| original |
Late Cambrian |
|
USSR(Leningrad) |
Volkova,N.A. et al. New Upper Cambrian acritarchs from the Leningrad Oblast, (Ladoga Formation). |
1985 |
| original |
Nd |
|
Nd |
Ribecai,C. et al. Latest Middle-Late Cambrian acritarchs from Belgium and northern France. (In: Contributions to Acritarch and Chitinozoan Research. S.G.Molyneux and K.J.Doring, editors) |
1993 |
| original |
Late Arenigian |
|
England(Cumberland) |
Arthurton,R.S. et al. Ordovician and Silurian. (In: Geology of the Country around Penrith.) |
1981 |
| original |
Late Cambrian |
|
Belgium |
Steemans,P. Stratigraphical study of the spores in the Gedinnian - Siegenian Transition Beds at Nonceveux and Spa, (Belgium). |
1981 |
| original |
Middle Cambrian |
|
Belgium |
Vanguestaine,M. Discovery of acritarchs in the Upper Revinian of the Stavelot Massif. |
1967 |