| details |
Early Whitcliffian |
Downtonian |
Wales(Denbighshire) |
Swanson,V. et al. Acritarchs and chitinozoa from the Whitcliffian (Silurian) Dinas Bran Beds of Llangollen, Clwyd, North Wales. |
1977 |
| details |
Ludlovian |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Late Llandoverian |
Early Wenlockian |
Canada(Ontario) |
Eley,B.E. et al. Acritarchs from the fossil Hill Formation (Silurian) of Southern Ontario, Canada |
1992 |
| details |
Late Gothlandian |
|
England |
Sarjeant,W.A.S. et al. The Micrhystridium and Veryhachium Complexes (Acritarcha: Acanthomorphitae and Polygonomorphitae): A taxonomic reconsideration. |
1994 |
| details |
Early Pridolian |
Late Ludlovian |
England(Herefordshire) |
Wetherall,P.M. et al. Palynology, biostratigraphy, and depositional environments around the Ludlow-Pridoli boundary at Woodbury Quarry, Herefordshire, England. |
1999 |