Aulopiformes is a diverse

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

consisting of some 15

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 ...

and several

prehistoric Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use o ...

families Family (from ) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictability, structure, and safety as ...

with about 45

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

and over 230

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), ...

. The common names grinners, lizardfishes and allies, or aulopiforms are sometimes used for this group. They are included in the superorder Cyclosquamata, though modern

taxonomist In biology, taxonomy () is the science, scientific study of naming, defining (Circumscription (taxonomy), circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxon, taxa (si ...

s consider this superorder to be unwarranted. Many

aulopiforms are

deep-sea fish Deep-sea fish are fish that live in the darkness below the sunlit surface waters, that is below the epipelagic or photic zone of the sea. The lanternfish is, by far, the most common deep-sea fish. Other deep-sea fishes include the flashlight f ...

es, with some

recognized as being

hermaphroditic A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many ...

, a number of which are able to self-fertilise. Some are

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

, but most are

pelagic The pelagic zone consists of the water column of the open ocean and can be further divided into regions by depth. The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the sur ...

swimmers (

nekton 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, ...

ic). A

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 ...

of Aulopiformes, the suborder

Enchodontoidei The Enchodontoidei are an extinct superorder of aulopiform fish known from the Early Cretaceous to the Eocene. They were among the dominant predatory marine fish groups in the Late Cretaceous, achieving a worldwide distribution. They were an ext ...

and its many constituent families, were dominant nektonic fish throughout much of the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

before the

extinction 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 ...

of most of their members around the K–Pg event, with the

Dercetidae The Dercetidae are an extinct family of aulopiform ray-finned fish that are known from the Late Cretaceous to the early Paleocene (and possibly to the Eocene if ''Stratodus'' is a member). They are among the many members of the diverse, extinct ...

surviving for some time in the

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 ...

Taxonomy

Past authors have considered aulopiforms to be so distinct as to warrant separation in a monotypic

superorder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...

of the

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 ...

, the Cyclosquamata. However,

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

taxa are generally avoided by modern

s if not necessary, and in this case a distinct superorder seems indeed unwarranted: together with the equally dubious superorder "

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 autapom ...

", the grinners appear to be closely related to some of the

Protacanthopterygii Protacanthopterygii is a superorder of ray-finned fish. They inhabit both Marine (ocean), marine and freshwater habitats. They appear to have evolved in the Cretaceous or perhaps late Jurassic, originating probably roughly 150 million years ago; ...

, namely, the

Salmoniformes Salmoniformes (, lit. "salmon-shaped") is an Order (biology), order of Actinopterygii, ray-finned fishes native to the temperate and subarctic Northern Hemisphere. It contains two suborders: Salmonoidei (containing only the Salmonidae) and Esocoi ...

(salmon, trout, and relatives), and should perhaps be part of that larger clade. As an alternative, the superorders are sometimes united as an unranked clade named Euteleostei, but in that case the Protacanthopterygii would need to be

split Split(s) or The Split may refer to: Places * Split, Croatia, the largest coastal city in Croatia * Split Island, Canada, an island in the Hudson Bay * Split Island, Falkland Islands * Split Island, Fiji, better known as Hạfliua Arts, enter ...

further to account for the

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

uncertainty. This would result in a highly cumbersome and taxonomically redundant group of two very small and no less than four monotypic superorders.

Description

In general, aulopiform fish have a mixture of

advanced The Advanced Party (), otherwise known as the Advanced Association () was a liberal and centrist Zionist political association in Mandatory Palestine founded by several urban liberal Zionists. The party was founded in order to represent the voice ...

and primitive characteristics relative to other

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 ...

fish. Aulopiformes are grouped together (claded) because of common features in the structure of their

gill arch Branchial arches or gill arches are a series of paired bony/ cartilaginous "loops" behind the throat ( pharyngeal cavity) of fish, which support the fish gills. As chordates, all vertebrate embryos develop pharyngeal arches, though the event ...

es; their second

pharyngobranchial Branchial arches or gill arches are a series of paired bony/cartilaginous "loops" behind the throat ( pharyngeal cavity) of fish, which support the fish gills. As chordates, all vertebrate embryos develop pharyngeal arches, though the eventual ...

bone (part of the gill arch) is greatly elongated posterolaterally away from third pharyngobranchial, which lacks a

cartilaginous Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...

condyle A condyle (;Entry "condyle"
in

to articulate with the preceding bone, but is contacted by the elongated uncinate process of the second epibranchial. Aulopiforms have a

gas bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled 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 via swimming, ...

which is either

vestigial Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on co ...

or entirely absent, a hypaxialis muscle that is unusually extended forward at its upper end, attaching to the

neurocranium In human anatomy, the neurocranium, also known as the braincase, brainpan, brain-pan, or brainbox, is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the cal ...

below the

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), ...

