Stenopterygii
Stenopterygii are a superorder of ray-finned fish in the infraclass Teleostei. Their validity is somewhat doubtful, as the group was established to separate, out of a large group of closely related Teleostei, a mere two rather peculiarly autapomorphic orders at best. In some treatments, it is even monotypic.

As originally conceived, the "Stenopterygii" include the Ateleopodiformes and Stomiiformes. Sometimes, the former are removed to form a monotypic superorder Ateleopodomorpha. These lineages are moderately advanced teleosts, but each is uniquely adapted to a deep-water oceanic environment. Their plesiomorphies are similar to the Salmoniformes and other Protacanthopterygii, but plesiomorphic traits are no reliable indicator of a close relationship. Nonwithstanding, the "Stenopterygii" appear to be close relatives of the Protacanthopterygii. Some cladistic analyses find at least the Stomiiformes deep within the latter superorder.

It thus cannot be ruled out that the "Stenopterygii" are better included in the Protacanthopterygii. An alternative approach is to consider the entire group – "Stenopterygii", Protacanthopterygii, the monotypic superorders "Cyclosquamata", and perhaps the monotypic superorders "Lampridiomorpha" and "Scopelomorpha" – an unranked clade named Euteleostei. But this would probably require splitting up the Protacanthopterygii, so that each euteleost superorder would at most contain 2 orders (though most would be monotypic), as the relative placement of all these groups is not very well resolved. Such a profusion of monotypic taxa is generally rejected by modern taxonomy, if it is not absolutely required to adequately reflect phylogeny.

Moreover, owing to the uncertain relationships of the euteleosts to the less advanced Otocephala (which include the superorders Clupeomorpha and Ostariophysi) and the more advanced teleosts (e.g. Acanthopterygii), it may well be that the supposed "clade" is merely an evolutionary grade. Such a paraphyletic group would according to modern understanding not warrant a taxon name at all. In this case, a possible solution would be to expand the Protacanthopterygii to subsume all the small "superorders", and to treat the Euteleostei as including the Protacanthopterygii and their more "modern" relatives.
Q36602
superorder
Concept
Q127282
ray-finned fish
Concept
Q37517
infraclass
Concept
Q204861
Teleostei
Concept
Q773887
autapomorph
UNK
Q36602
order
Concept
Q310890
monotypic
Concept
Q719810
Ateleopodiformes
Concept
Q657570
Stomiiformes
Concept
Q483921
adapted
Concept
Q9430
ocean
Concept
Q932223
plesiomorph
UNK
Q184238
Salmoniformes
Concept
Q149091
Protacanthopterygii
Concept
Q192210
cladistic
Concept
Q781440
Cyclosquamata
Concept
Q547507
Lampridiomorpha
Concept
Q581782
Scopelomorpha
Concept
Q713623
clade
Concept
Q16521
taxa
Concept
Q8269924
taxonomy
Concept
Q242125
phylogeny
Concept
Q22107399
Otocephala
Concept
Q193389
Clupeomorpha
Concept
Q149081
Ostariophysi
Concept
Q660475
Acanthopterygii
Concept
Q2612572
evolutionary grade
Concept
Q208755
paraphyletic
Concept
Q616727
Stenopterygii
Concept
Q616727
Stenopterygii
Concept
Q616727
Stenopterygii
Concept
Q616727
Stenopterygii
Concept
Q616727
Stenopterygii
Concept
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2
NUMBER
parent taxon
instance of
parent taxon
used by