| original |
Caradocian |
|
Indiana |
Loeblich,A.R.,Jr. et al. Some Middle and Late Ordovician microphytoplankton from Central North America. |
1978 |
| details |
Caradocian |
Ashgillian |
Canada(Newfoundland) |
Legault,J.A. First report of Ordovician, (Caradoc-Ashgill) palynomorphs from Orphan Knoll, Labrador Sea. |
1982 |
| details |
Caradocian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Late Ordovician |
|
Indiana |
Sarjeant,W.A.S. et al. The Micrhystridium and Veryhachium Complexes (Acritarcha: Acanthomorphitae and Polygonomorphitae): A taxonomic reconsideration. |
1994 |