The Amiiformes order of fish has only two extant species, the bowfins: Amia calva and Amia ocellicauda, the latter recognized as a separate species in 2022. These Amiiformes are found in the freshwater systems of North America, 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.
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, as well as the Ginglymodi, the sole living representatives being the gars (Lepisosteidae), represented by seven living species in two genera. The earliest members of the clade appeared during the Early Triassic, over 250 million years ago.
Birgeria is a genus of carnivorous marine ray-finned fish from the Triassic period. Birgeria had a global distribution. Fossils were found in 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.
Luisiella is an extinct genus of prehistoric bony fish that lived during the Kimmeridgian stage of the Late Jurassic epoch. Fossils of the genus have been found in either the Cañadón Calcáreo Formation or Cañadón Asfalto Formation in Chubut Province, Argentina.
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.
Gyrolepidoides is an extinct genus of prehistoric bony fish that lived during the Late Triassic epoch in what is now Mendoza, Argentina.
Ctenognathichthys is an extinct genus of prehistoric bony fish that lived during the Anisian and Ladinian ages of the Middle Triassic epoch in what is now southern/southeastern Switzerland and northern Italy.
Bobasatrania is an extinct genus of prehistoric bony 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 ray-finned fish. It was first described from the Arctic island of Spitsbergen, but was later also discovered in other parts of the world. The type species is Boreosomus arcticus.
Coccolepis is an extinct genus of prehistoric ray-finned fish in the family Coccolepididae. Originally including most species within the family, it is now restricted to two species from the Late Jurassic Solnhofen Limestone of Germany. The holotype of C. bucklandi, designated and described by Louis Agassiz, was thought to be lost but was later rediscovered in Neuchâtel.
Orthocormus is an extinct genus of prehistoric pachycormiform bony fish. It is known from three species found in Late Jurassic (Kimmeridgian) aged plattenkalk deposits in Bavaria, Germany. The species "Hypsocormus" tenuirostris Woodward 1889 from the late Middle Jurassic (Callovian) Oxford Clay is not closely related to the type species of Hypsocormus, and is more closely related to Orthocormus + Protosphyraena, and thus has sometimes been referred to in open nomenclature as Orthocormus? tenuirostris. The species of Orthocormus reached over a metre in length, and are thought to have been pelagic predators.
Ptycholepiformes are an extinct order of prehistoric ray-finned fish that existed during the Triassic period and the Early Jurassic epoch. The order includes the genera Acrorhabdus, Ardoreosomus, Boreosomus, Chungkingichthys, Ptycholepis, and Yuchoulepis. Although several families have been proposed, some studies place all these genera in the same family, Ptycholepididae.
Halecomorphi is a taxon of ray-finned bony fish in the clade Neopterygii. The only extant Halecomorph species are the bowfin and eyespot bowfin, but the group contains many extinct species in several families in the order Amiiformes, as well as the extinct orders Ionoscopiformes, Panxianichthyiformes, and Parasemionotiformes. The fossil record of halecomorphs goes back at least to the Early Triassic epoch.
The Los Rastros Formation is a Ladinian to Carnian fossiliferous formation of the Agua de la Peña Group in the Ischigualasto-Villa Unión Basin in northwestern Argentina. Fossil theropod tracks, as well as many insects, fossil fish of Myriolepis, bivalves and crustaceans and flora have been reported from the formation.
The Besano Formation is a geological formation in the southern Alps of northwestern Italy and southern Switzerland. This formation, a short 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 vicinity of Monte San Giorgio and 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.
Candelarialepis is an extinct genus of prehistoric ray-finned fish that lived during the Induan age of the Early Triassic epoch in what is now Nevada. It was described from the Candelaria Formation.
Ardoreosomus is an extinct genus of ray-finned fish. It was described from the Induan aged Candelaria Formation of Nevada, United States, which was located near the equator during the Early Triassic epoch. It contains only one species, A. occidentalis (monotypy).
Ginglymodi is a clade of ray-finned fish containing modern-day gars (Lepisosteidae) and their extinct relatives, including the family Lepidotidae and the orders Semionotiformes and Kyphosichthyiformes, and various other extinct taxa. Ginglymodi is one of the two major subgroups of the infraclass Holostei, the other one being Halecomorphi, which contains the bowfin and its fossil relatives.
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 species lived during the Early Triassic epoch.
Turseodus is an extinct genus of ray-finned fish found in Late Triassic freshwater sediments of the United States. Two species have been described, T. acutus from the Lockatong Formation of Pennsylvania, and T. dolorensis from the Chinle Formation of Colorado.
