Acestrus is an extinct genus of prehistoric marine ray-finned fish that lived during the lower Eocene in Europe. It contains one species, A. ornatus from the London Clay, known from a single braincase. It is thought to possibly be closely allied with billfish based on the braincase morphology, although it remains uncertain whether it had the rostrum characteristic of billfishes. Some authorities have suggested blochiid affinities.
Bobbichthys is an extinct genus of marine ray-finned fish that lived in what is now Chile during the Oxfordian stage of the Late Jurassic epoch. It was a member of the Varasichthyidae, a family of potentially crossognathiform fish.
Brookvalia is an extinct genus of prehistoric freshwater ray-finned fish that lived during the Middle Triassic epoch. It contains a single species, B. gracilis, known from the Hawkesbury Sandstone near Brookvale, New South Wales, Australia.
Bolbocara is an extinct genus of rattail that lived during the Upper Miocene subepoch of Southern California. It contains a single species, B. gyrinus. It may be related to the extant genus Bathygadus.
Absalomichthys velifer is an extinct, prehistoric manefish that lived during the Upper Miocene of what is now Southern California. Its dorsal fin was huge in comparison with living species. It is known from the Monterey Formation of Los Angeles County.
Asialepidotus is an extinct genus of prehistoric marine ray-finned fish that lived during the Ladinian stage of the Middle Triassic epoch. It contains a single species, A. shingyiensis, from Guizhou, China.
Acrolepis is an extinct genus of prehistoric marine bony fish that lived from the Famennian stage of the Devonian to the early Triassic epoch. Some species from the Early Triassic of Tasmania are also ascribed to Acrolepis.
Brachypareion is an extinct genus of prehistoric marine ray-finned fish that lived during the Pennsylvanian epoch. It contains a single species, B. insperatum, known from the Saur Mountains of Kazakhstan. It is placed in the paraphyletic group Palaeonisciformes.
Ainia is an extinct genus of prehistoric ray-finned fish that lived during the Kimmeridgian stage of the Late Jurassic epoch. It contains a single species, A. armata, known from the famous Solnhofen Limestone of Germany. It is a distant relative of the bowfin, although it is more closely related to genera such as Caturus and Osteorachis.
Balistomorphus is an extinct genus of prehistoric triggerfish during the early Oligocene epoch in what is now Canton Glarus, Switzerland. It inhabited the marine environment of the Tethys Ocean.
Besania is an extinct genus of prehistoric marine ray-finned fish that lived during the Anisian and Ladinian ages of the Middle Triassic epoch in what is now southern/southeastern Switzerland and northern Italy. Fossils were recovered from the Besano Formation of Monte San Giorgio area and the Prosanto Formation of canton Graubünden, Switzerland.
Aetheodontus is an extinct genus of prehistoric marine bony fish that lived during the early Ladinian stage of the Middle Triassic epoch of what is now Italy and Switzerland. It contains a single species, A. besanensis.
Avitolabrax is an extinct genus of prehistoric marine perciform fish that lived during the early part of the Miocene epoch. It has a single known species, A. denticulatus, from the Siramizu Formation of Fukushima, Japan.
Properca is an extinct genus of prehistoric marine perciform fish that lived in Europe throughout much of the Cenozoic, from the Paleocene to the Miocene epochs.
Shoshonia is a Devonian-era extinct genus of prehistoric sarcopterygians, or lobe-finned fish. It contains one species, Shoshonia arctopteryx. The fish was named in reference to the Shoshoni people and the Shoshone National Forest in Wyoming, in the United States.
Aetheretmon is an extinct genus of prehistoric freshwater and estuarine ray-finned fish that lived during the early Mississippian (Dinantian) age in what is now Europe, including Scotland, Belarus, and Russia. It contains only the species A. valentiacum. This genus has the oldest known actinopterygian growth series, indicating that juvenile Aetheretmon had tails similar to those of modern teleosts, but unlike teleosts, their upper tails continued to grow throughout their lives instead of truncating early. Initially classified as a "palaeoniscid", later studies have recovered it as a stem-neopterygian, or more recently a stem-actinopteran.
Isadia is an extinct genus of prehistoric freshwater ray-finned fish from the order Eurynotoidiformes. It is known from the Permian of European Russia. The genus Amblypterina is partially considered a junior synonym of both Isadia and Kichkassia.
Ascalabos is an extinct genus of marine ray-finned fish known from the Late Jurassic Solnhofen Limestone of Germany. It contains one species, A. voithii. Some authorities synonymize it with Leptolepis.
Bendenius is an extinct genus of prehistoric marine ray-finned fish. It is known from the Early Carboniferous of Belgium. It was named after Belgian paleontologist Pierre-Joseph van Beneden.
Boreolepis is an extinct genus of prehistoric marine ray-finned fish that lived from the Late Kungurian to the Wuchiapingian of the Permian period. It inhabited the high northern latitudes in what is now Greenland and European Russia.
