Vampyromorphida

Vampyromorphida is an order of cephalopods comprising one known extant species (Vampyroteuthis infernalis) and many extinct taxa. Physically, they somewhat resemble octopuses (their closest relatives), but are often called vampire squids. 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).

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

The following taxa were long considered to belong to Vampyromorphida, but this placement may be incorrect:
 * Family †Plesioteuthididae
 * Family †Leptotheuthidae
 * Family †Trachyteuthididae
 * Subfamily †Trachyteuthidinae
 * Subfamily †Actinosepiinae