Tylonautilus
Introduction '''''Tylonautilus''''' is an extinct genus in the nautiloid order Nautilida from the Lower Carboniferous of Europe and Permian of Japan. ''Tylonautilus'' has a coiled shell with a subquadrate whorl section, evolutely coiled with all whorls showing. The outer rim, the venter, has a smooth median depression bordered on either side by thread-like lirae, followed by rows of nodes, radially arranged. The suture has broad ventral and lateral lobes, the siphuncle is central. ''Tylonautilus'' is a member of the Tainoceratidae which, with other related families, forms the nautiloid superfamily Tainocerataceae. As with most if not all tainoceratids, ''Tylonautilus'' was probably a bottom dweller that spent its time crawling over, or perhaps swimming close to, the seafloor.
References * Kümmel, B. 1964; Nautiloidea - Nautilida, in the Treatise on Invertebrate Paleontology, Part K Nautiloidea; Geological Society of America and University of Kansas press. * Sepkoski, J.J. Jr. 2002.A compendium of fossil marine animal genera. D.J. Jablonski & M.L. Foote (eds.). ''Bulletins of American Paleontology'' '''363''': 1–560.Sepkoski's Online Genus Database (Cephalopoda)