Type species: Cellaria smithii Phillips, 1829
This genus includes the species:
| Simplicidium brandesi | (Voigt, 1968) | Cretaceous | Germany |
| Simplicidium smithii | (Phillips, 1829) | Jurassic | England |
Reference: Todd, Jonathan A., Taylor, Paul D., & Favorskaya, Tatjana A., 1997. A bioimmured ctenostome bryozoan from the Early Cretaceous of the Crimea and the new genus Simplicidium. Geobios,30: 205-213.