Incirrata (or Incirrina) is a suborder of the order Octopoda. The suborder contains the classic " benthic octopuses," as well as many pelagic octopus

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 ...

, including the paper nautiluses. The incirrate octopuses are distinguished from the cirrate octopuses by the absence in the former of the "cirri" filaments (found with the suckers) for which the cirrates are named, as well as by the lack of paired swimming fins on the head, and lack of a small internal shell (the "shell" of '' Argonauta'' species is not a true shell, but a thin

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

egg case).

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

Nautiloid 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 ...

ea: 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

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 ...

***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 ...

***Superorder

Octopodiformes Octopodiformes is a superorder of the subclass Coleoidea, comprising the octopuses and the vampire squid. All living members of Octopodiformes have eight arms, either lacking the two tentacles of squid (as is the case in octopuses) or modifying ...

****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 ****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 *****Suborder Incirrata ******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 ********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 ...

********subfamily Vitreledonellinae *******Family Bathypolypodidae *******Family Eledonidae *******Family Enteroctopodidae *******Family Megaleledonidae *******Family Octopodidae ******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 Note: A new unnamed white species was discovered February 26, 2016 by

NOAA The National Oceanic and Atmospheric Administration (NOAA ) is an American scientific and regulatory agency charged with forecasting weather, monitoring oceanic and atmospheric conditions, charting the seas, conducting deep-sea exploratio ...

’s '' Deep Discoverer'' about 2.5 miles below the ocean surface near the Hawaiian Archipelago.

References

Octopuses {{Octopus-stub