The family Alligatoridae of crocodylians includes alligators, caimans and their extinct relatives.
Lungfish are freshwater vertebrates belonging to the class Dipnoi. Lungfish are best known for retaining ancestral characteristics within the Osteichthyes, including the ability to breathe air, and ancestral structures within Sarcopterygii, including the presence of lobed fins with a well-developed internal skeleton. Lungfish represent the closest living relatives of the tetrapods. The mouths of lungfish typically bear tooth plates, which are used to crush hard shelled organisms.
Galeocerdo is a genus of ground shark. Only a single species, G. cuvier, the tiger shark is extant. The earliest fossils date back to the early Eocene epoch, (Ypresian), around 56–47.8 Million years ago. While historically considered a member of the requiem shark family Carcharhinidae, it is currently considered to be the only member of the family Galeocerdonidae. While this genus was historically considered diverse, including 21 extinct species, morphometric analysis conducted in 2021 suggested that the diversity of the genus included only 5 extinct species much lower than previously assumed. The oldest fossils of the extant G. cuvier date to the middle Miocene.
The Australian lungfish, also known as the Queensland lungfish, Burnett salmon and barramunda, is the only surviving member of the family Neoceratodontidae. It is one of only six extant lungfish species in the world. Endemic to Australia, the Neoceratodontidae are an ancient family belonging to the class Sarcopterygii, or lobe-finned fishes.
Ceratodontidae is an extinct family of lungfish with fossils known worldwide from the earliest Triassic to the Eocene.
The South American lungfish, also known as the American mud-fish and scaly salamanderfish, is the single species of lungfish found in swamps and slow-moving waters of the Amazon, Paraguay, and lower Paraná River basins in South America. Notable as an obligate air-breather, it is the sole member of its family Lepidosirenidae, although some authors also place Protopterus in the family. In Brazil, it is known by the indigenous language Tupi name piramboia, which means "snake-fish", and synonyms pirarucu-bóia, traíra-bóia, and caramuru.
Neoceratodus is a genus of lungfish in the family Neoceratodontidae. The extant Australian lungfish is the only surviving member of this genus, but it was formerly much more widespread, being distributed throughout Africa, Australia, and South America. Species were also much more diverse in body plan; for example, the Cretaceous species Neoceratodus africanus was a gigantic species that coexisted with Spinosaurus in what is now the Kem Kem Formation of Morocco. The earliest fossils from this genus are of Neoceratodus potkooroki from the mid Cretaceous (Albian-Cenomanian) Griman Creek Formation of Australia; remains from the Late Jurassic of Uruguay assigned to this genus probably do not belong to the genus.
Protopterus is the genus of four species of lungfish found in Africa. Protopterus is considered the sole genus in the family Protopteridae, which is grouped with Lepidosiren in the order Lepidosireniformes.
Hippopotamus is a genus of artiodactyl mammals consisting of one extant species, Hippopotamus amphibius, the river hippopotamus, and several extinct species from both recent and prehistoric times. It belongs to the family Hippopotamidae, which also includes the pygmy hippopotamus and a number of extinct genera.
The Gnathorhizidae are an extinct family of lungfish that lived from the late Carboniferous until the middle Triassic. Gnathorhizid fossils have been found in North America, Madagascar, Australia, and possibly Eastern Europe and South Africa. They are characterized by high-ridged toothplates that form cutting blades and a reduction in cranial bones.
Ceratodus is an extinct genus of lungfish. It has been described as a "catch all", and a "form genus" used to refer to the remains of a variety of lungfish belonging to the extinct family Ceratodontidae. Fossil evidence dates back to the Early Triassic. A wide range of fossil species from different time periods have been found around the world in places such as the United States, Argentina, Greenland, England, Germany, Egypt, Madagascar, China, and Australia. Ceratodus is believed to have become extinct sometime around the beginning of the Eocene Epoch.
Euryzygomatomys is a genus of South American rodents, commonly called guiaras, in the family Echimyidae. It contains two extant and one fossil species, found in Argentina, Brazil and Paraguay. They are as follows:
Ferganoceratodus is a genus of prehistoric lungfish known from the Mesozoic of Asia. Based on morphological evidence, it has either been recovered as a basal member of the Ceratodontiformes or to be the sister group of the Neoceratodontidae.
Gnathorhiza is an extinct genus of prehistoric lobe-finned fish (lungfish) which lived from the Carboniferous period to the Early Triassic epoch. It is the only known lungfish genus to have crossed the Permo-Triassic boundary. Several species have been described, ranging in size from 5 to 50 centimeters.
Mioceratodus is an extinct genus of lungfish in the family Neoceratodontidae, which also contains the extant Queensland lungfish. It is known only from Oligocene and Miocene-aged sediments in Australia, although phylogenetic evidence supports it having first diverged from its closest relative, Neoceratodus, during the Late Jurassic or Early Cretaceous period.
Metaceratodus is an extinct genus of prehistoric lungfish in the family Ceratodontidae, with an indeterminate specimen known from the Late Triassic (Norian)-aged Lissauer Breccia of Poland and more complete specimens known from the Late Cretaceous of Queensland, Australia and Argentina. The genus was named and described by Frederick Chapman in 1914.
Sagenodus is an extinct genus of prehistoric lungfish. It is a lungfish from the Permo-Carboniferous period found in Europe and North America.
Ptychoceratodus is an extinct genus of lungfish living from Early Triassic to Middle Jurassic. It was established by Otto Jaekel for one species, transferred from Ceratodus genus. Type species is P. serratus from the Middle Triassic of Switzerland and Germany. Ptychoceratodus had two pairs of massive dental plates, bearing 4-6 acute ridges. Its skull roof was composed from massive, plate-like bones. In the central part of skull roof was localized an unossified fenestra. Most of the Ptychoceratodus findings are isolated dental plates, some associated with jaws. Other parts of skull or postcranial skeleton are relatively rarely found as fossils. The anatomy of skull is the best recognized in P. serratus, whereas less complete cranial material is available also for P. concinuus, P. phillipsi, and P. rectangulus. Although Ptychoceratodus is known exclusively from the Triassic and Jurassic, there were also Cretaceous specimens referred to this genus. However, they are more often regarded as representants of Metaceratodus. Ptychoceratodus is the only member of the family Ptychoceratodontidae. The first named species is P. phillipsi by Louis Agassiz in 1837 as a species of Ceratodus and later moved to Ptychoceratodus genus. Occurrences of Ptychoceratodus come mainly from Europe. However, occurrences from other continents suggest it was dispersed globally during the Triassic. After 2010, the new fossil material behind the Europe was reported from South America, India, and Greenland
Paraceratodus is an extinct genus of prehistoric lungfish. Only one species, P. germaini, is known from the latest Permian or earliest Triassic period of Madagascar. Phylogenetic evidence supports it being the most basal member of the suborder Ceratodontoidei, which contains modern lungfish, and as with the rest of the order it likely diverged during the late Carboniferous.
Ceratodontiformes is the only extant order of lungfish, containing the families Neoceratodontidae, Lepidosirenidae, and Protopteridae as well as many other extinct groups. Members of this group are the only lungfish known to have survived the Permian-Triassic extinction event. Although lungfish originated in marine environments, the Ceratodontiformes have been an exclusively freshwater group since the Carboniferous.
