| original |
Late Cambrian |
|
USSR(Pre-Baltic) |
Timofeev,B.V. Ancient flora of the Prebaltic Region and its stratigraphic significance |
1959 |
| details |
Early Ordovician |
|
USSR(Russian Platform) |
Andreeva,E.M. et al. Palaeopalynology. (Three Volumes: Volume I: Methods. Volume II: Complexes of palynomorphs of the Precambrian-Holocene of the USSR. Volume III: Figures and Plates. Editor-I.M. Pokrovskaya) |
1966 |
| details |
Late Cambrian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |