Saivodus
Saivodus is an extinct genus of ctenacanthiform fish that existed from early Mississippian in the Carboniferous period. Fossils have been found in  Ireland, Scotland, England, Belgium, Morocco, and United States. Teeth assigned to that genus are also known from the Permian (Leonardian) Kaibab Formation. Taxonomy
Saivodus was erected in 2006. The single species belonging to this genus was formerly included in the unrelated genus Cladodus. Description
Based on tooth measurements, Saivodus would have been the largest member of its group currently known, reaching lengths of up to , although one study estimated its length around . The shape of the teeth suggest it targeted soft-bodied prey. References

Prehistoric cartilaginous fish genera
Carboniferous sharks