=2022PNAS..11914100J }}</ref> and ''[[Karaurus]]'' from the Middle-Late Jurassic of Kazakhstan, resembled modern [[mole salamander]]s in morphology and probably had a similar burrowing lifestyle.<ref name="Naish2013" /> They looked like robust modern salamanders but lacked a number of anatomical features that characterise all modern salamanders.<ref name="Jonesetal2022">{{Cite journal |last1=Jones |first1=Marc E. H. |last2=Benson |first2=Roger B. J. |last3=Skutschas |first3=Pavel |last4=Hill |first4=Lucy |last5=Panciroli |first5=Elsa |last6=Schmitt |first6=Armin D. |last7=Walsh |first7=Stig A. |last8=Evans |first8=Susan E. |date=2022-07-11 |title=Middle Jurassic fossils document an early stage in salamander evolution |journal=Proceedings of the National Academy of Sciences |volume=119 |issue=30 |pages=e2114100119 |doi=10.1073/pnas.2114100119 |issn=0027-8424|doi-access=free |pmid=35858401 |pmc=9335269 |bibcode=2022PNAS..11914100J }}</ref><ref>{{cite journal | last1 = Marjanovic | first1 = D. | last2 = Laurin | first2 = M. |name-list-style=vanc| year = 2014 | title = An updated paleontological timetree of lissamphibians, with comments on the anatomy of Jurassic crown-group salamanders (Urodela) | journal = Historical Biology |volume=26 |issue=4 |pages=535–550| doi = 10.1080/08912963.2013.797972| bibcode = 2014HBio...26..535M | s2cid = 84581331 }}</ref>

The two groups of extant salamanders are the [[Cryptobranchoidea]] (which includes Asiatic and giant salamanders) and the [[Salamandroidea]] (which includes all other living salamanders), also known as Diadectosalamandroidei. Both groups are known from the Middle-Late Jurassic of China. the former being exemplified by ''[[Chunerpeton tianyiensis]]'', ''[[Pangerpeton sinensis]]'', ''[[Jeholotriton paradoxus]]'', ''[[Regalerpeton|Regalerpeton weichangensis]]'', ''[[Liaoxitriton|Liaoxitriton daohugouensis]]'' and ''[[Iridotriton|Iridotriton hechti]]'', and the latter by ''[[Beiyanerpeton jianpingensis]]''. By the [[Upper Cretaceous]], most or all of the living salamander families had probably appeared.<ref name="Naish2013" />

The following cladogram shows the relationships between salamander families based on the molecular analysis of Pyron and Wiens (2011).<ref>{{cite journal |author1=R. Alexander Pyron |author2=John J. Wiens | year = 2011 | title= A large-scale phylogeny of Amphibia including over 2800 species, and a revised classification of extant frogs, salamanders, and caecilians | journal = Molecular Phylogenetics and Evolution | volume = 61 | issue = 2 | pages = 543–583 | doi=10.1016/j.ympev.2011.06.012| pmid = 21723399 | doi-access = free |bibcode=2011MolPE..61..543A }}</ref> The position of the Sirenidae is disputed, but the position as sister to the Salamandroidea best fits with the molecular and fossil evidence.<ref name="Jonesetal2022">{{Cite journal |last1=Jones |first1=Marc E. H. |last2=Benson |first2=Roger B. J. |last3=Skutschas |first3=Pavel |last4=Hill |first4=Lucy |last5=Panciroli |first5=Elsa |last6=Schmitt |first6=Armin D. |last7=Walsh |first7=Stig A. |last8=Evans |first8=Susan E. |date=2022-07-11 |title=Middle Jurassic fossils document an early stage in salamander evolution |journal=Proceedings of the National Academy of Sciences |volume=119 |issue=30 |pages=e2114100119 |doi=10.1073/pnas.2114100119 |issn=0027-8424|doi-access=free |pmid=35858401 |pmc=9335269 |bibcode=2022PNAS..11914100J }}</ref><ref name=Naish2013/>

{{clade| style=font-size:80%;line-height:100%
|1={{Clade
   |1={{clade
      |label1=[[Cryptobranchoidea]]
      |1={{Clade
         |1=[[Cryptobranchidae]] (giant salamanders & hellbenders) [[File:Erpétologie générale, ou, Histoire naturelle complète des reptiles (Cryptobranchus alleganiensis).jpg|70 px]]
         |2=[[Hynobiidae]] (Asiatic salamanders) [[File:Erpétologie générale, ou, Histoire naturelle complète des reptiles (Onychodactylus japonicus).jpg|70 px]]
         }}
       }}
   |2={{clade
      |label1=[[Sirenoidea]]
      |1=[[Sirenidae]] (sirens) [[File:Siren lacertina (white background).jpg|70 px]]
      |label2=[[Salamandroidea]] <!--[[Diadectosalamandroidei]] (synonym)-->
      |2={{Clade
         |1={{clade
            |label1=[[Treptobranchia]]
            |1={{Clade
               |1=[[Salamandridae]] (true salamanders & newts) [[File:Salamandra salamandra (white background).jpg|70 px]]
               |label2=
               |2={{Clade
                  |1=[[Ambystomatidae]] (axolotls & tiger salamanders) [[File:Erpétologie générale, ou, Histoire naturelle complète des reptiles (Ambystoma mexicanum).jpg|70 px]]
                  |2=[[Dicamptodontidae]] (Pacific giant salamanders)
               }}
               }}
            }}
         |2={{Clade
            |1=[[Proteidae]] (olms & waterdogs) [[File:Proteus anguinus - (white background).jpg|70 px]]
            |label2=[[Plethosalamandroidei]]
            |2={{Clade
               |1=[[Rhyacotritonidae]] (torrent salamanders)
               |label2=[[Xenosalamandroidei]]
               |2={{Clade
                  |1=[[Amphiumidae]] (amphiumas) [[File:Descriptiones et icones amphibiorum (Amphiuma means).jpg|70 px]]
                  |2=[[Plethodontidae]] (lungless salamanders) [[File:Erpétologie générale, ou, Histoire naturelle complète des reptiles (Bolitoglossa mexicana).jpg|70 px]]
                  }}
               }}
            }}
         }}
      }}
   }}
}}