Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a
class
Class, Classes, or The Class may refer to:
Common uses not otherwise categorized
* Class (biology), a taxonomic rank
* Class (knowledge representation), a collection of individuals or objects
* Class (philosophy), an analytical concept used d ...
of
bony fish
Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondricht ...
that comprise over 50% of living
vertebrate
Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain.
The vertebrates make up the subphylum Vertebra ...
species.
They are so called because of their lightly built
fin
A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. F ...
s made of webbings of
skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other animal coverings, such as the arthropod exoskeleton, have different ...
supported by radially extended thin bony
spine
Spine or spinal may refer to:
Science Biology
* Spinal column, also known as the backbone
* Dendritic spine, a small membranous protrusion from a neuron's dendrite
* Thorns, spines, and prickles, needle-like structures in plants
* Spine (zoology), ...
s called ''
lepidotrichia
In a zoological context, spines are hard, needle-like anatomical structures found in both vertebrate and invertebrate species. The spines of most spiny mammals are modified hairs, with a spongy center covered in a thick, hard layer of keratin and ...
'', as opposed to the bulkier, fleshy lobed fins of the
sister
A sister is a woman or a girl who shares parents or a parent with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to ref ...
clade
In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...
Sarcopterygii
Sarcopterygii (; )—sometimes considered synonymous with Crossopterygii ()—is a clade (traditionally a class (biology), class or subclass) of vertebrate animals which includes a group of bony fish commonly referred to as lobe-finned fish. The ...
(lobe-finned fish). Resembling
folding fan
A handheld fan, or simply hand fan, is a broad, flat surface that is waved back and forth to create an airflow. Generally, purpose-made handheld fans are folding fans, which are shaped like a sector of a circle and made of a thin material (such ...
s, the actinopterygian fins can easily change shape and
wetted area
In fluid dynamics, the wetted area is the surface area that interacts with the working fluid or gas.
* In maritime use, the wetted area is the area of the watercraft's hull which is immersed in water. This has a direct relationship on the overal ...
, providing superior
thrust-to-weight ratio
Thrust-to-weight ratio is a dimensionless ratio of thrust to weight of a rocket, jet engine, propeller engine, or a vehicle propelled by such an engine that is an indicator of the performance of the engine or vehicle.
The instantaneous thrust-to-w ...
s per movement compared to sarcopterygian and
chondrichthyian
Chondrichthyes (; ) is a class of jawed fish that contains the cartilaginous fish or chondrichthyans, which all have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fish'', which have skeletons p ...
fins. The fin rays attach directly to the proximal or basal skeletal elements, the radials, which represent the
articulation between these fins and the internal skeleton (e.g., pelvic and pectoral girdles).
The vast majority of actinopterygians are
teleost
Teleostei (; Ancient Greek, Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts (), is, by far, the largest group of ray-finned fishes (class Actinopterygii), with 96% of all neontology, extant species of f ...
s. By
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
count, they dominate the
subphylum
In zoological nomenclature, a subphylum is a taxonomic rank below the rank of phylum.
The taxonomic rank of " subdivision" in fungi and plant taxonomy is equivalent to "subphylum" in zoological taxonomy. Some plant taxonomists have also used th ...
Vertebrata
Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain.
The vertebrates make up the subphylum Verte ...
, and constitute nearly 99% of the over 30,000
extant
Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to:
* Extant hereditary titles
* Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English
* Exta ...
species of
fish
A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...
