1. Geologic Time
Mesozoic and Cenozoic

2. Mesozoic Era 248-65 mya “middle animals”
Great changes in animal life: reptilian forms dominant
Great changes in land plant life: gymnosperms become dominant, then angiosperms develop

3. Triassic period 248-206 mya Follows devastating extinction
Marine biosphere: molluscs, fish and corals dominant, along with marine reptiles
Land: reptiles radiate to pterosaurs and dinosaurs

4. Triassic Tectonics
Pangaea begins to break apart into Gondwana and Laurasia
Arid climate
Far north and south have swampy conditions

5. Triassic Land Life Stagonolepis: armored thecodont Cycad: gymnosperm
Pisanosaurus: ornithischian dinosaur
Tree fern
Exaeretodon: cynodont

6. Triassic Marine Life Ichthyosaurs dominant reptiles
Cephalopods recover in oceans
Small patches of coral reef
Fish of uniform variety, may indicate that Permian extinction affected them greatly

7. Jurassic Period
mya
Land: lush plant growth, large herbivorous dinosaurs
Marine: fish, cephalopods, ichthyosaurs, plesiosaurs

8. Jurassic Land Life Sauropod dinosaurs Large forests First birds
Early mammals

9. Cretaceous Period 144-65 mya
Breakup of Pangaea continued, massive volcanic eruptions
Climate begins to cool
Ended in mass extinction

10. Cretaceous Land Life Dinosaurs very diverse Mammals, birds
Angiosperms begin to spread

11. Cenozoic Era 65 mya to present Australia pulled away from Gondwana
Antarctica moved over South Pole
India moved north and collided with Asia

12. Cenozoic Era
Period of long-term cooling w/ a high temperature blip (PETM)
Antarctic Circumpolar current
Isthmus of Panama strengthened Gulf Stream and Humbolt Current

13. Cenozoic Era Land: Age of grasses, mammals, birds
Marine: fishes and gastropods common