''Luvaris necopinatus'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of extinct

louvar The louvar or luvar (''Luvarus imperialis'') is a species of perciform fish, the only extant species in the genus ''Luvarus'' and family Luvaridae. It is closely related to the surgeonfish. The juvenile form has a pair of spines near the base of ...

that lived in the

Tethys Ocean The Tethys Ocean ( el, Τηθύς ''Tēthús''), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean that covered most of the Earth during much of the Mesozoic Era and early Cenozoic Era, located between the ancient continents ...

during the early

Paleogene The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million yea ...

. It differs from the modern species, ''L. imperialis'', in that ''L. necopinatus'' has an oval body shape, and is around one foot in length when fully grown. The first specimens were found from the

Danata Formation The Danata Formation (or Danatinskaya, Danatinsk, Russian: Danata Svita) is an Upper Paleocene to Middle Eocene sedimentary succession located in Turkmenistan. It is mostly famous for its fish-bearing horizons (Ichthyofauna). The formation for ex ...

Lagerstätten, of the

Thanetian The Thanetian is, in the International Commission on Stratigraphy, ICS Geologic timescale, the latest age (geology), age or uppermost stage (stratigraphy), stratigraphic stage of the Paleocene epoch (geology), Epoch or series (stratigraphy), Serie ...

Ypresian In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

epochs of

Turkmenistan Turkmenistan ( or ; tk, Türkmenistan / Түркменистан, ) is a country located in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the sout ...

. ''L. necopinatus'' was originally described as "''Proluvarus necopinatus''," citing several anatomical differences between ''Proluvarus'' and ''Luvaris''. A later reexamination of the fossil specimens lead researchers to reappraise ''Proluvarus'' as a junior synonym, as well as determine that specimens of what were originally thought to be juveniles were actually two different species of a different genus of louvar, ''

Avitoluvarus ''Avitoluvarus'' ("Ancient Louvar") is a genus of extinct louvar that lived in the Tethys Ocean during the early Paleogene. The first specimens were found from the Danata Formation Lagerstätten, of the Thanetian age of Turkmenistan, where the ...

''.
Phylogenetic Revision of the Fish Families

Luvar The louvar or luvar (''Luvarus imperialis'') is a species of perciform fish, the only extant species in the genus ''Luvarus'' and family Luvaridae. It is closely related to the surgeonfish. The juvenile form has a pair of spines near the base of ...

idae and †

Kushlukiidae ''Kushlukia'' is an extinct genus of prehistoric bony fish, closely related to the luvar, that lived during the lower Eocene. ''K. permira'' is from Eocene portion of the Danata Formation Lagerstatten (which otherwise spans the Thanetian epoch ...

(

Acanthuroidei Acanthuroidei , is a clade of ray finned fishes which is a suborder of the Acanthuriformes, although it is regarded as a suborder of the Perciformes, the largest order of fish. The suborder includes the surgeonfish and Moorish idol. Members o ...

), with a New Genus and Two New Species of Eocene Luvarids

References

Luvaridae Paleocene fish of Asia Eocene fish of Asia Ypresian extinctions {{acanthuroidei-stub