Carcharodon is a genus of sharks within the family Lamnidae, colloquially called the "white sharks." The only extant member is the great white shark. The extant species was preceded by a number of fossil (extinct) species including C. hubbelli and C. hastalis. The first appearance of the genus may have been as early as the Early Miocene or Late Oligocene. Carcharocles megalodon is still argued by some paleontologists to be a close relative of Carcharodon carcharias - as well as being in the same genus. The megalodon's scientific name was originally 'Carcharodon' megalodon, but more recently, the giant shark has been assigned by most scientists to either the genus Carcharocles or Otodus.
Palaeoniscum is an extinct genus of ray-finned fish from the Permian period (Guadalupian-Lopingian) of England, Germany, Turkey, North America and Greenland, and possibly other regions. The genus was named Palaeoniscum in 1818 by Henri Marie Ducrotay de Blainville, but was later misspelled as Palaeoniscus by Blainville and other authors. Palaeoniscum belongs to the family Palaeoniscidae.
Gyrosteus is an extinct genus of very large ray-finned fish belonging to the family Chondrosteidae. It comprises the type species, Gyrosteus mirabilis, which lived during the early Toarcian in what is now northern Europe. A possible second species, "Gyrosteus" subdeltoideus, is known from otoliths.
Isurus is a genus of mackerel sharks in the family Lamnidae, commonly known as the mako sharks. They are largely pelagic, fast predatory fish capable of swimming at speeds up to 50 km/h (31 mph).
Sphenacanthus is an extinct genus of a chondrichtyan xenacanthiform that belongs to the Sphenacanthidae family and lived from the Late Devonian, through Carboniferous until the Late Permian period in Scotland, Spain, Russia and Brazil. It lived 359 million years ago, and probably it was one of the first member of the elasmobranchians, the lineage that leads to the modern sharks. Sphenacanthus probably hunts small fishes and, unlike their modern-day relatives, its inhabited fresh water lagoons. Sphenacanthus had seven fins, two in the upper part and five in the underside, and it had a heterodont dentition and mandibles relatively long and deeper. Sphenacanthus serrulatus is still only known from incomplete neurocranial remains and associated dermal material. These suggest that it was a relatively large shark, probably well over one meter in length when fully grown. Its body form was probably similar to that of other phalacanthous sharks.
Acrotemnus is an extinct genus of marine pycnodontid ray-finned fish from various areas of the Tethys Sea that lived during the Turonian stage of the Upper Cretaceous. The genus comprises three species A. faba, A. streckeri, and A. megafrendodon.
Scotiptera is a genus of flies in the family Tachinidae.
Chondrosteidae is a family of extinct marine actinopterygian fishes, known from the Early Jurassic of Europe. They are closely related to modern sturgeons and paddlefish of the order Acipenseriformes, and are either placed as part of that order or the separate order Chondrosteiformes within the Chondrostei. Three genera are known, Chondrosteus, Gyrosteus, and Strongylosteus. Included species were of large size, with body lengths ranging from 2 metres (6.6 ft) up to 7 metres (23 ft). Their skeleton was largely made up of bones, but ossification was reduced compared to other ray-fins.
Cretalamna is a genus of extinct otodontid shark that lived from the latest Early Cretaceous to Eocene epoch. It is considered by many to be the ancestor of the largest sharks to have ever lived, such as Otodus angustidens, Otodus chubutensis, and Otodus megalodon.
Palaeospinax is an extinct genus of synechodontiform cartilaginous fish. Although several species have been described, the genus is considered nomen dubium because the type-specimen of the type species, Palaeospinax priscus, from the Late Triassic-Early Jurassic of Europe lacks appropriate diagnostic characters to define the genus.
Ctenacanthus is an extinct genus of ctenacanthiform chondrichthyan. Remains have been found in the Bloyd Formation of Arkansas and the Cleveland Shale of Ohio in the United States and in South America.
Asteracanthus is an extinct genus of hybodont, known from the Middle Jurassic (Bathonian) to the Early Cretaceous (Valanginian).
Pseudocorax is an extinct genus of mackerel sharks that lived during the Late Cretaceous. It contains six valid species that have been found in Europe, the Middle East, North Africa, and North America. It was formerly assigned to the family Anacoracidae, but is now placed in its own family Pseudocoracidae along with Galeocorax. The former species "P." australis and "P." primulus have been reidentified as species of Echinorhinus and Squalicorax, respectively.
Nemacanthus is an extinct genus of prehistoric sharks in the family Palaeospinacidae.
Ophiopsiella is an extinct genus of prehistoric ray-finned fish.
Furo is an extinct genus of ray-finned fish belonging to the order Ioniscopiformes that has been found in Europe. The type species is F. orthostomus.
Avonacanthus is an extinct genus of cartilaginous fish from the lower Carboniferous. The name is derived from the type locality of Avon Gorge, near Bristol, England. It contains a single species, A. brevis, which was originally regarded as a species of Ctenacanthus. It is currently known only from fin spines. It is probably a cladistically basal Heslerodid.
Rhomphaiodon is an extinct genus of prehistoric sharks in the order Synechodontiformes that has been found in Late Triassic and Early Jurassic deposits located in Europe. The type species R. minor was originally named as a species of Hybodus in 1837 by Louis Agassiz. A second species, R. nicolensis, was added when the genus was named in 1993.
Pseudoscapanorhynchidae is a family of extinct mackerel sharks that lived during the Cretaceous and potentially the Paleogene. It currently includes Cretodus, Eoptolamna, Leptostyrax, Protolamna, Pseudoscapanorhynchus, and possibly Lilamna.
Arthrobatis is an extinct genus of possible rays that lived during the Late Triassic-Early Jurassic in the United Kingdom. It contains one species, A. rileyi, and is the only member of the family Arthrobatidae. It might be the oldest known batoid, but its exact age and affinities are uncertain.
