Octopodiformes is a superorder of the subclass

Coleoidea Subclass (biology), 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, ...

, 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, cuttle ...

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 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. ...

(all cephalopods closer to octopods than to true squid). Another term is Octobranchia, referring to cephalopods without prominent tentacles. '' Pohlsepia'', originally described as earliest octopod is considered as dubious for this group in later study. The oldest unambiguous vampyropod is '' Syllipsimopodi'', a squid-like cephalopod from the Mississippian-age Bear Gulch Lagerstätte of

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...

. ''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 hea ...

**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 species. ...

: 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 cuttle ...

: ammonites **Subclass

***Superorder

Decapodiformes Decapodiformes is a superorder of Cephalopoda comprising all cephalopod species with ten limbs, specifically eight short arms and two long tentacles. It is hypothesized that the ancestral coleoid had five identical pairs of limbs, and that one ...

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 t ...

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 of ...

***Clade Vampyropoda ****Genus †'' Syllipsimopodi'' ****Genus †''

Proteroctopus ''Proteroctopus'' is an extinct genus of cephalopod that lived in the Middle Jurassic, approximately 164 million years ago. It is only known from a single species ''P. ribeti''. The single fossil specimen assigned to this species originates from ...

'' ****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, uncertainty ...

'') *****Order

Vampyromorphida Vampyromorphida is an order of cephalopods comprising one known extant species (''Vampyroteuthis infernalis'') and many extinct taxa. Physically, they somewhat resemble octopuses (their closest relatives), but the eight arms are united by a web ...

: vampire squid *****Clade:

Muensterelloidea Muensterelloidea is a superfamily (or clade) of stem- octopod cephalopods from the Early Jurassic to Late Cretaceous. Two families are currently identified, Muensterellidae, and Patelloctopodidae. The clade is the ancestral group from which mode ...

******Family: †

Muensterellidae Muensterellidae is a family of stem- octopod cephalopods from the Late Jurassic to Late Cretaceous. Phylogeny Muensterellidae is one of two families in the superfamily Muensterelloidea along with the Patelloctopodidae. The muensterelloids are ...

******Family: † Patelloctopodidae ******Order Octopoda ******* Genus †''

Keuppia ''Keuppia'' is an extinct genus of octopus. Taxonomy It consists of two species, ''Keuppia hyperbolaris'' and ''Keuppia levante'', both of which lived approximately 95 million years ago. Both species were found in fossilized form, which is very ...

'' (''

'') ******* Genus †''

Palaeoctopus ''Palaeoctopus newboldi'' is an extinct basal octopod that lived in the Late Cretaceous, approximately 89 to 71 million years ago. Fossil material assigned to this species originates from the Mount Hajoula region in Lebanon. The holotype was fo ...

'' (''

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

'') ******* Genus †''

'' (''

'') ******* Genus †'' Styletoctopus'' (''

'') *******Suborder

Cirrina Cirrina or Cirrata is a suborder and one of the two main divisions of octopuses. Cirrate octopuses have a small, internal shell and two fins on their head, while their sister suborder Incirrina has neither. The fins of cirrate octopods are asso ...

: 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 ********Family Stauroteuthidae *******Suborder

Incirrina Incirrata (or Incirrina) is a suborder of the order Octopoda. The suborder contains the classic " benthic octopuses," as well as many pelagic octopus families, including the paper nautiluses. The incirrate octopuses are distinguished from th ...

********Family Amphitretidae: telescope octopus ********Family Bolitaenidae: gelatinous octopus ********Family

Octopodidae The Octopodidae comprise the family containing the majority of known octopus species. Genera The World Register of Marine Species lists these genera: *''Abdopus'' Norman & Finn, 2001 *''Ameloctopus'' Norman, 1992 *''Amphioctopus'' P. Fischer, 1 ...

: benthic octopus ********Family Vitreledonellidae: glass octopus ********Superfamily Argonautoidea *********Family Alloposidae: seven-arm octopus *********Family

Argonautidae The Argonautidae are a family of pelagic cephalopods that inhabit tropical and temperate oceans of the world. The family encompasses the modern paper nautiluses of the genus '' Argonauta'' along with several extinct genera of shelled octopods ...

: argonauts *********Family Ocythoidae: tuberculate pelagic octopus *********Family

Tremoctopodidae ''Tremoctopus'' is a genus of pelagic cephalopods, containing four species that occupy surface to mid-waters in subtropical and tropical oceans. They are commonly known as blanket octopuses, in reference to the long, transparent webs that connec ...

: blanket octopus

References

External links

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