| original |
Late Llanvirnian |
|
Germany |
Burmann,G. Diacrodia of the Lower Ordovician |
1968 |
| details |
Llanvirnian |
|
England(Lancashire) |
Downie,C. et al. Age of the Eycott Volcanic Group and its Conformable relationship to the Skiddaw Slates in the English Lake District. |
1972 |
| details |
Late Llanvirnian |
|
E.Germany |
Eisenack,A. et al. Catalog of fossil dinoflagellates, hystrichospheres and related microfossils. Acritarchs. |
1976 |
| details |
Late Llanvirnian |
|
Nd |
Diez,M.D.C.R. et al. Range chart of selected Lower Paleozoic acritarch Taxa. 2: Index to Parts 1 and 2. |
1977 |
| details |
Middle Arenigian |
Late Arenigian |
Bulgaria |
Kalvacheva,R.K. Palynological evidence for the Early-Ordovician (Arenigian) age of ophiolites in the Botevgran District (West Balkan Mountain) Bulgaria. |
1982 |
| details |
Late Arenigian |
|
Bulgaria |
Kalvacheva,R.K. Palynology and stratigraphy of the Diavase-Phyllitoid complex in the West Balkan Mountains. |
1982 |
| details |
Llanvirnian |
|
United Kingdom |
Downie,C. Acritarchs in British stratigraphy |
1984 |
| details |
Late Arenigian |
|
Bulgaria |
Kalvacheva,R.K. Acritarch evidence for Ordovician System in West Bulgaria |
1984 |
| details |
Tremadocian |
|
China(Shanghai) |
Hu,Y. Micropalaeoflora from the Early Ordovician in Gaoqiao Region of Shaanxi and its stratigraphic significance. |
1986 |
| details |
Early Llanvirnian |
|
Spain |
Mette,W. Acritarchs from Lower Paleozoic rocks of the Western Sierra Morena, southwest Spain and biostratigraphic results. |
1989 |
| details |
Late Llanvirnian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |