period 5 lopez puryear, History of Earth Timeline

birth of the solar system 5 billion years ago

Jan 1, 2011

sun and astriods

earth began to form 4.6 billion years ago

Jan 26, 2011

the earth started

3.8 billion years ago bacteria diversify

Mar 21, 2011

bacteria

2.2 billion years ago oxygen appears in the enviornment

Mar 30, 2011

life on earth

100,000 years ago modern humans

Mar 31, 2011

homo sapiens

3.7 billions years ago photosynthesizing bacteria

Apr 5, 2011

microbes

3.5 billion years ago oldest fossils

Apr 20, 2011

stromatolites

2.2 billion years ago oxygen appears

Jul 24, 2011

health

1.8 billion years ago oldest eukaryote fossils

Aug 22, 2011

acritarchs

800 million years ago major glaciation period begins

Nov 3, 2011

global ice ages

600 million years ago protective ozone layer in place

Nov 5, 2011

ozone layers over planet

480 million years ago land planets

Nov 14, 2011

planets in ocean

400 million years ago anthropods on land

Nov 20, 2011

insects

350 million years ago reptiles

Nov 23, 2011

reptiles roam earth

250 million years ago end permian

Dec 1, 2011

extinct

220 million years ago dinosaurs

Dec 3, 2011

dinosaurs roam earth

200 million years ago pangaea starts to break apart

Dec 4, 2011

heat

65 million years ago end cretaceous

Dec 26, 2011

extinct

60 million years ago primates

Dec 27, 2011

fossils

5.2 million years ago hominids

Dec 31, 2011

humanlike primates

100,000 years ago late pleistocene

Dec 31, 2011