GEOLOGICAL TIME SCALE |
|||
| MYA | ERA | PERIOD | DOMINANT LIFE FORM |
| 2 | Quaternary | age of angiosperms | |
| 65 | Cenozoic | Tertiary | |
| 150 | Cretaceous | rise of angiosperms | |
| 200 | Jurassic | age of cycads and cycadeoids; conifers widespread | |
| 250 | Mesozoic | Triassic | rise of cycadophytes and Gingkos; diversifying of conifers and ferms. |
| 300 | Permian | rise of Voltziales and conifers | |
| 350 | Carboniferous | age of lycopods, sphenopsids, ferns; mosses present | |
| 400 | Devonian | diversifying vascular plants; first seed plants | |
| 450 | Silurian | first known vascular plants | |
| 500 | Ordovician | algae abundant | |
| 600 | Cambrian | eukaryotic algae; evidence of fungi | |
| 4500 | Precambrian | prokaryotes | |
| 5 TO 6,000 | Origin of planet | ||