Taxonomy, morphology and phylogeny of plesioteuthidid coleoids from the Upper Jurassic (Tithonian) Plattenkalks of Solnhofen

摘要

Plesioteuthis prisca (RUPPELL, 1829) and "Senefelderiteuthis kraussi ENGESER & KEUPP, 1999" were previously the only two species of plesioteuthidid coleoids known from the Solnhofen Plattenkalks. Based on morphological comparisons of 154 specimens from the Solnhofen area, a third taxon must be considered as valid: Plesioteuthis subovata (MONSTER, 1846). Additionally, it turned out that "Senefelderiteuthis kraussi" is identical with Dorateuthis tricarinata (MONSTER, 1846). The stratigraphical range of the genus Dorateuthis can now be extended from the Late Cretaceous to the Late Jurassic. Despite a remarkable similarity between prototeuthid and teuthid gladii, Prototeuthidids are attributed to the Vampyropoda. Unambiguous characters of teuthid Decabrachia such as a ventrolateral pair of elongated tentacles are unknown from the fossil record. Instead, characters such as interbrachial web, radial suckers and cirri rather indicate a closer relationship with the Vampyropoda.