| details |
Middle Ordovician |
Late Ordovician |
USSR(Estonian SSR) |
Uutela,A. et al. Ordovician acritarchs from the Rapla borehole, Estonia |
1991 |
| details |
Harnagian |
Onnian |
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Caradocian |
Ashgillian |
Morocco |
Elaouad-Debbaj,Z. Acritarchs from the Upper Ordovician (Caradoc-Ashgill) of the Anti-Atlas, Morocco. |
1988 |
| original |
Harnagian |
Onnian |
England(Shropshire) |
Turner,R.E. Acritarchs from the type area of the Ordovician Caradoc Series, Shropshire, England. |
1984 |