Ceratodontiformes

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Ceratodontiformes
Temporal range: Late Carboniferous - Holocene, 318.1 - 0 mya
Neoceratodus forsteri Aquarium tropical du Palais de la Porte Doree 10042016 2.jpg
Neoceratodus forsteri , a neoceratodontid
Lepidosiren paradoxa 0.jpg
Lepidosiren paradoxa , a lepidosirenid
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Sarcopterygii
Clade: Rhipidistia
Clade: Dipnomorpha
Class: Dipnoi
Order: Ceratodontiformes
Berg, 1940
Type genus
Ceratodus
Agassiz, 1837
Families

Several extinct, see text

Ceratodontiformes range.jpg
Native distribution of Ceratodontiformes
Synonyms

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. [2] [3] Although lungfish originated in marine environments, the Ceratodontiformes have been an exclusively freshwater group since the Carboniferous. [4] This order was formerly considered the suborder Ceratodontoidei.

Contents

All lungfish of the order can and often do estivate (except the spotted African lungfish, which can but rarely does so). [5] All members of the order are obligatory air-breathers; only the Australian lungfish has functioning gills when adult; members of the Lepidosirenidae have gills only when they are larvae. [5] The South American and African lungfish also all have generally small scales and two lungs as opposed to the Australian lungfish's single lung. [5]

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.[ citation needed ] 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 Ceratodontiformes, redefined as including all lungfish more closely allied with Neoceratodontidae and Lepidosirenidae. [3]

This order contains the following subtaxa: [2] [3] [4] [6]

Some of these groups, such as Ceratodontidae, are thought to be paraphyletic due to being based entirely on morphology. [2] Other groups are often synonymized with one another or subsumed within others, due to the taxonomic confusion surrounding this group. [7]

Phylogenies

Kemp et al (2017) found the following taxonomy based on morphological evidence:

Ceratodontoidei

Based on this treatment, the oldest fossils of the Ceratodontiformes are of Gnathorhizidae from the Late Carboniferous, which are thought to be closely related to modern Lepidosirenidae and Protopteridae. This would indicate that the order itself originated slightly earlier in the late Carboniferous and rapidly diversified into the multiple families between then and the start of the Permian, leading to a very deep split between the Neoceratodontidae and the Lepidosirenidae + Protopteridae. [3] [8]

Brownstein, Harrington & Near (2023) found a different taxonomy, based on both phylogenetic and morphological evidence. In this treatment, the former Lepidosirenformes is kept. [4]

This analysis found a more recent divergence, with the Neoceratodontidae and the "Lepidosireniformes" diverging during the Late Jurassic, in contrast to the Paleozoic divergences estimated by Kemp et al's morphological study. This divergence was found to be tied to the breakup of Gondwana during the same time. [4]

Related Research Articles

<span class="mw-page-title-main">Lungfish</span> Type of lobefinned fishes

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.

<span class="mw-page-title-main">Ceratodontidae</span> Extinct family of fishes

Ceratodontidae is an extinct family of lungfish with fossils known worldwide from the earliest Triassic to the Eocene.

<span class="mw-page-title-main">South American lungfish</span> Species of fish

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.

<i>Neoceratodus</i> Genus of lungfish

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.

<i>Protopterus</i> Genus of Lungfish

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.

<span class="mw-page-title-main">Tournaisian</span> First stage of the Carboniferous

The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous. The Tournaisian age lasted from 358.9 Ma to 346.7 Ma. It is preceded by the Famennian and is followed by the Viséan. In global stratigraphy, the Tournaisian contains two substages: the Hastarian and Ivorian. These two substages were originally designated as European regional stages.

<span class="mw-page-title-main">Serpukhovian</span> Third stage of the Carboniferous

The Serpukhovian is in the ICS geologic timescale the uppermost stage or youngest age of the Mississippian, the lower subsystem of the Carboniferous. The Serpukhovian age lasted from 330.9 Ma to 323.2 Ma. It is preceded by the Visean and is followed by the Bashkirian. The Serpukhovian correlates with the lower part of the Namurian Stage of European stratigraphy and the middle and upper parts of the Chesterian Stage of North American stratigraphy.

<span class="mw-page-title-main">Late Paleozoic icehouse</span> Ice age

The late Paleozoic icehouse, also known as the Late Paleozoic Ice Age (LPIA) and formerly known as the Karoo ice age, was an ice age that began in the Late Devonian and ended in the Late Permian, occurring from 360 to 255 million years ago (Mya), and large land-based ice sheets were then present on Earth's surface. It was the second major icehouse period of the Phanerozoic, after the Late Ordovician Andean-Saharan glaciation.

