| original |
Llandeilian |
|
Oklahoma |
Loeblich,A.R.,Jr. et al. Some Middle and Late Ordovician microphytoplankton from Central North America. |
1978 |
| details |
Middle Ordovician |
|
Sweden |
GŠ³rka,H. Middle Ordovician (Viruan) acritarchs and Prasinophyceae from the Smedsby Gard No.1 borehole in (Gotland, Sweden). |
1987 |
| details |
Llandeilian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Late Arenigian |
Late Llandoverian |
USSR(Estonian SSR) |
Uutela,A. et al. Ordovician acritarchs from the Rapla borehole, Estonia |
1991 |
| details |
Kosovian |
|
Czechoslovakia |
Dufka,P. et al. Chitinozoans and acritarchs from the Ordovician - Silurian boundary of the Prague Basin, Czech Republic. (In: Contributions to Acritarch and Chitinozoan Research. S.G.Molyneux and K.J.Doring, editors) |
1993 |
| 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 |
Caradocian |
|
Iran |
Ghavidel-Syooki,M. Acritarch biostratigraphy of the Palaeozoic rock units in the Zagros Basin, Southern Iran. (In: Commision Internationale de microflore du Paleozoique (CIMP) Acritarch Subcommision: O.Fatka and T.Servais, editors) |
1996 |