Coelacanthus

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Coelacanthus
Temporal range: 260–247  Ma
Coelacanthus granulatus.JPG
Coelacanthus granulatus fossil
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Sarcopterygii
Class: Actinistia
Order: Coelacanthiformes
Family: Coelacanthidae
Genus: Coelacanthus
Agassiz, 1839
Type species
Coelacanthus granulatus
Agassiz, 1839
Other species

Coelacanthus ("hollow spine") is a genus of extinct coelacanths that first appeared during the Permian period. It was the first genus of coelacanths described, about a century before the discovery of the extant coelacanth Latimeria . [1] The order Coelacanthiformes is named after it.

Contents

Description

Coelacanthus bears a superficial similarity to the living coelacanth Latimeria , though it was smaller, and had a more elongated head. Individuals grew up to 0.7 metres (2.3 ft) in length, had an elongate codavypter or supplementary tail lobe, and had small lobed fins, suggesting that Coelacanthus were open-water predators. The fin rays of the caudal fin are hollow, which gave Coelacanthus its name. The name is an adaptation of the Modern Latin cœlacanthus ("hollow spine"), from the Greek κοῖλ-ος (koilos; "hollow") and ἄκανθ-α (akantha; "spine"). These hollow spines are a typical feature of coelacanths.

Restoration of C. granulatus Coelacanthus granulatus restoration.jpg
Restoration of C. granulatus

Distribution and time

The type species Coelacanthus granulatus was described from the late Permian (Wuchiapingian) Kupferschiefer of Germany and equivalent Marl Slate of England. Coelacanthus is primarily known from Late Permian and Early Triassic deposits in Europe and Canada, although the referred species C. welleri, known from Iowa, is of Late Devonian (Famennian) age. It survived the Permian–Triassic extinction event, and one species, C. banffensis, is known from the Early Triassic.

Several other species that were first referred to Coelacanthus were later reallocated to other genera. Coelacanthus minor was considered by Woodward (1891) as potentially belonging to the Triassic genus Heptanema , [2] while Martin and Wenz (1984) considered Coelacanthus lunzensis a possible synonym of Garnbergia . [3] Coelacanthus madagascariensis from the Early Triassic of Madagascar was reattributed to the genus Rhabdoderma , and Coelacanthus evolutus is a synonym of Whiteia woodwardi . [4]

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>Latimeria</i> Genus of lobe-finned fishes from the Indian Ocean

Latimeria is a rare genus of fish which contains the only living species of coelacanth. It includes two extant species: the West Indian Ocean coelacanth and the Indonesian coelacanth. They follow the oldest known living lineage of Sarcopterygii, which means they are more closely related to lungfish and tetrapods than to the common ray-finned fishes and cartilaginous fishes.

<i>Acanthodes</i> Genus of cartilaginous fishes

Acanthodes is an extinct genus of acanthodian fish. Species have been found in Europe, North America, and Asia, spanning the Early Carboniferous to the Early Permian, making it one of the youngest known acanthodian genera.

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

Saurichthys is an extinct genus of predatory ray-finned fish from the Triassic Period. It is the type genus of the family Saurichthyidae, and the most speciose and longest lasting genus in the family. This family also includes the Permian Eosaurichthys (China) and the Jurassic Saurorhynchus from Europe and North America, though it may be more appropriate to treat these as subgenera of Saurichthys, due to the genus Saurichthys otherwise being paraphyletic.

<span class="mw-page-title-main">West Indian Ocean coelacanth</span> Species of lobe-finned bony fish

The West Indian Ocean coelacanth is a crossopterygian, one of two extant species of coelacanth, a rare order of vertebrates more closely related to lungfish and tetrapods than to the common ray-finned fishes. The other extant species is the Indonesian coelacanth.

<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.

