Family
Orthothecidae Syssoiev, 1957
List of species
2. Semielliptotheca rosmara (Holm, 1893) | Kunda Stage
Luokittelu
| Organism group | Biota |
| Kingdom | Animalia |
| Phylum | Mollusca |
| Class | Hyolitha |
| Order | Orthothecida |
| Family | Novitatidae |
| Orthothecidae | |
| Genus | Nephrotheca |
| Semielliptotheca | |
| Family | Quadrothecidae |