| details |
Llandoverian |
|
Alabama |
Cramer,F.H. Paleographic considerations with regard to a microplanctonic association of the Gothlandian series of Birmingham, (Alabma, USA) |
1968 |
| details |
Early Gothlandian |
|
Pennsylvania |
Cramer,F.H. Possible implications for Silurian paleogeography from phytoplankton assemblages of the Rose Hill and Tuscarora Formations of Pennsylvania. |
1969 |
| details |
Llandoverian |
|
China(Szechwan) |
Fang,X. et al. Silurian microflora and chitinozoa in Guanyinqiao Qijiang County Sichuan Province and their stratigraphic significance |
1988 |