| details |
Pragian |
Early Givetian |
|
Grahn,Y. et al. Silurian and Lower Devonian chitinoan biostratigraphy of the Parana Basin in Brazil and Paraguay. |
2000 |
| original |
Early Givetian |
|
|
Grahn,Y. et al. Silurian and Lower Devonian chitinoan biostratigraphy of the Parana Basin in Brazil and Paraguay. |
2000 |
| details |
Late Eifelian |
Early Givetian |
|
Grahn,Y. et al. Middle and Upper Devonian Chitinozoan biostratigraphy of the Parana Basin in Brazil and Paraguay. |
2002 |
| details |
Late Eifelian |
Early Givetian |
Paraguay |
Grahn,Y. et al. Middle and Upper Devonian Chitinozoan biostratigraphy of the Parana Basin in Brazil and Paraguay. |
2002 |
| details |
Late Givetian |
Frasnian |
Brazil(Amazonas) |
Grahn,Y. Devonian chitinozoan biozones of Western Gondwana. |
2005 |