Carcharhiniformes , the ground sharks, are the largest order of

shark Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachi ...

s, with over 270 species. They include a number of common types, such as

catshark Catsharks are ground sharks of the family Scyliorhinidae. They are the largest family of sharks with around 160 species placed in 17 genera. Although they are generally known as catsharks, some species can also be called dogfish due to previous ...

swellshark The swell shark (''Cephaloscyllium ventriosum'') is a catshark in the family Scyliorhinidae. It is found in the tropical and subtropical eastern Pacific Ocean from between central California to southern Mexico, with an additional population off ...

s, and the

sandbar shark The sandbar shark (''Carcharhinus plumbeus'') also known as the brown shark or thickskin shark, is a species of requiem shark, and part of the family Carcharhinidae, native to the Atlantic Ocean and the Indo-Pacific. It is distinguishable by it ...

. Members of this order are characterized by the presence of a

nictitating membrane The nictitating membrane (from Latin '' nictare'', to blink) is a transparent or translucent third eyelid present in some animals that can be drawn across the eye from the medial canthus to protect and moisten it while maintaining vision. All ...

over the eye, two

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

s, an

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as see ...

, and five

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they ar ...

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 In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gr ...

. The oldest members of the order appeared during the Middle-Late

Jurassic The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...

, which have teeth and bodyforms that are morphologically similar to living catsharks. Carchariniformes first underwent major diversification during the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

, initially as small-sized forms, before radiating into medium and large body sizes during the

Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configu ...

Families

According to

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

, the nine families of ground sharks are:Fish Identification: Ground sharks
''

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

''. Retrieved 28 March 2013. * Carcharhinidae (requiem sharks) * Galeocerdonidae (Tiger shark) *

Hemigaleidae The weasel sharks are a family, the Hemigaleidae, of ground sharks found from the eastern Atlantic Ocean to the continental Indo-Pacific. They are found in shallow coastal waters to a depth of . Most species are small, reaching no more than l ...

(weasel sharks) *

Leptochariidae The barbeled houndshark (''Leptocharias smithii'') is a species of ground shark and the only member of the family Leptochariidae. This demersal species is found in the coastal waters of the eastern Atlantic Ocean from Mauritania to Angola, at de ...

(barbeled houndshark) * Proscylliidae (finback catsharks) * Pseudotriakidae (false catsharks) * Scyliorhinidae (catsharks) * Sphyrnidae (hammerhead sharks) * Triakidae (houndsharks)

Timeline of genera

ImageSize = width:1000px height:auto barincrement:15px PlotArea = left:10px bottom:50px top:10px right:10px Period = from:-199.6 till:15 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:10 start:-199.6 ScaleMinor = unit:year increment:1 start:-199.6 TimeAxis = orientation:hor AlignBars = justify Colors = #legends id:CAR value:claret id:ANK value:rgb(0.4,0.3,0.196) id:HER value:teal id:HAD value:green id:OMN value:blue id:black value:black id:white value:white id:mesozoic value:rgb(0.54,0.54,0.258) id:jurassic value:rgb(0.2,0.7,0.79) id:earlyjurassic value:rgb(0,0.69,0.89) id:middlejurassic value:rgb(0.52,0.81,0.91) id:latejurassic value:rgb(0.74,0.89,0.97) id:cretaceous value:rgb(0.5,0.78,0.31) id:earlycretaceous value:rgb(0.63,0.78,0.65) id:latecretaceous value:rgb(0.74,0.82,0.37) id:cenozoic value:rgb(0.54,0.54,0.258) id:paleogene value:rgb(0.99,0.6,0.32) id:paleocene value:rgb(0.99,0.65,0.37) id:eocene value:rgb(0.99,0.71,0.42) id:oligocene value:rgb(0.99,0.75,0.48) id:neogene value:rgb(0.999999,0.9,0.1) id:miocene value:rgb(0.999999,0.999999,0) id:pliocene value:rgb(0.97,0.98,0.68) id:quaternary value:rgb(0.98,0.98,0.5) id:pleistocene value:rgb(0.999999,0.95,0.68) id:holocene value:rgb(0.999,0.95,0.88) BarData= bar:eratop bar:space bar:periodtop bar:space bar:NAM1 bar:NAM2 bar:NAM3 bar:NAM4 bar:NAM5 bar:NAM6 bar:NAM7 bar:NAM8 bar:NAM9 bar:NAM10 bar:NAM11 bar:NAM12 bar:NAM13 bar:NAM14 bar:NAM15 bar:NAM16 bar:NAM17 bar:NAM18 bar:NAM19 bar:NAM20 bar:NAM21 bar:NAM22 bar:NAM23 bar:NAM24 bar:NAM25 bar:NAM26 bar:NAM27 bar:space bar:period bar:space bar:era PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 shift:(7,-4) bar:periodtop from: -199.6 till: -175.6 color:earlyjurassic text:

Early Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early ...

from: -175.6 till: -161.2 color:middlejurassic text: Middle from: -161.2 till: -145.5 color:latejurassic text: Late from: -145.5 till: -99.6 color:earlycretaceous text:

from: -99.6 till: -65.5 color:latecretaceous text: Late from: -65.5 till: -55.8 color:paleocene text: Paleo. from: -55.8 till: -33.9 color:eocene text: Eo. from: -33.9 till: -23.03 color:oligocene text: Oligo. from: -23.03 till: -5.332 color:miocene text: Mio. from: -5.332 till: -2.588 color:pliocene text: Pl. from: -2.588 till: -0.0117 color:pleistocene text: Pl. from: -0.0117 till: 0 color:holocene text: H. bar:eratop from: -199.6 till: -145.5 color:jurassic text:

from: -145.5 till: -65.5 color:cretaceous text:

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

from: -65.5 till: -23.03 color:paleogene text:

Paleogene The Paleogene ( ; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago ( Mya) to the beginning o ...

from: -23.03 till: -2.588 color:neogene text:

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

from: -2.588 till: 0 color:quaternary text: Q. PlotData= align:left fontsize:M mark:(line,white) width:5 anchor:till align:left color:latejurassic bar:NAM1 from:-152.57 till:-150.8 text: Macrourogaleus color:earlycretaceous bar:NAM2 from:-103.7 till:0 text: Scyliorhinus color:latecretaceous bar:NAM3 from:-93.5 till:-89.3 text: Pterolamiops color:latecretaceous bar:NAM4 from:-93.5 till:-70.6 text: Paratriakis color:latecretaceous bar:NAM5 from:-84.27 till:-65.5 text: Pteroscyllium color:latecretaceous bar:NAM6 from:-83.5 till:-70.6 text: Archaeotriakis color:latecretaceous bar:NAM7 from:-83.5 till:-58.7 text: Palaeogaleus color:latecretaceous bar:NAM8 from:-74.9 till:-68.9 text: Squatigaleus color:paleocene bar:NAM9 from:-65.5 till:-33.9 text: Abdounia color:paleocene bar:NAM10 from:-65.5 till:0 text: Triakis color:paleocene bar:NAM11 from:-56.0 till:-15.97 text:

Physogaleus ''Physogaleus'' is a small genus of prehistoric shark that lived from the Eocene to Miocene epochs. Description ''Physogaleus'' are only known from their fossil teeth and isolated vertebra. It has teeth similar to the modern tiger shark, but sma ...

color:eocene bar:NAM12 from:-55.8 till:-48.6 text: Pachygaleus color:eocene bar:NAM13 from:-55.8 till:-48.6 text: Premontreia color:eocene bar:NAM14 from:-55.8 till:-37.2 text:

Eogaleus ''Eogaleus'' is an Extinction, extinct genus of requiem shark from the Eocene, Eocene epoch. It contains a single species, ''E. bolcensis''. It is known from multiple articulated individuals from the Monte Bolca, Bolca Konservat−Lagerstätte of ...

color:eocene bar:NAM15 from:-55.8 till:0 text:

Carcharhinus ''Carcharhinus'' is the type genus of the family Carcharhinidae, the requiem sharks. One of 12 genera in its family, it contains over half of the species therein. It contains 35 extant and eight extinct species to date, with likely more species y ...

