Carpet sharks are

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 classified in the order Orectolobiformes . Sometimes the common name "carpet shark" (named so because many species resemble ornately patterned

carpet A carpet is a textile floor covering typically consisting of an upper layer of pile attached to a backing. The pile was traditionally made from wool, but since the 20th century synthetic fibers such as polypropylene, nylon, or polyester hav ...

s) is used interchangeably with "wobbegong", which is the common name of sharks in the family Orectolobidae. Carpet sharks have five

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, two spineless

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, and a small mouth that does not extend past the eyes. Many species 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 ...

Characteristics

The carpet sharks are a diverse group of sharks with differing sizes, appearances, diets, and habits. They first appeared in the

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

record in the

Early Jurassic The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-J ...

; the oldest known orectolobiform genera are '' Folipistrix'' (known from

Toarcian The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian ...

Aalenian The Aalenian () is a subdivision of the Middle Jurassic Epoch/Series of the geologic timescale that extends from about 174.1 Ma to about 170.3 Ma (million years ago). It was preceded by the Toarcian and succeeded by the Bajocian. Stratigraphi ...

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...

and

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

), '' Palaeobrachaelurus'' (Aalenian to

Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 129.4 ± 1.5 Ma (million years ago) and 121.4 ± 1.0 Ma). It is a subdivision of the Early Cretaceous Epoch (or Lower Cretaceous Series). It is precede ...

) and '' Annea'' (Toarcian to

Bajocian In the geologic timescale, the Bajocian is an age and stage in the Middle Jurassic. It lasted from approximately 170.3 Ma to around 168.3 Ma (million years ago). The Bajocian Age succeeds the Aalenian Age and precedes the Bathonian Age. Stra ...

of Europe). All species have two dorsal fins and a relatively short, transverse mouth that does not extend behind the eyes. Besides the nostrils are

barbels In fish anatomy and turtle anatomy, a barbel is a slender, whiskerlike sensory organ near the mouth. Fish that have barbels include the catfish, the carp, the goatfish, the hagfish, the sturgeon, the zebrafish, the black dragonfish and some s ...

, tactile sensory organs, and grooves known as nasoral grooves connect the nostrils to the mouth. Five short gill slits are just in front of the origin of the pectoral fin and the fifth slit tends to overlap the fourth one. A spiracle occurs beneath each eye which is used in respiration. The only exception to this rule is the whale shark, the spiracles of which are situated just behind the eyes. Carpet sharks derive their common name from the fact that many species have a mottled appearance with intricate patterns reminiscent of carpet designs. The patterning provides camouflage when the fish is lying on the seabed. The largest carpet shark is the

whale shark 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, ...

(''Rhincodon typus'') which can grow to a length of . It is the largest species of fish, but despite its size, is not dangerous, as it is a filter feeder, drawing in water through its wide mouth and sifting out the

plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucia ...

. The smallest carpet shark, at up to about long, is the barbelthroat carpet shark, (''Cirrhoscyllium expolitum''). Some of the most spectacularly coloured members of the order are the necklace carpet shark (''Parascyllium variolatum''), the

zebra shark The zebra shark (''Stegostoma tigrinum'') is a species of carpet shark and the sole member of the family Stegostomatidae. It is found throughout the tropical Indo-Pacific, frequenting coral reefs and sandy flats to a depth of . Adult zebra sharks ...

(''Stegostoma fasciatum''), and the

ornate wobbegong The ornate wobbegong (''Orectolobus ornatus'') is a species of carpet shark that lives in Australia and possibly other countries in the Western Pacific Ocean. It is coloured golden brown, yellow-green and blueish-grey, and it grows to maximum . ...

(''Orectolobus ornatus''). Nurse sharks and whale sharks have a fringe of barbels on their snouts, and barbelthroat carpet sharks (''Cirrhoscyllium expolitum'') have barbels dangling from their throat regions.

