| original |
Late Devonian |
|
Indiana |
Wicander,E.R. et al. Organic-walled microphytoplankton and its stratigraphic significance from the Upper Devonian Antrim Shale, Indiana USA. |
1977 |
| details |
Late Frasnian |
Early Famennian |
Indiana |
Wicander,R. A catalogue and biostratigraphic distribution of North American Devonian acritarchs. |
1983 |
| details |
Middle Ordovician |
|
Sweden |
GŠ³rka,H. Middle Ordovician (Viruan) acritarchs and Prasinophyceae from the Smedsby Gard No.1 borehole in (Gotland, Sweden). |
1987 |
| details |
Frasnian |
Famennian |
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |