| details |
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 |
| original |
Oligocene |
|
USSR(Khanty-Mansiysk) |
Dorofeyev,P.I. On the taxonomy of the Tertiary Azolla Lam. of the section Rhizosperma Meyen |
1980 |
| details |
Rupelian |
Chattian |
Worldwide |
Kovach,W.L. et al. Worldwide stratigraphic occurrences of Mesozoic and Tertiary megaspores. |
1989 |
| details |
Oligocene |
|
USSR(Siberia) |
Batten,D.J. et al. Catalog of Mesozoic and Tertiary megaspores |
1990 |