''Euomphalus'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of fossil marine

gastropods Gastropods (), commonly known as slugs and snails, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and from the land. Ther ...

known to have lived from the

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 ...

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) 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 In biological taxonomy, the type genus (''genus typica'') is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearin ...

of the family Euomphalidae. ''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 Paleozoic molluscs of North America Paleozoic life of Ontario Paleozoic life of Manitoba Paleozoic life of the Northwest Territories Paleozoic life of Nunavut Silurian gastropods Devonian gastropods Carboniferous gastropods Permian gastropods {{paleo-gastropod-stub