. They are the most abundant
nektonic
Nekton or necton (from the ) is any aquatic organism that can actively and persistently propel itself through a water column (i.e. swimming) without touching the bottom. Nektons generally have powerful tails and appendages (e.g. fins, pleopods ...
aquatic animal
An aquatic animal is any animal, whether vertebrate or invertebrate, that lives in a body of water for all or most of its lifetime. Aquatic animals generally conduct gas exchange in water by extracting dissolved oxygen via specialised respirato ...
s and are ubiquitous throughout
freshwater
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...
and
marine environments from the
deep sea
The deep sea is broadly defined as the ocean depth where light begins to fade, at an approximate depth of or the point of transition from continental shelves to continental slopes. Conditions within the deep sea are a combination of low tempe ...
to
subterranean waters to the highest
mountain stream
A mountain stream is a Stream, brook or stream, usually with a steep gradient, flowing down a mountainside. Its swift flow rate often transports large quantities of rock (geology), rock, gravel, soil, wood or even entire Trunk (botany), logs with ...
s. Extant species can range in size from ''
Paedocypris
''Paedocypris'' is a genus of tiny cyprinid fish found in swamps and streams on the Southeast Asian islands of Borneo, Sumatra and Bintan.
''Paedocypris progenetica'' has been claimed to be the one of smallest known species of fish in the worl ...
'', at ; to the massive
ocean sunfish
The ocean sunfish (''Mola mola''), also known as the common mola, is one of the largest bony fish in the world. It is the type species of the genus ''Mola'', and one of five extant species in the family Molidae. It was once misidentified as th ...
, at ; and to the giant
oarfish
Oarfish are large and extremely long pelagic lampriform fish belonging to the small family (biology), family Regalecidae. Found in areas spanning from Temperate climate, temperate ocean zones to tropical ones, yet rarely seen by humans, the oa ...
, at . The largest ever known ray-finned fish, the extinct ''
Leedsichthys
''Leedsichthys'' is an extinct genus of pachycormid fish that lived in the oceans of the Middle to Late Jurassic.Liston, JJ (2004). An overview of the pachycormiform ''Leedsichthys''. In: Arratia G and Tintori A (eds) Mesozoic Fishes 3 - Systema ...
'' from the
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...
, has been estimated to have grown to .
Characteristics

Ray-finned fishes occur in many variant forms. The main features of typical ray-finned fish are shown in the adjacent diagram.
The
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 ...
is a more derived structure and used for
buoyancy
Buoyancy (), or upthrust, is the force exerted by a fluid opposing the weight of a partially or fully immersed object (which may be also be a parcel of fluid). In a column of fluid, pressure increases with depth as a result of the weight of t ...
.
Except from the
bichir
Bichirs and the reedfish comprise Polypteridae , a family (biology), family of archaic Actinopterygii, ray-finned fishes and the only family in the order (biology), order Polypteriformes .Helfman GS, Collette BB, Facey DE, Bowen BW. 2009. The D ...
s, which just like the
lung
The lungs are the primary Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their ...
s of
lobe-finned fish
Sarcopterygii (; )—sometimes considered synonymous with Crossopterygii ()—is a clade (traditionally a class or subclass) of vertebrate animals which includes a group of bony fish commonly referred to as lobe-finned fish. These vertebrates ar ...
have retained the ancestral condition of ventral budding from the
foregut
The foregut in humans is the anterior part of the alimentary canal, from the distal esophagus to the first half of the duodenum, at the entrance of the bile duct. Beyond the stomach, the foregut is attached to the abdominal walls by mesentery. ...
, the swim bladder in ray-finned fishes derives from a dorsal bud above the foregut.
In early forms the swim bladder could still be used for breathing, a trait still present in
Holostei
Holostei is a group of ray-finned bony fish. It is divided into two major clades, the Halecomorphi, represented by the single living genus, '' Amia'' with two species, the bowfins (''Amia calva'' and '' Amia ocellicauda''), as well as the Gin ...
(
bowfin
The ruddy bowfin (''Amia calva'') is a ray-finned fish native to North America. Common names include mudfish, mud pike, dogfish, grindle, grinnel, swamp trout, and choupique. It is regarded as a relict, being one of only two surviving species ...
s and
gar
Gars are an ancient group of ray-finned fish in the family Lepisosteidae. They comprise seven living species of fish in two genera that inhabit fresh, brackish, and occasionally marine waters of eastern North America, Central America and Cuba ...
s). In some fish like the
arapaima
The arapaima, pirarucu, or paiche is any large species of bonytongue in the genus ''Arapaima'' native to the Amazon Basin, Amazon and Essequibo River, Essequibo basins of South America. ''Arapaima'' is the type genus of the subfamily Arapaiminae ...
