| details |
Late Arenigian |
Early Llanvirnian |
Morocco |
Cramer,F.H. et al. Early Ordovician acritarchs from the Tadla Basin of Morocco. |
1974 |
| details |
Middle Wenlockian |
Early Ludlovian |
Belgium |
Cramer,F.H. et al. Early Ordovician acritarchs from the Tadla Basin of Morocco. |
1974 |
| details |
Early Paleozoic |
|
Nd |
Cramer,F.H. et al. Lower Paleozoic acritarchs. |
1979 |
| details |
Middle Wenlockian |
Early Ludlovian |
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |