The Greenhouse Effect and Global Warming - Air Pollution and Global Warming: History, Science, and Solutions - page 278

Eon Era Period Epoch m.y.a

Holocene

Quaternary 0.0117

Pleistocene

Homo habilis (2.0)
Greenland ice sheet (2.4-4)

2.588

Pliocene

5.332 Arctic sea ice/Alaskan glaciers (5-6)

Age of mammals Cenozoic Miocene

23.03

Tertiary Oligocene

33.9

Antarctic ice (40)

Eocene

P
h
a
n
e
r
o
z
o
i
c

55.8

Paleocene

65.5

Cretaceous

145.5

Age of dinosaurs Mesozoic Jurassic

199.6

Triassic

251

Permian

299

Coal formation (280-320)

Carboniferous

359

Devonian

Paleozoic 416

First land plants (395-430)

Silurian

443.7

Ordovician

First primitive fish (430-500)

488.3

Cambrian

542

First shelled invertebrates (570)

Neoproterozoic

1000

Proterozoic Mesoproterozoic

1600 First eukaryotic bacteria (2100-1850)

Paleoproterozoic

2500 Great Oxygenation Event (2450)

Neoarchean

2800

Mesoarchean

Archean 3200

Paleoarchean

Earliest prokaryotic bacteria (3500)
Oldest recorded rocks (3800)

3600

Eoarchean

4000

Hadean

Meterorite bombardment (4600-4100)

4600

Figure 12.15. Geologic time scale and important events since the formation of the Earth. Time before present
is measured in million years ago (m.y.a.).