, the swim bladder has been modified for breathing air again, and in other lineages it has been completely lost.
The teleosts have urinary and reproductive tracts that are fully separated, while the Chondrostei have common urogenital ducts, and partially connected ducts are found in Cladistia and Holostei.
Ray-finned fishes have many different types of
scales; but all
teleost
Teleostei (; Ancient Greek, Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts (), is, by far, the largest group of ray-finned fishes (class Actinopterygii), with 96% of all neontology, extant species of f ...
s have
leptoid scale
A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as we ...
s. The outer part of these scales fan out with bony ridges, while the inner part is crossed with fibrous connective tissue. Leptoid scales are thinner and more transparent than other types of scales, and lack the hardened
enamel- or
dentine
Dentin ( ) (American English) or dentine ( or ) (British English) () is a calcified tissue of the body and, along with enamel, cementum, and pulp, is one of the four major components of teeth. It is usually covered by enamel on the crown ...
-like layers found in the scales of many other fish. Unlike
ganoid scale
A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as w ...
s, which are found in non-teleost actinopterygians, new scales are added in concentric layers as the fish grows.
Teleosts and chondrosteans (sturgeons and paddlefish) also differ from the bichirs and holosteans (bowfin and gars) in having gone through a whole-genome duplication (
paleopolyploidy
Paleopolyploidy is the result of genome duplications which occurred at least several million years ago (MYA). Such an event could either double the genome of a single species (autopolyploidy) or combine those of two species (allopolyploidy). Bec ...
). The WGD is estimated to have happened about 320 million years ago in the teleosts, which on average has retained about 17% of the gene duplicates, and around 180 (124–225) million years ago in the chondrosteans. It has since happened again in some teleost lineages, like Salmonidae (80–100 million years ago) and several times independently within the
Cyprinidae
Cyprinidae is a family of freshwater fish commonly called the carp or minnow family, including the carps, the true minnows, and their relatives the barbs and barbels, among others. Cyprinidae is the largest and most diverse fish family, and t ...
(in goldfish and common carp as recently as 14 million years ago).
Body shapes and fin arrangements
Ray-finned fish vary in size and shape, in their feeding specializations, and in the number and arrangement of their ray-fins.
Reproduction

In nearly all ray-finned fish, the sexes are separate, and in most species the females spawn eggs that are fertilized externally, typically with the male inseminating the eggs after they are laid. Development then proceeds with a free-swimming larval stage. However other patterns of
ontogeny
Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the ovum, egg to adult. The term can also be used to refer to t ...
exist, with one of the commonest being
sequential hermaphroditism
Sequential hermaphroditism (called dichogamy in botany) is one of the two types of hermaphroditism, the other type being simultaneous hermaphroditism. It occurs when the organism's sex changes at some point in its life. A sequential hermaphrodit ...
. In most cases this involves
protogyny
Sequential hermaphroditism (called dichogamy in botany) is one of the two types of hermaphroditism, the other type being simultaneous hermaphroditism. It occurs when the organism's sex changes at some point in its life. A sequential hermaphrodit ...
, fish starting life as females and converting to males at some stage, triggered by some internal or external factor.
Protandry
Sequential hermaphroditism (called dichogamy in botany) is one of the two types of hermaphroditism, the other type being simultaneous hermaphroditism. It occurs when the organism's sex changes at some point in its life. A sequential hermaphrodit ...
, where a fish converts from male to female, is much less common than protogyny.
Most families use
external rather than
internal fertilization
Internal fertilization is the union of an egg and sperm cell during sexual reproduction inside the female body. Internal fertilization, unlike its counterpart, external fertilization, brings more control to the female with reproduction. For inte ...
