Sphenothallus
| Sphenothallus Temporal range: | |
|---|---|
| Sphenothallus holdfast from the Kope Formation (Upper Ordovician), Gunpowder Creek, Kentucky. | |
| Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Order: | †Conulatae |
| Clade: | †Conulariida |
| Genus: | †Sphenothallus Hall, 1847 |
Sphenothallus is a problematic extinct genus lately attributed to the conulariids. It was widespread in shallow marine environments during the Paleozoic.