| original |
Ashgillian |
|
Oklahoma |
Loeblich,A.R.,Jr. et al. Some Middle and Late Ordovician microphytoplankton from Central North America. |
1978 |
| details |
Actonian |
Onnian |
England(Shropshire) |
Turner,R.E. Acritarchs from the type area of the Ordovician Caradoc Series, Shropshire, England. |
1984 |
| details |
Nd |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Ordovician |
|
Nd |
Servais,T. An annotated bibliographical review of Ordovician acritarchs |
1997 |