.
Of the
oviparous
Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...
teleosts, most (79%) do not provide parental care.
Viviparity
In animals, viviparity is development of the embryo inside the body of the mother, with the maternal circulation providing for the metabolic needs of the embryo's development, until the mother gives birth to a fully or partially developed juv ...
,
ovoviviparity
Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop inside eggs that r ...
, or some form of parental care for eggs, whether by the male, the female, or both parents is seen in a significant fraction (21%) of the 422 teleost families; no care is likely the ancestral condition.
The oldest case of viviparity in ray-finned fish is found in
Middle Triassic
In the geologic timescale, the Middle Triassic is the second of three epoch (geology), epochs of the Triassic period (geology), period or the middle of three series (stratigraphy), series in which the Triassic system (stratigraphy), system is di ...
species of ''
Saurichthys
''Saurichthys'' (from , 'lizard' and 'fish') is an extinct genus of predatory Actinopterygii, ray-finned fish from the Triassic period (geology), Period. It is the type genus of the family (taxonomy), family Saurichthyidae (Changhsingian-Ju ...
''. Viviparity is relatively rare and is found in about 6% of living teleost species; male care is far more common than female care.
Male territoriality
"preadapts" a species for evolving male parental care.
There are a few examples of fish that self-fertilise. The
mangrove rivulus
The mangrove rivulus or mangrove killifish, ''Kryptolebias marmoratus'' (syn. ''Rivulus marmoratus''), is a species of killifish in the Family (biology), family Rivulidae. It lives in brackish and marine waters (less frequently in fresh water) a ...
is an amphibious, simultaneous hermaphrodite, producing both eggs and spawn and having internal fertilisation. This mode of reproduction may be related to the fish's habit of spending long periods out of water in the mangrove forests it inhabits. Males are occasionally produced at temperatures below and can fertilise eggs that are then spawned by the female. This maintains genetic variability in a species that is otherwise highly inbred.
Classification and fossil record

Actinopterygii is divided into the subclasses
Cladistia
Cladistia is a subclass of bony fishes whose only living members are the bichirs of tropical Africa. Their major synapomorphies are a heterocercal tail in which the dorsal fin has independent rays, and a posteriorly elongated parasphenoid.
...
,
Chondrostei
Chondrostei is a subclass of non- neopterygian ray-finned fish. While the term originally referred to the paraphyletic grouping of all non-neopterygian ray-finned fish, it was redefined by Patterson in 1982 to be a clade comprising the Acipenser ...
and
Neopterygii
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 ...
. The
Neopterygii
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 ...
, in turn, is divided into the infraclasses
Holostei
Holostei is a group of ray-finned bony fish. It is divided into two major clades, the Halecomorphi, represented by the single living genus, '' Amia'' with two species, the bowfins (''Amia calva'' and '' Amia ocellicauda''), as well as the Gin ...
and
Teleostei
Teleostei (; Ancient Greek, Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts (), is, by far, the largest group of ray-finned fishes (class Actinopterygii), with 96% of all neontology, extant species of f ...
. During the
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 ...
(
Triassic
The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...
,
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...
,
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
) and
Cenozoic
The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three g ...
the teleosts in particular
diversified widely. As a result, 96% of living fish species are teleosts (40% of all fish species belong to the teleost subgroup
Acanthomorpha
Acanthomorpha (meaning "thorn-shaped") is an extraordinarily diverse taxon of teleost fishes with spiny fin rays. The clade contains about one-third of the world's modern species of vertebrates: over 14,000 species.
A key anatomical innovatio ...
), while all other groups of actinopterygians represent depauperate lineages.
