Permonautilus
Introduction '''''Permonautilus''''' is an extinct genus of nautilids from the Upper Permian of Russia, named and described by Kruglov in 1933. ''Permonautilus'' is an involute, globular, spinose member of the Lirocertidae which are included in the Clydonautilaceae. Whorl sections are broad, with a rounded venter. The umbilicus in the middle of the shell is deep, from which spine-like processes extend laterally in the mature portion near the aperture. The siphuncle in ''Permonautilus'' is subcentral, the suture, slightly sinuous.Externally, ''Permonautilus'' closely resembles the Pennsylvanian - Lower Permian ''Solenochilus'' and the Upper Mississippian ''Acanthonautilus'', both which belong to the superfamily Aipocerataceae: ''Permonautilus'' differs from the latter two genera in the anatomy of the subcentral siphuncle.
See also * Nautiloid** List of nautiloids
References * , B. 1964;Nautiloidea—Nautilida, in the Treatise on Invertebrate Paleontology, Part K Nautiliodea, 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)