Decapodiformes is a
superorder
Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...
of
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, ...
comprising all cephalopod species with ten
limbs, specifically eight short arms and two long tentacles. It is hypothesized that the ancestral
coleoid
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 Nautiloide ...
had five identical pairs of limbs, and that one branch of descendants evolved a modified arm pair IV to become the Decapodiformes, while another branch of descendants evolved and then eventually lost its arm pair II, becoming the
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 ...
.
Taxonomy
The following orders are recognised in the superorder Decapodiformes:
*
Bathyteuthida
Bathyteuthida is an order of cephalopods, consisting of small, mesopelagic to bathypelagic squid that in some ways resemble myopsid squid, such as ''Loligo'' and in others the pelagic oegopsid squid. Its two families, the Bathyteuthidae and ...
* †
Belemnitida
Belemnitida (or belemnites) is an extinct order (biology), order of squid-like cephalopods that existed from the Late Triassic to Late Cretaceous (And possibly the Eocene). Unlike squid, belemnites had an internal skeleton that made up the cone ...
* †
Diplobelida
*
Idiosepida – pygmy squid
*
Myopsida
Myopsida is one of the four orders of squid. It consists of two families: the monotypic '' Australiteuthis'' and the diverse and commercially important Loliginidae (~50 species). Some taxonomists classify this taxon as a suborder of the order T ...
– coastal squid
*
Oegopsida
Oegopsida is one of the four orders of squid in the superorder Decapodiformes, in the class Cephalopoda. Together with the Myopsina, it was formerly considered to be a suborder of the order Teuthida, in which case it was known as Oegopsina. Thi ...
– neritic squid
*
Sepiida
Cuttlefish, or cuttles, are marine molluscs of the suborder Sepiina. 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 ...
– cuttlefish, bobtail and bottletail squid
*
Spirulida – ram's horn squid
References
Further reading
*
abstract
External links
The Taxonomicon: Superorder Decapodiformes
10 (number)
Neocoleoidea
Cenozoic cephalopods
Protostome superorders
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