1. Well, here’s the periods!

2. Cambrian Period
Cambrian explosion!

3. Ordovician Period
end
Beginning and middle
Marine invertebrates
trilobites & brachiopods
Extinction (60% of invertabrates
extinct due to climate change)

4. Coral reef
Silurian Period
Stable climate
Glaciers melted
Ocean levels went up
Vascular plants
Ancestors of spiders and centipedes

5. North=dry
Devonian Period South =cool,
temperate, ocean-
covered
Age of fishes!
Increase of
terrestrial
animals
Seed plants like gymnosperms Tetrapods!

6. Carboniferous Period
Forest swamps
amphibians
covered land!
Reptiles - Amniotic egg was
covered with a leathery/hard
shell
Large plants and trees

7. Permian
Pangaea formed & it was
DRY!
Great seasonal
amphibians fluctuations
More prevalent
prevalent
Gymnosperms replaced ferns

8. triassic
Gymnosperms
still dominant
plant
LOTS OF REPTILES!

9. jurassic
Gymnosperm still
plentiful
Early bird-like creatures/archaeopteryx
Reptiles continued to be
dominant including
dinos

10. cretaceous

11. tertiary
Angiosperm =dominant land
plant
Mammals diversify

12. quaternary
Hominids become more like humans 