| original |
Middle Devonian |
|
Canada(Ontario) |
Legault,J.A. Chitinozoa and acritarcha of the Hamilton Formation, (Middle Devonian), southwestern Ontario. |
1973 |
| details |
Emsian |
Givetian |
Canada(Ontario) |
Playford,G. Lower to Middle Devonian acritarchs of the Moose River Basin, Ontario. |
1977 |
| details |
Givetian |
|
Ohio |
Wicander,R. et al. Systematics and biostratigraphy of the organic-walled microphytoplankton from the Middle Devonian, (Givetian), Silica Formation, Ohio, USA. |
1981 |
| details |
Givetian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |