| original |
Late Pliocene |
Early Pleistocene |
France(Pyrenees,Orient.) |
Florschutz,F. et al. A fossil Azolla in the eastern Pyrenees |
1960 |
| details |
Late Pliocene |
Pleistocene |
France |
Potonie,R. Synopsis of the Sporae in situ. |
1962 |
| details |
Pleistocene |
|
Canada(British Columbia) |
Hills,L.V. et al. Azolla primaeva and its phylogenetic significance. |
1967 |
| details |
Late Neogene |
|
USSR |
Friis,E.M. EM: Studies on Salviniaceae megaspores from the Middle Miocene Fasterholt Flora, Denmark. |
1977 |
| details |
Late Neogene |
|
Poland |
Friis,E.M. EM: Studies on Salviniaceae megaspores from the Middle Miocene Fasterholt Flora, Denmark. |
1977 |
| details |
Piacenzian |
|
Worldwide |
Kovach,W.L. et al. Worldwide stratigraphic occurrences of Mesozoic and Tertiary megaspores. |
1989 |
| details |
Late Pliocene |
Early Pleistocene |
Spain |
Batten,D.J. et al. Catalog of Mesozoic and Tertiary megaspores |
1990 |