| EON
|
ERA
|
PERIOD
|
EPOCH
|
millions
of years ago
|
Important Events
|
| HADEAN
|
4600
|
Earth
is formed
| |||
| ARCHEAN
|
3500
|
First
fossil prokaryotes
| |||
| 2500
|
oxygen
appears in atmostphere
| ||||
| PROTEROZOIC
|
1500
|
First
fossil eukaryotes
| |||
| 700
|
First
fossil animals
| ||||
| Cambrian
|
600
|
Fossils
of most invertebrate phyla
Algae diversifying
| |||
| Ordovician
|
500
|
First
fossil vertebrates (jawless fishes) Marine algae abundance
Mass extinction at end of period
| |||
| Silurian
|
440
|
Diversification
of jawless fishes
First land plants and arthropods
| |||
| PALEOZOIC
|
Devonian
|
400
|
Diversification
of bony fishes
First fossil amphibians & insects
| ||
| Carboniferous
|
360
|
Vascular
plants dominant; First fossil seed plants Amphibians dominant
Reptiles appear
| |||
| Permian
|
286
|
Continents
joined as Pangaea Most modern insect orders present Diversification of reptiles First mammal-like reptiles appear Largest mass extinction ever recorded occurred near
end of period (possibly related to asteroid impact)
| |||
| Triassic
|
248
|
Continents
begin to break apart & drift Gymnosperms dominant plants Dinosaurs appear First birds and mammals appear
Mass extinction at end of period
| |||
| PHANEROZOIC
|
MESOZOIC
|
Jurassic
|
213
|
Gymnosperms
still dominant
Dinosaurs dominant animals
| |
| Cretaceous
|
144
|
Most
continents widely separated Anthophytes appear Mass extinction near end
of period; most severe and swift in North America | |||
| Paleocene
|
65
|
Continents
near present positions Radiation & diversification of insects (anthophyte pollinators), anthophytes increase greatly in diversity!
birds and mammals
| |||
| Eocene
|
54
|
Anthophyte
dominance/diversity increases
Mammal diversity increases
| |||
| Tertiary
|
Oligocene
|
38
|
Modern
mammal orders present
(Primate fossis include apes)
| ||
| CENOZOIC
|
Miocene
|
24
|
Increased
diversification of
mammals and anthophytes
| ||
| Pliocene
|
5
|
Bipedal
ape fossils
| |||
| Pleistocene
|
1.8
|
Homo
sapiens appears (uh oh.....) Great Ice ages Mass extinctions of large
memmals near end of period
| |||
| Quaternary
|
Recent
|
0.01
|
10,000
years of time recorded by Homo sapiens in artifact and written word.
Mass extinction occurring presently
|