| original |
Tremadocian |
|
USSR(Russian Platform) |
Umnova,N.I. et al. Acritarch assemblages from the Cambrian and Early Ordovician sediments of western and northwestern Russian Platform. (In: Palynology research in Byelorussia and other Regions of the USSR) |
1971 |
| details |
Tremadocian |
|
USSR(Russian Platform) |
Umnova,N.I. Silurian and Ordovician acritarch assemblages from the northern and western parts of the Russian Platform. |
1974 |
| details |
Tremadocian |
|
USSR(Pre-Baltic) |
Umnova,N.I. Silurian and Ordovician acritarch assemblages from the northern and western parts of the Russian Platform. |
1974 |
| details |
Tremadocian |
|
USSR(Russian Platform) |
Umnova,N.I. Ordovician and Silurian acritarchs of the Moscow Basin and Prebaltic |
1975 |
| details |
Early Ordovician |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |