''Cosmonautilus'' is a genus of cephalopods included in the nautilid family

Clydonautilidae The Clydonautilidae are Middle and Upper Triassic nautiloid cephalopods, which are derivatives of the clydonautiloidean family Liroceratidae, that have generally smooth, involute, globular to compressed shells, characterized by a suture with p ...

. Its shell is involute, with only the outer whorl exposed. Early whorls are with nodes on ventral shoulder, which disappear on the later growth staged. Later whorls are smooth. ''Cosmonautilus'' has been found in Siberian Russia, e.g. in eastern Taimyr and in the lower Lena River region, and in Alaska on Gravina Island, and California from Shasta County in the US, as well as Mexico, India, and Timor. '' Callaionautilus'' and ''

Clydonautilus ''Clydonautilus'' is a genus of nautiloids and type for the Clydonautilidae that has been found in the Upper Triassic of Europe, India, and Timor. Its type is ''C. noricus''. ''Clydonautilus'' is the most derived of the Clydonautilitidae, evide ...

'' are among related genera included in the Clydonautilidae.

References

* Bernhard Kummel, 1964. Nautiloidea-Nautilida. Treatise on Invertebrate Paleontology, Part K. Geological Society of America.
''Cosmonautilus''
in Fossilworks gateway. Prehistoric nautiloid genera {{paleo-nautiloidea-stub