| details |
Early Gothlandian |
|
Pennsylvania |
Sarjeant,W.A.S. et al. The Micrhystridium and Veryhachium Complexes (Acritarcha: Acanthomorphitae and Polygonomorphitae): A taxonomic reconsideration. |
1994 |
| details |
Llandoverian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| original |
Llandoverian |
|
Pennsylvania |
Johnson,N.G. Early Silurian palynomorphs from the Tuscarora Formation in Central Pennsylvania and their paleobotanical and geological significance |
1985 |