BCB705 Biodiversity: Chapter2 - Evolution of Biodiversity

Table of Contents

1. THE INFINITE VARIETY: THE BEGINNING OF LIFE
2. BUILDING BODIES: INVERTEBRATES OF THE OCEANS
3. THE FIRST FORESTS
4. THE SWARMING HORDES
5. THE CONQUEST OF THE WATER AND THE BIRTH OF THE VERTEBRATES
6. THE INVASION OF THE LAND
7. A WATER-TIGHT SKIN AND THE SHELLED EGG
   1. Issues: Ectothermy vs Endothermy
   2. Breeding mechanisms of the ancestral reptile
   3. Skull structure
   4. The Anapsids
   5. The Diapsids
   6. The Synapsids
   7. First dinosaur characteristics
   8. Dinosaur fossils
   9. Gigantic herbivores and carnivores
   10. Temperature regulation limits energy use
   11. The beginning of the end for the kings
   12. Impressive parental care
   13. Conquering various living environments
   14. The flight of the dinosaur
   15. The Pterosaur: The take-off
   16. The Ptesosaurs: Not just a gliding motion
   17. The extinction
   18. Mammals' role in extinction
   19. Change in climate
   20. Crocodiles
   21. Crocodiles: Social life
   22. The Order Chelonia: Modified
   23. The lizard
   24. Modifying the scales
   25. Limb reduction
   26. Snakes
   27. Snakes: Making waves
   28. Snakes: The predator
   29. Snakes: Nurturing the young
   30. Snakes: The nocturnal hunter
   31. Test Yourself
   32. Assignments
8. LORDS OF THE AIR
9. EGGS, POUCHES AND PLACENTAS
10. THEME AND VARIATION
11. THE HUNTERS AND THE HUNTED
12. A LIFE IN THE TREES
13. THE COMPULSIVE COMMUNICATORS

The beginning of the end for the kings

The dinosaurs had several extinction phases, with the gigantic dinosaurs, being replaced by smaller, low browsing, beaked dinosaurs at the end of the Jurassic and early Cretaceous. Again, another extinction occurred and marked the late Cretaceous period. These dinosaur extinctions may have been related to the radiation of angiosperm plants (viz plants possessing flowers) which attracted animals to disseminate their pollen and seeds. A new generation of low browsing dinosaurs may have promoted the spread of these plants. Overgrazing by dinosaurs may have threatened many low-growing plants with extinction, except for the angiosperms which possessed reproductive superiority. The late Cretaceous period witnessed the Hadrosaurs or duckbill dinosaurs (Anatosaurus, Lambeosaurus, Corythosaurus and Parasaurolophus) occupying swamps and forests and large herds of Triceratops and their relatives on the grass plains together with Tyrannosaurus rex.

Anatosaurus