<i>Weigeltisaurus</i> Extinct genus of reptiles

Weigeltisaurus is an extinct genus of weigeltisaurid reptile from the Late Permian Kupferschiefer of Germany and Marl Slate of England. It has a single species, originally named as Palaechamaeleo jaekeli in 1930 and later assigned the name Weigeltisaurus jaekeli in 1939, when it was revealed that Palaeochamaeleo was a preoccupied name. A 1987 review by Evans and Haubold later lumped Weigeltisaurus jaekeli under Coelurosauravus as a second species of that genus. A 2015 reassessment of skull morphology study substantiated the validity of Weigeltisaurus and subsequent authors have used this genus. Like other Weigeltisaurids, they possessed long rod-like bones that radiated from the trunk that were likely used to support membranes used for gliding, similar to extant Draco lizards.

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

Birgeria is a genus of carnivorous marine ray-finned fish from the Triassic period. Birgeria had a global distribution. Fossils were found in Madagascar, Spitsbergen, Germany, Switzerland, Italy, Slovenia, China, Russia, Canada and Nevada, United States. The oldest fossils are from Griesbachian aged beds of the Wordie Creek Formation of East Greenland.

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

Rhabdoderma is an extinct genus of coelacanth fish in the class Sarcopterygii. It lived in the Carboniferous and Early Triassic (Induan), and its fossils have been found in Europe, Madagascar and North America. The type species was originally described as Coelacanthus elegans.

<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>Whiteia</i> Extinct genus of coelacanths

Whiteia is an extinct genus of prehistoric coelacanth fish which lived during the Triassic period. It is named after Errol White.

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

Australosomus is an extinct genus of prehistoric ray-finned fish that lived during the Early Triassic epoch in what is now Greenland, Kenya, Tanzania, Madagascar, South Africa and Canada.

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

Acrolepis is an extinct genus of prehistoric bony fish that lived from the Tournaisian stage of the Mississippian to the late Permian epoch. Some species from the Early Triassic of Tasmania are also ascribed to Acrolepis.

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

Heptanema is an extinct genus of prehistoric coelacanth from the Middle Triassic (Ladinian) of northern Italy and southern Switzerland.

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

Mylacanthus is an extinct genus of prehistoric coelacanth lobe-finned fish that lived during the Smithian age of the Early Triassic epoch in what is now Svalbard.

Sassenia is an extinct genus of prehistoric coelacanth lobe-finned fish that lived during the Early Triassic epoch in what is now East Greenland and Svalbard.

Spermatodus is an extinct genus of prehistoric coelacanth lobe-finned fish, which lived during the Artinskian age of the Cisuralian epoch in what is now Oklahoma and Texas, United States.

<span class="mw-page-title-main">Bobasatraniiformes</span> Extinct order of fishes

Bobasatraniiformes is an extinct order of durophagous ray-finned fish that existed from the late Permian to the Middle Triassic in both marine and freshwater environments. The order includes two families: Bobasatraniidae, with the genera Bobasatrania, Ebenaqua, and Ecrinesomus, and Dorypteridae, comprising only the genus Dorypterus (monotypy). Bobasatraniiformes had a somewhat global distribution; fossils are found in Africa (Madagascar), Asia (Pakistan), Australia, Europe, and North America.

<span class="mw-page-title-main">Fish fin</span> Bony skin-covered spines or rays protruding from the body of a fish

Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of Actinopterygii, Dipnomorpha, Actinistia and Chondrichthyes fishes. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim.

<i>Serenichthys</i> Genus of coelacanth fish

Serenichthys kowiensis is a fossil species of coelacanth described in 2015 from near Grahamstown in South Africa.

References

  1. Agassiz, L. 1839. Recherches sur les poissons fossiles II. Petitpierre, Neuchâtel.
  2. Woodward A. S. 1891. Catalogue of the Fossil Fishes in the British Museum (Natural History). Part II. London.
  3. M. Martin and S. Wenz. 1984. Découverte d'un nouveau Coelacanthidé, Garnbergia ommata n.g., n.sp., dans le Muschelkalk supérieur du Baden-Württemberg. Stuttgarter Beiträge zur Naturkunde, Serie B (Geologie und Paläontologie) 105:1-17
  4. Forey P. L. (1998) History of the coelacanth fishes (Chapman & Hall, London).

Mikko's Phylogeny Archive on Coelacanthiformes