Octopodiformes is a superorder of the subclass

Coleoidea Coleoidea or Dibranchiata is one of the two subclasses of cephalopod molluscs containing all the various taxa popularly thought of as "soft-bodied" or "shell-less" (i.e. octopus, squid and cuttlefish). Unlike its extant sister group Nauti ...

, comprising the

octopus An octopus (: octopuses or octopodes) 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, cuttlefish, and nautiloids. Like oth ...

es and the vampire squid. 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 Octobrachia, referring to cephalopods without prominent tentacles. It is considered one of the two extant groups of the

Neocoleoidea Neocoleoidea is a large group of marine cephalopods. This cohort contains two extant groups: Decapodiformes (squid, cuttlefish, and relatives) and Octopodiformes (octopuses and the vampire squid). Species within this group exist in all major ...

. '' Pohlsepia'', originally described as earliest octopod is considered as dubious for this group in later study. ''Syllipsimopodi'', a squid-like cephalopod from the Mississippian-age Bear Gulch Lagerstätte of

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

, was originally described as the oldest unambiguous vampyropod. However, further analyses might be necessary to unequivocally assign this cephalopod to Vampyropoda. ''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 cephalopods (Mollusca) which originated in the Late Cambrian and are represented today by the living ''Nautilus'' and ''Allonautilus''. Fossil nautiloids are diverse and species rich, with over 2,500 recorded species. Th ...

: nautilus **Subclass †

Ammonoidea Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

: ammonites **Subclass

***Superorder Decapodiformes:

squid A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ...

cuttlefish Cuttlefish, or cuttles, are Marine (ocean), marine Mollusca, molluscs of the order (biology), suborder Sepiina. They belong to the class (biology), class Cephalopoda which also includes squid, octopuses, and nautiluses. Cuttlefish have a unique ...

***Clade Vampyropoda ****Genus †'' Syllipsimopodi'' ****Genus †'' Proteroctopus'' ****Superorder Octopodiformes / Octobrachia *****Family † Trachyteuthididae (''

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 ...

'') *****Order Vampyromorphida: vampire squid *****Clade: Muensterelloidea ******Family: † Muensterellidae ******Family: † Patelloctopodidae ******Order Octopoda ******* Genus †'' Keuppia'' (''

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

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

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

'') ******* 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 ass ...

: finned deep-sea octopus ********Family Opisthoteuthidae: umbrella octopus ********Family Cirroteuthidae ********Family Stauroteuthidae *******Suborder Incirrina ********Superfamily Octopodoidea ********* Family

Amphitretidae Amphitretidae is a Family (biology), family of mesopelagic octopods which contains three subfamily, subfamilies, formerly classified as families in their own right. It is classified in the Superfamily (taxonomy), superfamily Octopodoidea. Species ...

********** subfamily Amphitretinae: telescope octopus ********** subfamily

Bolitaeninae The Bolitaeninae are a subfamily, in the Family (biology), family Amphitretidae, of small, common pelagic zone, pelagic octopuses found in all tropical and temperate oceans of the world. The Taxonomy (biology), taxonomy of this taxon is not entir ...

: gelatinous octopus ********** subfamily Vitreledonellinae ********* Family Bathypolypodidae ********* Family Eledonidae ********* Family Enteroctopodidae ********* Family Megaleledonidae *********Family Bolitaenidae: gelatinous octopus *********Family Octopodidae: benthic 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 octopo ...

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

References

External links

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