Caumontisphinctes

{{Short description|Genus of molluscs (fossil)}}

{{italic title}}

{{Taxobox

|name = Caumontisphinctes

|fossil_range = {{fossil range|Bajocian|ref=}}

|regnum = Animalia

|phylum = Mollusca

|classis = Cephalopoda

|subclassis = Ammonoidea

|ordo = Ammonitida

|superfamilia = Perkinsonatoidea

|familia = Perkinsoniidae

|genus = Caumontisphinctes

}}

Caumontisphinctes is an ammonoid genus from the ammonitid superfamily Perkinsonatoidea that lived during the Bajocian stage of the Middle Jurassic.{{cite journal|last=Sepkoski |first=Jack |title=A compendium of fossil marine animal genera (Cephalopoda entry) | journal=Bulletins of American Paleontology |volume=363 |pages=1–560 | year=2002 | url=http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=231&rank=class |accessdate=2017-10-18 |url-status=dead | archiveurl=https://web.archive.org/web/20080507014300/http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=231&rank=class | archivedate=2008-05-07 }}

Chaumontisphinctis, named by Buckman, is like the genus Perisphinctis in being compressed with an ovoid whorl section but perkinsoniid in having sharp ribbing, a smooth or grooved venter, and tubercles commonly developed at bifurcation points on the ribs and at the ventral edge or on the venter.