| details |
Middle Ordovician |
|
Sweden |
Gгrka,H. Middle Ordovician (Viruan) acritarchs and Prasinophyceae from the Smedsby Gard No.1 borehole in (Gotland, Sweden). |
1987 |
| details |
Late Llanvirnian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| original |
Early Llanvirnian |
|
Poland |
Gгrka,H. Middle Ordovician microplankton from Strabla (Poland). |
1980 |
| original |
Early Llanvirnian |
|
Baltic |
Gгrka,H. Middle Ordovician microplankton from Strabla (Poland). |
1980 |