| details |
Middle Eocene |
Late Oligocene |
Canada(British Columbia) |
Hills,L.V. et al. Azolla primaeva and its phylogenetic significance. |
1967 |
| details |
Late Eocene |
Early Oligocene |
Nd |
Fowler,K. Megaspores and Massulae of Azolla prisca from the Oligocene of the Isle of Wight. |
1975 |
| details |
Oligocene |
|
USSR |
Friis,E.M. EM: Studies on Salviniaceae megaspores from the Middle Miocene Fasterholt Flora, Denmark. |
1977 |
| details |
Oligocene |
|
Poland |
Friis,E.M. EM: Studies on Salviniaceae megaspores from the Middle Miocene Fasterholt Flora, Denmark. |
1977 |
| details |
Lutetian |
Chattian |
Worldwide |
Kovach,W.L. et al. Worldwide stratigraphic occurrences of Mesozoic and Tertiary megaspores. |
1989 |
| details |
Late Eocene |
Early Oligocene |
USSR(Kazakh SSR) |
Batten,D.J. et al. Catalog of Mesozoic and Tertiary megaspores |
1990 |