Centrifugus

†Centrifugus is an extinct species of fossil sea snail, a marine gastropod mollusk in the family Euomphalidae, which paleontologists place in the order Archaeogastropoda.

Centrifugus Temporal range: Upper Silurian
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Eogastropoda
Order:	Archaeogastropoda
Suborder:	Euomphalina
Family:	Euomphalidae
Genus:	†Centrifugus Bronn, 1934

This species was originally known from the Upper Silurian of northern Europe (Gotland).

Description

The shell has a nearly flat spire, and is widest across the base, which is marked by a peripheral keel. The upper side of the aperture has a narrow slit, and a selenizone located close to the upper suture. Five strong spiral cords alternating with weaker ones cover the upper surface of the shell.

References

• J.Brooks Knight et al. 1960. Systematic Descriptions. Treatise on Invertebrate Paleontology Part I Mollusca 1. Geological Society of America and University of Kansas Press.