(perhaps to snap the upper part of the skull down when catching prey), and the position of the

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

ry bone. Other features include the position of the

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...

s far back on the body, the fused medial processes of

pelvic girdle The hip bone (os coxae, innominate bone, pelvic bone or coxal bone) is a large flat bone, constricted in the center and expanded above and below. In some vertebrates (including humans before puberty) it is composed of three parts: the Ilium (bone) ...

, and the presence of an

adipose fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only b ...

(which is also typical for the Protacanthopterygii). The

larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...

of some Aulopiformes are extremely bizarre-looking, with elongated fins, and do not resemble the adult animals. They were not only described as distinct species, but also even separated as

and finally in a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

"Macristiidae" which was allied with various Protacanthopterygii (''

sensu lato ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...

''), but the initial assessment – which found ''"Macristium"'' to resemble the

deepwater lizardfish The Bathysauridae are a small family of deepwater aulopiform fish, related to the telescopefishes. The two species in the family both belong to the genus ''Bathysaurus''. Commonly called deepwater lizardfishes or deepsea lizardfishes, the latte ...

es (Bathysauridae) in some details – was in fact not far off the mark: "''Macristium''" species are now known to be the larvae of '' Bathysaurus'', while the supposed other "macristiids" "''Macristiella spp.''" are larvae of the deepsea tripodfish ''

Bathytyphlops ''Bathytyphlops'' is a genus of deepsea tripod fishes known only from the eastern Atlantic Ocean. Species There are currently two recognized species in this genus: * '' Bathytyphlops marionae'' Mead, 1958 (Marion's spiderfish) * '' Bathytyphlop ...

''. Several extant aulopiform families have Cretaceous representatives, and phylogenetic evidence indicates that the extant families of the order diversified around the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

, making it rather ancient. These diversification events included the earliest

adaptation In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the p ...

s for deep-sea living, which is common among many extant aulopiform taxa. Below is a timeline indicating

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 ...

evidence for the group: ImageSize = width:1000px height:auto barincrement:15px PlotArea = left:10px bottom:50px top:10px right:10px Period = from:-105.0 till:15 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:10 start:-105.0 ScaleMinor = unit:year increment:1 start:-105.0 TimeAxis = orientation:hor AlignBars = justify Colors = #legends id:CAR value:claret id:ANK value:rgb(0.4,0.3,0.196) id:HER value:teal id:HAD value:green id:OMN value:blue id:black value:black id:white value:white id:cretaceous value:rgb(0.5,0.78,0.31) id:earlycretaceous value:rgb(0.63,0.78,0.65) id:latecretaceous value:rgb(0.74,0.82,0.37) id:cenozoic value:rgb(0.54,0.54,0.258) id:paleogene value:rgb(0.99,0.6,0.32) id:paleocene value:rgb(0.99,0.65,0.37) id:eocene value:rgb(0.99,0.71,0.42) id:oligocene value:rgb(0.99,0.75,0.48) id:neogene value:rgb(0.999999,0.9,0.1) id:miocene value:rgb(0.999999,0.999999,0) id:pliocene value:rgb(0.97,0.98,0.68) id:quaternary value:rgb(0.98,0.98,0.5) id:pleistocene value:rgb(0.999999,0.95,0.68) id:holocene value:rgb(0.999,0.95,0.88) BarData= bar:eratop bar:space bar:periodtop bar:space bar:NAM1 bar:NAM2 bar:NAM3 bar:NAM4 bar:NAM5 bar:NAM6 bar:NAM7 bar:NAM8 bar:NAM9 bar:space bar:period bar:space bar:era PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 shift:(7,-4) bar:periodtop from: -105.0 till: -99.6 color:earlycretaceous text:

Early Early may refer to: Places in the United States * Early, Iowa, a city * Early, Texas, a city * Early Branch, a stream in Missouri * Early County, Georgia * Fort Early, Georgia, an early 19th century fort Music * Early B, stage name of Jamaican d ...

from: -99.6 till: -65.5 color:latecretaceous text:

Late Late or LATE may refer to: Everyday usage * Tardy, or late, not being on time * Late (or the late) may refer to a person who is dead Music * ''Late'' (The 77s album), 2000 * Late (Alvin Batiste album), 1993 * Late!, a pseudonym used by Dave Groh ...

