| details |
Tremadocian |
|
Spain |
Wolf,R. The Lower and Upper boundary of the Ordovician System of some selected regions, (Celtiberia, Eastern Sierra Morena) in Spain. Part 1: The Lower Ordovician Sequence of Celtiberia. |
1980 |
| details |
Tremadocian |
|
Norway |
Welsch,M. The acritarchs of the Upper Digermul Group, Middle Cambrian to Tremadoc, Eastern Finnmark, Northern Norway. |
1986 |
| details |
Late Cambrian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |