Palaeoniscum

***Palaeoniscum*** is an extinct genus of palaeoniscoid from the Permian of England, Turkey, North America, and more. The type species is _Palaeoniscum freieslebeni_. It is commonly misspelled as "_Palaeoniscus_" by many people.

## Etymology

The _palaeo_ part means "ancient" in Greek and the _niscum_ part means "woodlouse".

### Physical appearance

This fish had a torpedo-shaped body and reached 30 cm. The dorsal fin was developed in height and the tail was forked. _Palaeoniscum_ had a "swim bladder" made of air sacs. Its sharp teeth could grow back again when they were lost, just like today's sharks.

### Biology/Lifestyle

_Palaeoniscum_ was probably a predatory carnivore.

## Classification

_Palaeoniscum_ is the type genus of the family Palaeoniscidae in the order Palaeonisciformes.

### Naming

_Palaeoniscum_ was named by Henri Marie Ducrotay de Blainville in 1818. However, it was mistakenly called _Palaeoniscus_ by others.

### Species

- <abbr>†</abbr>_Palaeoniscum angustum_ <small>Rzehak, 1881</small>
- <abbr>†</abbr>_Palaeoniscum antipodeum_ <small>Egerton, 1864</small>
- <abbr>†</abbr>_Palaeoniscum antiquum_ <small>Williams, 1886</small>
- <abbr>†</abbr>_Palaeoniscum arenaceum_ <small>Berger, 1832</small>
- <abbr>†</abbr>_Palaeoniscum capense_ <small>Bloom, 1913</small>
- <abbr>†</abbr>_Palaeoniscum comtum_ <small>Agassiz, 1833</small>
- <abbr>†</abbr>_Palaeoniscum crassum_ <small>Woodward, 1908</small>
- <abbr>†</abbr>_Palaeoniscum daedalium_ <small>Yankevich & Minich, 1998</small>
- <abbr>†</abbr>_Palaeoniscum devonicum_ <small>Clarke, 1885</small>
- <abbr>†</abbr>_Palaeoniscum elegans_ <small>Sedgwick, 1829</small>
- <abbr>†</abbr>_Palaeoniscum freieslebeni_ <small>de Blainville, 1818</small> (type species)
- <abbr>†</abbr>_Palaeoniscum hassiae_ <small>Jaekel, 1898</small>
- <abbr>†</abbr>_Palaeoniscum kasanense_ <small>Geinitz & Vetter, 1880</small>
- <abbr>†</abbr>_Palaeoniscum katholitzkianum_ <small>Rzehak, 1881</small>
- <abbr>†</abbr>_Palaeoniscum landrioti_ <small>le Sauvage, 1890</small>
- <abbr>†</abbr>_Palaeoniscum longissimum_ <small>Agassiz, 1833</small>
- <abbr>†</abbr>_Palaeoniscum macrophthalmum_ <small>McCoy, 1855</small>
- <abbr>†</abbr>_Palaeoniscum moravicum_ <small>Rzehak, 1881</small>
- <abbr>†</abbr>_Palaeoniscum promtus_ <small>Rzehak, 1881</small>
- <abbr>†</abbr>_Palaeoniscum reticulatum_ <small>Williams, 1886</small>
- <abbr>†</abbr>_Palaeoniscum scutigerum_ <small>Newberry, 1868</small>
- <abbr>†</abbr>_Palaeoniscum vratislavensis_ <small>Agassiz, 1833</small>

## References

1. <small>"_Palaeoniscum freieslebeni_ Blainville, 1818". _GBIF_.</small>
1. <small>Agassiz, Louis (1833–1843). "_Recherches sur les poissons fossiles_". Petitpierre, Neuchâtel.</small>
1. <small>Hoşgör, Izzet; Štamberg, Stanislav (2014). "A first record of late Middle Permian actinopterygian fish from Anatolia, Turkey" . _Acta Geologica Polonica_.</small>
1. <small>Henderson, Struan; Dunne, Emma M.; Fasey, Sophie A.; Giles, Sam (February 2023). "The early diversification of ray‐finned fishes ( Actinopterygii ): hypotheses, challenges and future prospects". _Biological Reviews_.</small>

## Other websites

- https://www.researchgate.net/figure/Fossil-records-of-A-cf-Palaeoniscum-sp-between-275-and-265-Ma-and-B-Palaeoniscum_fig5_370637624