Eons/Eras

Hadean eon

• 4.6-4.5 bya

• precambrian

• formation of earth

• moon forms

• ends w prokaryotic life

Archean eon

• 4-2.5 bya

• precambrian

• prokaryotes

• ended in photosynthesis + rise in oxygen

Proterozoic eon

• 2.5 bya-540 mya

• eukaryotes

• snowball earth glaciation

• multicellular life begins

Phanerozoic eon + 3 periods

• 541 mya-now

• paleozoic era

  • Cambrian explosion

  • vertebrates

  • insects

  • land plants

  • amphibians

  • reptiles

  • ends in permian mass extinction

• Mesozoic

  • dinos

  • mammals

  • birds

  • primates

  • ends in cretaceous mass extinction (dino extinction)

• cenozoic

  • 1st hominids

  • homosapiens evolve

Paleozoic Era

289-300 mya

• Cambrian explosion

• vertebrates

• insects

• land plants

• amphibians

• reptiles

• ends in permian mass extinction

Mesozoic Era

186-66 mya

• dinos

• mammals

• birds

• primates

• ends in cretaceous mass extinction (dino extinction)

Cenozoic Era

66 mya - now

• 1st hominids

• homosapiens evolve