color:eocene bar:NAM16 from:-55.8 till:0 text:

Galeocerdo ''Galeocerdo'' is a genus of requiem sharks that have lived since the Paleocene epoch. While these sharks were formerly diverse, only ''G. cuvier'' (the modern tiger shark) survives today. Species Species in the genus ''Galeocerdo'' include: ...

color:eocene bar:NAM17 from:-55.8 till:0 text:

Hemipristis ''Hemipristis'' (from el, ἡμι , 'half' and el, πρίστης 'saw') is a genus of weasel sharks, family Hemigaleidae. It contains one extant species, the snaggletooth shark (''H. elongata'') and several extinct species. ''Hemipristis'' ...

color:eocene bar:NAM18 from:-55.8 till:0 text:

Isogomphodon The daggernose shark (''Isogomphodon oxyrhynchus'') is a little-known species of requiem shark, in the family Carcharhinidae, and the only extant member of its genus. It inhabits shallow tropical waters off northeastern South America, from Trin ...

color:eocene bar:NAM19 from:-55.8 till:-0.0117 text: Megascyliorhinus color:eocene bar:NAM20 from:-55.8 till:0 text:

Mustelus ''Mustelus'', also known as the smooth-hounds, is a genus of sharks in the family Triakidae. The name of the genus comes from the Latin word ''mustela'', meaning weasel. It should not be confused with the genus name ''Mustela'', which is used ...

color:eocene bar:NAM21 from:-55.8 till:0 text:

Rhizoprionodon ''Rhizoprionodon'' is a genus of requiem sharks, and part of the family Carcharhinidae, commonly known as sharpnose sharks because of their long, pointed snouts. Species * '' Rhizoprionodon acutus'' ( Rüppell, 1837) (milk shark) * '' Rhizopri ...

color:eocene bar:NAM22 from:-48.6 till:0 text: Negaprion color:miocene bar:NAM23 from:-23.03 till:0 text:

Chaenogaleus ''Chaenogaleus'' is a genus of shark containing two species. Only one is extant. * Hooktooth shark The hooktooth shark (''Chaenogaleus macrostoma''), is a weasel shark of the family Hemigaleidae, the only extant member of the genus ''Chaeno ...

color:miocene bar:NAM24 from:-23.03 till:0 text:

Galeorhinus The school shark (''Galeorhinus galeus'') is a houndshark of the family Triakidae, and the only member of the genus ''Galeorhinus''. Common names also include tope, tope shark, snapper shark, and soupfin shark. It is found worldwide in temperate ...

color:miocene bar:NAM25 from:-23.03 till:0 text:

Paragaleus ''Paragaleus'' is a genus of weasel shark in the family Hemigaleidae. This genus has a rounded or slightly pointed snout, short gill slits, and a broadly arched mouth. The upper teeth have long cusps, and no toothless spaces occur at the jaw midl ...

color:miocene bar:NAM26 from:-15.97 till:0 text:

Sphyrna ''Sphyrna'' (from the Greek word σφῦρα, "hammer") is a genus of hammerhead sharks with a cosmopolitan distribution in the world's oceans. Members of ''Sphyrna'' have a tendency to inhabit coastal waters along the intertidal zone rather th ...

color:pliocene bar:NAM27 from:-5.332 till:0 text: Prionace PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 bar:period from: -199.6 till: -175.6 color:earlyjurassic text:

from: -175.6 till: -161.2 color:middlejurassic text: Middle from: -161.2 till: -145.5 color:latejurassic text: Late from: -145.5 till: -99.6 color:earlycretaceous text:

from: -145.5 till: -65.5 color:cretaceous text:

from: -65.5 till: -23.03 color:paleogene text:

from: -23.03 till: -2.588 color:neogene text:

from: -2.588 till: 0 color:quaternary text: Q.

References

Further references

* Froese, Rainer, and Daniel Pauly, eds. (2013
Fish Identification: Ground sharks
in

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

. March 2013 version. *

External links

Order Carcharhiniformes
{{Taxonbar, from=Q48178 Articles which contain graphical timelines Cartilaginous fish orders Taxa named by Leonard Compagno Extant Albian first appearances