''Coelacanthus'', from

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

κοῖλος (''koîlos''), meaning "hollow", and ἄκανθα (''ákantha''), meaning "spine", is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

marine

coelacanth 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 (the terrestrial vertebrates including living amphibians, reptiles, bi ...

s known from the late

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 251.902 Mya. It is the s ...

period Period may refer to: Common uses * Period (punctuation) * Era, a length or span of time *Menstruation, commonly referred to as a "period" Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (o ...

. It was the first genus of coelacanths described, about a

century A century is a period of 100 years or 10 decades. Centuries are numbered ordinally in English and many other languages. The word ''century'' comes from the Latin ''centum'', meaning ''one hundred''. ''Century'' is sometimes abbreviated as c. ...

before the discovery of the

extant Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Exta ...

coelacanth ''

Latimeria ''Latimeria'' is a rare genus of fish which contains the two only living species of coelacanth. It includes two Extant taxon, extant species: the West Indian Ocean coelacanth (''Latimeria chalumnae'') and the Indonesian coelacanth (''Latimeria me ...

''. The

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Coelacanthiformes Coelacanths ( ) are an ancient group of Sarcopterygii, lobe-finned fish (Sarcopterygii) in the Class (biology), class Actinistia. As sarcopterygians, they are more closely related to lungfish and tetrapods (the terrestrial vertebrates including ...

is named after it.

Taxonomy

The only definitive species in this genus is ''C. granulatus'' from the

late Permian Late or LATE may refer to: Everyday usage * Tardy, or late, not being on time * Late (or the late) may refer to a person who is dead Music * ''Late'' (The 77s album), 2000 * Late (Alvin Batiste album), 1993 * Late!, a pseudonym used by Dave Groh ...

(

Wuchiapingian In the geologic timescale, the Wuchiapingian or Wujiapingian (from in the Liangshan area of Hanzhong, Shaanxi Province ) is an age or stage of the Permian. It is also the lower or earlier of two subdivisions of the Lopingian Epoch or S ...

stage)

Kupferschiefer The Kupferschiefer (German for Copper Shale, Copper Schist or Copper Slate) or Kupfermergel (Copper Marl), (T1 or Z1) is an extensive and remarkable sedimentary unit in Central Europe. The relatively monotonous succession is typically and maximu ...

of Germany and equivalent

Marl Slate The Marl Slate Formation is a geological formation in England. Despite its name, it is mostly dolomite rock. The Marl Slate Formation was formed about 273 to 259 million years ago, during the Guadalupian and Lopingian epochs of the late Permian ...

of England. The genus has long been used to group unrelated species of coelacanths, and 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 ''Heptanema'' is an extinct genus of prehistoric coelacanth from the Middle Triassic ( Ladinian) of northern Italy and southern Switzerland (Monte San Giorgio). The type and only species is ''Heptanema paradoxa''. Woodward (1891) suggested tha ...

'', while Martin and Wenz (1984) considered ''Coelacanthus lunzensis'' a possible synonym of ''

Garnbergia ''Garnbergia'' is an extinct genus of prehistoric coelacanth that lived during the Anisian stage of the Middle Triassic epoch. It was discovered by Martin and Wenz in 1984. It comprises a single species, ''Garnbergia ommata''. Classification In ...

''. ''Coelacanthus madagascariensis'' from the Early Triassic of Madagascar was reattributed to the genus ''

Rhabdoderma ''Rhabdoderma'' is an extinct genus of coelacanth fish in the class Sarcopterygii. Fossils of ''Rhabdoderma'' have been found in Europe, Madagascar and North America, in Carboniferous and Early Triassic (Induan) aged rocks, with a hiatus in betwe ...

'', and ''Coelacanthus evolutus'' is a synonym of '' Whiteia woodwardi''. The following are considered species that likely do not belong to this genus due to either lack of phylogenetic analysis or incomplete remains, but have not yet been reclassified: *C.'' ''banffensis'' Lambe, 1916 -

Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between 251.9 Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which ...

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

, Canada (sometimes considered a species of ''Whiteia'', as ''W. banffensis'') * C.'' ''dendrites''

Gardiner Gardiner may refer to: Places Settlements ;Canada * Gardiner, Ontario ;United States * Gardiner, Maine * Gardiner, Montana * Gardiner (town), New York ** Gardiner (CDP), New York * Gardiner, Oregon * Gardiner, Washington * West Gardiner, ...

, 1973 - Wuchiapingian,

Ecca Group The Ecca Group is the second of the main subdivisions of the Karoo Supergroup of geological strata in southern Africa. It mainly follows conformably after the Dwyka Group in some sections, but in some localities overlying unconformably over much ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

and Madumabisa Shales of

Zimbabwe file:Zimbabwe, relief map.jpg, upright=1.22, Zimbabwe, relief map Zimbabwe, officially the Republic of Zimbabwe, is a landlocked country in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Bots ...

* C.'' ''gracilis''

Agassiz Jean Louis Rodolphe Agassiz ( ; ) FRS (For) FRSE (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history. Spending his early life in Switzerland, he recei ...

, 1844 -

Middle Triassic In the geologic timescale, the Middle Triassic is the second of three epoch (geology), epochs of the Triassic period (geology), period or the middle of three series (stratigraphy), series in which the Triassic system (stratigraphy), system is di ...

of Germany * C.'' ''lunzensis'' Reis, 1900 -

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch a ...

(

Carnian The Carnian (less commonly, Karnian) is the lowermost stage (stratigraphy), stage of the Upper Triassic series (stratigraphy), Series (or earliest age (geology), age of the Late Triassic Epoch (reference date), Epoch). It lasted from 237 to 227.3 ...

) of

Austria Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Aust ...

(

Lunz Formation The Lunz Formation is a geologic formation in Austria and other Tethyan regions. It is composed of quartz sandstone, shales and claystones, locally with coal interbeds. The basal part of the formation may contain marine fossils. It preserves fos ...

) * C.'' ''phillipsii''

, 1844 -

Pennsylvanian Pennsylvanian may refer to: * A person or thing from Pennsylvania * Pennsylvanian (geology) The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, on the International Commission on Stratigraphy, ICS geologic timesc ...

of England * C.'' ''stensioei'' Aldinger, 1931 - Pennsylvanian of Germany * C.'' ''welleri'' Eastman, 1908 -

Mississippian Mississippian may refer to: * Mississippian (geology), a subperiod of the Carboniferous period in the geologic timescale, roughly 360 to 325 million years ago * Mississippian cultures, a network of precontact cultures across the midwest and Easte ...

Iowa Iowa ( ) is a U.S. state, state in the upper Midwestern United States, Midwestern region of the United States. It borders the Mississippi River to the east and the Missouri River and Big Sioux River to the west; Wisconsin to the northeast, Ill ...

, USA ( Kinderhook Formation)

Description

''Coelacanthus'' bears a superficial similarity to the living

'', though it was smaller, and had a more elongated head. Individuals grew up to 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 Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

are hollow, which gave ''Coelacanthus'' its name. The name is an adaptation of the Modern Latin ("hollow spine"), from the Greek κοῖλ-ος (koilos; "hollow") and ἄκανθ-α (akantha; "spine"). These hollow spines are a typical feature of coelacanths.

References

External links

Mikko's Phylogeny Archive o
Coelacanthiformes
Coelacanthidae Prehistoric lobe-finned fish genera Lopingian sarcopterygians of Europe Wuchiapingian genera Fossils of England Fossils of Germany Taxa named by Louis Agassiz Fossil taxa described in 1839 {{paleo-lobefinned-fish-stub