Octopodiformes is a superorder of the subclass

Coleoidea Subclass Coleoidea, or Dibranchiata, is the grouping of cephalopods containing all the various taxa popularly thought of as "soft-bodied" or "shell-less" (i.e., octopuses, squid and cuttlefish). Unlike its extant sister group, Nautiloidea, whos ...

, comprising the

octopus An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefis ...

es and the

vampire squid The vampire squid (''Vampyroteuthis infernalis'', lit. 'vampire squid from hell') is a small cephalopod found throughout temperate and tropical oceans in extreme deep sea conditions. The vampire squid uses its bioluminescent organs and its uniq ...

. All living members of Octopodiformes have eight

arms Arms or ARMS may refer to: *Arm or arms, the upper limbs of the body Arm, Arms, or ARMS may also refer to: People * Ida A. T. Arms (1856–1931), American missionary-educator, temperance leader Coat of arms or weapons *Armaments or weapons **Fi ...

, either lacking the two tentacles of squid (as is the case in octopuses) or modifying the tentacles into thin filaments (as in vampire squid). Octopodiformes is often considered the

crown group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

of octopuses and vampire squids, including all descendants of their common ancestor. Some authors use the term Vampyropoda for the same general category, though others use "Vampyropoda" to refer to the total group (all cephalopods closer to octopods than to true squid). Another term is Octobranchia, referring to cephalopods without prominent tentacles. ''

Pohlsepia ''Pohlsepia mazonensis'' is a species of fossil organism with unknown affinity. Although it was originally identified as an extinct cephalopod, later studies denied that interpretation. The species is known from a single exceptionally preserved f ...

'', originally described as earliest octopod is considered as dubious for this group in later study. The oldest unambiguous vampyropod is ''

Syllipsimopodi ''Syllipsimopodi'' is an extinct member of the cephalopod subclass Coleoidea belonging to the clade Vampyropoda, which includes octopuses (Octopoda) and vampire squids (Vampyromorphida). The type and only known species is ''Syllipsimopodi bid ...

'', a squid-like cephalopod from the

Mississippian Mississippian may refer to: * Mississippian (geology), a subperiod of the Carboniferous period in the geologic timescale, roughly 360 to 325 million years ago *Mississippian culture, a culture of Native American mound-builders from 900 to 1500 AD ...

-age

Bear Gulch Lagerstätte The Bear Gulch Limestone is a limestone-rich geological lens in central Montana, renowned for the quality of its late Mississippian-aged fossils. It is exposed over a number of outcrops northeast of the Big Snowy Mountains, and is often considere ...

Montana Montana () is a U.S. state, state in the Mountain states, Mountain West List of regions of the United States#Census Bureau-designated regions and divisions, division of the Western United States. It is bordered by Idaho to the west, North ...

. ''Syllipsimopodi'' has a combination of squid-like features (like 10 arms) and octopod-like features (like biserial suckers and a simplified internal shell).

Classification

*Class

Cephalopoda A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, ...

**Subclass

Nautiloidea Nautiloids are a group of marine cephalopods ( Mollusca) which originated in the Late Cambrian and are represented today by the living ''Nautilus'' and '' Allonautilus''. Fossil nautiloids are diverse and speciose, with over 2,500 recorded speci ...

: nautilus **Subclass †

Ammonoidea Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttl ...

: ammonites **Subclass

***Superorder Decapodiformes:

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting ...

cuttlefish Cuttlefish or cuttles are marine molluscs of the order Sepiida. They belong to the class Cephalopoda which also includes squid, octopuses, and nautiluses. Cuttlefish have a unique internal shell, the cuttlebone, which is used for control ...

***Clade Vampyropoda ****Genus †''

'' ****Genus †'' Proteroctopus'' ****Superorder Octopodiformes / Octobranchia *****Family † Trachyteuthididae (''

incertae sedis ' () or ''problematica'' is a term used for a 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, uncertain ...

'') *****Order Vampyromorphida: vampire squid *****Clade: Muensterelloidea ******Family: † Muensterellidae ******Family: †

Patelloctopodidae Patelloctopodidae is a family of stem-octopod cephalopods from the Middle and Late Jurassic of Europe. Five genera are currently placed in the family, '' Etchesia, Muenstellerina,'' '' Patelloctopus,'' '' Pearciteuthis'' and '' Tyrionella,'' Pat ...

******Order Octopoda ******* Genus †'' Keuppia'' (''

'') ******* Genus †'' Palaeoctopus'' (''

'') ******* Genus †'' Paleocirroteuthis'' (''

'') ******* Genus †'' Proteroctopus'' (''

'') ******* Genus †''

Styletoctopus ''Styletoctopus'' is an extinct genus of octopus. The genus consists of the single species ''Styletoctopus annae'', which lived approximately 95 million years ago. Very few octopus species appear in the fossil record, as octopuses consist of soft ...

'' (''

'') *******Suborder Cirrina: finned deep-sea octopus ********Family

Opisthoteuthidae Umbrella octopuses (family Opisthoteuthidae) are a group of pelagic octopuses. Umbrella octopuses are characterized by a web of skin between the tentacles, causing them to somewhat resemble an opened umbrella when the tentacles are spread. De ...

: umbrella octopus ********Family

Cirroteuthidae Cirroteuthidae is a family of cirrate octopuses comprising three species in two genera. Species *Genus ''Cirroteuthis'' **'' Cirroteuthis muelleri'' *Genus '' Cirrothauma'' **'' Cirrothauma magna'' **''Cirrothauma murrayi ''Cirrothauma murray ...

********Family Stauroteuthidae *******Suborder Incirrina ********Family

Amphitretidae Amphitretidae is a family of mesopelagic octopods which contains three subfamilies, formerly classified as families in their own right. It is classified in the superfamily Octopodoidea. Species in the family Amphipetridae are characterised by ...

: telescope octopus ********Family

Bolitaenidae The Bolitaeninae are a subfamily, in the family Amphitretidae, of small, common pelagic octopuses found in all tropical and temperate oceans of the world. The taxonomy of this taxon is not entirely certain; recent research suggests just two gener ...

: gelatinous octopus ********Family Octopodidae: benthic octopus ********Family Vitreledonellidae: glass octopus ********Superfamily Argonautoidea *********Family

Alloposidae The seven-arm octopus (''Haliphron atlanticus'') is one of the two largest known species of octopus; based on scientific records, it has a maximum estimated total length of and mass of . The only other similarly large extant species is the gian ...

: seven-arm octopus *********Family Argonautidae: argonauts *********Family

Ocythoidae ''Ocythoe tuberculata'', also known as the tuberculate pelagic octopus or football octopus, is a pelagic octopus. It is the only known species in the family Ocythoidae. ''Ocythoe tuberculata'' is found in warm and temperate seas, especially ...

: tuberculate pelagic octopus *********Family Tremoctopodidae: blanket octopus

References

External links

Tree of Life web project: Octopodiformes
Protostome superorders Extant Pennsylvanian first appearances {{cephalopod-stub