| details |
Ordovician |
Early Ludlovian |
Belgium |
Martin,F. The acritarchs from the Belgian Ordovician and Silurian. Determination and stratigraphic value. |
1968 |
| details |
Nd |
|
Nd |
Deflandre,G. et al. Nomenclature and systematics of Hystrichospheres (Sens.Lat.) observations and recitifications. |
1961 |
| details |
Nd |
|
Nd |
Downie,C. et al. Bibliography and index of fossil dinoflagellates and acritarchs. |
1965 |
| original |
Tremadocian |
|
Algeria |
Deunff,J. A microplankton of hystrichospheres in the Tremadocian of the Sahara. |
1961 |
| details |
Tremadocian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |