''Palaeoniscum'' (from , 'ancient' and 'cod-fish' or 'woodlouse') is an extinct

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 ...

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

from the

Middle Middle or The Middle may refer to: * Centre (geometry), the point equally distant from the outer limits. Places * Middle (sheading), a subdivision of the Isle of Man * Middle Bay (disambiguation) * Middle Brook (disambiguation) * Middle Creek ...

Late 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 ...

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 (

Guadalupian The Guadalupian is the second and middle Series (stratigraphy), series/Epoch (geology), epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico an ...

Lopingian The Lopingian is the uppermost series/last epoch of the Permian. It is the last epoch of the Paleozoic. The Lopingian was preceded by the Guadalupian and followed by the Early Triassic. The Lopingian is often synonymous with the informal te ...

) of

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

Turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

and

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

, and possibly other regions. The genus was named ''Palaeoniscum'' in 1818 by

Henri Marie Ducrotay de Blainville Henri Marie Ducrotay de Blainville (; 12 September 1777 – 1 May 1850) was a French zoologist and anatomist. Life Blainville was born at Arques-la-Bataille, Arques, near Dieppe, Seine-Maritime, Dieppe. As a young man, he went to Paris to study a ...

, but was later misspelled as ''Palaeoniscus'' by Blainville and other authors (notably

Louis 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 ...

). ''Palaeoniscum'' belongs to the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Palaeoniscidae Palaeoniscidae is an extinct family of "palaeoniscoid" ray-finned fishes (Actinopterygii). The family includes the genus ''Palaeoniscum'' and potentially other Palaeozoic and Mesozoic early actinopterygian genera. The name is derived from the Anc ...

The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

''Palaeoniscum freieslebeni'' was named after Johann Carl Freiesleben (1774–1846), mining commissioner of

Saxony Saxony, officially the Free State of Saxony, is a landlocked state of Germany, bordering the states of Brandenburg, Saxony-Anhalt, Thuringia, and Bavaria, as well as the countries of Poland and the Czech Republic. Its capital is Dresden, and ...

. ''P. freieslebeni'' is the most common

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

in the

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 ...

aged

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 ...

and

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 ...

, where it constitutes 80% of all fish fossils. The genus is considered to be a poorly defined

wastebasket taxon Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the purpose of classifying organisms that do not fit anywhere else. They are typically defined by e ...

. ''Palaeoniscum'' had a

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such ...

-shaped body in length, with a deeply forked

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 ...

and tall

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

, indicating that it was a fast swimmer. It was probably an active predator, feeding on other freshwater fish. Its sharp

teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

could be replaced when lost, a trait also seen in modern

shark Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...

s. Like other early ray-finned fish, ''Palaeoniscum'' had air sacs connected to the mouth, which served as a primitive

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ (anatomy), organ in bony fish that functions to modulate buoyancy, and thus allowing the fish to stay at desired water depth without having to maintain lift ...

. Several

Palaeozoic The Paleozoic ( , , ; or Palaeozoic) Era is the first of three geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic (the last era of the Proterozoic Eon) and ends 251.9 Ma at the start of ...

and

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

species that have been ascribed to the genus ''Palaeoniscum'' were later shown to be only distantly related with ''P. freieslebeni''. These species were subsequently removed and transferred to other genera (e.g., ''

Acentrophorus ''Acentrophorus'' is an extinct genus of prehistoric freshwater and marine ray-finned fish from the Roadian (Guadalupian/Middle Permian) to the Wuchiapingian (Lopingian/late Permian) of England (Marl Slate), Germany (Kupferschiefer), Italy (Val G ...

'', ''

Aeduella ''Aeduella'' is an extinct genus of freshwater ray-finned fish that lived during the Gzhelian (Late Pennsylvanian, Carboniferous ) and Asselian-Sakmarian (Cisuralian/early Permian epoch) ages in what is now France (Auvergne, Burgundy and Aveyro ...

'', ''

Paramblypterus ''Paramblypterus'' is an extinct genus of Paleozoic bony fish. This taxon would often fall under predation from Paleozoic tetrapods such as '' Sclerocephalus'' See also * Prehistoric fish * List of prehistoric bony fish This list of prehis ...

'', see list below). The allocation of other species to ''Palaeoniscum'' (see list below) is often doubtful and mostly based on superficial resemblance with ''P. freieslebeni''. ''Palaeoniscum'' is the name giving taxon of the

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 ...

Palaeonisciformes The Palaeonisciformes, commonly known as "palaeoniscoids" (also spelled "paleoniscoid", or alternatively "paleoniscids") are an extinct grouping of primitive ray-finned fish (Actinopterygii), spanning from the Silurian/Devonian to the Cretaceous. ...

