Characiformes is an order of ray-finned fish, comprising the characins and their allies. Grouped in 18 recognized families, more than 2000 different species are described, including the well-known piranha and tetras.
Lungfish are freshwater vertebrates belonging to the order 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.
Sarcopterygii — sometimes considered synonymous with Crossopterygii — is a taxon of the bony fishes known as the lobe-finned fishes. The group Tetrapoda, a mostly terrestrial superclass including amphibians, sauropsids and synapsids, evolved from certain sarcopterygians; under a cladistic view, tetrapods are themselves considered a subgroup within Sarcopterygii.
Bichirs and the reedfish comprise Polypteridae, a family of archaic ray-finned fishes and the only family in the order Polypteriformes.
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 from the earliest Triassic to the Eocene.
The South American lungfish 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. Relatively little is known about the South American lungfish. Additional common names include American mud-fish and scaly salamanderfish. The South American Lungfish have adapted to cope with both droughts and floods. This is normal due to the South American Lungfish adapting pulmonary mechanoreceptors. 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 was formerly thought to be the sole genus in the family Protopteridae, but more recent studies have classified it with Lepidosiren in the family Lepidosirenidae.
"Labyrinthodontia" is an informal grouping of extinct predatory amphibians which were major components of ecosystems in the late Paleozoic and early Mesozoic eras. Traditionally considered a subclass of the class Amphibia, modern classification systems recognize that labyrinthodonts are not a formal natural group (clade) exclusive of other tetrapods. Instead, they consistute an evolutionary grade, ancestral to living tetrapods such as lissamphibians and amniotes. "Labyrinthodont"-grade vertebrates evolved from lobe-finned fishes in the Devonian, though a formal boundary between fish and amphibian is difficult to define at this point in time.
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.
Ferganoceratodus is a genus of prehistoric lungfish known from the Mesozoic of Asia. It is a basal member of the suborder Ceratodontoidei. Despite only being known from Mesozoic-aged rocks, phylogenetic analyses indicate that it diverged from the rest of the suborder around 300 million years ago, during the late Carboniferous.
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.
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.
The gilled lungfish, also known as the East African lungfish, is a species of African lungfish. It is found in the swamps and flood plains of East Africa, and has been positively identified in Kenya, Somalia and Mozambique. Records from Tanzania require confirmation and may be the result of introductions.
The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fish lineages belong to the Agnatha, or jawless fish. Early examples include Haikouichthys. During the late Cambrian, eel-like jawless fish called the conodonts, and small mostly armoured fish known as ostracoderms, first appeared. Most jawless fish are now extinct; but the extant lampreys may approximate ancient pre-jawed fish. Lampreys belong to the Cyclostomata, which includes the extant hagfish, and this group may have split early on from other agnathans.
Neoceratodontidae is a family of lungfish containing the extant Australian lungfish and several extinct genera. It and Lepidosirenidae represent the only lungfish families still extant.
Ceratodontoidei is a suborder of lungfish that is defined as "the clade including all taxa more closely related to Lepidosiren, Neoceratodus and Gnathorhiza than to Uronemus, Conchopoma and Sagenodus". Members of this suborder are known as ceratodontoids. The only presently extant lungfish in the families Neoceratodontidae and Lepidosirenidae belong to this suborder.
Anne Kemp is an Australian ichthyologist and paleoichthyologist who specializes in lungfishes. Her primary area of study is the Australian lungfish. She has served as a research fellow at Griffith University since 2010. Prior to this, she had also served as a research fellow at Queensland Museum between 1980 and 1991, and at the Centre of Microscopy at the University of Queensland between 1999 and 2008.
