Trachymetopon

Last updated

Trachymetopon
Temporal range: Sinemurian-Callovian
~199–163.5  Ma
O
S
D
C
P
T
J
K
Pg
N
Possible Kimmeridgian record
Trachymetopon liasicum (cropped).JPG
Trachymetopon liassicum
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Sarcopterygii
Class: Actinistia
Order: Coelacanthiformes
Family: Mawsoniidae
Genus: Trachymetopon
Hennig, 1951
Species

Trachymetopon liasicumHennig, 1951

Trachymetopon is an extinct genus of prehistoric coelacanth from the Jurassic of Europe. Fossils have been found in the Early Jurassic Posidonia Shale of Germany the Middle Jurassic Marnes de Dives of France, and probably the Late Jurassic Kimmeridge Clay of England. [1] [2] Only one species has been named, Trachymetopon liassicum, described by Henning in 1951 from an almost complete specimen found in the Lower Toarcian of Ohmden in Baden-Württemberg. [3] Another specimen is known from the same site, and two older specimens come from the Sinemurian of Holzmaden. [4] The holotype of this species is 1.6 metres (5 ft 3 in) in length. [4] A giant specimen of an undetermined species of Trachymetopon found at the Middle Jurassic (Late Callovian) Falaises des Vaches Noires of Normandy. This specimen, composed of a 53 cm long palatoquadrate, belongs to an individual 4 metres (13 ft) in length. [5] A basisphenoid found in a museum in Switzerland that likely originates from the same locaity probably belonged to an individual around 5 m (16 ft) long, making Trachymetopon the largest of all coelacanths alongside Mawsonia . [1] A study published in 2015 revealed that this coelacanth belongs to the Mawsoniidae. [4] Trachymetopon is one of the few known mawsoniids to have been exclusively marine (with an indeterminate form from the Triassic of France), while most of the other members of the group have lived in fresh and brackish waters. [6]

Contents

Phylogeny

Trachymetopon life restoration Trachymetopon life restoration.png
Trachymetopon life restoration

A phylogenetic analysis of the mawsoniids published in 2020 found a polytomy grouping together Trachymetopon and the Cretaceous genera “ Lualabaea ”, Axelrodichthys , and Mawsonia . The genus “Lualabaea” could be congeneric with Axelrodichthys. [7]

Outgroup

Diplurus

Parnaibaia

Chinlea

Trachymetopon liassicum

“Mawsonia” lavocati

Mawsonia

Axelrodichthys + “ Lualabaea

See also

Related Research Articles

<span class="mw-page-title-main">Coelacanth</span> Order of lobe-finned fishes

Coelacanths are an ancient group of lobe-finned fish (Sarcopterygii) in the class Actinistia. As sarcopterygians, they are more closely related to lungfish and tetrapods than to ray-finned fish.

<i>Chinlea</i> Extinct genus of coelacanths

Chinlea is an extinct genus of late Triassic Mawsoniid coelacanth fish found in and named after the Chinle Formation that crops out in the southwestern states of Arizona and New Mexico. The word “Chinle” comes from the Navajo word meaning "flowing out", referencing the location where water flows out of the Canyon de Chelly. They were also possibly found in the Dockum Group.

<span class="mw-page-title-main">Latimeriidae</span> Family of fishes

Latimeriidae is the only extant family of coelacanths, an ancient lineage of lobe-finned fish. It contains two extant species in the genus Latimeria, found in deep waters off the coasts of southern Africa and east-central Indonesia. In addition, several fossil genera are known from the Mesozoic of Europe, the Middle East, and the southeastern United States, dating back to the Triassic.

Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1994.

<i>Axelrodichthys</i> Extinct genus of coelacanths

Axelrodichthys is an extinct genus of mawsoniid coelacanth from the Cretaceous of Africa, North and South America, and Europe. Several species are known, the remains of which were discovered in the Lower Cretaceous (Aptian-Albian) of Brazil, North Africa, and possibly Mexico, as well as in the Upper Cretaceous of Morocco (Cenomanian), Madagascar and France. The Axelrodichthys of the Lower Cretaceous frequented both brackish and coastal marine waters while the most recent species lived exclusively in fresh waters. The French specimens are the last known fresh water coelacanths. Most of the species of this genus reached 1 metre to 2 metres in length. Axelrodichthys was named in 1986 by John G. Maisey in honor of the American ichthyologist Herbert R. Axelrod.

<i>Mawsonia</i> (fish) Extinct genus of coelacanths

Mawsonia is an extinct genus of prehistoric coelacanth fish. It is amongst the largest of all coelacanths, with one quadrate specimen possibly belonging to an individual measuring 5.3 metres in length. It lived in freshwater and brackish environments from the late Jurassic to the mid-Cretaceous of South America, eastern North America, and Africa. Mawsonia was first described by British paleontologist Arthur Smith Woodward in 1907.

<i>Holophagus</i> Extinct genus of coelacanths

Holophagus is an extinct genus of coelacanth belonging to Latimeriidae. The type species, Holophagus gulo, is known from the Lower Jurassic marine Lias of England. Some authors have considered the genus restricted to the Lias of England.

<i>Alcoveria</i> Extinct genus of coelacanths

Alcoveria is an extinct genus of mawsoniid coelacanth fish which lived during the Triassic period. Alcoveria is known from a well preserved specimen from Spain. It lived in a marine environment.

