Galeomorphii is a superorder of cartilaginous fishes which includes all modern sharks except the dogfish and its relatives. They are sometimes called galea or galean sharks. There are about 300 living

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

in 23

families Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideal ...

. Galean sharks are divided into four orders: the Heterodontiformes, Orectolobiformes,

Lamniformes The Lamniformes (, from Greek ''lamna'' "fish of prey") are an order of sharks commonly known as mackerel sharks (which may also refer specifically to the family Lamnidae). It includes some of the most familiar species of sharks, such as the grea ...

, and

Carcharhiniformes Carcharhiniformes , the ground sharks, are the largest order of sharks, with over 270 species. They include a number of common types, such as catsharks, swellsharks, and the sandbar shark. Members of this order are characterized by the presen ...

Classification

Order Heterodontiformes

The bullhead sharks are a small order of basal modern

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 (

Neoselachii Elasmobranchii () is a subclass of Chondrichthyes or cartilaginous fish, including sharks (superorder Selachii), rays, skates, and sawfish (superorder Batoidea). Members of this subclass are characterised by having five to seven pairs of gi ...

). All are relatively small, with the largest species being just in adult length. They are bottom feeders in tropical and subtropical waters. They appear in the fossil record in the Early

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 ...

, well before any of the other galean sharks. However, they have never been common, and it is likely their origin lies even further back. There are nine living species in a single genus, ''Heterodontus'' and a single family. * Family Heterodontidae (Bullhead sharks)

Order Orectolobiformes

Carpet sharks are another small order of sharks, so called because many members have ornate patterns reminiscent of carpets. Sometimes the term "carpet shark" is used interchangeably with

wobbegong The wobbegong is the common name given to the 12 species of carpet sharks in the family Orectolobidae. They are found in shallow temperate and tropical waters of the western Pacific Ocean and eastern Indian Ocean, chiefly around Australia and I ...

, which are a subgroup of the order. Carpet sharks have 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, without spines, and a small mouth that is forward of the eyes. Many have

barbel Barbel may refer to: *Barbel (anatomy), a whisker-like organ near the mouth found in some fish (notably catfish, loaches and cyprinids) and turtles *Barbel (fish), a common name for certain species of fish **''Barbus barbus'', a species of cyprinid ...

s and small

gill slit Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of cartilaginous fish such as sharks and rays, as well as deep-branching vertebrates such as lampreys. In con ...

s, with the fifth slit overlapping the fourth. The upper lobe of the

caudal 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 ...

tends to be mostly in line with the body, while the lower lobe is poorly developed. The order has around 43 species in seven families and 13 genera: * Family Brachaeluridae Applegate (Blind sharks) * Family

Ginglymostomatidae The Ginglymostomatidae are a cosmopolitan family of carpet sharks known as nurse sharks, containing four species in three genera. Common in shallow, tropical and subtropical waters, these sharks are sluggish and docile bottom-dwellers.

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 are ...

, 1862 (Nurse sharks) * Family Hemiscylliidae

, 1862 (Bamboo sharks) * Family Orectolobidae

, 1896 (Wobbegong sharks) * Family Parascylliidae

, 1862 (Collared carpet sharks) * Family

Rhincodontidae The whale shark (''Rhincodon typus'') is a slow-moving, filter-feeding carpet shark and the largest known extant fish species. The largest confirmed individual had a length of .McClain CR, Balk MA, Benfield MC, Branch TA, Chen C, Cosgrove J, D ...

( J. P. Müller &

Henle Henle can refer to: * Friedrich Gustav Jakob Henle, a German physician, pathologist and anatomist (1809–1885) ** Loop of Henle in the kidney, named after Henle *Fritz Henle, a photographer, known as "Mr. Rollei" for his use of the 2.25" square for ...

, 1839) (Whale sharks) * Family Stegostomatidae

, 1862 (Zebra sharks)

Order Lamniformes

Mackerel sharks are an order which includes some of the most familiar species of sharks, such as the

great white shark The great white shark (''Carcharodon carcharias''), also known as the white shark, white pointer, or simply great white, is a species of large Lamniformes, mackerel shark which can be found in the coastal surface waters of all the major ocean ...

, as well as more unusual representatives, such as the goblin shark and the

megamouth shark The megamouth shark (''Megachasma pelagios'') is a species of deepwater shark. It is rarely seen by humans and is the smallest of the three extant filter-feeding sharks alongside the relatively larger whale shark and basking shark. Since its d ...

. Members of the order are distinguished by possessing two

s, an anal fin, five gill slits, eyes without nictitating membranes, and a mouth extending behind the eyes. Mackerel sharks may also refer specifically to the family

Lamnidae The Lamnidae are the family of mackerel sharks known as white sharks. They are large, fast-swimming predatory fish found in oceans worldwide, though prefer environments with colder water. The name of the family is formed from the Greek word ''la ...

. The order includes seven families and sixteen living species: * Family

Alopiidae Thresher sharks are large lamniform sharks of the family Alopiidae found in all temperate and tropical oceans of the world; the family contains three extant species, all within the genus ''Alopias''. All three thresher shark species have been l ...

Bonaparte, 1838 (Thresher sharks) * Family Cetorhinidae

, 1862 (Basking sharks) * Family

J. P. Müller and

, 1838 * Family

Megachasmidae ''Megachasma'' is a genus of sharks. It is usually considered to be the sole genus in the distinct family Megachasmidae, though suggestion has been made that it may belong in the family Cetorhinidae, of which the basking shark is currently the s ...

Taylor Taylor, Taylors or Taylor's may refer to: People * Taylor (surname) ** List of people with surname Taylor * Taylor (given name), including Tayla and Taylah * Taylor sept, a branch of Scottish clan Cameron * Justice Taylor (disambiguation) Pl ...

, Compagno & Struhsaker, 1983 (Megamouth shark) * Family Mitsukurinidae D. S. Jordan, 1898 * Family Odontaspididae Müller &

, 1839 (Sand sharks) * Family Pseudocarchariidae Compagno, 1973 (Crocodile shark) * Family

Cretoxyrhinidae ''Cretoxyrhina'' (; meaning 'Cretaceous sharp-nose') is an extinct genus of large mackerel shark that lived about 107 to 73 million years ago during the late Albian to late Campanian of the Late Cretaceous. The type species, ''C. mantelli'', is m ...

(Extinct) * Family

Otodontidae Otodontidae is an extinct family of sharks belonging to the order Lamniformes. Its members have been described as megatoothed sharks. They lived from the Early Cretaceous to the Pliocene, and included genera such as ''Carcharocles'' and ''Otod ...

(Extinct)

Order Carcharhiniformes

Ground sharks are the largest order of sharks, and include a number of common types such as the blue shark, catsharks, swellsharks and

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 ...

s. Members of the orders are characterized by the presence of a nictitating membrane over the eye, two

s, an anal fin, 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 are ...

slits. The families in the order Carcharhiniformes are expected to be revised; recent DNA studies show that some of the traditional groups are not monophyletic. The order includes eight families and over 270 species: * Family Carcharhinidae (Requiem sharks) * Family

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 ...

(Weasel sharks) * Family

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) * Family

Proscylliidae The finback catsharks are a small family, the Proscylliidae, of ground sharks. They can be found in warm seas worldwide and are often the most numerous and common shark in tropical regions. They are generally less than 1 m in length, and are slow ...

(Finback catsharks) * Family

Pseudotriakidae The Pseudotriakidae are a small family of ground sharks, belonging to the order Carcharhiniformes, containing the false catsharks (genera '' Pseudotriakis'' and '' Planonasus'') and gollumsharks (genus ''Gollum''). It contains the only ground s ...

(False catsharks) * Family Scyliorhinidae (Catsharks) * Family Sphyrnidae (Hammerhead sharks) * Family Triakidae (Houndsharks)

References

External links

* . Database of bibliography of living/fossil sharks and rays (Chondrichtyes: Selachii) with more than 15.000 listed papers and many download links.
Superorder Galeomorphii
Marine Species Identification Portal. Retrieved 10 February 2017. {{Taxonbar, from=Q47969 Elasmobranchii Chordate superorders