C. G. Crick (1898)[REF] described an Acanthoteuthis, A ferussachi with four pairs of arms, all eight of which have two rows of hooklets.
Acanthoteuthis has a distinctive V-shaped ridge on the dorsal side at the back of its internal shell[REF] which seems to be analogous to the median keel in the posterior part of the gladius in most recent squids to which the fins are attached.