Cladistia is a subclass of

bony fishes Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes (cartila ...

whose only living members are the bichirs of tropical Africa. Their major

synapomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to ...

are a heterocercal tail in which the

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

has independent rays, and a posteriorly elongated

parasphenoid The parasphenoid is a bone which can be found in the cranium of many vertebrates. It is an unpaired dermal bone which lies at the midline of the roof of the mouth. In many reptiles (including birds), it fuses to the endochondral (cartilage-derived ...

. Cladistia are the earliest diverging branch of living

Actinopterygii Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class (biology), class of Osteichthyes, bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built ...

, and are thought to have diverged from the

Actinopteri Actinopteri () is the sister group of Cladistia (bichirs) in the class Actinopterygii (ray-finned fish). Dating back to the Permian period, the Actinopteri comprise the Chondrostei (sturgeons and paddlefish), the Holostei ( bowfins and gars), ...

, the group which includes all other living ray finned fish, by the

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

. However, the fossil range for the only extant order (

Polypteriformes Bichirs and the reedfish comprise Polypteridae , a family of archaic ray-finned fishes and the only family in the order Polypteriformes .Helfman GS, Collette BB, Facey DE, Bowen BW. 2009. The Diversity of Fishes. West Sussex, UK: Blackwell Pu ...

) is comparatively young, only reaching as far back as the mid-

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

of South America and Africa, and the two extant genera of bichir only diverged around the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

. Aside from bichirs, other extinct fish groups thought to be members of the group include the Scanilepiformes, known from

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

(and possibly

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

) of the Northern Hemisphere. The Guildayichthyiformes of

North America are also sometimes considered cladistians, but this is thought to be dubious, with other authorities placing them as a

stem-group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

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 ...

Taxonomy

Based on work done by

Near NEAR or Near may refer to: People * Thomas J. Near, US evolutionary ichthyologist * Near, a developer who created the higan emulator Science, mathematics, technology, biology, and medicine * National Emergency Alarm Repeater (NEAR), a form ...

''et al'' (2017) and Lund (2000): * Order

Bleeker 1859 ** Genus †'' Latinopollia'' Meunier and Gayet 1998 *** Species †'' Latinopollia suarezi'' (Meunier & Gayet 1996) Meunier & Gayet 1998 ** Genus †'' Dagetella'' Gayet & Meunier 1991 *** Species †'' Dagetella sudamericana'' Gayet & Meunier 1991 ** Genus †'' Bartschichthys'' Gayet & Meunier 1996 'Bartschia'' Gayet & Meunier 1996 non Rehder 1943*** Species †'' B. arnoulti'' (Gayet & Meunier 1996) 'Bartschia arnoulti'' Gayet & Meunier 1996">Bartschia_arnoulti.html" ;"title="' 'Bartschia arnoulti'' Gayet & Meunier 1996*** Species †''Bartschichthys napatensis">B. napatensis'' Werner & Gayet 1997 *** Species †''Bartschichthys tubularis">B. tubularis'' (Gayet & Meunier 1996) [''Bartschia tubularis'' Gayet & Meunier 1996] ** Genus †''Sudania'' Werner & Gayet 1997 *** Species †''Sudania gracilis, S. gracilis'' Werner & Gayet 1997 *** Species †'' S. oblonga'' Werner & Gayet 1997 ** Genus †'' Saharichthys'' Werner & Gayet 1997 *** Species †'' S. nigeriensis'' (Gayet & Meunier 1996) 'Sainthilairia nigeriensis'' Gayet & Meunier 1996">Sainthilairia_nigeriensis.html" ;"title="'Sainthilairia nigeriensis">'Sainthilairia nigeriensis'' Gayet & Meunier 1996*** Species †''Saharichthys africanus">S. africanus'' (Gayet & Meunier 1996) [''Sainthilairia africana'' Gayet & Meunier 1996] ** Genus †''Sainthilairia'' Gayet & Meunier 1996 *** Species †''S. beccussiformis'' Gayet & Meunier 1996 *** Species †''S. elongata'' Werner & Gayet 1997 *** Species †''S. falciformis'' Gayet & Meunier 1996 *** Species †''S. grandis'' Gayet & Meunier 1996 *** Species †''S. intermedia'' Werner & Gayet 1997 ** Genus †'' Inbecetemia'' Werner & Gayet 1997 *** Species †'' I. torta'' (Gayet & Meunier 1996) 'Sainthilairia torta'' Gayet & Meunier 1996">Sainthilairia_torta.html" ;"title="'Sainthilairia torta">'Sainthilairia torta'' Gayet & Meunier 1996*** Species †''Inbecetemia tortissima">I. tortissima'' (Gayet & Meunier 1996) [''Sainthilairia tortissima'' Gayet & Meunier 1996] ** Genus †''Nagaia'' Werner & Gayet 1997 *** Species †''Nagaia extrema'' Werner & Gayet 1997 ** Family Polypteridae Lacépède 1803 sensu stricto *** Genus †'' Bawitius'' Grandstaff et al. 2012 **** Species †''

Bawitius bartheli ''Bawitius'' is an extinct genus of giant polypterid from the Upper Cretaceous (lower Cenomanian) Bahariya Formation of Egypt. The type species is ''B. bartheli'', named as a species of ''Polypterus'' in 1984, and the genus etymology comes from B ...

