Teudopseina Starobogatov, 1983

Fuchs, Dirk, Engeser, Theo & Keupp, Helmut, 2007, Gladius shape variation in coleoid cephalopod Trachyteuthis from the Upper Jurassic Nusplingen and Solnhofen Plattenkalks, Acta Palaeontologica Polonica 52 (3), pp. 575-589 : 578

Suborder Teudopseina Starobogatov, 1983

Emended diagnosis.—Gladius with clearly reduced and opened conus (spoon−shaped conus). Lateral fields and hyperbolar zones less than the half gladius length. Hyperbolar zones between lateral and median field as well−developed broad furrows. Anterior median field more or less pointed.

Families included.— Trachyteuthididae Naef, 1921 , Palaeololiginidae Naef, 1921 , Teudopseidae Van Regteren Altena, 1949 , and Muensterellidae Roger, 1952 .

Remarks.—As mentioned above the phylogenetic and systematic position of the Teudopseina is controversial. Owing to remarkable similarities between a trachyteuthid gladius and sepiid cuttlebones, particularly neontologists doubt in vampyropod affinities. However, fossil evidences which could support sepiid affiliations (i.e., calcified phragmocone, ten arms) are unknown. Instead, the characters eight arms, two pairs of fins, interbrachial web, cirri, uniserial suckers and Octopus −like lower beak strongly support relationship with vampyropods ( Bandel and Leich 1986; Donovan et al. 2003; Fuchs et al. 2003; Klug et al. 2004; Fuchs 2006a). One may argue that some of these characters might be interpreted as diagenetical artefacts, others as plesiomorphic within the Coleoidea and/or also as decabrachian features, but the combination is striking and convinced us to attribute Teudopseina to the vampyropod branch. Finally, both Haas (2002) and Bizikov (2004) claimed that the shell vestiges of Recent Octopoda and Cirroctopoda developed from a teudopseid gladius by reducing the median field. Following that assumption, Teudopseina would represent a stem−group of the Octobrachia .