Stearoceras
Introduction '''''Stearoceras''''' is an extinct genus of prehistoric nautiloids from the Lower Pennsylvanian (Upper Carboniferous) - Lower Permian with a fair worldwide distribution. (Kümmel 1964)''Stearoceras'' is recognized by its involute shell with a depressed subtrapizoidal whorl section and slight ventral and lateral lobes. In contrast Stenoporceras is subdiscoidal and has a suture with broad lateral lobes and a deep ventral saddle as found in syringonautilids. (ibid)Nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
See also * Nautiloid** List of nautiloids
References * Kümmel, B. 1964.Nautiloidea -Nautilida; Treatise on Invertebrate PaleontologyPart K, Curt Teichert & R.C Moore,(eds) Geological Society of America & Univ. 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)