| original |
Late Tremadocian |
Early Arenigian |
Italy(Sardinia) |
Pittau Demelia,P. Tremadocian (Early Ordovician) acritarchs of the Arburese Unit southwest Sardinia, (Italy). |
1985 |
| details |
Late Tremadocian |
Early Arenigian |
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Arenigian |
Ashgillian |
China(Hupei) |
Tongiorgi,M. et al. Arenigian acritarchs from the Daping section (Yangtze Gorges area, Hubei Province, southern China) and their palaeogeographic significance. |
1995 |