| original |
Tremadocian |
Early Arenigian |
Italy(Sardinia) |
Pittau Demelia,P. Tremadocian (Early Ordovician) acritarchs of the Arburese Unit southwest Sardinia, (Italy). |
1985 |
| details |
Tremadocian |
|
Sweden |
Bagnoli,G. et al. Acritarchs and conodonts from the Cambro-Ordovician Furuhall, (Kopingsklint) Section (Oland, Sweden). |
1988 |
| details |
Tremadocian |
|
Italy(Sardinia) |
Barca,S. et al. New geological and stratigraphical data and discovery of Lower Ordovician acritarchs in the San Vito Sandstone of the Genn'Argiolas Unit (Sarrabus, Southeastern Sardinia) |
1989 |
| details |
Tremadocian |
|
Austria |
Reitz,E. et al. Lower Ordovician acritarchs of the northern Graywacke Zone, (Eastern Alps). |
1989 |
| details |
Tremadocian |
Late Arenigian |
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Early Tremadocian |
|
Italy(Sardinia) |
Di Milia,A. et al. Acritarch findings in Early Paleozoic, low-grade metasediments of Sardinia (Italy): A review. |
1993 |
| details |
Late Cambrian |
|
USSR(Estonian SSR) |
Mens,K.A. et al. Upper Cambrian biostratigraphy of Estonia. |
1993 |