| details |
Middle Gothlandian |
Late Gothlandian |
Spain |
Cramer,F.H. et al. Taxonomic considerations on the acritarchs of the Middle and Upper Silurian of northern Spain. |
1968 |
| original |
Ludlovian |
Early Gedinnian |
Spain |
Cramer,F.H. Palynomorphs from the Siluro-Devonian boundary in northwest Spain |
1966 |
| details |
Late Ludlovian |
|
Spain |
Cramer,F.H. Palynology of Silurian and Devonian rocks in northwest Spain. |
1966 |
| details |
Late Llandoverian |
Early Gedinnian |
Spain |
Cramer,F.H. Consideration on the palynology and Silurian paleolatitudes based on microplankton of the Cantabrian Mountains of the Northwest of Spain. |
1969 |