Genus
Pycnoceras Hyatt, 1894
Luokittelu
| Organism group | Biota |
| Kingdom | Animalia |
| Phylum | Mollusca |
| Class | Cephalopoda |
| Subclass | Tarphyceratia |
| Order | Tarphyceratida |
| Family | Estonioceratidae |
| Genus | Aethoceras |
| Aphetoceras | |
| Aserioceras | |
| Bentoceras | |
| Clytoceras | |
| Eichwaldoceras | |
| Estonioceras | |
| Falcilituites | |
| Pakrioceras | |
| Planctoceras | |
| Pycnoceras | |
| Shumardoceras | |
| Tragoceras |