Vampyromorphida is an

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 ...

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

s comprising one known

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 ...

species (''

Vampyroteuthis infernalis 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 unique ...

'') and many

extinct 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 ...

taxa In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

. Physically, they somewhat resemble

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 (their closest relatives), but are often called vampire

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 ...

s. Unlike octopuses, their eight arms are united by a web of skin, and two smaller cilia are also present. Properly speaking, the vampire squid does not possess cilia, but cirri (cilia-like projections). Unlike most cephalopods, which are high-energy hunters, the vampire squid has an extremely low metabolic rate. This adaptation means it requires less oxygen and its food lasts longer, helping it conserve energy and thrive in these harsh deep-sea conditions. Studies show its oxygen consumption is among the lowest of any cephalopod, allowing it to occupy a competition-free niche in the deep sea where few predators or competitors can follow, since not many can survive.

Classification

*Order Vampyromorphida **Suborder † Kelaenina ***Family † Muensterellidae **Suborder † Prototeuthina ***Family † Loligosepiidae ***Family † Geopeltididae ***Family † Lioteuthididae ***Family † Mastigophoridae **Suborder † Mesoteuthina ***Family † Palaeololiginidae ****Subfamily † Teudopseinae ****Subfamily † Palaeololigininae **Suborder Vampyromorphina ***Family

Vampyroteuthidae Vampyroteuthidae is a family of vampyromorph cephalopods containing the extant vampire squid, ''Vampyroteuthis infernalis'', and the extinct genera ''Necroteuthis ''Necroteuthis'' is an extinct genus of vampire squids from the Oligocene of ...

The following taxa were long considered to belong to Vampyromorphida, but this placement may be incorrect:Fischer, Jean-Claude & Riou, Bernard (2002): ''Vampyronassa rhodanica'' nov. gen. nov sp., vampyromorphe (Cephalopoda, Coleoidea) du Callovien inférieur de la Voulte-sur-Rhône (Ardèche, France). ''Annales de Paléontologie'' 88(1) 1−17. rench with English abstract (HTML abstract) *Family †

Plesioteuthididae Plesioteuthididae is an extinct family of 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 ...

*Family † Leptotheuthidae

*Family † Trachyteuthididae **Subfamily † Trachyteuthidinae **Subfamily † Actinosepiinae

References

The Taxonomicon: Order Vampyromorphida
Octopodiformes Cephalopod orders {{cephalopod-stub