| original |
Arenigian |
|
Sweden |
Eisenack,A. On the reproduction of Palaeozoic hystrichospheres. |
1968 |
| details |
Ordovician |
|
Sweden |
Eisenack,A. Microfossils of the Vaginatum Limestone of Halludden, Oland. |
1976 |
| details |
Early Llanvirnian |
Middle Llanvirnian |
Nd |
Diez,M.D.C.R. et al. Range chart of selected Lower Paleozoic acritarch Taxa. 2: Index to Parts 1 and 2. |
1977 |
| details |
Arenigian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Volkhov |
Aseri |
Estonia |
Magi,S. Locality 4:2 Cntika Clint |
1990 |