| original |
Maastrichtian |
|
Montana |
Hall,J.W. et al. Studies on fossil Azolla |
1968 |
| details |
Eocene |
|
North Dakota |
Jain,R.K. et al. A contribution to the Early Tertiary fossil record of the Salviniaceae |
1969 |
| details |
Late Cretaceous |
|
Montana |
Hall,J.W. Studies on fossil Azolla |
1969 |
| details |
Cretaceous |
|
Nd |
Jain,R.K. Pre-Tertiary records of Salviniaceae. |
1971 |
| details |
Late Cretaceous |
|
North Dakota |
Bergad,R.D. et al. A Cretaceous Azolla Massula with large Glochidia |
1971 |
| details |
Late Cretaceous |
Recent |
Nd |
Bergad,R.D. An ultrastructural comparison of walls of living and fossil Salviniaceous and Marsileaceous megaspores |
1972 |
| details |
Nd |
|
Nd |
Bergad,R.D. Ultrastructure of living and fossil Salviniaceous megaspores. |
1974 |
| details |
Nd |
|
Montana |
Hall,J.W. Cretaceous Salviniaceae. |
1974 |
| details |
Maastrichtian |
|
North Dakota |
Bergad,R.D. Palynology of the Hell Creek Formation (Maastrichtian) in South-Central North Dakota. |
1974 |
| details |
Cretaceous |
Early Eocene |
Nd |
Fowler,K. Megaspores and Massulae of Azolla prisca from the Oligocene of the Isle of Wight. |
1975 |
| details |
Nd |
|
North Dakota |
Hickey,L.J. Stratigraphy and paleobotany of the Golden Valley Formation (Early Tertiary) of Western North Dakota. |
1977 |
| details |
Maastrichtian |
|
Montana |
Srivastava,S.K. Cretaceous spore-pollen floras |
1978 |
| details |
Paleocene |
|
Nd |
Collinson,M.E. A new multiple-floated Azolla from the Eocene of Britian with a brief review of the genus. |
1980 |
| details |
Maastrichtian |
Ypresian |
Worldwide |
Kovach,W.L. et al. Worldwide stratigraphic occurrences of Mesozoic and Tertiary megaspores. |
1989 |
| details |
Maastrichtian |
|
Montana |
Batten,D.J. et al. Catalog of Mesozoic and Tertiary megaspores |
1990 |
| details |
Cretaceous |
|
Nd |
Ramanujam,C.G.K. et al. Remain of Azollaceae from Late Albian of Cauvery Basin and their evolutionary significance. |
1996 |