Caumontisphinctes
Encyclopedia
Caumontisphinctes is an ammonoid genus from the ammonitid
superfamily Perkinsonataceae that lived during the Bajocian stage of the Middle Jurassic. (approx 180-175 m.y.a.)
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.
Ammonitida
The Ammonitida is an order of more highly evolved ammonoid cephalopods from the Jurassic and Cretaceous time periods, commonly with intricate ammonitic sutures....
superfamily Perkinsonataceae that lived during the Bajocian stage of the Middle Jurassic. (approx 180-175 m.y.a.)
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.
References
- Treatise on Invertebrate Paleontology, Part L Ammonoidea (L309); Geological Society of America and Univ of Kansas press, 5th printing, 1990