Geological Time Scale

Eon

Era
 

Period

Epoch

Abs. Age (Ma)

Age of

Events

 

Phanerozoic

 

Cenozoic
 

 

 

Quaternary

Holocene 0-2  

Age of
 

Humans
Pleistocene Scabland Floods

 

Tertiary

Neogene Pliocene 2-5  
Miocene 5-24 Columbia Basalts
Paleogene Oligocene 24-37  
Eocene 37-58  
Paleocene 58-66 Extinction of Dinosaurs
 

Mesozoic

 

Cretaceous

66-144

Age of
Reptiles

Flowering Plants

Jurassic

144-208 1st Birds/Mammals

Triassic

208-245 1st Dinosaurs
 

Paleozoic

Permian

245-286

Amphibians

Extinction of Trilobites
Carboniferous

Pennsylvanian

286-320 1st Reptiles

Mississippian

320-360 Large Primitive Trees

Devonian

360-408 Fishes 1st Amphibians

Silurian

408-438 1st Land Plants

Ordovician

438-505 Invertebrates 1st Fish

Cambrian

505-545 1st Shells, Trilobites

Proterozoic

Precambrian 545-2,500   1st Multi-celled organisms

Archean

2,500-3,800   1st One-celled organisms

Hadean

3,800-4,600   Origin of the Earth