| Name | From | To | Age range |
|---|---|---|---|
| Tetrad type B | Late Telychian | Early Sheinwoodian |
|
| Tetrad sp.1 Rubi.& Stee.,2002 | Late Ludlovian | Early Pridolian |
|
| Tetrad sp.D | Pridolian | Gedinnian |
|
| Tetrad type 2 | Wenlockian | Gedinnian |
|
| Tetrad sp.B | Wenlockian | Gedinnian |
|
| Tetrad sp.C | Wenlockian | Gedinnian |
|
| Tetrad sp.3350 Magl.,1967 | Middle Llandoverian | Lochkovian |
|
| Tetrad type 39 | Early Triassic | Jurassic |
|
| Tetrad sp | Proterozoic | Hauterivian |
|
| Tetrad type 1 | Wenlockian | Middle Cenomanian |
|
| Tetrad forma 12 | Albian | Turonian |
|
| Tetrad planar | Late Cretaceous | Middle Paleocene |
|
| Tetrad small | Paleocene | Early Eocene |
|
| Tetrad tetrahedral | Early Eocene | Middle Eocene |
|
| Tetrad | Late Precambrian | Oligocene |
|
| Tetrad type xxx | Miocene | Late Neogene |
|
| Tetrad type xxxi | Miocene | Late Neogene |
|