Amphiscapha is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of marine mollusks that may be fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 sea snail

Sea snail

Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....

s. It is an euomphalid

Euomphalidae

Euomphalidae is an extinct family of Paleozoic molluscs which may possibly be gastropods with anisostrophically coiled shells .- Genera :Genera in the family Euomphalidae include:...

 genus which is found in the Pennsylvanian

Pennsylvanian

The Pennsylvanian is, in the ICS geologic timescale, the younger of two subperiods of the Carboniferous Period. It lasted from roughly . As with most other geochronologic units, the rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain...

 and Lower Permian of North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

.

Description

The shell in this genus is hyperstrophic discoidal with a flat base and a concave upper side. The location of what is presumed to be the exhalent channel is marked by a smooth or rugose ridge along the upper-outer margin, which lies along the edge of a flat to concave outer rim.

References

• J. B. Knight et al. 1960. Systematic descriptions; Treatise on Invertebrate Paleontology; Part I, Mollusca(1): I192.
• Paleobiology database info on Amphiscapha