Behaviour

Most carpet sharks feed on the seabed in shallow to medium-depth waters, detecting and picking up molluscs, crustaceans, and other small creatures. The

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 ...

s tend to be

ambush predator Ambush predators or sit-and-wait predators are carnivorous animals that capture or trap prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey ...

s, lying hidden on the seabed until

prey Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...

approaches. One has been observed swallowing a

bamboo shark 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, ...

whole. The methods of reproduction of carpet sharks varies. Some species are oviparous and lay eggs which may be liberated directly into the water or may be enclosed in horny egg cases. Some female sharks have been observed to push egg cases into crevices and this would be an added protection for the developing embryos. Other species are

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...

and the fertilised eggs are retained in the mother's

oviduct The oviduct in mammals, is the passageway from an ovary. In human females this is more usually known as the Fallopian tube or uterine tube. The eggs travel along the oviduct. These eggs will either be fertilized by spermatozoa to become a zygote, o ...

. There, the developing embryos, which are usually few in number, feed on their

yolk sac The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though ''yolk sac'' is ...

s at first and later hatch out and feed on nutrients secreted by the walls of the oviduct. The young are born in an advanced state, ready to live independent lives.

Distribution

Carpet sharks are found in all the oceans of the world but predominantly in tropical and temperate waters. They are most common in the western Indo-Pacific region and are usually found in relatively deep water.

Classification

The order is small, with seven

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 ...

in 13 genera and with a total of around 43

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 ...

: Order Orectolobiformes * 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 (blind sharks) ** Genus '' Brachaelurus'' Ogilby, 1908 *** '' Brachaelurus colcloughi'' (Ogilby, 1908) (bluegrey carpetshark) *** '' Brachaelurus waddi'' ( Bloch & J. G. Schneider, 1801) (blind shark) * 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) ** Genus '' Ginglymostoma'' 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 ...

, 1837 *** '' Ginglymostoma cirratum'' Bonnaterre, 1788 (nurse shark) *** '' Ginglymostoma unami'' Del-Moral-Flores, Ramírez-Antonio, Angulo & Pérez-Ponce de León, 2015 ** Genus ''

Nebrius ''Nebrius'' is a genus of carpet sharks in the family Ginglymostomatidae. It contains a single extant species, the tawny nurse shark (''Nebrius ferrugineus''), as well as a number of extinct species dating back to the Early Paleocene.Bourdon, ...

'' Rüppell, 1837 *** ''

Nebrius ferrugineus The tawny nurse shark (''Nebrius ferrugineus'') is a species of carpet shark in the family Ginglymostomatidae, and the only extant member of the genus ''Nebrius''. It is found widely along coastlines in the Indo-Pacific, preferring reefs, sa ...

'' (

Lesson A lesson or class is a structured period of time where learning is intended to occur. It involves one or more students (also called pupils or learners in some circumstances) being taught by a teacher or instructor. A lesson may be either one ...

, 1831) (tawny nurse shark) ** Genus ''

Pseudoginglymostoma The short-tail nurse shark (''Pseudoginglymostoma brevicaudatum'') is a nurse shark in the family Ginglymostomatidae, the only member of the genus ''Pseudoginglymostoma''. It is found in the tropical western Indian Ocean between latitudes 0° a ...

'' Dingerkus, 1986 *** '' Pseudoginglymostoma brevicaudatum'' ( Günther, 1867) (short-tail nurse shark) * 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 ...

Gill, 1862 (bamboo sharks) ** Genus '' Chiloscyllium'' J. P. Müller & Henle, 1837 *** ''

Chiloscyllium arabicum The Arabian carpetshark (''Chiloscyllium arabicum'') is a species of carpet shark in the family Hemiscylliidae, inhabiting coral reefs and other shallow coastal habitats from the Persian Gulf to India. Reaching long, this shark is characterized b ...

'' Gubanov, 1980 (Arabian carpetshark) *** ''

Chiloscyllium burmensis The Burmese bamboo shark, ''Chiloscyllium burmensis'', is an extremely rare bamboo shark in the family Hemiscylliidae. The first specimen was caught 1963 off the coast from Rangoon in Burma in a depth of 29 – 33 m. This holotype is an adul ...

'' Dingerkus & DeFino, 1983 (Burmese bamboo shark) *** ''

Chiloscyllium griseum The grey bamboo shark, ''Chiloscyllium griseum'', is a species of carpet shark in the family Hemiscylliidae, found in the Indo-West Pacific Oceans from the Arabian Sea to Pakistan, India, Malaysia, Thailand, Indonesia, China, Japan, the Philippin ...

'' J. P. Müller & Henle, 1838 (grey bamboo shark) *** ''

Chiloscyllium hasselti Hasselt's bamboo shark (''Chiloscyllium hasseltii'') is a bamboo shark in the family Hemiscylliidae found around Thailand, Malaysia and Indonesia, between latitudes 23° N and 10° S, and longitude 91° E and 133° E; residing inshore. Its le ...

'' Bleeker, 1852 (Hasselt's bamboo shark) *** ''

Chiloscyllium indicum The slender bamboo shark, ''Chiloscyllium indicum'', is a bamboo shark in the family Hemiscylliidae found in the Indo-West Pacific Oceans between latitudes 40° N and 10° S, and longitude 65° E and 160° E. It is harmless to humans. Descr ...

'' ( J. F. Gmelin, 1789) (slender bamboo shark) *** '' Chiloscyllium plagiosum'' (Anonymous, referred to Bennett, 1830) (white-spotted bamboo shark) *** '' Chiloscyllium punctatum'' J. P. Müller & Henle, 1838 (brownbanded bamboo shark) ** Genus ''

Hemiscyllium ''Hemiscyllium'' is a genus of sharks in the family Hemiscylliidae. Overview This genus is confined to tropical waters off Australia, Papua New Guinea, and Indonesia, but an individual from this genus, possibly representing an undescribed speci ...

'' J. P. Müller & Henle, 1837 *** '' Hemiscyllium freycineti'' ( Quoy &

Gaimard Joseph Paul Gaimard (31 January 1793 – 10 December 1858) was a French naval surgeon and naturalist. Biography Gaimard was born at Saint-Zacharie on January 31, 1793. He studied medicine at the naval medical school in Toulon, subsequent ...

, 1824) (Indonesian speckled carpetshark) *** '' Hemiscyllium galei'' G. R. Allen & Erdmann, 2008 (Cenderwasih epaulette shark) *** '' Hemiscyllium hallstromi'' Whitley, 1967 (Papuan epaulette shark) *** '' Hemiscyllium halmahera'' G. R. Allen, Erdmann &

Dudgeon Dudgeon is a surname. Notable people with the surname include: * Cecil Dudgeon, politician * Gus Dudgeon, record producer * James Dudgeon, footballer * Joe Dudgeon, English footballer * John Dudgeon, physician * Neil Dudgeon, actor * Patrick Dud ...

, 2013Allen, G.R., Erdmann, M.V. & Dudgeon, C.L. (2013): ''Hemiscyllium halmahera'', a new species of Bamboo Shark (Hemiscylliidae) from Indonesia. ''aqua, International Journal of Ichthyology, 19 (3): 123-136.'' (Halmahera epaulette shark) *** '' Hemiscyllium henryi'' G. R. Allen & Erdmann, 2008 (Henry's epaulette shark) *** '' Hemiscyllium michaeli'' G. R. Allen & Dudgeon, 2010 (Milne Bay epaulette shark) *** '' Hemiscyllium ocellatum'' ( Bonnaterre, 1788) (epaulette shark) *** ''

Hemiscyllium strahani The hooded carpetshark (''Hemiscyllium strahani'') is a bamboo shark in the family Hemiscylliidae found around Papua New Guinea, between latitudes 5° S and 10° S, and longitude 144° E and 153° E. Its length is up to 75 cm. Like other ...

