Editing Elasmobranchii (section)

==Taxonomy==
Elasmobranchii was first coined in 1838 by [[Charles Lucien Bonaparte]]. Bonaparte's original definition of Elasmobranchii was effectively identical to modern [[Chondrichthyes]], and was based around gill architecture shared by all 3 living major cartilaginous fish groups. During the 20th century it became standard to exclude [[Chimaera|chimaeras]] from Elasmobranchii; along with including many fossil chondrichthyans within the group. The definition of Elasmobranchii has since been subject to much confusion with regard to fossil chondrichthyans. Maisey (2012) suggested that Elasmobranchii should exclusively be used for the last common ancestor of modern sharks and rays, a grouping which had previously been named Neoselachii by Compagno (1977).<ref name=":1" /> Other recent authors have used Elasmobranchii in a broad sense to include all chondrichthyans more closely related to modern sharks and rays than to chimaeras.<ref name=":0" />

The [[total group]] of Elasmobranchii includes the [[Taxonomic rank|cohort]] Euselachii Hay, 1902, which groups the Hybodontiformes and a number of other extinct chondrichthyans with Elasmobrachii ''sensu stricto''/Neoselachii, to the exclusion of more primitive total group elasmobranchs, which is supported by a number of shared morphological characters of the skeleton.<ref>{{Cite journal |last=Maisey |first=John G. |date=March 2011 |title=The braincase of the Middle Triassic shark Acronemus tuberculatus (Bassani, 1886) |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1475-4983.2011.01035.x |journal=Palaeontology |language=en |volume=54 |issue=2 |pages=417–428 |doi=10.1111/j.1475-4983.2011.01035.x |bibcode=2011Palgy..54..417M |s2cid=140697673 |issn=0031-0239|url-access=subscription }}</ref><ref>{{Cite journal |last1=Coates |first1=Michael I. |last2=Tietjen |first2=Kristen |date=March 2017 |title=The neurocranium of the Lower Carboniferous shark Tristychius arcuatus (Agassiz, ) |url=https://www.cambridge.org/core/product/identifier/S1755691018000130/type/journal_article |journal=Earth and Environmental Science Transactions of the Royal Society of Edinburgh |language=en |volume=108 |issue=1 |pages=19–35 |doi=10.1017/S1755691018000130 |bibcode=2017EESTR.108...19C |s2cid=135297534 |issn=1755-6910|url-access=subscription }}</ref><ref>{{Cite journal |last1=Villalobos-Segura |first1=Eduardo |last2=Stumpf |first2=Sebastian |last3=Türtscher |first3=Julia |last4=Jambura |first4=Patrick |last5=Begat |first5=Arnaud |last6=López-Romero |first6=Faviel |last7=Fischer |first7=Jan |last8=Kriwet |first8=Jürgen |date=2023-03-08 |title=A Synoptic Review of the Cartilaginous Fishes (Chondrichthyes: Holocephali, Elasmobranchii) from the Upper Jurassic Konservat-Lagerstätten of Southern Germany: Taxonomy, Diversity, and Faunal Relationships |journal=Diversity |language=en |volume=15 |issue=3 |pages=386 |doi=10.3390/d15030386 |doi-access=free |issn=1424-2818 |pmc=7614348 |pmid=36950327}}</ref><ref>{{Cite journal |last1=Luccisano |first1=Vincent |last2=Rambert-Natsuaki |first2=Mizuki |last3=Cuny |first3=Gilles |last4=Amiot |first4=Romain |last5=Pouillon |first5=Jean-Marc |last6=Pradel |first6=Alan |date=2021-12-02 |title=Phylogenetic implications of the systematic reassessment of Xenacanthiformes and 'Ctenacanthiformes' (Chondrichthyes) neurocrania from the Carboniferous–Permian Autun Basin (France) |url=https://www.tandfonline.com/doi/full/10.1080/14772019.2022.2073279 |journal=Journal of Systematic Palaeontology |language=en |volume=19 |issue=23 |pages=1623–1642 |doi=10.1080/14772019.2022.2073279 |bibcode=2021JSPal..19.1623L |issn=1477-2019|url-access=subscription }}</ref>
*[[Total group]] Elasmobranchii
**†Order [[Phoebodontiformes]]
**†Order [[Squatinactis|Squatinactiformes]]
**†Infraclass Xenacanthimorpha
***†Order [[Xenacanthiformes]]
**†Order [[Ctenacanthiformes]]
**†Order [[Jalodontiformes]]
**†''[[Bandringa]]''
**Infraclass Euselachii
***†Order [[Hybodontiformes]]
***†Family [[Protacrodontidae]]
***†Family Tristychiidae
****''[[Tristychius]]''
****''[[Acronemus]]''
***†''[[Artiodus]]''
***Division '''Neoselachii (Elasmobranchii''' ''sensu stricto''''')'''
****†Family [[Anachronistidae]]
****†Order [[Synechodontiformes]] (''incertae sedis'')
****Subdivision [[shark|Selachii]] (Selachimorpha) (modern sharks)
*****Superorder [[Galeomorphi]]
******Order [[Heterodontiformes]] (bullhead sharks)
******Order [[Orectolobiformes]] (carpet sharks)
******Order [[Lamniformes]] (mackerel sharks)
******Order [[Carcharhiniformes]] (ground sharks)
*****Superorder [[Squalomorphi]]
******Order [[Echinorhiniformes]] (bramble sharks)<ref>{{Cite book |last1=Ebert |first1=David A. |title=Sharks of the world: a complete guide |last2=Fowler |first2=Sarah |last3=Dando |first3=Marc |date=2021 |publisher=Princeton University Press |isbn=978-0-691-20599-1 |location=Princeton}}</ref><ref>{{Cite web |title=WoRMS - World Register of Marine Species - Echinorhiniformes |url=https://www.marinespecies.org/aphia.php?p=taxdetails&id=1517433 |access-date=2022-01-04}}</ref>
******Order [[Hexanchiformes]] (frilled and cow sharks)
******Order [[Squaliformes]] (dogfish sharks)
******†Family [[Protospinax|Protospinacidae]]
******Order [[Squatiniformes]] (angel sharks)
******Order [[Pristiophoriformes]] (sawsharks)
****Subdivision [[Batoidea]] (rays, skates, and sawfish)
*****Order [[Torpediniformes]] (electric rays)
*****Order [[Rhinopristiformes]] (sawfishes, guitarsfishes, wedgefishes and relatives)
*****Order [[Rajiformes]] (skates and relatives)
*****Order [[Myliobatiformes]] (stingrays and relatives)

