Genus Tetrachacysta
- Species total:
- 12
- Age range:
- 163.5 - 27.5 MA (obsolete dating)
- IRMNG:
- find
| Name | From | To | Age range |
|---|---|---|---|
| Tetrachacysta | Middle Valanginian | Barremian |
|
| Tetrachacysta allenii | Valanginian | Late Eocene |
|
| Tetrachacysta baculata | Late Tithonian | Albian |
|
| Tetrachacysta granulata | Cenomanian | Middle Oligocene |
|
| Tetrachacysta keenei | Turonian | Early Santonian |
|
| Tetrachacysta sp. Xu et al,1997 | Middle Eocene | Late Eocene |
|
| Tetrachacysta sp.A Bint.& Mars.,1994 | Nd | Nd |
|
| Tetrachacysta sp.A Bren.,1992 | Middle Berriasian | Late Berriasian |
|
| Tetrachacysta sp.B Bren.,1992 | Middle Berriasian | Early Valanginian |
|
| Tetrachacysta spinosigibberosa | Callovian | Early Barremian |
|
| Tetrachacysta spinulosa | Cenomanian | Turonian |
|
| Tetrachacysta tuberculata | Cenomanian | Turonian |
|