Chondrostei is a group of non-
neopterygian ray-finned fish
Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species.
The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...
, while the term originally referred to a
paraphyletic group of all non-neopterygian ray-finned fish, it was redefined by Patterson in 1982 to be a clade comprising the
Acipenseriformes
Acipenseriformes is an order of basal ray-finned fishes that includes living and fossil sturgeons and paddlefishes (Acipenseroidei), as well as the extinct families Chondrosteidae and Peipiaosteidae. They are the second earliest div ...
(which includes
sturgeon and
paddlefish
Paddlefish (family Polyodontidae) are a family of ray-finned fish belonging to order Acipenseriformes, and one of two living groups of the order alongside sturgeons (Acipenseridae). They are distinguished from other fish by their titular elongla ...
) and their extinct relatives.
Taxa commonly suggested to represent relatives of the Acipenseriformes include the Triassic marine fish ''
Birgeria'' and the
Saurichthyiformes
Saurichthyiformes is an extinct order of ray-finned fish which existed in Asia, Africa, Australia, Europe and North America, during the late Permian to early Middle Jurassic. Saurichthyiiformes comprise two families, Saurichthyidae and ...
, but their the relationship with the Acipenseriformes has been strongly challenged on
cladistical grounds.
, a group of small weakly ossified Jurassic and Cretaceous fish found in both marine and freshwater environments, have been suggested to be close relatives of the Acipenseriformes, however, this has never been subject to cladistical analysis.
Classification
*
Acipenseriformes
Acipenseriformes is an order of basal ray-finned fishes that includes living and fossil sturgeons and paddlefishes (Acipenseroidei), as well as the extinct families Chondrosteidae and Peipiaosteidae. They are the second earliest div ...
**
Acipenseridae — sturgeons
**
Polyodontidae — paddlefishes
**
Chondrosteidae
Chondrosteidae is a family of extinct marine actinopterygian fishes in the order Acipenseriformes. Three genera are known from the Early Jurassic of Europe, ''Chondrosteus'', '' Gyrosteus'', and '' Strongylosteus''. Included species were of l ...
(†)
**
Errolichthyidae(†)
*
Cheirolepidiformes(†)
*
Coccolepididae(†)
*
Guildayichthyiformes(†)
*
Luganoiiformes(†)
*
Palaeonisciformes(†)
**
Acrolepidae
Acrolepididae is an extinct family of ray-finned fish. Genera referred to Acrolepididae existed from the Early Carboniferous period to the Early Triassic epoch. They were nektonic carnivores with a fusiform body.
Acrolepididae may be closely re ...
(†)
**
Birgeriidae(†)
**
Palaeoniscidae(†)
*
Perleidiformes(†)
*
Phanerorhynchiformes(†)
*
Pholidopleuriformes(†)
*Polypteriformes
**
Polypteridae
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 Pub ...
- bichirs and reedfish
*
Ptycholepiformes(†)
*
Saurichthyiformes
Saurichthyiformes is an extinct order of ray-finned fish which existed in Asia, Africa, Australia, Europe and North America, during the late Permian to early Middle Jurassic. Saurichthyiiformes comprise two families, Saurichthyidae and ...
(†)
*
Tarrasiiformes(†)
References
{{Taxonbar, from=Q275646
Extant Silurian first appearances
Paraphyletic groups