Neopterygii (from Greek νέος neos 'new' and πτέρυξ pteryx 'fin') is a
subclass of
ray-finned fish (Actinopterygii). Neopterygii includes the
Holostei and the
Teleostei, of which the latter comprise the vast majority of extant
fishes, and over half of all living
vertebratespecies.[2] While living holosteans include only freshwater
taxa, teleosts are diverse in both
freshwater and
marine environments. Many new species of teleosts are
scientifically described each year.[2]
Neopterygians are a very speciose group. They make up over 50% of the total
vertebratediversity today, and their diversity grew since the
Mesozoicera.[11][13] However, the diversity of the various groups of neopterygians (or of
fishes in general) is unevenly distributed, with teleosts making up the vast majority (96%) of living species.[2]
Early in their
evolution, neopterygians were a very successful group of fish, because they could move more rapidly than their ancestors. Their scales and skeletons began to lighten during their evolution, and their jaws became more powerful and efficient.[2] While
electroreception and the
ampullae of Lorenzini are present in all other extant groups of fish (except for
hagfish), neopterygians have lost this sense, even if it has later re-evolved within
Gymnotiformes and
catfishes, which possess
non-homologous teleost ampullae.[14]
Only a few changes occurred during the evolution of neopterygians from the earlier
actinopterygians. However, a very important step in the evolution of neopterygians is the acquisition of a better control of the movements of both
dorsal and
anal fins, resulting in an improvement in their swimming capabilities. They additionally acquired several modifications in the
skull, which allowed the evolution of different
feeding mechanisms and consequently the colonization of new ecological
niches. All of these characters represented major improvements, resulting in Neopterygii becoming the dominant group of fishes (and, thus,
taxonomically of
vertebrates in general) today.[11]
The great diversity of extant teleosts has been linked to a
whole genome duplication event during their evolution.[15]
^
abcdeNelson, Joseph, S. (2016). Fishes of the World. John Wiley & Sons, Inc.
ISBN978-1-118-34233-6.{{
cite book}}: CS1 maint: multiple names: authors list (
link)