| original |
Llandoverian |
|
Argentina(San Juan) |
Volkheimer,W. et al. Lowermost Silurian chitinozoa from the Sierra de Villicum, San Juan, Argentina. |
1980 |
| original |
Early Caradocian |
|
Sweden |
Schallreuter,R. Chitinozoans from the Sularp Shale (Middle Ordovician) of Skane, (Sweden). |
1981 |
| original |
Pridolian |
|
Spain |
Schweineberg,J. Silurian chitinozoa from the Palencia Province (Cantabrian Mountains, North Spain). |
1987 |
| original |
Early Llandoverian |
Middle Llandoverian |
Argentina(San Juan) |
Baldis,B. et al. The Ordovician-Silurian boundary in the Sierra de Villicum, Argentine Precordillera. (In: A Global Analysis of the Ordovician-Silurian Boundary. L.R.M.Cocks and R.B.Rickards, editors) |
1988 |
| original |
Llandoverian |
|
Argentina(San Juan) |
Cuerda,A. et al. The Ordovician-Silurian boundary in Bolivia and Argentina. (In: A Global Analysis of the Ordovician-Silurian Boundary. L.R.M.Cocks and R.B.Rickards, editors) |
1988 |