| details |
Middle Ordovician |
|
Finland |
Tynni,R. Ordovician hystrichospheres and chitinozoans in limestone from the Bothnian Sea. |
1975 |
| details |
Tremadocian |
|
France(Lot-et-Garonne) |
Baudelot,S. et al. Paleozoic basins hidden under the Aquitaine: Micropaleontological study of core collected during petroleum investigations. (In: Program of deep geology of France first phase of investigation-1983-1984) |
1984 |
| details |
Early Ordovician |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Late Arenigian |
Early Llandoverian |
USSR(Estonian SSR) |
Uutela,A. et al. Ordovician acritarchs from the Rapla borehole, Estonia |
1991 |
| details |
Nd |
|
Nd |
Eiserhardt,K.H. The Acritarchs of the –jlemyrflintes. |
1992 |
| details |
Early Ordovician |
|
USSR |
Sarjeant,W.A.S. et al. The Micrhystridium and Veryhachium Complexes (Acritarcha: Acanthomorphitae and Polygonomorphitae): A taxonomic reconsideration. |
1994 |
| 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 |
Oandu |
Rakvere |
Lithuania |
Pa?keviciene,L. Taxonomical composition and distribution of acritarchs in the deposits of Oandu Ravere Regional Stages of the Middle Lithuanian Depression. |
2001 |