''Cliftonoceras'' is a genus of barrandeoceroid type tarphycerids from the Uranoceratidae characterized by a smooth gyroconic shell with a rounded dorsum and flattened venter, and by a subvental siphuncle composed of thin connecting rings and necks that are straight ventrally, recumbent dorsally. ''Cliftonoceras'' has been found in Middle

Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...

age sediments in

Tennessee Tennessee (, ), officially the State of Tennessee, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Kentucky to the north, Virginia to the northeast, North Carolina t ...

and

Indiana Indiana ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Michigan to the northwest, Michigan to the north and northeast, Ohio to the east, the Ohio River and Kentucky to the s ...

. The type species is ''C. quadratum''.

References

* Sweet, Walter C. 1964. Nautiloidea-Barrandeocerida.

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 Kansas Press. Prehistoric nautiloid genera {{paleo-nautiloid-stub