The classification of ray-finned fishes can be summarized as follows:
* Cladistia, which include bichirs and reedfish
* Actinopteri, which include:
** Chondrostei, which include Acipenseriformes (paddlefishes and sturgeons)
** Neopterygii, which include:
***Teleostei (most living fishes)
***Holostei, which include:
****Lepisosteiformes (gars)
****Amiiformes (bowfin)
The
cladogram
A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...
below shows the main clades of living actinopterygians and their evolutionary relationships to other
extant
Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to:
* Extant hereditary titles
* Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English
* Exta ...
groups of
fishes
A fish (: fish or fishes) is an aquatic, anamniotic, gill-bearing vertebrate animal with swimming fins and a hard skull, but lacking limbs with digits. Fish can be grouped into the more basal jawless fish and the more common jawed ...
and the four-limbed vertebrates (
tetrapods
A tetrapod (; from Ancient Greek τετρα- ''(tetra-)'' 'four' and πούς ''(poús)'' 'foot') is any four- limbed vertebrate animal of the clade Tetrapoda (). Tetrapods include all extant and extinct amphibians and amniotes, with the lat ...
).
The latter include mostly terrestrial
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
but also groups that became
secondarily aquatic (e.g.
whales and dolphins
Cetacea (; , ) is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively c ...
). Tetrapods
evolved
Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...
from a group of
bony fish
Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondricht ...
during the
Devonian
The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...
period
Period may refer to:
Common uses
* Period (punctuation)
* Era, a length or span of time
*Menstruation, commonly referred to as a "period"
Arts, entertainment, and media
* Period (music), a concept in musical composition
* Periodic sentence (o ...
.
Approximate
divergence
In vector calculus, divergence is a vector operator that operates on a vector field, producing a scalar field giving the rate that the vector field alters the volume in an infinitesimal neighborhood of each point. (In 2D this "volume" refers to ...
dates for the different actinopterygian clades (in
millions of years, mya) are from Near et al., 2012.
The polypterids (bichirs and reedfish) are the
sister lineage
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree.
Definition
The expression is most easily illustrated by a cladogram:
Taxon A and t ...
of all other actinopterygians, the Acipenseriformes (sturgeons and paddlefishes) are the sister lineage of Neopterygii, and Holostei (bowfin and gars) are the sister lineage of teleosts. The
Elopomorpha
The superorder Elopomorpha contains a variety of types of fishes that range from typical silvery-colored species, such as the tarpons and ladyfishes of the Elopiformes and the bonefishes of the Albuliformes, to the long and slender, smooth-bodie ...
(
eel
Eels are ray-finned fish belonging to the order Anguilliformes (), which consists of eight suborders, 20 families, 164 genera, and about 1000 species. Eels undergo considerable development from the early larval stage to the eventual adult stage ...
s and
tarpon
Tarpon are fish of the genus ''Megalops''. They are the only members of the family Megalopidae. Of the two species, one (''M. atlanticus'') is native to the Atlantic, and the other (''M. cyprinoides'') to the Indo-Pacific Oceans.
Species and ...
s) appear to be the most
basal teleosts.
The earliest known
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...
actinopterygian is ''
Andreolepis hedei'', dating back 420 million years (
Late Silurian
The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...
), remains of which have been found in
Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...
,
Sweden
Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...
, and
Estonia
Estonia, officially the Republic of Estonia, is a country in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the Baltic Sea across from Sweden, to the south by Latvia, and to the east by Ru ...
. Crown group actinopterygians most likely originated near the Devonian-Carboniferous boundary.
The earliest fossil relatives of modern teleosts are from the
Triassic
The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...
period
Period may refer to:
Common uses
* Period (punctuation)
* Era, a length or span of time
*Menstruation, commonly referred to as a "period"
Arts, entertainment, and media
* Period (music), a concept in musical composition
* Periodic sentence (o ...
(''
Prohalecites
''Prohalecites'' is an extinct genus of ray-finned fish from the Ladinian and possibly Carnian (Triassic) of Italy. It is the oldest known teleosteomorph, a group that includes extant teleosts and their close fossil relatives.
The type and on ...
'', ''
Pholidophorus
''Pholidophorus'' (from , 'horny scale' and , 'to bear') is an extinct genus of Stem group, stem-teleost fish. Numerous species were assigned to this genus in the past, but only the type species ''Pholidophorus latiusculus'', from the Late Tria ...
''),
although it is suspected that teleosts originated already during the
Paleozoic
The Paleozoic ( , , ; or Palaeozoic) Era is the first of three Era (geology), 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 a ...
Era
An era is a span of time.
Era or ERA may also refer to:
* Era (geology), a subdivision of geologic time
* Calendar era
Education
* Academy of European Law (German: '), an international law school
* ERA School, in Melbourne, Australia
* E ...
.
Taxonomy
The listing below is a summary of all
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 ...
(indicated by a
dagger
A dagger is a fighting knife with a very sharp point and usually one or two sharp edges, typically designed or capable of being used as a cutting or stabbing, thrusting weapon.State v. Martin, 633 S.W.2d 80 (Mo. 1982): This is the dictionary or ...
, †) and living groups of Actinopterygii with their respective
taxonomic rank
In biology, taxonomic rank (which some authors prefer to call nomenclatural rank because ranking is part of nomenclature rather than taxonomy proper, according to some definitions of these terms) is the relative or absolute level of a group of or ...
. The
taxonomy
image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy
Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...
follows ''
Eschmeyer's Catalog of Fishes
Catalog of Fishes is a comprehensive on-line database and reference work on the scientific names of fish species and genera. It is global in its scope and is hosted by the California Academy of Sciences. It has been compiled and is continuously up ...
'' and Phylogenetic Classification of Bony Fishes
with notes when this differs from Nelson,
ITIS
The Integrated Taxonomic Information System (ITIS) is an American partnership of federal agencies designed to provide consistent and reliable information on the taxonomy of biological species. ITIS was originally formed in 1996 as an interagenc ...
and
FishBase
FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web. and extinct groups from Van der Laan 2016 and Xu 2021.
* Order †?
Asarotiformes
''Asarotus'' is an extinct genus of prehistoric marine ray-finned fish from the Niobrara Formation of Nebraska, during the Campanian
The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the Intern ...
Schaeffer 1968
* Order †?
Discordichthyiformes Minikh 1998
* Order †?
Paphosisciformes Grogan & Lund 2015
* Order †?
Scanilepiformes
Cladistia is a subclass of bony fishes whose only living members are the bichirs of tropical Africa. Their major synapomorphies are a heterocercal tail in which the dorsal fin has independent rays, and a posteriorly elongated parasphenoid.
Cl ...
Selezneya 1985
* Order †
Cheirolepidiformes Kazantseva-Selezneva 1977
* Order †
Paramblypteriformes Heyler 1969
* Order †
Rhadinichthyiformes
* Order †
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. ...
Hay 1902
* Order †
Tarrasiiformes
Tarasiiformes is an extinct order of prehistoric Actinopterygii, ray-finned fish.
Taxonomy
* Order †Tarrasiiformes sensu Lund & Poplin 2002 aplistia** Family †Tarrasiidae Traquair 1881 emend. Woodward 1891
*** Genus †''Apholidotos'' Lu ...
sensu Lund & Poplin 2002
* Order †
Ptycholepiformes
Ptycholepiformes are an extinct order (biology), order of prehistoric Actinopterygii, ray-finned fish that existed during the Triassic period (geology), period and the Early Jurassic epoch (geology), epoch. The order includes the genera ''Acrorha ...
Andrews et al. 1967
* Order †
Haplolepidiformes Westoll 1944
* Order †
Aeduelliformes Heyler 1969
* Order †
Platysomiformes Aldinger 1937
* Order †
Dorypteriformes Cope 1871
* Order †
Eurynotiformes Sallan & Coates 2013
* Subclass
Cladistia
Cladistia is a subclass of bony fishes whose only living members are the bichirs of tropical Africa. Their major synapomorphies are a heterocercal tail in which the dorsal fin has independent rays, and a posteriorly elongated parasphenoid.
