| details |
Ordovician |
|
USSR(Russian Platform) |
Umnova,N.I. et al. Acritarchs from the Yaroslavskoi series of the northern part of the Russian Platform |
1970 |
| original |
Middle Ordovician |
|
USSR(Yaroslav) |
Umnova,N.I. et al. Acritarchs from the Yaroslavskoi series of the northern part of the Russian Platform |
1970 |
| details |
Tremadocian |
Early Caradocian |
USSR(Russian Platform) |
Umnova,N.I. Silurian and Ordovician acritarch assemblages from the northern and western parts of the Russian Platform. |
1974 |
| details |
Tremadocian |
Early Caradocian |
USSR(Pre-Baltic) |
Umnova,N.I. Silurian and Ordovician acritarch assemblages from the northern and western parts of the Russian Platform. |
1974 |
| details |
Llandeilian |
Early Caradocian |
USSR(Russian Platform) |
Umnova,N.I. Ordovician and Silurian acritarchs of the Moscow Basin and Prebaltic |
1975 |
| details |
Ordovician |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Ordovician |
|
USSR(Yaroslav) |
Sarjeant,W.A.S. et al. The Micrhystridium and Veryhachium Complexes (Acritarcha: Acanthomorphitae and Polygonomorphitae): A taxonomic reconsideration. |
1994 |