'' Whitley, 1967 (hooded carpetshark) *** ''

Hemiscyllium trispeculare The speckled carpetshark, ''Hemiscyllium trispeculare'', is a bamboo shark in the family Hemiscylliidae found around north and west Australia between latitudes 8° S and 22° S, and longitude 114° E and 152° E. Its length is up to 79 c ...

'' J. Richardson, 1843 (speckled carpetshark) * Family Orectolobidae Gill, 1896 (wobbegong sharks) ** Genus ''

Eucrossorhinus The tasselled wobbegong (''Eucrossorhinus dasypogon'') is a species of carpet shark in the family Orectolobidae and the only member of its genus. It inhabits shallow coral reefs off northern Australia, New Guinea, and adjacent islands. Reachin ...

Regan The family name Regan, along with its cognates O'Regan, O Regan, Reagan, and O'Reagan, is an Anglicized form of the Irish surname Ó Riagáin or Ó Ríogáin, from Ua Riagáin. The meaning is likely to have originated in ancient Gaelic ''ri'' ...

, 1908 *** ''

Eucrossorhinus dasypogon The tasselled wobbegong (''Eucrossorhinus dasypogon'') is a species of carpet shark in the family Orectolobidae and the only member of its genus. It inhabits shallow coral reefs off northern Australia, New Guinea, and adjacent islands. Reachin ...

'' (Bleeker, 1867) (tasselled wobbegong) ** Genus ''

Orectolobus ''Orectolobus'' is a genus of carpet sharks in the family Orectolobidae. They are commonly known as wobbegongs, although this name also applies to the other members of the family. They are found in shallow temperate and tropical waters of th ...

'' Bonaparte, 1834 *** '' Orectolobus floridus''

Last A last is a mechanical form shaped like a human foot. It is used by shoemakers and cordwainers in the manufacture and repair of shoes. Lasts typically come in pairs and have been made from various materials, including hardwoods, cast iron, an ...

& Chidlow, 2008 (floral banded wobbegong) *** ''

Orectolobus halei The Gulf wobbegong or banded wobbegong (''Orectolobus halei'') is a species of carpet shark in the family (biology), family Orectolobidae, found in southern Australia between Southport, Queensland and Norwegian Bay (Australia), Norwegian Bay, West ...

'' Whitley, 1940. *** '' Orectolobus hutchinsi''

, Chidlow & Compagno, 2006. (western wobbegong) *** ''

Orectolobus japonicus The Japanese wobbegong (''Orectolobus japonicus'') is a carpet shark in the family Orectolobidae of the wobbegong family, found in the tropical western Pacific Ocean from Japan and Korea to Viet Nam and the Philippines, between latitudes 43 an ...

, 1906 (Japanese wobbegong) *** '' Orectolobus leptolineatus''

, Pogonoski & W. T. White, 2010 (Indonesian wobbegong) *** ''

Orectolobus maculatus The spotted wobbegong (''Orectolobus maculatus'') is a carpet shark in the family Orectolobidae, endemic to Australia. It is a large, robust species, typically reaching in length. Coloured green, yellow, or brown, it has distinctive O-shaped ...

'' ( Bonnaterre, 1788) (spotted wobbegong) *** ''

Orectolobus ornatus The ornate wobbegong (''Orectolobus ornatus'') is a species of carpet shark that lives in Australia and possibly other countries in the Western Pacific Ocean. It is coloured golden brown, yellow-green and blueish-grey, and it grows to maximum . ...

'' (

De Vis Charles Walter de Vis (Birmingham, England, 9 May 1829 – Brisbane, Queensland, Australia, 30 April 1915),

, 1883) (ornate wobbegong) *** '' Orectolobus parvimaculatus''

& Chidlow, 2008 (dwarf spotted wobbegong) *** '' Orectolobus reticulatus'' Last, Pogonoski & W. T. White, 2008 (network wobbegong) *** ''

Orectolobus wardi The northern wobbegong (''Orectolobus wardi'') is a carpet shark in the family Orectolobidae, found in the western Pacific Ocean around Australia, between latitudes 9° S to 26° S. It reaches a length of 63 cm. Captivity Northern wobbe ...

