''Paranautilus'' is a genus of the

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 ...

family Liroceratidae with a very involute, moderately globular, smooth shell. The venter, at the outer rim, is arched, grading into broadly convex flanks. The dorsom, on the inner rim, is deeply impressed. Septa a close spaced, with slightly sinuous sutures. A member of the Clydonautilaceae, ''Paranautilus'' lived during the Middle and Late Triassic (

Anisian In the geologic timescale, the Anisian is the lower stage (stratigraphy), stage or earliest geologic age, age of the Middle Triassic series (stratigraphy), series or geologic epoch, epoch and lasted from million years ago until million years ag ...

Norian The Norian is a division of the Triassic geological period, Period. It has the rank of an age (geology), age (geochronology) or stage (stratigraphy), stage (chronostratigraphy). It lasted from ~227.3 to Mya (unit), million years ago. It was prec ...

) in what is now North America, Europe, and south Asia. Contemporary Liroceratids include '' Indonautilus'' and '' Sibyllonautilus''.

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. Geological Soc. of America and University of Kansas press. Teichert and Moore (eds)
Paranautilus -Paleodb
Prehistoric nautiloid genera Anisian first appearances Norian extinctions {{paleo-Nautiloidea-stub