...
Pander 1860
** Order †
Guildayichthyiformes
Guildayichthyidae is a prehistoric family of marine fish from the Mississippian Bear Gulch Limestone of Montana
Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It ...
Lund 2000
** Order
Polypteriformes
Bichirs and the reedfish comprise Polypteridae , a family of archaic ray-finned fishes and the only family in the order Polypteriformes .Helfman GS, Collette BB, Facey DE, Bowen BW. 2009. The Diversity of Fishes. West Sussex, UK: Blackwell Pu ...
Bleeker 1859 (
bichir
Bichirs and the reedfish comprise Polypteridae , a family (biology), family of archaic Actinopterygii, ray-finned fishes and the only family in the order (biology), order Polypteriformes .Helfman GS, Collette BB, Facey DE, Bowen BW. 2009. The D ...
s and
reedfish
The reedfish, ropefish (more commonly used in the United States), or snakefish, ''Erpetoichthys calabaricus'', is a species of fish in the family Polypteridae alongside the bichirs. It is the only member of the genus ''Erpetoichthys''. It is n ...
es)
** Subclass
Actinopteri
Actinopteri () is the sister group of Cladistia (bichirs) in the class Actinopterygii (ray-finned fish).
Dating back to the Permian period, the Actinopteri comprise the Chondrostei (sturgeons and paddlefish), the Holostei ( bowfins and gars), ...
Cope 1972 s.s.
*** Order †
Elonichthyiformes Kazantseva-Selezneva 1977
*** Order †
Phanerorhynchiformes
*** Order †
Bobasatraniiformes
Bobasatraniiformes is an extinct order of durophagous ray-finned fish that existed from the late Permian to the Middle Triassic in both marine and freshwater environments. The order includes two families: Bobasatraniidae, with the genera ''Bo ...
Berg 1940
*** Order †
Saurichthyiformes
Saurichthyiformes is an extinct order (biology), order of Actinopterygii, ray-finned fish which existed in Asia, Africa, Australia (continent), Australia, Europe and North America, during the late Permian to early Middle Jurassic. Saurichthy ...
Aldinger 1937
** Subclass
Chondrostei
Chondrostei is a subclass of non- neopterygian ray-finned fish. While the term originally referred to the paraphyletic grouping of all non-neopterygian ray-finned fish, it was redefined by Patterson in 1982 to be a clade comprising the Acipenser ...
Müller, 1844
*** Order †
Birgeriiformes Heyler 1969
*** Order †
Chondrosteiformes
Chondrosteidae is a family of extinct marine actinopterygian fishes, known from the Early Jurassic of Europe. They are closely related to modern sturgeons and paddlefish of the order Acipenseriformes, and are either placed as part of that orde ...
Aldinger, 1937
*** Order
Acipenseriformes
Acipenseriformes is an order (biology), order of basal (phylogenetics), basal Actinopterygii, ray-finned fishes that includes living and fossil sturgeons and paddlefishes (Acipenseroidei), as well as the extinct family (biology), families C ...
Berg 1940 (includes
sturgeon
Sturgeon (from Old English ultimately from Proto-Indo-European language, Proto-Indo-European *''str̥(Hx)yón''-) is the common name for the 27 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the ...
s and
paddlefish
Paddlefish (family Polyodontidae) are a family of ray-finned fish belonging to order Acipenseriformes, and one of two living groups of the order alongside sturgeons (Acipenseridae). They are distinguished from other fish by their elongated rost ...
es)
** Subclass
Neopterygii
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 ...
Regan 1923 sensu Xu & Wu 2012
*** Order †
Pholidopleuriformes
Pholidopleuriformes is an extinct order of Actinopterygii, ray-finned fish containing a single family, Pholidopleuridae.
Classification
** Family †Pholidopleuridae Othenio Abel, Abel, 1919 / Wade, 1932
*** Genus †''Arctosomus'' Berg 1941 Berg 1937
*** Order †
' ...