'' Whitley, 1939 (northern wobbegong) ** Genus '' Sutorectus'' Whitley, 1939 *** '' Sutorectus tentaculatus'' ( W. K. H. Peters, 1864) (cobbler wobbegong) * Family Parascylliidae Gill, 1862 (collared carpet sharks) ** Genus '' Cirrhoscyllium'' H. M. Smith & Radcliffe, 1913 *** '' Cirrhoscyllium expolitum'' H. M. Smith & Radcliffe, 1913 (barbelthroat carpetshark) *** '' Cirrhoscyllium formosanum''

Teng Teng may refer to: *Teng (surname) (滕), a Chinese surname *Teng (state), an ancient Chinese state *Teng (mythology), a flying dragon in Chinese mythology *Teng County Teng County or Tengxian (; za, Dwngz Yen) is a county of eastern Guangxi, C ...

, 1959 (Taiwan saddled carpetshark) *** '' Cirrhoscyllium japonicum'' Kamohara, 1943 (saddle carpetshark) ** Genus ''

Parascyllium ''Parascyllium'' is a genus of carpetsharks in the family Parascylliidae. Species in this genus are distributed in waters around Australia. Species * ''Parascyllium collare'' E. P. Ramsay & Ogilby, 1888 (collared carpetshark) * '' Parascyl ...

'' Gill, 1862 *** ''

Parascyllium collare The collared carpetshark (''Parascyllium collare'') is a poorly understood species of carpetshark of the family Parascylliidae endemic to the waters of eastern Australia between latitudes 26°S and 38°S. It is typically found in depth nea ...

'' E. P. Ramsay & Ogilby, 1888 (collared carpetshark) *** ''

Parascyllium elongatum The elongate carpet shark (''Parascyllium elongatum'') is a species of carpetshark in the family Parascylliidae. It is known from a single female specimen long, recovered from the stomach of a school shark (''Galeorhinus galeus'') caught from ...

& Stevens, 2008 (elongate carpetshark) *** ''

Parascyllium ferrugineum The rusty carpetshark (''Parascyllium ferrugineum'') is a carpetshark of the family Parascylliidae found off southern Australia between latitudes 31°S and 41°S near the ocean floor on the continental shelf. It inhabits rocky reefs and s ...

McCulloch McCulloch is a Scottish surname. It's a variation of the Northern Irish surname McCullough. It's commonly found in Galloway. Notable people with the surname include: *Alan McCulloch (politician), New Zealand politician *Alan McLeod McCulloch ( ...

, 1911 (rusty carpetshark) *** ''

Parascyllium sparsimaculatum The ginger carpetshark (''Parascyllium sparsimaculatum'') is a species of carpetshark of the family Parascylliidae endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, n ...

'' T. Goto & Last, 2002 (ginger carpetshark) *** ''

Parascyllium variolatum The necklace carpetshark (''Parascyllium variolatum''), also known as the varied carpetshark, is a carpetshark of the family Parascylliidae endemic to the waters off Australia's southern coast between latitudes 37°S and 41°S. It is found ...

'' ( A. H. A. Duméril, 1853) (necklace carpetshark) * 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, 1839) (whale sharks) ** Genus '' Rhincodon'' A. Smith, 1828 *** ''

Rhincodon typus 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 ...

'' A. Smith, 1828 (whale shark) * Family Stegostomatidae

, 1862 (zebra sharks) ** Genus '' Stegostoma'' J. P. Müller &

, 1837 *** ''

Stegostoma fasciatum The zebra shark (''Stegostoma tigrinum'') is a species of carpet shark and the sole member of the family Stegostomatidae. It is found throughout the tropical Indo-Pacific, frequenting coral reefs and sandy flats to a depth of . Adult zebra sharks ...

'' ( Hermann, 1783) (zebra shark)

References

External links

FishBase page on Orectolobiformes
* http://www.elasmo-research.org/education/topics/d_checklist.htm {{Authority control Extant Early Jurassic first appearances