Subgenus
Tetrada (Tetrada) Neckaja, 1958
| Images | ||||||
|---|---|---|---|---|---|---|
| TUG 1610-102 | Tetrada (Tetrada) grandis | Tetrada grandis | Keila Stage | DII | ||||
| TUG 1610-27 | Tetrada (Tetrada) memorabilis | Tetrada memorabilis | Keila Stage | DII | ||||
| TUG 1610-28 | Tetrada (Tetrada) memorabilis | Tetrada memorabilis | Keila Stage | DII | ||||
| TUG 1610-44 | Tetrada (Tetrada) krausei | Tetrada krausei | Keila Stage | DII | ||||
| TUG 1610-45 | Tetrada (Tetrada) krausei | Tetrada krausei | Keila Stage | DII | ||||
| TUG 1610-47 | Tetrada (Tetrada) harpa | Tetrada harpa | Keila Stage | DII | ||||
| TUG 1610-48 | Tetrada (Tetrada) harpa | Tetrada harpa | Keila Stage | DII | ||||
| GIT 229-10 | Tetrada (Tetrada) variabilis | Tetrada neckajae Meidla, 1986 | 15.5 | Nabala Stage | Paekna Formation | |||
| GIT 229-11 | Tetrada (Tetrada) variabilis | Tetrada neckajae Meidla, 1986 | 15.5 | Nabala Stage | Paekna Formation | |||
| GIT 229-12 | Tetrada (Tetrada) variabilis | Tetrada variabilis Meidla, 1986 | 434.9 | Nabala Stage | holotype |