''Euomphalus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of fossil marine

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

known to have lived from the Silurian 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 ± ...

.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 ...

) on the upper surface of the whorls. The lower surface of the whorls is rounded to angular. ''

Amphiscapha ''Amphiscapha'' is a fossil gastropod mollusk, or less likely a monoplacophoran, genus from the Pennsylvanian and Lower Permian of North and South America, included in the family Euomphalidae Euomphalidae is an extinct family of Paleozoic ...

'', '' 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 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-bearing type of a nominal ...

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 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