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 |
details |
Maestrichtian |
|
Colombia |
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 |
details |
Aptian |
Santonian |
North America |
Lupia,R. Discordant morphological disparity and taxonomic diversity during the Cretaceous angiosperm radiation: North American pollen record. |
1999 |