| details |
Tremadocian |
Arenigian |
USSR(Russian Platform) |
Umnova,N.I. Silurian and Ordovician acritarch assemblages from the northern and western parts of the Russian Platform. |
1974 |
| details |
Tremadocian |
Arenigian |
USSR(Pre-Baltic) |
Umnova,N.I. Silurian and Ordovician acritarch assemblages from the northern and western parts of the Russian Platform. |
1974 |
| original |
Tremadocian |
|
USSR(Estonian SSR) |
Umnova,N.I. Ordovician and Silurian acritarchs of the Moscow Basin and Prebaltic |
1975 |
| details |
Ordovician |
|
USSR(Bashkir ASSR) |
Chibrikova,E.V. Stratigraphy of Devonian and older Paleozoic deposits of the Southern Urals and the Pre-Urals (According to plant Microfssils). |
1977 |