Chondrostei is a group 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 and their extinct relatives.
The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between 251.9 Ma and 247.2 Ma. Rocks from this epoch are collectively known as the Lower Triassic Series, which is a unit in chronostratigraphy. The Early Triassic is the oldest epoch of the Mesozoic Era. It is preceded by the Lopingian Epoch and followed by the Middle Triassic Epoch. The Early Triassic is divided into the Induan and Olenekian ages. The Induan is subdivided into the Griesbachian and Dienerian subages and the Olenekian is subdivided into the Smithian and Spathian subages.
In the geologic timescale, the Olenekian is an age in the Early Triassic epoch; in chronostratigraphy, it is a stage in the Lower Triassic series. It spans the time between 251.2 Ma and 247.2 Ma. The Olenekian is sometimes divided into the Smithian and the Spathian subages or substages. The Olenekian follows the Induan and is followed by the Anisian.
The Induan is the first age of the Early Triassic epoch in the geologic timescale, or the lowest stage of the Lower Triassic series in chronostratigraphy. It spans the time between 251.9 Ma and 251.2 Ma. The Induan is sometimes divided into the Griesbachian and the Dienerian subages or substages. The Induan is preceded by the Changhsingian and is followed by the Olenekian.
Saurichthys is an extinct genus of predatory ray-finned fish from the Triassic Period. It is the type genus of the family Saurichthyidae, and the most speciose and longest lasting genus in the family. This family also includes the Permian Eosaurichthys (China) and the Jurassic Saurorhynchus from Europe and North America, though it may be more appropriate to treat these as subgenera of Saurichthys, due to the genus Saurichthys otherwise being paraphyletic.
Cleithrolepis is an extinct genus of freshwater ray-finned fish that lived from the Induan age to the Anisian in what is now Australia and Libya. A species from Late Triassic Germany, C. brueckneri, was also ascribed to Cleithrolepis.
Australosomus is an extinct genus of prehistoric ray-finned fish that lived during the Early Triassic epoch in what is now Greenland, Kenya, Tanzania, Madagascar, South Africa and Canada.
Pteronisculus is an extinct genus of prehistoric ray-finned fish that lived during the Early Triassic and Middle Triassic epochs of the Triassic period worldwide.
Eosaurichthys is an extinct genus of saurichthyid ray-finned fish that lived during the late Permian epoch in what is now China.
Bobasatrania is an extinct genus of prehistoric marine ray-finned fish that survived the Permian-Triassic extinction event. Fossils of Bobasatrania were found in beds of Changhsingian to Ladinian age. It was most speciose during the Early Triassic.
Boreosomus is an extinct genus of Triassic marine ray-finned fish. It was first described from the Arctic island of Spitsbergen, hence its genus name, but was later also discovered in other parts of the world. The type species is Boreosomus arcticus.
Colobodus is an extinct genus of marine Triassic ray-finned fish of the family Colobodontidae and order Perleidiformes. Fossils have been found in Europe and China, encompassing the former Tethys Ocean. It could reach body lengths of about 70 cm.
Saurorhynchus is an extinct genus of carnivorous bony fish that lived during the Early and Middle Jurassic epochs. Fossils have been found in Europe and North America (Canada). It is commonly found in pelagic and lagoonal deposits, but mostly marine. Largest specimens can grow up to 1.9 metres (6.2 ft).
Sinosaurichthys is an extinct genus of saurichthyid ray-finned fish, which existed in south-western China during the Middle Triassic. Fossils have been found in the Upper Member of the Guanling Formation of two localities: Yangjuan of Panxian County, Guizhou Province, and Dawazi of Luoping, Yunnan Province, China.
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 Yelangichthyidae. Yelangichthyidae is monotypic, containing only the genus Yelangichthys. The gar or needlefish-like Saurichthyidae is primarily known from the genus Saurichthys. Additionally, the subgenera SaurorhynchusCostasaurichthys, 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 and Middle Triassic. Their phylogenetic position is uncertain, while they have often been considered members of Chondrostei, and thus related to living sturgeons and paddlefish, phylogenetic analysis of well-preserved remains has considered this relationship equivocal. They may actually belong to the stem-group of Actinopterygii, and thus not closely related to any living group of ray-finned fish.
The Wordie Creek Formation is an uppermost Permian and Lower Triassic geologic formation in Greenland, outcrops of which are located in Northeast Greenland National Park. In 2017, it was suggested to be raised to group status, as the Wordie Creek Group.
The Vikinghøgda Formation is a geologic formation in Svalbard, Norway. It preserves fossils dating back to the Early Triassic (Griesbachian-Spathian) period. It is split into three members, from oldest to youngest: the Deltadalen Member (Induan), Lusitaniadalen Member (Smithian), and Vendomdalen Member (Spathian). The formation can be found in central Spitsbergen, southern Spitsbergen, as well as the smaller islands of Barentsøya and Edgeøya. The type locality is positioned in the vicinity of Vikinghøgda and Sticky Keep, two low peaks along the southeast edge of Sassendalen in Spitsbergen. The two upper members of the Vikinghøgda Formation were previously grouped together as the Sticky Keep Formation.
The Vardebukta Formation is a geologic formation in Norway. It preserves fossils dating back to the Induan stage. Outcrops are known from the Hornsund area but also from Bellsund and Isfjorden areas.
The Besano Formation is a geological formation in the southern Alps of northwestern Italy and southern Switzerland. This formation, a thin but fossiliferous succession of dolomite and black shale, is famous for its preservation of Middle Triassic (Anisian–Ladinian) marine life including fish and aquatic reptiles. It is exposed in the Monte San Giorgio and Besano area. It is among the formations responsible for the area being designated as a UNESCO World Heritage Site. In Switzerland, it is also known as the Grenzbitumenzone. The Anisian-Ladinian boundary lies in the upper part of the Besano Formation.
Brazilichthys is an extinct genus of prehistoric freshwater ray-finned fish that lived during the Cisuralian epoch in what is now Maranhão, Brazil. The type and only species, B. macrognathus, is known from a single partially complete skull, which was recovered from the Pedra de Fogo Formation near Pastos Bons, Maranhão, Brazil.
