The Amiiformes

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

has only two

extant Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Exta ...

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, the

bowfin The ruddy bowfin (''Amia calva'') is a ray-finned fish native to North America. Common names include mudfish, mud pike, dogfish, grindle, grinnel, swamp trout, and choupique. It is regarded as a relict, being one of only two surviving species ...

s: ''

Amia calva The ruddy bowfin (''Amia calva'') is a ray-finned fish native to North America. Common names include mudfish, mud pike, dogfish, grindle, grinnel, swamp trout, and choupique. It is regarded as a relict species, relict, being one of only two sur ...

'' and ''

Amia ocellicauda ''Amia ocellicauda'', the eyespot bowfin or emerald bowfin, is a species of Amia (fish), bowfin native to North America. Originally described by John Richardson (naturalist), John Richardson from Lake Huron in 1836, it was synonymized with ''Amia ...

'', the latter recognized as a separate species in 2022. These Amiiformes are found in the

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

systems of

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, in the United States and parts of southern Canada. They live in freshwater streams, rivers, and swamps. The order first appeared in the Triassic, and the extinct members include both marine and freshwater species, many of which are morphologically disparate from bowfins, such as the caturids.

Evolution and diversity

The

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

species of the Amiiformes can be found as

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 preserve ...

s in

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

and

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

, but the bowfin is the last living species in the order. Amiiformes is therefore the last surviving

Halecomorphi Halecomorphi is a taxon of Actinopterygii, ray-finned bony fish in the clade Neopterygii. The only extant Halecomorph species are the bowfin (''Amia calva'') and eyespot bowfin (''Amia ocellicauda''), but the group contains many extinct species i ...

, the

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

to which the bowfin and its fossil relatives belong. Other orders, such as the

Parasemionotiformes Parasemionotiformes is an extinct order of neopterygian ray-finned fish that existed globally during the Triassic period. It comprises the families Parasemionotidae and Promecosominidae. Many of the included genera are monotypic and most specie ...

, are all extinct. Halecomorphs, and its

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

Ginglymodi Ginglymodi is a clade of ray-finned fish containing modern-day gars (Lepisosteidae) and their extinct relatives (including the family (biology), family Lepidotidae) in the Order (biology), order Lepisosteiformes, the extinct orders Semionotiforme ...

, belong to

Holostei Holostei is a group of ray-finned bony fish. It is divided into two major clades, the Halecomorphi, represented by the single living genus, '' Amia'' with two species, the bowfins (''Amia calva'' and '' Amia ocellicauda''), as well as the Gin ...

. Holosteans are the sister group of

teleosteans Teleostei (; Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts (), is, by far, the largest group of ray-finned fishes (class Actinopterygii), with 96% of all extant species of fish. The Teleostei, which i ...

, the group to which nearly all (i.e., 96%) living

fishes A fish (: fish or fishes) is an aquatic, anamniotic, gill-bearing vertebrate animal with swimming fins and a hard skull, but lacking limbs with digits. Fish can be grouped into the more basal jawless fish and the more common jawed ...

belong to. Holosteans and Teleosts form a clade called

Neopterygii Neopterygii (from Greek νέος ''neos'' 'new' and πτέρυξ ''pteryx'' 'fin') is a subclass of ray-finned fish (Actinopterygii). Neopterygii includes the Holostei and the Teleostei, of which the latter comprise the vast majority of extant ...

. The following

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

summarizes the

evolutionary relationships Evolution is the change in the heritable characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certai ...

of living and fossil Halecomorphs, and other neopterygians. Possible specimens of caturoids are known from the Late Triassic, with the earliest unambiguous members being known from the Early Jurassic. Amiiformes had spread to North America and Africa by the end of the Middle Jurassic, reaching an apex of diversity during the Early Cretaceous, during the Late Cretaceous and Cenozoic, the group declined until only a single genus, ''Amia'', containing the bowfin remained.

Taxonomy

* Order Amiiformes Hay, 1929 ** Genus †'' Guizhouamia'' Liu, Yin & Wang, 2002 ** Genus †'' Otomitla'' Felix, 1891 ** Genus †'' Paraliodesmus'' Dunkle, 1969 ** Superfamily † Caturoidea *** Genus †'' Eurypoma'' Huxley, 1866 *** Genus †'' Gymnoichthys''? Tintori ''et al.'', 2010 *** Genus †'' Liodesmus'' Wagner, 1859 *** Genus †'' Strobilodus'' Wagner, 1851 *** Family †

Caturidae Caturidae is an extinct Family (biology), family of predatory Amiiformes, amiiform Actinopterygii, ray-finned fish, being the sister-group to the extant family Amiidae. Though their body form is very different than the modern bowfin, a number of f ...

