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 the tentacles into thin filaments (as in vampire squid). Octopodiformes is often considered the crown group 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.
Pohlsepia, originally described as the earliest octopod, is now considered as dubious for this group according to a later study. Syllipsimopodi, a squid-like cephalopod from the Mississippian-age Bear Gulch Lagerstätte of Montana, 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 Subclass Nautiloidea: nautilus Subclass †Ammonoidea: ammonites Subclass Coleoidea Superorder Decapodiformes: squid, cuttlefish Clade Vampyropoda Genus †Syllipsimopodi Genus †Proteroctopus Superorder Octopodiformes / Octobrachia Family †Trachyteuthididae (incertae sedis) Order Vampyromorphida: vampire squid Clade: Muensterelloidea Family: †Muensterellidae Family: †Patelloctopodidae Order Octopoda Genus †Keuppia (incertae sedis) Genus †Palaeoctopus (incertae sedis) Genus †Proteroctopus (incertae sedis) Genus †Styletoctopus (incertae sedis) Suborder Cirrina: finned deep-sea octopus Family Opisthoteuthidae: umbrella octopus Family Cirroteuthidae Family Stauroteuthidae Suborder Incirrina Superfamily Octopodoidea Family Amphitretidae subfamily Amphitretinae: telescope octopus subfamily Bolitaeninae: gelatinous octopus subfamily Vitreledonellinae Family Bathypolypodidae Family Eledonidae Family Enteroctopodidae Family Megaleledonidae Family Octopodidae: benthic octopus Superfamily Argonautoidea Family Alloposidae: seven-arm octopus Family Argonautidae: argonauts Family Ocythoidae: tuberculate pelagic octopus Family Tremoctopodidae: blanket octopus
References
External links
Tree of Life web project: Octopodiformes