| details |
Ludlovian |
Early Downtonian |
Libya |
Al-Ameri,T.K. Acid resistant microfossils used in the determination of Paleozoic palaeoenvironments in Libya. |
1983 |
| original |
Early Ludlovian |
Middle Ludlovian |
Argentina(San Juan) |
Rubinstein,C.V. Acritarch from the Silurian of the Jachal River Valley (Los Esp Formation), San Juan Province, Republica Argentina Subgroups Herkumorphita, Netromorphitae and Polgonomorphitae |
1989 |
| details |
Late Ludlovian |
Early Pridolian |
Argentina(San Juan) |
Rubinstein,C.V. Acritarchs from the Upper Silurian of San Juan, Argentina: Biostratigraphy and palaeobiogeography. (In: Contributions to Acritarch and Chitinozoan Research. S.G.Molyneux and K.J.Doring, editors) |
1993 |