<span class="mw-page-title-main">Gnathorhizidae</span> Extinct family of fishes

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.

The Hangenberg event, also known as the Hangenberg crisis or end-Devonian extinction, is a mass extinction that occurred at the end of the Famennian stage, the last stage in the Devonian Period. It is usually considered the second-largest extinction in the Devonian Period, having occurred approximately 13 million years after the Late Devonian mass extinction at the Frasnian-Famennian boundary. The event is named after the Hangenberg Shale, which is part of a sequence that straddles the Devonian-Carboniferous boundary in the Rhenish Massif of Germany.

Diabolepis is an extinct genus of very primitive marine lungfish which lived during in the Early Devonian period. It contains a single species, D. speratus of Yunnan, China, from the mid-late Lochkovian of the Xitun Formation. It is one of the oldest known lungfish genera. It is the only member of the family Diabolepididae and the order Diabolepidiformes, although neither of these parent taxa have been officially described, despite their names being in scientific usage.

Arganodus is an extinct genus of freshwater lungfish that had a wide global distribution throughout much of the Triassic period, with a single species surviving across Gondwana into the Cretaceous. It is the only member of the family Arganodontidae, although it is sometimes placed in the Ceratodontidae or synonymized with the genus Asiatoceratodus.

Ferganoceratodus is a genus of prehistoric lungfish known from the Mesozoic of Asia and Africa. 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.

Asiatoceratodus is an extinct genus of lungfish which lived during the Middle-Late Triassic, Jurassic and Cretaceous periods in what is now Asia (Kyrgyzstan), Africa and South America.

<i>Gnathorhiza</i> Extinct genus of fishes

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.

<i>Ptychoceratodus</i> Extinct genus of fishes

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

<i>Paraceratodus</i> Extinct genus of fishes

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.

<span class="mw-page-title-main">Neoceratodontidae</span> Family of chordates

Neoceratodontidae is a family of lungfish containing Neoceratodus and the extinct Mioceratodus. It, Lepidosirenidae, and Protopteridae represent the only lungfish families still extant.

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.

References

  1. Nicholas R. Longrich (2017). "A Stem Lepidosireniform Lungfish (Sarcopterygia: Dipnoi) from the Upper Eocene of Libya, North Africa and implications for Cenozoic lungfish evolution". Gondwana Research. 42: 140–150. Bibcode:2017GondR..42..140L. doi:10.1016/j.gr.2016.09.007.
  2. 1 2 3 Nelson, Joseph S.; Grande, Terry C.; Wilson, Mark V. H. (2016-02-22). Fishes of the World. Wiley. ISBN   978-1-118-34233-6.
  3. 1 2 3 4 Kemp, Anne; Cavin, Lionel; Guinot, Guillaume (2017-04-01). "Evolutionary history of lungfishes with a new phylogeny of post-Devonian genera". Palaeogeography, Palaeoclimatology, Palaeoecology. 471: 209–219. doi: 10.1016/j.palaeo.2016.12.051 . ISSN   0031-0182.
  4. 1 2 3 4 Brownstein, Chase Doran; Harrington, Richard C; Near, Thomas J. (2023-04-12). "The biogeography of extant lungfishes traces the breakup of Gondwana". Journal of Biogeography. doi: 10.1111/jbi.14609 . ISSN   0305-0270.
  5. 1 2 3 Kemp, Anne; Cavin, Lionel; Guinot, Guillaume (2017-04-01). "Evolutionary history of lungfishes with a new phylogeny of post-Devonian genera". Palaeogeography, Palaeoclimatology, Palaeoecology. 471: 209–219. Bibcode:2017PPP...471..209K. doi: 10.1016/j.palaeo.2016.12.051 . ISSN   0031-0182.
  6. "PBDB Taxon". paleobiodb.org. Retrieved 2024-04-06.
  7. Kemp, A. (1998-04-10). "Skull structure in post-Paleozoic lungfish". Journal of Vertebrate Paleontology. 18 (1): 43–63. doi:10.1080/02724634.1998.10011033. ISSN   0272-4634.
  8. "Fossilworks: Gnathorhizidae". fossilworks.org. Retrieved 17 December 2021.