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

Modifying the scales

Lizards belong to the suborder Sauria and includes geckos (Family Gekkonidae), iguanas (Iguanidae), chameleons (Chamaeleonidae), skinks (Scincidae), worm lizards (Amphisbaeridae) and monitor lizards (Varanidae). They have all enhanced their water-tight integument with the development of scales, which have become highly modified. The Australian shingleback skink (Trachysaurus) has stout polished scales, the Gila monster (Neloderma) has round pink and black ones (and has additional protection by being venomous) and the horned lizards occurring in arid areas have enlarged them into spiny appendages which are scored with fine grooves which allow dew to condense on them and be collected in the mouth. Spines in the chameleons have also become horned with one to four occurring in the head region. The scales on the underside of the toes of geckoes have become highly modified with numerous microscopic hairs (lamellae) which enable them to climb smooth surfaces (including glass) with relative ease by each hair engaging on the smallest irregularity of the surface.

Coal Skink