| Name | From | To | Age range |
|---|---|---|---|
| Tetrad type 1 | Wenlockian | Middle Cenomanian |
|
| Tetrad sp.B | Wenlockian | Gedinnian |
|
| Tetrad sp.C | Wenlockian | Gedinnian |
|
| Tetrad type B | Late Telychian | Early Sheinwoodian |
|
| Tetrad sp.3350 Magl.,1967 | Middle Llandoverian | Lochkovian |
|
| Tetrad type A Vavr.,1984 | Ashgillian | Ashgillian |
|
| Tetrad type C Vavr.,1984 | Late Ordovician | Late Ordovician |
|
| Tetrad type F | Late Ordovician | Late Ordovician |
|
| Tetrad sp. Vavr.,1984 | Late Ordovician | Late Ordovician |
|
| Tetrad type A | Late Ordovician | Late Ordovician |
|
| Tetrad type 3 | Late Ordovician | Late Ordovician |
|
| Tetrad | Late Precambrian | Oligocene |
|
| Tetrad sp | Proterozoic | Hauterivian |
|