<span class="mw-page-title-main">Mawsoniidae</span> Extinct family of coelacanths

Mawsoniidae is an extinct family of prehistoric coelacanth fishes which lived during the Triassic to Cretaceous periods. Members of the family are distinguished from their sister group, the Latimeriidae by the presence of ossified ribs, a coarse rugose texture on the dermatocranium and cheek bones, the absence of the suboperculum and the spiracular, and reduction or loss of the descending process of the supratemporal. Mawsoniids are known from North America, Europe, South America, Africa, Madagascar and Asia. Unlike Latimeriidae, which are exclusively marine, Mawsoniidae were also native to freshwater and brackish environments. Mawsoniids represent among the youngest known coelacanths, with the youngest known remains of the freshwater genus Axelrodichthys from France and an indeterminate marine species from Morocco being from the final stage of the Cretaceous, the Maastrichtian, roughly equivalent in age to the youngest known fossils of latimeriids. Species of Mawsonia and Trachymetopon are known to have exceeded 5 metres in length, making them among the largest known bony fish to have ever existed.

<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

This list of fossil fishes described in 2013 is a list of new taxa of placoderms, fossil cartilaginous fishes and bony fishess of every kind that have been described during the year 2013. The list only includes taxa at the level of genus or species.

<i>Megalocoelacanthus</i> Extinct genus of coelacanths

Megalocoelacanthus dobiei is an extinct species of giant latimeriid coelacanth lobe-finned fish which lived during the Lower Campanian epoch until possibly the early Maastrichtian in the Late Cretaceous period in Appalachia, the Western Interior Seaway and Mississippi Embayment. Its disarticulated remains have been recovered from the Eutaw Formation, Mooreville Chalk Formation, and Blufftown Formation of Alabama, Mississippi, and Georgia, and also from the Niobrara Formation of Kansas. Although no complete skeleton is known, careful examination of skeletal elements demonstrate it is closely related to the Jurassic-aged coelacanthid Libys. The species is named for herpetologist James L. Dobie. It has been estimated to have been 3.5—4.5 meters in length.

This list of fossil fishes described in 2016 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes and other fishes of every kind that have been described during the year 2016, as well as other significant discoveries and events related to paleontology of fishes that occurred in the year 2016. The list only includes taxa at the level of genus or species.

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<i>Foreyia</i> Extinct genus of coelacanths

Foreyia is an extinct genus of coelacanth lobe-finned fish which lived during the Middle Triassic period in what is now Canton of Graubünden, Switzerland. It contains a single species F. maxkuhni.

This list of fossil fishes described in 2019 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes, and other fishes of every kind that were described during the year 2019, as well as other significant discoveries and events related to paleoichthyology that occurred in 2019.

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This list of fossil fish research presented in 2021 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes, and other fishes that were described during the year, as well as other significant discoveries and events related to paleoichthyology that occurred in 2021.

This list of fossil fish research presented in 2022 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes, and other fishes that were described during the year, as well as other significant discoveries and events related to paleoichthyology that occurred in 2022.

This list of fossil fish research presented in 2023 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes, and other fishes that were described during the year, as well as other significant discoveries and events related to paleoichthyology that occurred in 2023.

References

  1. 1 2 Cavin, Lionel; Piuz, André; Ferrante, Christophe; Guinot, Guillaume (2021-06-03). "Giant Mesozoic coelacanths (Osteichthyes, Actinistia) reveal high body size disparity decoupled from taxic diversity". Scientific Reports. 11 (1): 11812. Bibcode:2021NatSR..1111812C. doi:10.1038/s41598-021-90962-5. ISSN   2045-2322. PMC   8175595 . PMID   34083600.
  2. Toriño, Pablo; Gausden, Shane F.; Etches, Steve; Rankin, Kathryn; Marshall, John E. A.; Gostling, Neil J. (2022). "An enigmatic large mawsoniid coelacanth (Sarcopterygii, Actinistia) from the Upper Jurassic Kimmeridge Clay Formation of England". Journal of Vertebrate Paleontology. 42 (1). e2125813. Bibcode:2022JVPal..42E5813T. doi:10.1080/02724634.2022.2125813. S2CID   253141244.
  3. Hennig, E. (1951). Trachymetopon liassicum, Ald., ein Reisen-Crossopterygier aus Schwäbischem Ober-Lias. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, Stuttgart, 94, 67-79.
  4. 1 2 3 Dutel, H.; Herbin, M.; Clément, G. (2015). "First Occurrence of a Mawsoniid Coelacanth in the Early Jurassic of Europe". Journal of Vertebrate Paleontology. 35 (3): e929581. Bibcode:2015JVPal..35E9581D. doi:10.1080/02724634.2014.929581. S2CID   140557693.
  5. Dutel, H.; Pennetier, E.; Pennetier, G. (2014). "A Giant Marine Coelacanth from the Jurassic of Normandy, France". Journal of Vertebrate Paleontology. 34 (5): 1239–1242. Bibcode:2014JVPal..34.1239D. doi:10.1080/02724634.2014.838176. S2CID   130632357.
  6. Deesri, U.; Cavin, L.; Amiot, R.; Bardet, N.; Buffetaut, E.; Cuny, G.; Giner, S.; Martin, J.E.; Suan, G. (2018). "A mawsoniid coelacanth (Sarcopterygii: Actinistia) from the Rhaetian (Upper Triassic) of the Peygros quarry, Le Thoronet (Var, southeastern France)". Geological Magazine. 155 (1): 187–192. Bibcode:2018GeoM..155..187D. doi:10.1017/S0016756817000619. S2CID   134867757.
  7. Cavin, L.; Buffetaut, E.; Dutour, Y.; Garcia, G.; Le Loeuff, J.; Méchin, A.; Méchin, P.; Tong, H.; Tortosa, T.; Turini, E.; Valentin, X. (2020). "The last known freshwater coelacanths: New Late Cretaceous mawsoniids remains (Osteichthyes: Actinistia) from Southern France". PLOS ONE. 15 (6): e0234183. Bibcode:2020PLoSO..1534183C. doi: 10.1371/journal.pone.0234183 . PMC   7274394 . PMID   32502171.