Owen, 1860 **** Genus †'' Catutoichthys'' Gouiric-Cavalli, 2016 **** Genus †'' Amblysemius'' Agassiz, 1844 **** Genus †''

Caturus ''Caturus'' (from , 'down' and 'tail') is an extinct genus of predatory marine fishes in the family Caturidae in the order Amiiformes, related to modern bowfin. It has been suggested that the genus is non-monophyletic with respect to other c ...

'' Agassiz, 1834 ** Superfamily Amioidea Bonaparte, 1838 *** Genus †'' Amiidarum''? Lange, 1968 tolith*** Genus †'' Ferganamia''? Kaznyshkin, 1990 *** Genus †'' Lehmanamia''? Casier, 1966 *** Genus †'' Tomognathus'' Dixon, 1850 ***Family †

Sinamiidae Sinamiidae is an extinct family of ray-finned fish. They are halecomorph fishes endemic to Early Cretaceous freshwater environments in East and Southeast Asia. Along with Amiidae, it is one of two families that makes up the superfamily Amioide ...

Berg, 1940 ****Genus †'' Ikechaoamia'' Liu, 1961 ****Genus †''

Siamamia ''Siamamia'' is an extinct genus of ray-finned fish in the family Amiidae.Deesri, U.; Naksri, W.; Jintasakul, P.; Noda, Y.; Yukawa, H.; Hossny, T.E.; Cavin, L. A New Sinamiin Fish (Actinopterygii) from the Early Cretaceous of Thailand: Implicati ...

'' Cavin ''et al.'', 2007 ****Genus †'' Sinamia'' Stensiö, 1935 *** Family

Amiidae The Amiidae are a family of basal ray-finned fishes. The bowfin and the eyespot bowfin ('' Amia ocellicauda'') are the only two species to survive today, although additional species in all four subfamilies of Amiidae are known from Jurassic, Cre ...

Bonaparte, 1837 **** Subfamily Amiinae Bonaparte, 1837 (sensu Grande & Bemis, 1998) ***** Genus '' Amia'' Linnaeus, 1766 ***** Genus †''

Cyclurus ''Cyclurus'' (Ancient Greek for "rounded tail") is an extinct genus of freshwater Amiidae, amiid Actinopterygii, ray-finned fish known from the Late Cretaceous to the Rupelian, Early Oligocene across much of the Northern Hemisphere. It is though ...

'' Agassiz, 1839 ***** Genus †'' Pseudamiatus'' Whitley, 1954 **** Subfamily † Amiopsinae Grande & Bemis, 1998 ***** Genus †'' Amiopsis'' Kner, 1863 **** Subfamily † Solnhofenamiinae Grande & Bemis, 1998 ***** Genus †'' Solnhofenamia'' Grande & Bemis, 1998 **** Subfamily †

Vidalamiinae The Amiidae are a family of basal (phylogenetics), basal ray-finned fishes. The bowfin and the eyespot bowfin (''Amia ocellicauda'') are the only two species to survive today, although additional species in all four subfamilies of Amiidae are kno ...

Grande & Bemis, 1998 ***** Tribe † Calamopleurini Grande & Bemis, 1998 ****** Genus †''

Calamopleurus ''Calamopleurus'' is a prehistoric genus of marine halecomorph ray-finned fish from the Early Cretaceous of South America and northern Africa. It was a relative of the modern bowfin, with both belonging to the family Amiidae. ''C. cylindricus'' ...

'' Agassiz, 1841 ****** Genus †''

Maliamia ''Maliamia'' ("Malian bowfin") is an extinct genus of Amiidae, amiid ray-finned fish from the Early Eocene, known from fragmentary remains found in the Tamaguélelt Formation of Mali. It was described in 1989, based on fossils recovered by three ...

'' Patterson & Longbottom, 1989 ***** Tribe † Vidalamiini Grande & Bemis, 1998 ****** Genus †''

Melvius ''Melvius'' is a genus of vidalamiin amiid ray-finned fish from the Late Cretaceous. The type species, ''Melvius thomasi'', was described by Bryant in 1987 from Hell Creek Formation.L. J. Bryant. 1987. A new genus and species of Amiidae (Holost ...

'' Bryant, 1987 ****** Genus †'' Pachyamia'' Chalifa & Tchernov 1982 ****** Genus †'' Vidalamia'' White &

Moy-Thomas James Alan Moy-Thomas (12 September 1908 – 29 February 1944) was an English palaeontological ichthyologist. The son of Alan Moy-Thomas and his wife Gertrude, he was born in London. He had a younger brother Edward and an older sister Joan Car ...

, 1941 ****** Genus †'' Nipponamia'' Yabumoto, 1994

References

External links

{{Taxonbar, from=Q3314611 Articles which contain graphical timelines Ray-finned fish orders