from: -65.5 till: -55.8 color:paleocene text: Paleo. from: -55.8 till: -33.9 color:eocene text: Eo. from: -33.9 till: -23.03 color:oligocene text: Oligo. from: -23.03 till: -5.332 color:miocene text: Mio. from: -5.332 till: -2.588 color:pliocene text: Pl. from: -2.588 till: -0.0117 color:pleistocene text: Pl. from: -0.0117 till: 0 color:holocene text: H. bar:eratop from: -105.0 till: -65.5 color:cretaceous text:

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 ...

from: -65.5 till: -23.03 color:paleogene text:

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

from: -23.03 till: -2.588 color:neogene text:

Neogene The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of th ...

from: -2.588 till: 0 color:quaternary text: Q. PlotData= align:left fontsize:M mark:(line,white) width:5 anchor:till align:left color:latecretaceous bar:NAM1 from:-99.6 till:-97.6 text:

Nematonotus ''Nematonotus'' is an extinct genus of prehistoric ray-finned fish that lived during the Lower Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age ...

color:latecretaceous bar:NAM2 from:-99.6 till:-83.5 text: Acrognathus color:eocene bar:NAM3 from:-55.8 till:-48.6 text: Aulopopsis color:eocene bar:NAM4 from:-55.8 till:-48.6 text:

Labrophagus ''Labrophagus'' is an extinct genus of prehistoric bony fish that lived during the lower Eocene. See also * Prehistoric fish * List of prehistoric bony fish References Eocene fish † A dagger, obelisk, or obelus is a typographic ...

color:eocene bar:NAM5 from:-55.8 till:0 text:

Aulopus ''Aulopus'' is a genus of flagfins native to the Atlantic Ocean and the Pacific Ocean. Although ''Aulopus'' is native to both the Atlantic and the Pacific oceans, for the first time in 2010 ''Aulopus filamentosus'' (the royal flagfin), was spott ...

color:eocene bar:NAM6 from:-37.2 till:0 text: Chlorophthalmus color:eocene bar:NAM7 from:-37.2 till:0 text: Scopelosaurus color:oligocene bar:NAM8 from:-28.4 till:0 text: Scopelarchus color:pliocene bar:NAM9 from:-5.332 till:0 text:

Notolepis ''Notolepis'' is a genus of barracudinas. Species There are currently two recognized species in this genus: * '' Notolepis annulata'' Post Post, POST, or posting may refer to: Postal services * Mail, the postal system, especially in Commonw ...

PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 bar:period from: -105.0 till: -99.6 color:earlycretaceous text:

from: -99.6 till: -65.5 color:latecretaceous text:

from: -65.5 till: -23.03 color:paleogene text:

from: -23.03 till: -2.588 color:neogene text:

from: -2.588 till: 0 color:quaternary text: Q.

Classification

* Suborder Alepisauroidei ** Family

Alepisauridae Lancetfishes are large oceanic predatory ray-finned fishes in the genus ''Alepisaurus'' ("scaleless lizard") in the monotypic taxon, monogeneric family Alepisauridae. Lancetfishes grow up to in length. Very little is known about their biology, ...

– lancetfishes ** Family

Anotopteridae The daggertooths (genus ''Anotopterus'') are a genus of marine mesopelagic fish in the order Aulopiformes, the sole genus of the family Anotopteridae. They are found in oceans worldwide, but prefer cooler waters. Description Daggertooths are sim ...

– daggertooths (may belong in Paralepididae) ** Family Evermannellidae – sabertooth fishes ** Family Omosudidae – hammerjaw (sometimes included in Alepisauridae) ** Family

Paralepididae Barracudinas are any member of the marine mesopelagic fish family (biology), family Paralepididae: 50 or so extant species are found almost worldwide in deep waters. Several genera, including ''Holosteus'' and ''Drimys (fish), Drimys'', are kn ...

– barracudinas ** Family † Polymerichthyidae – an extinct alepisauroid closely related to the daggertooths and lancetfishUyeno, Teruya. "A Miocene alepisauroid fish of a new family, Polymerichthyidae, from Japan." Bull. Nat. Sci. Mus 10 (1967): 383–394. ** Family Scopelarchidae – pearleyes * Suborder Chlorophthalmoidei ** Family Bathysauroididae – pale deepsea lizardfish ** Family Bathysauropsidae – lizard greeneyes (sometimes included in Ipnopidae) ** Family

Chlorophthalmidae Greeneyes are deep-sea aulopiform marine fishes in the small family Chlorophthalmidae. Thought to have a circumglobal distribution in tropical and temperate waters, the family contains just 18 species in two genera. The family name Chlorophthal ...

– greeneyes ** Family

Ipnopidae The Ipnopidae (deepsea tripod fishes) are a family of fishes in the order Aulopiformes. They are small, slender fishes, with maximum length ranging from about . They are found in temperate and tropical deep waters of the Atlantic, Indian Ocean, I ...

– deepsea tripodfishes ** Family Notosudidae – waryfishes * Suborder

(including Halecoidei, Ichthyotringoidei, may belong in Alepisauroidei;

) ** Genus ''

Nardorex ''Nardorex zorzini'' is an extinct nektonic predatory aulopiform ray-finned fish from Late Cretaceous Italy.Taverne, L. "Les poissons crétacés de Nardò. 19. Nardorex zorzoni gen. et sp. nov.(Teleostei, Aulopiformes, Alepisauroidei)." Bollet. ...

'' (fossil, tentatively placed here) ** Genus '' Serrilepis'' (fossil, tentatively placed here) ** Genus '' Yabrudichthys'' (fossil, tentatively placed here) ** Family Apateopholidae (fossil) ** Family Cimolichthyidae (fossil) ** Family

(fossil) ** Family

Enchodontidae Enchodontidae is an extinct family of marine enchodontoid aulopiform ray-finned fish from the Cretaceous to potentially the Eocene, being found worldwide. The family itself was diverse within its body form though unlike other enchodontoids, most ...

(fossil) ** Family

Eurypholidae Enchodontidae is an extinct Family (biology), family of marine Enchodontoidei, enchodontoid Aulopiformes, aulopiform Actinopterygii, ray-finned fish from the Cretaceous to potentially the Eocene, being found worldwide. The family itself was diverse ...

(fossil) ** Family

Halecidae Halecidae is an extinct family of aulopiform ray-finned fish known from the Cretaceous Period. It is one of the Enchodontoidei, a diverse group of aulopiforms that were dominant marine fish during the Cretaceous Period. It contains the followi ...

(fossil) ** Family

Ichthyotringidae Ichthyotringidae is an extinct family of aulopiform ray-finned fish known from the Early to Late Cretaceous. It is one of the Enchodontoidei, a diverse group of aulopiforms that were dominant marine fish during the Cretaceous. The following gen ...

(fossil) ** Family

Prionolepididae ''Prionolepis'' is a genus of prehistoric ray-finned fish belonging to the order Alepisauriformes. Fossil record These ray-finned fish lived in the Upper Cretaceous (Cenomanian - Turonian, about 95-90 million years ago). Fossils have been found ...

(fossil) * Suborder Giganturoidei ** Family

Bathysauridae The Bathysauridae are a small family of deepwater aulopiform fish, related to the telescopefishes. The two species in the family both belong to the genus ''Bathysaurus''. Commonly called deepwater lizardfishes or deepsea lizardfishes, the latt ...

– deepwater lizardfishes ** Family Giganturidae – telescopefishes * Suborder Synodontoidei ** Family

Aulopidae The Aulopidae are a small family of aulopiform ray-finned fish. They are found in most tropical and subtropical oceans, such as the Atlantic, Mediterranean, and Pacific. The aulopids are commonly known as flagfins. The aulopids resemble lizard ...

– flagfins ** Family Paraulopidae – "cucumberfishes" ** Family Pseudotrichonotidae – sandliving lizardfishes, sand-diving lizardfishes ** Family

Synodontidae The Synodontidae or lizardfishes(or typical lizardfish to distinguish them from the Bathysauridae and Pseudotrichonotidae) are benthic (bottom-dwelling) marine and estuarine bony fishes that belong to the aulopiform fish order, a diverse grou ...

– typical lizardfishes *Suborder ''

incertae sedis or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

'' **?Family

Cheirothricidae Cheirothricidae is a family of extinct marine ray-finned fish, perhaps belonging to the Aulopiformes, although they are tentatively placed as indeterminate eurypterygians. They lived during the Upper Cretaceous (Cenomanian - Campanian, about 95 ...

(fossil, generally considered indeterminate eurypterygians) **Genus '' Aulopopsis'' (fossil) means extinct.

Footnotes

References

* * * * * * * * {{Authority control Articles which contain graphical timelines Ray-finned fish orders