Belongs within: Chondrichthyes.
Contains: Carcharhiniformes, Lamniformes, Orectolobiformes, Hexanchiformes, Squalidae.
The Selachimorpha are the clade including all modern sharks, distinguished from the rays by the pectoral fins remaining separate from the head. Most living sharks can be divided between the clades Galeomorphii and Squalomorphii with members of the latter clade being characterised by a projection into the orbit from the upper-jaw cartilage (Mallatt & Winchell 2007).
<==Selachimorpha [Palaeichthyes]
| i. s.: Scylliodus antiquus [=Scyliorhinus antiquus, Scyllium antiquum]B18
| Acanthidium [Centrinidae]L43
| `--A. pusillum Lowe 1843L43
|--GaleomorphiiB96
| | i. s.: Synechodontiformes [Palaeospinacomorphii]D01
| | | i. s.: SynechodusD01
| | | |--S. enniskilleniD01
| | | |--S. occultidensD01
| | | |--S. pinnai Duffin 1987D01
| | | `--S. riegrafiD01
| | `--PalaeospinacidaeCDZ93
| | |--Palaeospinax priscus (Duffin 1872)D93
| | `--ParaorthacodusD01
| | |--P. arduennae Delsate 2001D01
| | |--P. clarkii (Eastman 1901)CDZ93
| | |--P. eocaenus (Leriche 1902)CDZ93
| | |--P. jurensisD01
| | `--P. kruckowiD01
| |--CarcharhiniformesMW07
| `--Lamnoidei [Galeoidea]M58
| |--LamniformesMW07
| `--OrectolobiformesMW07
`--+--Heterodontus Blainville 1816MW07, O89 [Heterodontidae, Heterodontiformes]
| |--H. duffini Thies 1983CDZ93
| |--H. eocaenus (Regan 1864) [=Asteracanthus eocaenus]CDZ93
| |--H. falcifer (Wagner 1857)CDZ93
| |--H. francisciB96
| |--H. galeatusG75
| |--H. japonicaM96
| |--H. phillipiO86 [=Cestracion philippiH72]
| `--H. portusjacksoniG75
`--SqualomorphiiB96
| i. s.: Protospinax [Protospinacidae, Protospinaciformes]B96
| |--P. annectans Woodward 1919CDZ93
| `--P. planusDC02
|--HexanchiformesMW07
`--+--Pristiophoridae [Pristiophoriformes]MW07
| |--Pristiophorus Müller & Henle 1837O89
| | |--P. cirratusO89
| | |--P. nudipinnisO89
| | `--P. tumidens (Woodward 1932)CDZ93
| `--PliotremaB96
`--+--Squatina Duméril 1806MW07, O89 (see below for synonymy)
| |--S. acanthoderma Fraas 1854CDZ93
| |--S. aculeataVF21
| |--S. angeloidesF91
| |--S. californicaC84
| |--S. dumerilC84
| |--S. japonicaVF21
| `--S. tergocellataKW70
`--Squaliformes [Squaloidea]MW07
| i. s.: Zameus squamulosusVF21
|--SqualidaeC84
`--EchinorhinidaeCDZ93
|--Gibbechinorhinus lewyi Cappetta 1990CDZ93
`--Echinorhinus Blainville 1816O89
|--E. brucus (Bonnaterre 1788) [incl. E. mccoyi]G60
|--E. cookei Pitschmann 1928G60
`--E. spinosusO89
Squatina Duméril 1806MW07, O89 [Rhinae, Rhinida, Rhiniformes, Rhinoidei, Squatinae, Squatinidae, Squatiniformes, Squatinina, Squatinoidea, Squatinoidei, Squatinomorphii, Tectospondyli]
*Type species of generic name indicated
References
[B18] Bernárdez, E. 2018. Truyolsodontos estauni n. gen., n. sp., Truyolsodontidae, a new family of lamniform sharks from the Cenomanian of northern Spain. Annales de Paléontologie 104: 175–181.
