''Aphelaeceras'' is an extinct genus from the nautilid family

Trigonoceratidae The Trigonoceratidae is a family of coiled nautiloid cephalopods that lived during the period from the Early Carboniferous ( Mississippian) to the Early Permian. Diagnosis Trigonoceratidae comprise members of the order Nautilida characterized ...

which is part of the

Trigonocerataceae The Trigonoceratoidea are a superfamily within the Nautilida that ranged from the Devonian to the Triassic, thought to have contained the source for the Nautilaceae in which ''Nautilus'' is found. Trigonoceratoidea are characterized by open-spir ...

, that lived during the Mississippian Period in the late Paleozoic. Aphelaeceras'' is evolute, compressed, with a wide umbilicus and small dorsal impression. Whorl section is subrectangular with convex sides that slope toward a concave venter. Ventral shoulder are subangular, umbilical shoulders broadly rounded. The suture has a narrow ventral lobe and broad lateral lobes. The siphuncle is barely ventral from the center. ''Aphelaeceras'' has been found in Mississippian (L. Carb) strata in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

and

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

. The genus was named by Hyatt, 1844. The type, ''A. difficile'' (DeKoninck) came from

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...

. '' Mesochasmoceras'', from the Lower Carboniferous of Europe is similar in having a concave venter but early whorls are nearly ovate in cross section and the umbilicus has a wide perforation.

References

* Kummel, B, 1964; Nautiloidea- Nautilida; Treatise on Invertebrate Paleontology Part K Nautiloidea; Geological Society of America and University of Kansas Press. * Flower, R.H and Kummel, B. 1950; A Classification of the Naulioidea; Journal of Paleontology, V 24, no 5. pp604–616, Sept 1950 {{Taxonbar, from=Q4779533 Prehistoric nautiloid genera