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
(543 to 248 mya)

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
(248 to 65 mya)

Triassic

354.8

1.40E+08

Flowering plants evolve

Jurassic

Pics of Jurassic petrified trees

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 Africa

Cenozoic Era
(65 mya to today)

Tertiary

365.992

1.00E+05

First Homo sapiens appears

Quaternary

 

Graphics from http://www.scotese.com/paleocli.htm