| original |
Ashgillian |
|
Indiana |
Loeblich,A.R.,Jr. et al. Some Middle and Late Ordovician microphytoplankton from Central North America. |
1978 |
| details |
Early Ordovician |
|
China(Hopei) |
Li,Z.P. Acritarchs from the Upper Machiakou Formation of North China and its geological age. |
1982 |
| details |
Ashgillian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Late Ordovician |
|
USSR(Lithuanian SSR) |
Pa?keviciene,L. Acritarchs from the Upper Ordovician of East Lithuania |
1993 |
| details |
Vormsi |
Pirgu |
Lithuania |
Pa?keviciene,L. et al. The composition, distribution and evolution of Ordovician brachiopods, conodonts and acritarchs in the South-eastern part of the Baltic basin. |
2001 |