vampire squid taxonomy
vampire squids are cephalopods in the family vampyroteuthis
they are the only extant species in this family, but there are 3 extinct genera in this family. (https://www.sciencedirect.com/science/article/pii/S1055790307001698)
despite the name, vampire squid are more closely related to octopi than squid, this is due to their 8 arms, placing them in the superorder Octopodiformes, instead of Decapodiformes (the squid and cuttlefish)
it was discovered in the late 1890s, and described later in 1903.
the feature that distinguishes the vampire squid from both octopi and squid, is two retractible filaments, which are separate from the arms, and this is why it is neither a true octopus, or a squid (Young, R. E. (1967). Homology of Retractile Filaments of Vampire Squid. Science, 156(3782), 1633–1634. http://www.jstor.org/stable/1721610)
