| details |
Early Caradocian |
|
Sweden |
Grahn,Y. et al. Chitinozoan dating of Ordovician impact events in Sweden and Estonia; a preliminary note. |
1993 |
| details |
Late Llanvirnian |
|
Baltic |
Nolvak,J. et al. Ordovician chitinozoan zones from Baltoscandia |
1993 |
| details |
Late Llanvirnian |
|
Scandinavia |
Nolvak,J. et al. Ordovician chitinozoan zones from Baltoscandia |
1993 |
| details |
Late Kukruse |
|
Sweden |
Grahn,Y. et al. Precise chitinozoan dating of Ordovician impact events in Baltoscandia. |
1996 |
| details |
Uhaku |
|
USSR(Estonian SSR) |
Grahn,Y. et al. Precise chitinozoan dating of Ordovician impact events in Baltoscandia. |
1996 |
| details |
Llanvirnian |
|
Saudi Arabia |
Paris,F. et al. Ordovician chitinozoans from central Saudi Arabia. |
2000 |
| details |
Late Ordovician |
|
Sweden |
Bergstrжm,S.M. et al. A proposed global boundary stratotype for the base of the Upper Series of the Ordovician System: The FҐgelsҐng section, Scania, southern Sweden. |
2000 |