1. Mesozoic Era (Age of the Reptiles)
248 million years ago to 65 million years ago
Pangaea separates
Three Periods
Triassic
Jurassic
Cretaceous

3. Triassic Period (225-180 MYA)
Pangaea (supercontinent) formed

4. Triassic Period (225-180 MYA)
First Dinosaurs (small in size)

5. Triassic Period (225-180 MYA)
Conifers and Cycad Forests Dominate (Gymnosperms)

7. Jurassic Period (180-135 MYA)
Pangaea starts to separate

8. Jurassic Period (180-135 MYA)
Dinosaurs Dominate: Allosaurus, Diplodocus, Brachiosaurus, Stegasaurus.

9. Jurassic Period (180-135 MYA)
Reptiles in the sea - Icthyosaurs – 8 m; Plesiosaurs – 15 m.

10. Jurassic Period (180-135 MYA)
1st mammals (small rodents).

11. Jurassic Period (180-135 MYA)
1st birds.
Evidence that birds evolved from Dinosaurs tomorrow...

13. Cretaceous Period (135-65 MYA)
Continents in modern positions

14. Cretaceous Period (135-65 MYA)
Dinosaurs still dominate: T. rex (carnivore); Triceratops (horned); Trachadon (duck-billed)

15. Cretaceous Period (135-65 MYA)
Angiosperms (flowering plants with fruit) evolve & dominate

16. Cretaceous Period (135-65 MYA)
Mass Extinction: 50% of all plant and animal groups die
Alvarez’s Meteor Impact Theory-
KT Boundary: iridium layer (common in meteors) in rock record
Dust from impact blocked out the sun and caused major climate change and plants to die.
VIDEO

18. Cenozoic Era (Age of the Mammals)
65 million years ago to Present Day
Two Periods
Tertiary
Quaternary

20. Tertiary Period (65 MYA to 1.8 MYA)
Starts with a warm and humid climate
Mammals dominate: increasing in size
Angiosperms (flowering plants) dominate
Grasses develop, grazing animals become even larger
Earliest prehistoric humans (approximately 6 to 7 MYA).

21. Animals of the Tertiary
Organisms that have been found in the La Brea tar pits of Los Angeles
Megatherium, a giant ground sloth (20 ft long).

22. Animals of the Tertiary
Indricotherium, measured up to 13 ft at the shoulder.
Diatryma, a giant predatory bird.

24. The Great Ice Age

25. Quaternary Period (1.8 MYA to Present)
The “Great Ice Age”, ice sheets covered 30% of all land
Land & ice bridges connected many continents allowing animal migration
Large North American animals go extinct: elephants (mastodons, mammoths), giant sloths & armadillos, and saber-toothed cats
Modern humans evolve, maybe causing the above extinctions from hunting.

26. A Sixth Mass Extinction?
Are we the cause of a sixth mass extinction that is currently taking place?
Round Table Discussion