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Chondrostei
Chondrostei is a subclass of non- neopterygian ray-finned fish. While the term originally referred to the paraphyletic grouping of all non-neopterygian ray-finned fish, it was redefined by Patterson in 1982 to be a clade comprising the Acipenseriformes (which includes sturgeon and paddlefish) and their extinct relatives. Taxa commonly suggested to represent relatives of the Acipenseriformes include the Triassic marine fish '' Birgeria'' and the Saurichthyiformes, but their relationship with the Acipenseriformes has been strongly challenged on cladistic grounds. Coccolepididae, a group of small weakly ossified Jurassic and Cretaceous fish found in both marine and freshwater environments, have also been suggested to be close relatives of the Acipenseriformes. However, this has never been subject to cladistic analysis. Near & Thacker (2024) also recovered the ptycholepiform '' Boreosomus'' as a stem-acipenseriform. The following taxa are known: * Subclass Chondrostei ** Genus � ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ray Finned Fish
Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of skin supported by radially extended thin bony spines called ''lepidotrichia'', as opposed to the bulkier, fleshy lobed fins of the sister clade Sarcopterygii (lobe-finned fish). Resembling folding fans, the actinopterygian fins can easily change shape and wetted area, providing superior thrust-to-weight ratios per movement compared to sarcopterygian and chondrichthyian fins. The fin rays attach directly to the proximal or basal skeletal elements, the radials, which represent the articulation between these fins and the internal skeleton (e.g., pelvic and pectoral girdles). The vast majority of actinopterygians are teleosts. By species count, they dominate the subphylum Vertebrata, and constitute nearly 99% of the over 30,000 extant species of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acipenseriformes
Acipenseriformes is an order (biology), order of basal (phylogenetics), basal Actinopterygii, ray-finned fishes that includes living and fossil sturgeons and paddlefishes (Acipenseroidei), as well as the extinct family (biology), families Chondrosteidae and Peipiaosteidae. They are the second earliest diverging group of living ray-finned fish after the bichirs. Despite being early diverging, they are highly Primitive (phylogenetics), derived, having only weakly Ossification, ossified skeletons that are mostly made of cartilage, and in modern representatives highly modified skulls. Description The axial skeleton of Acipenseriformes is only partially ossified, with the majority of the bones being replaced with cartilage. The notochord, usually only found in fish embryos, is unconstricted and retained throughout life. The premaxilla and maxilla bones of the skull present in other vertebrates have been lost. While larvae and early juvenile acipenseriforms have teeth, the adult ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acipenseroidei
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 diverging group of living ray-finned fish after the bichirs. Despite being early diverging, they are highly derived, having only weakly ossified skeletons that are mostly made of cartilage, and in modern representatives highly modified skulls. Description The axial skeleton of Acipenseriformes is only partially ossified, with the majority of the bones being replaced with cartilage. The notochord, usually only found in fish embryos, is unconstricted and retained throughout life. The premaxilla and maxilla bones of the skull present in other vertebrates have been lost. While larvae and early juvenile acipenseriforms have teeth, the adults are toothless, or nearly so. The infraorbital nerve is carried by a series of separate canals, rather than bein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrostei
Chondrostei is a subclass of non- neopterygian ray-finned fish. While the term originally referred to the paraphyletic grouping of all non-neopterygian ray-finned fish, it was redefined by Patterson in 1982 to be a clade comprising the Acipenseriformes (which includes sturgeon and paddlefish) and their extinct relatives. Taxa commonly suggested to represent relatives of the Acipenseriformes include the Triassic marine fish '' Birgeria'' and the Saurichthyiformes, but their relationship with the Acipenseriformes has been strongly challenged on cladistic grounds. Coccolepididae, a group of small weakly ossified Jurassic and Cretaceous fish found in both marine and freshwater environments, have also been suggested to be close relatives of the Acipenseriformes. However, this has never been subject to cladistic analysis. Near & Thacker (2024) also recovered the ptycholepiform '' Boreosomus'' as a stem-acipenseriform. The following taxa are known: * Subclass Chondrostei ** Genus � ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrosteidae
Chondrosteidae is a family (biology), family of extinct marine actinopterygian fishes, known from the Early Jurassic of Europe. They are closely related to modern Sturgeon, sturgeons and paddlefish of the order Acipenseriformes, and are either placed as part of that order or the separate order Chondrosteiformes within the Chondrostei. Three genera are known, ''Chondrosteus'', ''Gyrosteus'', and ''Strongylosteus''. Included species were of large size, with body lengths ranging from up to . Their skeleton was largely made up of bones (unlike living chondrosteans), but ossification was reduced compared to other ray-fins. See also * Prehistoric fish * List of prehistoric bony fish References External links * Acipenseriformes Fossils of Great Britain Jurassic fish of Europe Jurassic bony fish Prehistoric ray-finned fish families {{Jurassic-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrosteiformes
Chondrosteidae is a family of extinct marine actinopterygian fishes, known from the Early Jurassic of Europe. They are closely related to modern sturgeons and paddlefish of the order Acipenseriformes, and are either placed as part of that order or the separate order Chondrosteiformes within the Chondrostei. Three genera are known, '' Chondrosteus'', '' Gyrosteus'', and '' Strongylosteus''. Included species were of large size, with body lengths ranging from up to . Their skeleton was largely made up of bones (unlike living chondrosteans), but ossification was reduced compared to other ray-fins. See also * Prehistoric fish * List of prehistoric bony fish This list of prehistoric bony fish is an attempt to create a comprehensive listing of all Genus, genera from the fossil record that have ever been considered to be bony fish (class Osteichthyes), excluding purely vernacular terms. The list includ ... References External links * Acipenseriformes Fossils of Great Br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sturgeon
Sturgeon (from Old English ultimately from Proto-Indo-European language, Proto-Indo-European *''str̥(Hx)yón''-) is the common name for the 27 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the Late Cretaceous, and are descended from other, earlier Acipenseriformes, acipenseriform fish, which date back to the Early Jurassic period, some 174 to 201 million years ago. They are one of two living families of the Acipenseriformes alongside paddlefish (Polyodontidae). The family is grouped into five genera: ''Acipenser'', ''Huso'', ''Scaphirhynchus,'' ''Sinosturio'', and ''Pseudoscaphirhynchus''. Two species (''Adriatic sturgeon, H. naccarii'' and ''Dabry's sturgeon, S. dabryanus'') may be extinct in the wild, and one (''Syr Darya sturgeon, P. fedtschenkoi'') may be entirely extinct. Sturgeons are native to subtropical, temperate and sub-Arctic rivers, lakes and coastlines of Eurasia and North America. A Maastrichtian-age fossil found i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coccolepididae
Coccolepididae is an extinct family of ray-finned fish, known from the Early Jurassic to Early Cretaceous, most of which were originally referred to the type genus '' Coccolepis.'' They had a widespread distribution, being found in North and South America, Australia, Asia and Europe. They are mostly known from freshwater environments, though several species have been found in marine environments. They are morphologically conservative, and have poorly ossified endo and exoskeletons, which usually results in poor preservation. Historically, they have been classified as members "Palaeonisciformes”, a paraphyletic grouping of non-neopterygian fish, due to their plesiomorphic conservative morphology closely resembling those of many other groups of earlier ray-finned fish. Some recent authors have suggested that they may belong to the order Chondrostei as relatives of the Acipenseriformes (which contains sturgeons and paddlefish). History and classification The type species, ''Cocco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eochondrosteus
''Eochondrosteus'' (meaning "dawn '' Chondrosteus''") is a genus of extinct marine actinopterygian (ray-finned fish), comprising one species, ''E. sinensis'' ( monotypy) from the Early Triassic strata in Gansu Province (Beishan Hills), China (previously interpreted as Permian in age). It is suggested to be the most basal acipenseriform (sturgeon Sturgeon (from Old English ultimately from Proto-Indo-European language, Proto-Indo-European *''str̥(Hx)yón''-) is the common name for the 27 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the ..., paddlefish, and their fossil relatives). It was originally described in 2005, and then redescribed in 2020 in Chinese. Other authors have considered the placement of ''Eochondrosteus'' within the Acipenseriformes as tentative, or have expressed doubt about its placement in the order References Acipenseriformes {{Triassic-fish-stub Monotypic prehistoric ray-finned fish gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birgeria
''Birgeria'' is a genus of carnivorous marine ray-finned fish from the Triassic period. ''Birgeria'' had a global distribution, with fossil known from Madagascar, Spitsbergen, Germany, Switzerland, Italy, Slovenia, China, Russia, Canada and Nevada, United States. The oldest fossils are from Griesbachian aged beds of the Wordie Creek Formation of East Greenland. ''Birgeria'' existed throughout the entire Triassic period, from the very beginning just after the Permian-Triassic mass extinction, up to the very end with its extinction during the Triassic-Jurassic mass extinction. The type species was first described as ''Saurichthys mougeoti''. Following a reinvestigation, Erik Stensiö concluded that this species cannot be ascribed to ''Saurichthys''. He thus erected a new genus, which he named after his colleague Birger Sjöström, who had joined him on an expedition to the Arctic island of Spitsbergen (Svalbard) in 1915. Systematics ''Birgeria'' is the only genus of the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saurichthyiformes
Saurichthyiformes is an extinct order (biology), order of Actinopterygii, ray-finned fish which existed in Asia, Africa, Australia (continent), Australia, Europe and North America, during the late Permian to early Middle Jurassic. Saurichthyiiformes comprise two families, Saurichthyidae and Yelangichthyidae. Yelangichthyidae is monotypy, monotypic, containing only the genus ''Yelangichthys.'' The gar or needlefish-like Saurichthyidae is primarily known from the genus ''Saurichthys.'' Additionally, the subgenus, subgenera ''Saurorhynchus'' ''Costasaurichthys'', ''Eosaurichthys'', ''Lepidosaurichthys'', and ''Sinosaurichthys'' are frequently used to group species, and are sometimes considered separate genera. Species are known from both marine end freshwater deposits. They had their highest diversity during the Early Triassic, Early and Middle Triassic. Their phylogenetic position is uncertain, while they have often been considered members of Chondrostei, and thus related to liv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
