''Euomphalus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of fossil

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

gastropods known to have lived from the

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 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 shortest period of the Paleozo ...

to the

Middle Permian The Guadalupian is the second and middle series/epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ± 0. ...

.J.B.Knight,et al 1960. Treatise on Invertebrate Paleontology, Part I, Mollusca 1, ch on systematic descriptions. Geol Soc of America and Univ Kansas Press.(in Czech) Pek I., Vašíček Z., Roček Z., Hajn. V. & Mikuláš R.: ''Základy zoopaleontologie''. - Olomouc, 1996. 264 pp., .

Description

''Euomphalus'' is characterized by a closely coiled shell with a depressed to slightly elevated spire and a channel-bearing angulation (a

selenizone A selenizone (from the Greek "selene" meaning "moon", and "zone" meaning "girdle") is an anatomical structure that exists in the shells of some families of living sea snails: the slit shells, the little slit shells and the abalones, which are m ...

) on the upper surface of the whorls. The lower surface of the whorls is rounded to angular. '' Amphiscapha'', '' Philoxene'', and '' Straparollus'' are among similar related genera. '' Serpulospira'', also related, differs in having a broadly open spiral in the adult form.

Taxonomy

''Euomphalus'' is the type genus of the family

Euomphalidae Euomphalidae is an extinct family of Paleozoic to early Mesozoic marine molluscs which may be gastropods with anisostrophically coiled shells (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). The shells show a selenizone ...

. ''Euomphalus pentangulatus'' (Sowerby, 1814) is its type species.

Species

* ''Euomphalus pentangulatus'' Sowerby, 1814(type) * ''Euomphalus radiatus'' Menke, 1850: synonym of ''Heliacus (Heliacus) areola bicanaliculatus'' (Valenciennes, 1832) represented as ''Heliacus areola bicanaliculatus'' (Valenciennes, 1832)

References

Euomphalidae Silurian first appearances Permian genus extinctions Carboniferous molluscs Paleozoic molluscs of North America Paleozoic life of Ontario Paleozoic life of Manitoba Paleozoic life of the Northwest Territories Paleozoic life of Nunavut {{paleo-gastropod-stub