EON

ERA

PERIOD

EPOCH

DATES

AGE of

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

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