| details |
Cenomanian |
|
Kansas |
Kovach,W.L. et al. Megaspores and other dispersed plant remains from the Dakota Formation (Cenomanian) of Kansas, USA. |
1988 |
| details |
Campanian |
Maastrichtian |
Canada(Alberta) |
Gunther,P.R. et al. Megaspores and other palynomorphs of the Brazeau Formation (Upper Cretaceous) Nordegg area, Alberta, Canada. |
1972 |
| details |
Middle Cenomanian |
|
Iowa |
Ravn,R.L. et al. The palynostratigraphy of the Dakota Formation, (?Late Albian-Cenomanian) in its type area, northwestern Iowa and northeastern Nebraska, USA. |
1995 |