|
Calendar
day |
Actual
time (years
ago) |
EVENT |
ERA |
PERIODS |
|
1 |
4.55E+09 |
Earth forms from planetesimals,
along with their planets |
Precambrian time (4,500 to 543 mya) |
|
|
69.2 |
3.70E+09 |
Earth's crust solidified |
||
|
85.2 |
3.50E+09 |
First life appears in oceans |
||
|
105.3 |
3.25E+09 |
Photosynthesis begins in oceans(O2
appears in atmosphere) |
||
|
173.5 |
2.40E+09 |
Oceans contain significant amounts of
oxygen |
||
|
213.6 |
1.90E+09 |
First cells with nuclei appear in
oceans |
||
|
313.9 |
6.50E+08 |
Frst multicellular organisms appear |
||
|
322.4 |
5.43E+08 |
Most animal phyla appear |
Paleozoic Era
Most of limestone and coal
used today formed here. |
Cambrian
|
|
Ordovician |
||||
|
Silurian |
||||
|
Devonian |
||||
|
Mississipian |
||||
|
346.1 |
2.48E+08 |
Mass extinction of 90% of all life |
Pennsylvanian |
|
|
Permian
|
||||
|
351.6 |
1.80E+08 |
Pangaea supercontinent break up
begins; continents drift apart |
Mesozoic Era |
Triassic |
|
354.8 |
1.40E+08 |
Flowering plants evolve |
Jurassic
|
|
|
360.8 |
6.50E+07 |
Age of Dinosaurs ends, with mass
extinction of 70% of all living things |
Cretaceous
|
|
|
365.8 |
2.20E+06 |
Homo habilis
appear, in what is now |
Cenozoic Era |
Tertiary |
|
365.992 |
1.00E+05 |
First Homo sapiens appears |
Quaternary
|
Graphics from http://www.scotese.com/paleocli.htm