Omphalotrochus

Omphalotrochus is an extinct taxonomic genus of Paleozoic gastropods. It is widely distributed in the upper Paleozoic and has been an important index fossil.

Species
Species in the genus Omphalotrochus include:
 * O. alleni Yochelson, 1956
 * O. antiquus d'Orbigny, 1842
 * O. calaniculatus Trautschold, 1879
 * O. cochisensis Yochelson, 1956
 * O. hessensis Yochelson, 1956
 * O. kalitvaensis Licharev, 1940
 * O. kalmiussi Zernetskaya, 1967
 * O. karakubensis Zernetskaya, 1967
 * O. obtusispira Shumard, 1859
 * O. spinosus Yochelson, 1956
 * O. whitneyi Meek, 1864
 * O. wolfcampensis Yochelson, 1956