(or Palaeoniscoidei), a

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

group comprising several superficially similar looking but not closely related early

actinopterygian Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of skin ...

taxa. Palaeonisciformes is considered a

by modern taxonomic standards.

Species

* ''Palaeoniscum angustum'' ( Rzehak, 1881) 'Palaeoniscas angustus'' Rzehak, 1881* ''Palaeoniscum antipodeum'' (Egerton, 1864) 'Palaeoniscus antipodeus'' Egerton, 1864* ''Palaeoniscum antiquum'' Williams, 1886 * ''Palaeoniscum arenaceum'' Berger, 1832 * ''Palaeoniscum capense'' (Bloom, 1913) 'Palaeoniscus capensis'' Bloom, 1913* ''Palaeoniscum comtum'' (

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 ...

, 1833) 'Palaeoniscus comtus'' Agassiz, 1833* ''Palaeoniscum crassum'' ( Woodward, 1908) 'Palaeoniscus crassus'' Woodward, 1908* ''Palaeoniscum daedalium'' Yankevich & Minich, 1998 * ''Palaeoniscum devonicum'' Clarke, 1885 * ''Palaeoniscum elegans'' ( Sedgwick, 1829) 'Palaeoniscus elegans'' Sedgwick, 1829* ''Palaeoniscum freieslebeni''

de Blainville Henri Marie Ducrotay de Blainville (; 12 September 1777 – 1 May 1850) was a French zoologist and anatomist. Life Blainville was born at Arques, near Dieppe. As a young man, he went to Paris to study art, but ultimately devoted himself to natur ...

, 1818 (

) [''Eupalaeoniscus freieslebeni'' (de Brainville, 1818); ''Palaeoniscus freieslebeni'' (de Brainville, 1818); ''Palaeoniscus macropomus'' Agassiz, 1833; ''Palaeoniscus magnus'' Woodward, 1937] * ''Palaeoniscum hassiae'' (Otto Jaekel, Jaekel, 1898) [''Galeocerdo contortus hassiae'' Jaekel, 1898; ''Palaeomyzon hassiae'' (Jaekel, 1898)] * ''Palaeoniscum kasanense'' Geinitz & Vetter, 1880 * ''Palaeoniscum katholitzkianum'' (Rzehak, 1881) 'Palaeoniscas katholitzkianus'' Rzehak, 1881* ''Palaeoniscum landrioti'' (le Sauvage, 1890) 'Palaeoniscus landrioti'' le Sauvage, 1890* ''Palaeoniscum longissimum'' (Agassiz, 1833) 'Palaeoniscus longissimus'' Agassiz, 1833* ''Palaeoniscum macrophthalmum'' (McCoy, 1855) 'Palaeoniscus macrophthalmus'' McCoy, 1855* ''Palaeoniscum moravicum'' (Rzehak, 1881) 'Palaeoniscas moravicus'' Rzehak, 1881* ''Palaeoniscum promtus'' (Rzehak, 1881) 'Palaeoniscas promtus'' Rzehak, 1881* ''Palaeoniscum reticulatum'' Williams, 1886 * ''Palaeoniscum scutigerum''

Newberry Newberry is a surname, a variant of Newbury. Notable people with the surname include: * Booker Newberry III (1956–2023), American singer and keyboardist * Brennan Newberry (born, 1990), American professional stock car racing driver * Brian Ne ...

, 1868

Species moved to other genera

* ''Palaeoniscum abbsi'' Kirkby, 1862 → †'' Acentrophorus varians'' (Kirkby, 1862) * ''Palaeoniscum glaphyrus'' (Agassiz, 1835) 'Palaeoniscus glaphyrus''Agassiz, 1835 → †'' Acentrophorus glaphyrus'' (Agassiz, 1835) * ''Palaeoniscum blainvillei'' (Agassiz, 1833) 'Palaeoniscus blainvillei'' Agassiz, 1833→ †'' Aeduella blainvillei'' (Agassiz, 1833) * ''Palaeoniscum delessei'' (Sauvage, 1878) → †'' Aeduella blainvillei'' (Agassiz, 1833) * ''Palaeoniscum gelberti'' Goldfuss, 1847 → †'' Paramblypterus duvernoyi'' (Agassiz, 1833) * ''Palaeoniscum vratislaviensis'' (Agassiz, 1833) 'Palaeoniscus vratislaviensis'' Agassiz, 1833→ †'' Paramblypterus vratislaviensis'' (Agassiz, 1833)

References

{{Taxonbar, from=Q429002 Prehistoric ray-finned fish genera Permian bony fish Palaeonisciformes Permian fish of Europe Permian fish of North America Fossil taxa described in 1818 Lopingian life Wuchiapingian life