Gonionautilidae is a family in the nautilid superfamily Clydonautiliaceae that contains only the genus ''Gonionautilus'', known from the Upper Triassic (Norian) of Europe and North America. (Alps, state of Nevada) ''Gonionautilus'' has a smooth, compressed involute shell with a narrow flattened venter and angular ventral shoulders. The suture resembles that of ''

Clydonautilus ''Clydonautilus'' is a genus of nautiloid Nautiloids are a group of cephalopods (Mollusca) which originated in the Late Cambrian and are represented today by the living ''Nautilus'' and ''Allonautilus''. Fossil nautiloids are diverse and speci ...

'', from which it must have been derived, except for the more highly developed median saddle and bifurcated dorsal lobe. ''Gonionautilus'' (Gonionautilidae) is one of a number of advanced

nautiloid Nautiloids are a group of cephalopods (Mollusca) which originated in the Late Cambrian and are represented today by the living ''Nautilus'' and ''Allonautilus''. Fossil nautiloids are diverse and species rich, with over 2,500 recorded species. Th ...

cephalopods that developed sutures resembling those of some

goniatites ''Goniatites'' is a genus of extinct cephalopods belonging to the family Goniatitidae, included in the superfamily Goniatitaceae. ''Hibernicoceras'' and ''Hypergoniatites'' are among related genera. Species Description The shell is generally ...

in the

Ammonoidea Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

References

* Bernhard Kummel, 1964. Nautiloidea -Nautilida;

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...

, Part K. Geol Soc of America and Univ of Kansas press, R.C. Moore (ed) {{Taxonbar, from=Q5581948 Prehistoric nautiloid families Norian first appearances Norian extinctions