1. The Mesozoic Era When Dinosaurs Ruled the Earth

2. The Mesozoic Era §Began approximately 245 million years ago after a major mass extinction. §Is subdivided into 3 periods: l Triassic l Jurassic l Cretaceous §Ends about 66 million years ago with a major mass extinction

3. The Triassic Period 245 - 206 million years ago §Immediately after the Permian Mass Extinction §Lots of new area is open for animals to live §Three general types of animals: l holdovers from before the extinction l new groups that lasted only a short time l new groups that lasted a long time

4. The Triassic World

5. Triassic Plant Life §Mosses §Scale Trees (like palm trees) §Ginkos

6. Two Groups of Dinosaurs §Ornithischian l Hips were similar to modern bird hips l Carnivorous short-necked l Herbivorous, long-necked §Saurischian l Hips were similar to reptile hips l Herbivorous with grinding-teeth l Herbivorous without grinding-teeth

7. Earliest Dinosaurs (Triassic) Eoraptor: Length:3 feet Height:1 feet Weight:20 pounds Pisanosaurus Length:3 feet Height:1 foot Weight:15 pounds Lesothsaurus: Length:3 feet Height:1 foot Weight:15 pounds

8. The Jurassic Period 206 - 144 Million Years Ago §Giant plant-eating dinosaurs §Vicious carnivore dinosaurs §Oceans full of fish, squid, sharks, etc. §Ichthyosaurs and Plesiosaurs §Pterosaurs §Birds

9. The Jurassic World

10. Jurassic Plant Eating Dinosaurs §Many different forms §Many had ‘armor’ to protect themselves l Triceratops l Ankylosaurus §Many very large (larger than a Rhino/Hippo) §Some were extremely large (as long as a city block): Diplodocus Triceratops

11. Diplodocus Ankyloasaurus

12. Jurassic Carnivorous Dinosaurs §Many different forms §Some were very large: l Tyrannosaurus Rex l Allasaurus §Some were smaller: l Raptors, and many more §All had sharp teeth, claws, and speed

13. Jurassic Marine Dinosaurs §Most with similar shapes as dolphins or sharks §Ate fish and other marine animals §Some were VERY large §All could swim VERY fast Ichthyosaurus

14. Jurassic Pterosaurs §Pterodactyls and Pterosaurs §Most had trouble walking §Were very good flyers §Had hollow bones §Small (~ 1 foot) and very large (~ 16 feet)

15. More Pterodactyls

16. Jurassic Birds(?) - Archaeopteryx §Not a Pterosaur §Jaws and bone structure like dinosaurs §Bones are hollow, like birds §Feathers §Was this an evolutionary link between dinosaurs and birds?

17. The Cretaceous Period 144 - 66 million years ago §The last period when Dinosaurs lived §Ends with a mass extinction around 66 million years ago §First flowering plants!

18. The Cretaceous World

19. Cretaceous Plants §First plants with flowers l Their appearance was very rapid l They appeared at the same time as the number of insects increased… §Could insects have helped the flowering plants evolve?

20. The Cretaceous Mass Extinction §Approximately 60% of all species went extinct. §Affected many land animals/plants §Affected fewer marine animals

21. What organisms went extinct? §All dinosaurs §All pterosaurs §All ichthyosaurs §Many terrestrial plants §Many marine animals

22. What organisms survived? §MAMMALS (!) §Birds §Many plants (ferns were the most successful plant for a while) §Trees with flowers §Small lizards/crocodiles/alligators/turtles §Fish, squids, sharks, etc.

23. What caused the extinction? §Meteorite impact theory l 66 million years ago, a ~10 km wide meteorite struck the Earth near what is now Mexico.