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 Octobranchia, referring to cephalopods without prominent tentacles.[3]
Pohlsepia, originally described as earliest octopod is considered as dubious for this group in later study.[1][3] The oldest unambiguous vampyropod is Syllipsimopodi, a squid-like cephalopod from the Mississippian-age Bear Gulch Lagerstätte of Montana. Syllipsimopodi has a combination of squid-like features (like 10 arms) and octopod-like features (like biserial suckers and a simplified internal shell).[3]