# Carcharhiniformes

Carcharhiniformes /kɑːrkəˈraɪnɪfɔːrmiːz/, commonly known as ground sharks, are the largest order of sharks, with over 270 species. They include a number of common types, such as catsharks, swellsharks, and requiem sharks.
Members of this order are characterized by the presence of a nictitating membrane over the eye, two dorsal fins, an anal fin, and five gill slits.
The families in the order Carcharhiniformes are expected to be revised; recent DNA studies show that some of the conventional groups are not monophyletic.
The oldest members of the order appeared during the Middle-Late Jurassic, which have teeth and body forms that are morphologically similar to living catsharks. Carchariniformes first underwent major diversification during the Late Cretaceous, initially as mostly small-sized forms, before radiating into medium and large body sizes during the Cenozoic.

## Families

Eschmeyer's Catalog of Fishes classifies the Carcharhiniformes into two suborders and nine families:
* Suborder Scyliorhinoidei
** Family Scyliorhinidae Gill, 1862 (catsharks)
* Suborder Carcharhinoidei
** Family Atelomycteridae E. G. White, 1936 (coloured catsharks)
** Family Pentanchidae Smith, 1912 (deepwater catsharks)
** Family Dichichthyidae W. T. White, Stewart, Reuben O'Neill & Naylor, 2024 (bristle sharks)
** Family Pseudotriakidae Gill, 1893 (false catsharks)
** Family Proscylliidae Fowler, 1941 (finback catsharks)
** Family Leptochariidae Gray, 1851 (barbeled houndsharks)
** Family Triakidae Gray, 1851 (houndsharks)
*** Subfamily Triakinae Gray, 1851 (smouth-hounds)
*** Subfamily Galeorhininae Gill, 1862 (school sharks)
** Family Hemigaleidae J.C.F. Hasse, 1878 (weasel sharks)
** Family Carcharhinidae D. S. Jordan & Evermann, 1896 (requiem sharks)
** Family Galeocerdonidae Poey, 1875 (tiger sharks)
** Family Sphyrnidae Bonaparte, 1840 (hammerhead sharks)

### Fossil genera

The following fossil genera of Carcharhiniformes are also known:
* Genus †Altusmirus Fuchs, Engelbrecht, Lukeneder & Kriwet, 2017
* Genus †Corysodon Saint-Seine, 1949
* Genus †Platyrhizodon Guinot, Underwood, Cappetta & Ward, 2013
* Genus †Vectiscyllium Duffin & Batchelor, 2024
* Family Carcharhinidae
** Genus †Abdounia Cappetta, 1980
** Genus †Archaeogaleus Guinot, Cappetta & Adnet, 2014
** Genus †Danogaleus Noubhani & Cappetta, 1997
** Genus †Eogaleus Cappetta, 1975
** Genus †Eorhincodon Li, 1997
** Genus †Fornicatus Fuchs, Engelbrecht, Lukeneder & Kriwet, 2018
** Genus †Kruckowlamna Laurito Mora, 1999
** Genus †Misrichthys Case & Cappetta, 1990
** Genus †Pseudabdounia Ebersole, Cicimurri & Stringer, 2019
* Family †Florenceodontidae Cappetta, Morrison & Adnet, 2019
** Genus †Florenceodon Cappetta, Morrison & Adnet, 2019
* Family Hemigaleidae
** Genus †Moerigaleus Underwood & Ward, 2011
* Family Galeocerdonidae
** Genus †Physogaleus Cappetta, 1980
* Family †Pseudoscyliorhinidae Stumpf, Scheer & Kriwet, 2019
** Genus †Diprosopovenator Stumpf, Scheer & Kriwet, 2019
** Genus †Pseudoscyliorhinus Müller & Diedrich, 1991
* Family Pentanchidae
** Genus †Pseudoapristurus Pollerspöck & Straube, 2017
* Family Proscyllidae
** Genus †Praeproscyllium Underwood & Ward, 2004
* Family Scyliorhinidae
** Genus †Bavariscyllium Thies, 2005
** Genus †Cadiera Guinot, Cappetta & Adnet, 2014
** Genus †Casieria Noubhani & Cappetta, 1997
** Genus †Crassescyliorhinus Underwood & Ward, 2008
** Genus †Cretascyliorhinus Underwood & Mitchell, 1999
** Genus †Foumtizia Noubhani & Cappetta, 1997
** Genus †Megascyliorhinus Cappetta & Ward, 1977
** Genus †Microscyliorhinus Case, 1994
** Genus †Orthodon Coquand, 1860
** Genus †Pachyscyllium Reinecke, Moths, Grant & Breitkreuz, 2005
** Genus †Palaeoscyllium Wagner, 1857
** Genus †Platyrhizoscyllium Adnet, 2006
** Genus †Porodermoides Noubhani & Cappetta, 1997
** Genus †Premontreia Cappetta, 1992
** Genus †Prohaploblepharus Underwood & Ward, 2008
** Genus †Protoscyliorhinus Herman, 1977
** Genus †Pteroscyllium Cappetta, 1980
** Genus †Scyliorhinotheca Kiel, Peckmann & Simon, 2013
** Genus †Sigmoscyllium Guinot, Underwood, Cappetta & Ward, 2013
** Genus †Stenoscyllium Noubhani & Cappetta, 1997
** Genus †Thiesus Guinot, Cappetta & Adnet, 2014
** Genus †Tingaleus Cappetta, 1993
* Family Triakidae
** Genus †Archaeotriakis Case, 1978
** Genus †Gomphogaleus Adnet & Cappetta, 2008
** Genus †Kallodentis Engelbrecht, Mörs, Reguero & Kriwet, 2017
** Genus †Khouribgaleus Noubhani & Cappetta, 1997
** Genus †Meridiogaleus Engelbrecht, Mörs, Reguero & Kriwet, 2017
** Genus †Pachygaleus Cappetta, 1992
** Genus †Palaeogaleus Gurr, 1962
** Genus †Palaeotriakis Guinot, Underwood, Cappetta & Ward, 2013
** Genus †Rhaibodus Böhm, 1926
** Genus †Squatigaleus Cappetta, 1989
** Genus †Xystrogaleus Adnet, 2006