The Geologic Time Scale
EON |
ERA |
PERIOD |
EPOCH |
DATES |
AGE of |
Interesting Biological Events: |
Phanerozoic |
Cenozoic |
Quaternary |
Holocene |
0-2 |
Mammals |
Humans |
Pleistocene |
- |
Tertiary |
Neogene |
Pliocene |
2-5 |
- |
Miocene |
5-24 |
- |
Paleogene |
Oligocene |
24-37 |
- |
Eocene |
37-58 |
- |
Paleocene |
58-66 |
Extinction of dinosaurs |
Mesozoic |
Cretaceous |
66-144 |
Reptiles |
Flowering plants |
Jurassic |
144-208 |
1st birds/mammals |
Triassic |
208-245 |
First Dinosaurs |
Paleozoic |
Permian |
245-286 |
Amphibians |
End of trilobites |
Carboniferous |
Pennsylvanian |
286-320 |
First reptiles |
Mississippian |
320-360 |
Large primitive trees |
Devonian |
360-408 |
Fishes |
First amphibians |
Silurian |
408-438 |
First land plant fossils |
Ordovician |
438-505 |
Invertebrates |
First Fish |
Cambrian |
505-570 |
1st shells, trilobites dominant |
Proterozoic |
Also known as Precambrian |
570-2,500 |
1st Multicelled organisms |
Archean |
2,500-3,800 |
1st one-celled organisms |
Hadean |
3,800-4,600 |
Approx age of oldest rocks 3,800 |