| original |
Late Ordovician |
|
Indiana |
Colbath,G.K. Organic-walled microphytoplankton from the Eden Shale, (Upper Ordovician), Indiana, USA. |
1979 |
| details |
Late Ordovician |
|
Indiana |
Colbath,G.K. Abundance fluctuations in Upper Ordovician organic-walled microplankton from Indiana. |
1980 |
| details |
Llandoverian |
|
China(Szechwan) |
Fang,X. et al. Silurian microflora and chitinozoa in Guanyinqiao Qijiang County Sichuan Province and their stratigraphic significance |
1988 |
| details |
Late Ordovician |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Late Caradocian |
|
USA |
Playford,G. et al. Ordovician acritarch genera Peteinosphaeridium, Liliosphaeridium and Cycloposphaeridium: Morphology, taxonomy, biostratigraphy and palaeogeographic significance |
1995 |