Galeomorphii is a

superorder Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and ...

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 appropriat ...

in 23 families. Galean sharks are divided into four

orders Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

: 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 gre ...

, 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 presenc ...

Classification

Order Heterodontiformes

The bullhead sharks are a small

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

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). 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

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 barbels 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 co ...

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 se ...

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 ''Brachaelurus'' (blind sharks) is the sole genus of sharks in the family Brachaeluridae in the order Orectolobiformes. Only two species of blind sharks occur, both of which are native to shallow coastal waters up to deep, off the eastern coast ...

Applegate Applegate may refer to: Places * Applegate, California, United States * Applegate, Michigan, United States * Applegate, Oregon, United States * Applegate Peak in Oregon * The Applegate River in Oregon ** Applegate Lake, on the Applegate River ...

(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 ar ...

, 1862 (Nurse sharks) * Family

Hemiscylliidae The Hemiscylliidae are a family of sharks in the order Orectolobiformes, commonly known as longtail carpet sharks and sometimes as bamboo sharks. They are found in shallow waters of the tropical Indo-Pacific. They are relatively small sharks, ...

, 1862 (Bamboo sharks) * Family Orectolobidae

, 1896 (Wobbegong sharks) * Family

Parascylliidae The Parascylliidae, or collared carpet sharks, are a family of sharks only found in shallow waters of the western Pacific. They are relatively small sharks, with the largest species reaching no more than 91.0 cm in adult length. They have elon ...

, 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, ...

( 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, the loop of Henle () (or Henle's loop, Henle loop, nephron loop or its Latin counterpart ''ansa nephroni ...

, 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 mackerel shark which can be found in the coastal surface waters of all the major oceans. It is nota ...

, as well as more unusual representatives, such as the

goblin shark The goblin shark (''Mitsukurina owstoni'') is a rare species of deep-sea shark. Sometimes called a "living fossil", it is the only extant representative of the family Mitsukurinidae, a lineage some 125 million years old. This pink-skinned anim ...

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 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 ...

, five gill slits, eyes without

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 ...

s, 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 ''l ...

. The order includes seven families and sixteen living species: * Family Alopiidae Bonaparte, 1838 (Thresher sharks) * Family

Cetorhinidae Cetorhinidae is a family of filter feeding mackerel sharks, whose members are commonly known as basking sharks. It includes the extant basking shark, ''Cetorhinus'', as well as two extinct genera, '' Caucasochasma'' and ''Keasius ''Keasius'' ...

, 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 so ...

Taylor, Compagno & Struhsaker, 1983 (Megamouth shark) * Family

Mitsukurinidae Mitsukurinidae is a family of sharks with one living genus, ''Mitsukurina'', and four fossil genera: '' Anomotodon'', '' Protoscapanorhynchus'', ''Scapanorhynchus'', and '' Woellsteinia'', though some taxonomists consider ''Scapanorhynchus'' to ...

D. S. Jordan, 1898 * Family Odontaspididae Müller &

, 1839 (Sand sharks) * Family Pseudocarchariidae Compagno, 1973 (Crocodile shark) * Family Cretoxyrhinidae (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 The blue shark (''Prionace glauca''), also known as the great blue shark, is a species of requiem shark, in the family Carcharhinidae, which inhabits deep waters in the world's temperate and tropical oceans. Averaging around and preferring ...

, 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

over the eye, two

s, an

, 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 traditional 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 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 l ...

(Weasel sharks) * Family Leptochariidae (Barbeled houndshark) * Family Proscylliidae (Finback catsharks) * Family Pseudotriakidae (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