'' (Schaal 1984) Grandstaff et al. 2012 'Polypterus bartheli'' Schaal 1984">Polypterus_bartheli.html" ;"title="'Polypterus bartheli">'Polypterus bartheli'' Schaal 1984*** Genus †''Serenoichthys'' Dutheil 1999 **** Species †''Serenoichthys kemkemensis'' Dutheil 1999 *** Genus ''Erpetoichthys'' Smith 1865 [''Calamoichthys'' Smith 1866] **** Species '' Erpetoichthys calabaricus'' *** Genus ''

Polypterus ''Polypterus'' is a genus of freshwater fish in the bichir family ( Polypteridae) of order Polypteriformes. The type species is the Nile bichir (''P. bichir''). Fish in this genus live in various areas in Africa. ''Polypterus'' is the only kno ...

'' Lacepède 1803 **** Species '' Polypterus ansorgii'' Boulenger, 1910 **** Species ''

Polypterus bichir ''Polypterus'' is a genus of freshwater fish in the bichir family (biology), family (Polypteridae) of order (biology), order Polypteriformes. The type species is the Polypterus bichir, Nile bichir (''P. bichir''). Fish in this genus live in vario ...

'' Lacépède, 1803 **** Species '' Polypterus congicus'' Boulenger, 1898 **** Species '' Polypterus delhezi'' Boulenger, 1899 **** Species '' Polypterus endlicherii'' Heckel, 1847 **** Species '' Polypterus mokelembembe'' Schliewen & Schäfer, 2006 **** Species '' Polypterus ornatipinnis'' Boulenger, 1902 **** Species '' Polypterus palmas'' Ayres, 1850 **** Species ''

Polypterus polli ''Polypterus polli'', Poll's bichir, is a species of bichir from the Malebo Pool and the lower and central basins of the Congo River. It was named in honor of Belgium, Belgian ichthyologist Max Poll. Description ''P. polli'' is an “upper-jaw” ...

'' J. P. Gosse, 1988 **** Species '' Polypterus retropinnis'' Vaillant, 1899 **** Species ''

Polypterus senegalus ''Polypterus senegalus'', commonly known as the Senegal bichir, gray bichir or Cuvier's bichir, is an African species of Actinopterygii, ray-finned fish in the bichir Family (biology), family, Bichir, Polypteridae. It is a typical example of poly ...

Cuvier Jean Léopold Nicolas Frédéric, baron Cuvier (23 August 1769 – 13 May 1832), known as Georges Cuvier (; ), was a French natural history, naturalist and zoology, zoologist, sometimes referred to as the "founding father of paleontology". Cuv ...

, 1829 **** Species '' Polypterus teugelsi'' Britz, 2004 **** Species '' Polypterus weeksii'' Boulenger, 1898 *Order † Scanilepiformes Sytchevskaya, 1999 **Genus †'' Beishanichthys'' Xu and Gao, 2011 ***Species †'' Beishanichthys brevicaudalis'' Xu and Gao, 2011 **Genus †'' Fukangichthys'' Su, 1978 ***Species †'' Fukangichthys longidorsalis'' Su, 1978 **Genus †'' Mizhilepis'' Liu & Shen, 2006 ***Species †'' Mizhilepis zhangyaensis'' Liu & Shen, 2006 **Genus †'' Tanaocrossus'' Schaeffer, 1967 ***Species †'' Tanaocrossus kalliokoskii'' Schaeffer, 1967 **Family † Scanilepididae Aldinger, 1935 ***Genus †'' Scanilepis'' Aldinger, 1935 ****Species †'' Scanilepis dubius'' (Woodward, 1893) ****?Species †'' Scanilepis spitzbergensis'' Aldinger, 1935 **Family † Evenkiidae Selezneva, 1985 ***Genus †'' Evenkia'' Berg, 1941 ****Species †'' Evenkia eunotoptera'' Berg, 1941 ***Genus †'' Oshiaichthys'' Schultze ''et al''., 2021 ****Species †'' Oshiaichthys ferganica'' Schultze ''et al.'', 2021 ***Genus †'' Toyemia'' Minikh, 1990 ****Species †'' Toyemia blumentalis'' Minikh, 1995 ****Species †'' Toyemia tverdochlebovi'' Minikh, 1990

Disputed members

* Order † Guildayichthyiformes Lund 2000 ** Family † Guildayichthyidae Lund 2000 *** Genus †'' Guildayichthys'' Lund 2000 **** Species †'' Guildayichthys carnegiei'' Lund 2000 *** Genus †'' Discoserra'' Lund 2000 **** Species †'' Discoserra pectinodon'' Lund 2000

References

{{Taxonbar, from=Q144462 Ray-finned fish taxonomy Vertebrate subclasses Extant Permian first appearances