Kingdom Animalia Class Cephalopoda Order Nautilida Rank Genus | Phylum Mollusca Subclass Nautiloidea Family Tainoceratidae | |
Trachynautilus is a member of the Tainoceratidae, named by Mojsisovics in 1902, with longitudial ridges on the flanks of its high-arched involute shell. Phloiocedas from the Upper Triassic of North America is similar except that its venter also has longitudinal ridges. Trachynautilus from the middle and Upper Triassic of Europe has a smooth venter.
References
Trachynautilus Wikipedia(Text) CC BY-SA