Eels are ray-finned fish belonging to the order Anguilliformes, which consists of eight suborders, 20 families, 164 genera, and about 1000 species. Eels undergo considerable development from the early larval stage to the eventual adult stage and are usually predators.
Chanopsis is an extinct genus of prehistoric freshwater bonytongue relative that lived from the late Aptian to the Albian stage of the Early Cretaceous epoch. It contains a single species, C. lombardi from the Democratic Republic of the Congo.
Mesoclupea showchangensis is an extinct ichthyodectiform ray-finned fish that lived in freshwater environments in what is now China during the Early Cretaceous epoch. It differs from its sister genus, Chuhsiungichthys, primarily by having a more posteriorly-placed dorsal fin.
Aphnelepis is an extinct genus of prehistoric freshwater ray-finned fish that lived during the Late Jurassic epoch. It contains a single species, A. australis, from the Talbragar River beds of New South Wales, Australia.
Arctosomus is an extinct genus of prehistoric freshwater bony fish that lived during the Early Triassic epoch of Krasnoyarsk Krai, Russia. It contains a single species, A. sibiricus.
Agecephalichthys is an extinct genus of prehistoric freshwater "palaeonisciform" ray-finned fish that lived during the Anisian age. It contains a single species, A. granulatus from the Hawkesbury Sandstone in what is now New South Wales, Australia.
Austropleuropholis is an extinct genus of freshwater ray-finned fish that lived during the Late Jurassic. It contains a single species, A. lombardi, from the Kimmeridigian of the Democratic Republic of the Congo, from the terrestrial/freshwater series of the Stanleyville Formation.
Scanilepis is an extinct genus of prehistoric bony fish that lived during the Rhaetian-?Hettangian ages. The type species, S. dubia, is known from the Rhaetian freshwater deposits of the Bjuv member of the Höganäs Formation, southwestern Sweden. A second species, S. spitzbergensis was mentioned from the Hettangian of the Festning section of the Grøfjorden area in Spitsbergen, Norway but was never described.
Retodus is an extinct genus of prehistoric lungfish found in Cretaceous-aged freshwater strata of Egypt, Algeria and Niger. The type species, R. tuberculatus, was named in 2006. It was originally named as a species of Ceratodus and Neoceratodus in 1963.
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.
Amiopsis is an extinct genus of prehistoric freshwater and marine bony fish belonging to the family Amiidae, making it closely related to the modern bowfin. Fossils are known from the Late Jurassic Solnhofen Limestone, Germany, the Early Cretaceous Purbeck Group, England, La Pedrera de Rúbies Formation, Spain and Bernnissant Iguanodon locality, Belgium and the Late Cretaceous (Cenomanian) of the Balkans. The monophyly of the genus is questionable, due to it being based on a single character, "the presence of three or more lateral fossae on each side of most abdominal centra". Remains previously assigned to this genus from the Early Cretaceous Las Hoyas, Spain have been moved into the new genus Hispanamia.
Cycloptychius is an extinct genus of prehistoric freshwater & marine ray-finned fish that existed throughout much of the Carboniferous period in Eurasia, and possibly into the Early Permian in South Africa. It was a member of the Rhadinichthyidae, a family of basal ray-finned fish that was formerly placed in the now-paraphyletic order Palaeonisciformes.
Charleuxia is an extinct genus of prehistoric freshwater ray-finned fish that lived during the Asselian age in what is now Burgundy, France (Autun). It may possibly belong to the genus Paramblypterus.
Decazella is an extinct genus of prehistoric freshwater ray-finned fish that lived during the late Carboniferous period. It contains a single species, D. vetteri from the Gzhelian (Stephanian) age of what is now Occitania, France.
Gardinerichthys is an extinct genus of freshwater actinopterygian bony fish from the Cisuralian epoch of Germany, and the middle Permian of India. The type species, G. latus, was discovered in Asselian aged layers (Rotliegend).
Phareodus is a genus of freshwater fish from the Paleocene to the Eocene of Australia, Europe and North and South America.
Chuhsiungichthys is an extinct genus of ichthyodectiform ray-finned fish that lived in freshwater environments in what is now Yunnan, China, and Kyushu, Japan during the Cretaceous. It differs from its sister genus, Mesoclupea, primarily by having a comparatively more anteriorly-placed dorsal fin.
Archaeomaenidae is an extinct family of stem-teleost fish found in freshwater environments of Jurassic New South Wales of Australia, China, and Antarctica, and in Lower Cretaceous New South Wales and Mongolia.
Dorsetichthys is an extinct genus of stem-teleost ray-finned fish from the Early Jurassic period of Europe.
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.