[B96] Bond, C. E. 1996. Biology of Fishes 2nd ed. Saunders College Publishing: Fort Worth.
[CDZ93] Cappetta, H., C. Duffin & J. Zidek. 1993. Chondrichthyes. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 593–609. Chapman & Hall: London.
[C84] Compagno, L. J. V. 1984. FAO Species Catalogue vol. 4. Sharks of the World: An annotated and illustrated catalogue of shark species known to date. Part 2—Carcharhiniformes. United Nations Development Programme, Food and Agriculture Organization of the United Nations: Rome.
[D01] Delsate, D. 2001. L’ichthyofaune du Pliensbachian (Jurassique inferieur) de Lorraine et des Ardennes (France): premiers resultats. Bulletin de l’Académie Lorraine des Sciences 40 (1–2): 47–69.
[DC02] Delsate, D., & L. Candoni. 2002. Les premieres raies (Chondrichthyes—Elasmobranchii) au Jurassique inferieur en Lorraine (Luxembourg, Belgique, France) et dans le Bassin de Paris. Bulletin de l’Académie Lorraine des Sciences 41 (3–4): 93–103.
[D93] Duffin, C. J. 1993. Mesozoic chondrichthyan faunas 1. Middle Norian (Upper Triassic) of Luxembourg. Palaeontographica Abteilung A: Paläozoologie—Stratigraphie 229: 15–36.
[F91] Freess, W. B. 1991. Beiträge zur Kenntnis von Fauna und Flora des marinen Mitteloligozäns bei Leipzig. Altenburger Naturwissenschaftliche Forschungen 6: 3–74.
[G60] Garrick, J. A. F. 1960. Studies on New Zealand Elasmobranchii. Part XII. The species of Squalus from New Zealand and Australia; and a general account and key to the New Zealand Squaloidea. Transactions of the Royal Society of New Zealand 88 (3): 519–557.
[G75] Grant, E. M. 1975. Guide to Fishes. The Co-ordinator-General’s Department: Brisbane (Australia).
[H72] Hulley, P. A. 1972. The origin, interrelationship and distribution of southern African Rajidae (Chondrichthyes, Batoidei). Annals of the South African Museum 60 (1): 1–103.
[KW70] Kirkegaard, I., & R. H. Walker. 1970. Synopsis of biological data on the eastern king prawn Penaeus plebejus Hess, 1865. C.S.I.R.O. Fisheries and Oceanography Fisheries Synopsis 7.
[L43] Lowe, R. T. 1843. On the fishes of Madeira. Proceedings of the Zoological Society of London 11: 81–95.
[M96] Mallatt, J. 1996. Ventilation and the origin of jawed vertebrates: a new mouth. Zoological Journal of the Linnean Society 117: 329–404.
[MW07] Mallatt, J., & C. J. Winchell. 2007. Ribosomal RNA genes and deuterostome phylogeny revisited: more cyclostomes, elasmobranchs, reptiles, and a brittle star. Molecular Phylogenetics and Evolution 43: 1005–1022.
[M58] Munro, I. S. R. 1958. The fishes of the New Guinea region: a check-list of the fishes of New Guinea incorporating records of species collected by the Fisheries Survey Vessel “Fairwind” during the years 1948 to 1950. Papua and New Guinea Agricultural Journal 10 (4): 97–369 (reprinted: 1958. Territory of Papua and New Guinea Fisheries Bulletin 1).
[O89] Ogilby, J. D. 1889. List of the Australian Palaeichthyes, with notes on their synonymy and distribution. Part II. Proceedings of the Linnean Society of New South Wales, series 2, 4 (1): 178–186.
[VF21] Vullo, R., E. Frey, C. Ifrim, M. A. González González, E. S. Stinnesbeck & W. Stinnesbeck. 2021. Manta-like planktivorous sharks in Late Cretaceous oceans. Science 371: 1253–1256.