Ceratodontoidei is a suborder of

lungfish 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, i ...

that is defined as "the clade including all taxa more closely related to ''

Lepidosiren The South American lungfish (''Lepidosiren paradoxa'') 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 ...

'', '' Neoceratodus'' and '' Gnathorhiza'' than to '' Uronemus'', '' Conchopoma'' and ''

Sagenodus ''Sagenodus'' is an extinct genus of prehistoric lungfish. It is a lungfish from the Permo-Carboniferous period found in Europe and North America. See also * Sarcopterygii * List of sarcopterygians * List of prehistoric bony fish References

''". Members of this suborder are known as ceratodontoids. The only presently extant lungfish in the families

Neoceratodontidae 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. Fossils from this family are first known from Triassic-aged ...

and

Lepidosirenidae Lepidosirenidae is a family of lungfish containing the genera ''Lepidosiren'' (the South American lungfish) and '' Protopterus'' (the African lungfish). Both genera were formerly thought to represent the distinct families Lepidosirenidae and Prot ...

belong to this suborder.

Taxonomy

The suborder was formerly defined as being within the order Ceratodontiformes and including the families Neoceratodontidae and Ceratodontidae, as they were formerly thought to be closely related to one another. However, phylogenetic analyses indicate that this classification is paraphyletic, as Ceratodontidae was found to be a sister group to a clade containing Lepidosirenidae, which was formerly classified as Lepidosireniformes, a distinct order from Ceratodontiformes. Due to this, Lepidosireniformes and Ceratodontiformes were redefined as families within the order

Dipnoi 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, i ...

, and Ceratodontei was redefined as including all lungfish more closely allied with Neoceratodontidae and Lepidosirenidae. The current taxa within the suborder are listed below: The oldest fossils from this suborder are of

Gnathorhizidae 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. ...

from the

Late Carboniferous Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...

. Phylogenetic evidence indicates that the suborder itself originated slightly earlier in the late Carboniferous and rapidly diversified into the multiple families between then and the start of the

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last ...

References

{{Taxonbar, from=Q21230686 Lungfish Extant Pennsylvanian first appearances Fish suborders