The 5th edition of Fishes of the World sets out the following classification of the Elasmobranchs:<ref name = Nelson5>{{cite book |author1=Nelson, J.S. |author1-link=Joseph S. Nelson |author2=Grande, T.C. |author3=Wilson, M.V.H. |year=2016 |title=Fishes of the World |edition=5th |publisher=[[John Wiley & Sons]] |place=Hoboken, NJ |pages=56 |isbn=978-1-118-34233-6 |lccn=2015037522 |oclc=951899884 |ol=25909650M |doi=10.1002/9781119174844}}</ref>
*Infraclass Elasmobranchii
**Division Selachii (sharks)
***Superorder Galeomorphi
****†Order Synechodontiformes 
****Order Heterodontiformes 
****Order Orectolobiformes 
*****Suborder Parascyllioidei 
*****Suborder Orectoloboidei 
****Order Lamniformes 
****Order Carcharhiniformes 
***Superorder Squalomorphi
****Series Hexanchida 
*****Order Hexanchiformes 
****Series Squalida
*****Order Squaliformes 
****Series Squatinida
*****†Order Protospinaciformes 
*****Order Echinorhiniformes 
*****Order Squatiniformes
*****Order Pristiophoriformes 
**Division Batomorphi (rays)
***Order Torpediniformes 
***Order Rajiformes 
***Order Pristiformes
***Order Myliobatiformes 
****Suborder Platyrhinoidei 
****Suborder Myliobatoidei

Recent molecular studies suggest the Batoidea are not derived selachians as previously thought. Instead, skates and rays are a monophyletic superorder within Elasmobranchii that shares a common ancestor with the selachians.<ref>{{cite journal |doi=10.1016/j.ympev.2003.07.010 |pmid=15019621 |title=Phylogeny of elasmobranchs based on LSU and SSU ribosomal RNA genes |journal=Molecular Phylogenetics and Evolution |volume=31 |issue=1 |pages=214–24 |year=2004 |last1=Winchell |first1=Christopher J |last2=Martin |first2=Andrew P |last3=Mallatt |first3=Jon }}</ref><ref>{{cite journal |doi=10.1016/S1055-7903(02)00333-0 |pmid=12565032 |title=Molecular phylogenetic evidence refuting the hypothesis of Batoidea (rays and skates) as derived sharks |journal=Molecular Phylogenetics and Evolution |volume=26 |issue=2 |pages=215–21 |year=2003 |last1=Douady |first1=Christophe J. |last2=Dosay |first2=Miné |last3=Shivji |first3=Mahmood S. |last4=Stanhope |first4=Michael J. }}</ref>