| details |
Early Devonian |
|
Nd |
Kremp,G.O.W. Tetrad Markings of Pteridophytic spores and their evolutionary significance. |
1967 |
| details |
Downtonian |
|
England |
Boureau,E. et al. Paleobotanical Treatise. 2. Bryophyta, Psilophyta, Lycophyta. |
1968 |
| details |
Devonian |
|
England |
Balme,B.E. Fossil in situ, spores and pollen grains: An annotated catalogue. |
1995 |
| details |
Pridolian |
|
Wales |
Edwards,D. et al. In situ, pollen and spores in plant evolution. 14A -Review of in situ, spores in early land plants. (Principles and Applications. Applications. J.Jansonius and D.C.McGregor, editors.) |
1996 |