Xiphactinus is an extinct genus of large predatory marine ray-finned fish that lived during the late Albian to the late Maastrichtian. The genus grew up to 5–6 metres (16–20 ft) in length, and superficially resembled a gargantuan, fanged tarpon. It is a member of the extinct order Ichthyodectiformes, which represent close relatives of modern teleosts.
Caturus is an extinct genus of predatory marine fishes in the family Caturidae in the order Amiiformes, related to modern bowfin. It has been suggested that the genus is non-monophyletic with respect to other caturid genera.
Lepidotes is an extinct genus of Mesozoic ray-finned fish. It has long been considered a wastebasket taxon, characterised by "general features, such as thick rhomboid scales and, for most of the species, by semi-tritorial or strongly tritorial dentition". with dozens of species assigned to it. Fossils attributed to Lepidotes have been found in Jurassic and Cretaceous rocks worldwide. It has been argued that Lepidotes should be restricted to species closely related to the type species L. gigas, which are only known from the Early Jurassic of Western and Central Europe, with most other species being not closely related, with other species transferred to new genera such as Scheenstia.Lepidotes belongs to Ginglymodi, a clade of fish whose only living representatives are the gars (Lepisosteidae). The type species L. gigas and close relatives are thought to be members of the family Lepidotidae, part of the order Lepisosteiformes within Ginglymodi, with other species occupying various other positions within Ginglymodi.
Thrissops is an extinct genus of stem-teleost fish from the Jurassic period. Its fossils are known from the Solnhofen Limestone, as well as the Kimmeridge Clay.
Diplomystus is an extinct genus of freshwater and marine clupeomorph fish distantly related to modern-day extant herrings, anchovies, and sardines. It is known from the United States, China, and Lebanon from the Late Cretaceous to the middle Eocene. Many other clupeomorph species from around the world were also formerly placed in the genus, due to it being a former wastebasket taxon. It was among the last surviving members of the formerly-diverse order Ellimmichthyiformes, with only its close relative Guiclupea living for longer.
Megalneusaurus is an extinct genus of large pliosaurs that lived during the Oxfordian and Kimmeridgian stages of the Late Jurassic in what is now North America. It was provisionally described as a species of Cimoliosaurus by the geologist Wilbur Clinton Knight in 1895, before being given its own genus by the same author in 1898. The only species identified to date is M. rex, known from several specimens identified in the Redwater Shale Member, within the Sundance Formation, Wyoming, United States. A specimen discovered in the Naknek Formation in southern Alaska was referred to the genus in 1994. In Ancient Greek, the generic name literally translates to "large swimming lizard", due to the measurement of the fossils of the holotype specimen.
Cooyoo is an extinct genus of ichthyodectid ray-finned fish known from the Lower Cretaceous. It contains a single species, C. australis, known from the Albian-aged Toolebuc and Allaru Formations of Queensland, Australia. C. australis was originally named by Arthur Smith Woodward as a species of Portheus in 1894, which was later amended to Xiphactinus.
Ichthyodectiformes is an extinct order of marine stem-teleost ray-finned fish. The order is named after the genus Ichthyodectes, established by Edward Drinker Cope in 1870. Ichthyodectiforms are usually considered to be some of the closest relatives of the teleost crown group.
Gillicus was a relatively small, 2 metres (6.6 ft) long ichthyodectiform ray-finned fish that lived in central North America, Europe and East Asia, from the late Albian to the early Maastrichtian.
Saurodon is an extinct genus of ichthyodectiform ray-finned fish from the Late Cretaceous.
Aidachar is an extinct genus of marine ichthyodectiform ray-finned fish from the Late Cretaceous (Cenomanian-Turonian) of Central Asia and North Africa.
Cladocyclus is an extinct genus of marine ichthyodectiform ray-finned fish from the middle Cretaceous. It was a predator of about 1.20 metres (3.9 ft) in length.
Chirocentrites is an extinct genus of marine ray-finned fish in the order Ichthyodectiformes. It contains a single species, C. coroninii, from the Late Cretaceous (Cenomanian) of Slovenia. A potential specimen is also known from the Albian-aged Pietraroja Plattenkalk of southern Italy, but it has been suggested that this specimen actually represents Cladocyclus.
Allothrissops is an extinct genus of marine ray-finned fish in the order Ichthyodectiformes, or bulldog fish. It is known from the Late Jurassic of Germany, where it has been found in the famous Solnhofen Limestone.
Clupavus is an extinct genus of marine ray-finned fish that lived during the middle of the Cretaceous period. It is known from North Africa, Europe, Brazil, and possibly North America.
Saurocephalus is an extinct genus of ray-finned fishes within the family Saurodontidae. The genus was first described in 1824 and contains six or seven species, including the type species S. lanciformis. Saurocephalus first appeared during the early Valanginian and continued on to the Maastrichtian, where it nearly went extinct. However, the recent discovery of S. lanciformis remains from the earliest Paleocene indicates that it just barely survived into the Cenozoic. This would make it the last surviving ichthyodectiform.
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.
Aratasaurus is an extinct genus of basal coelurosaurian theropod dinosaur from the Early Cretaceous (Aptian) Romualdo Formation of Brazil. The genus contains a single species, A. museunacionali, known from a partial right leg. Aratasaurus represents the only tetrapod fossil known from the lower levels of the Romualdo Formation.
Amakusaichthys is an extinct genus of ichthyodectiform ray-finned fish which lived during the Late Cretaceous, known from only one species A. goshouraensis. Fossils are known from Kumamoto Prefecture in Japan.
