| original |
Chesterian |
Springerian |
Utah |
Schemel,M.P. Carboniferous plant spores from Daggett County, Utah |
1950 |
| details |
Late Westphalian B |
Middle Westphalian C |
W.Germany(N.Rhine) |
Potonie,R. et al. The spore dispersae of the Rhur Carboniferous, their morphography and stratigraphy with reviews of species of other areas.Part 2 |
1956 |
| details |
Chesterian |
Springerian |
Utah |
Potonie,R. et al. The spore dispersae of the Rhur Carboniferous, their morphography and stratigraphy with reviews of species of other areas.Part 2 |
1956 |