| original |
Ludlovian |
|
USSR(Russian Platform) |
Umnova,N.I. Structural types of the Prosome and Operculum in the chitinozoa and their association with genera and species. |
1976 |
| details |
Ludlovian |
|
USSR(Russian Platform) |
Umnova,N.I. Ordovician and Silurian chitinozoa from the northern part of the Russian Platform. |
1981 |
| details |
Late Ludlovian |
Early Pridolian |
China(Jiangxi) |
Li,J. et al. Late Ludlow - Early Pridoli palynomorphs from northern Jiangsu, South China. |
2000 |
| details |
Gorstian |
Ludfordian |
China(Kiangsu) |
Geng,L.-Y. et al. Chitinozoan biostratigraphy in China. |
2000 |