| original |
Llandeilian |
|
Baltic |
Eisenack,A. New Mikrofossils of the Baltic Silurian.1. |
1931 |
| details |
Ordovician |
|
W.Germany(Rhineland) |
Eisenack,A. Chitinozoans and Hystrichospheres in the Ordovician of the Rhine Schiefergebirge. |
1939 |
| details |
Ordovician |
|
Czechoslovakia |
Eisenack,A. Microfossils from Flintstones of the Ordovician in Bohemia. |
1948 |
| details |
Middle Ordovician |
|
Worldwide |
Achab,A. Biogeography of Ordovician chitinozoa. (In: Advances in Ordovician Geology. C.R.Barnes and S.H.Williams, editors) |
1991 |