| details |
Late Miocene |
|
USSR(WSL) |
Dorofeev,P.I. Fossil flora from the Bol'Shaya Yuksa River in Western Siberia. |
1955 |
| details |
Middle Oligocene |
Middle Miocene |
Canada(British Columbia) |
Hills,L.V. et al. Azolla primaeva and its phylogenetic significance. |
1967 |
| details |
Oligocene |
Late Miocene |
Nd |
Fowler,K. Megaspores and Massulae of Azolla prisca from the Oligocene of the Isle of Wight. |
1975 |
| details |
Middle Miocene |
|
Denmark |
Friis,E.M. EM: Studies on Salviniaceae megaspores from the Middle Miocene Fasterholt Flora, Denmark. |
1977 |
| details |
Late Oligocene |
Miocene |
Nd |
Collinson,M.E. A new multiple-floated Azolla from the Eocene of Britian with a brief review of the genus. |
1980 |
| original |
Oligocene |
|
USSR(Tomskaya Oblast) |
Dorofeyev,P.I. On the taxonomy of the Tertiary Azolla Lam. of the section Rhizosperma Meyen |
1980 |
| details |
Early Miocene |
|
Czechoslovakia(Bohemia) |
Buzek,C. et al. Azolla remains from the Lower Miocene of the North-Bohemian Bas Czechoslovakia |
1988 |
| details |
Rupelian |
Piacenzian |
Worldwide |
Kovach,W.L. et al. Worldwide stratigraphic occurrences of Mesozoic and Tertiary megaspores. |
1989 |
| details |
Tertiary |
|
USSR(Siberia) |
Batten,D.J. et al. Catalog of Mesozoic and Tertiary megaspores |
1990 |