| details |
Early Caradocian |
|
Sweden |
Wallin,A. et al. Biostratigraphical investigation of Middle Ordovician acritarch the post-impact sequence in the Tvaren-2 core, Sweden. |
1996 |
| details |
Nd |
|
Nd |
Sarjeant,W.A.S. et al. The acritarch genus Polygonium, Vavrdova emend. Sarjeant and Stancliffe 1994: a reassessment of its constituent species. (In: Stratigraphie du Mesozoique et du Cenozoique. M.Streel, editor) |
1996 |
| details |
Arenigian |
Llanvirnian |
Baltic |
Tongiorgi,M. et al. Differentiation and spread of the Baltic Acritarch Province (Arenig-Llanvirn). |
1999 |