1. The Cenozoic Era The Modern World Emerges Climate and Life
Earth History GEOL 2110
The Cenozoic Era
The Modern World Emerges
Climate and Life

2. Major Concepts
Greenhouse conditions that prevailed in the Cretaceous continued into the Early Cenozoic. But dramatic cooling episodes began in the late Eocene. This appears to be due to changes in ocean circulation as Pangea continued to break apart.
This climate change resulted in a dramatic change in the biosphere which change from tropical jungles in the early Cenozoic to grasslands, savanahs, and temperate forests in the Late Cenozoic.
After the Cretaceous extinctions of the dinosaurs, mammals saw an explosive radiation . The change over from jungles to grass lands also caused a change from leaf-eating to grazing mammals with more speed.

3. Summary of the Cenozoic
PEOMPP

4. Climate Change in the Cenozoic
Methane Degassing Event

5. Degassing of Methane Hydrates in Early Eocene
USGS map of known and suspected methane hydrate deposits
Seismic profile off
North Carolina
3000 m
Methane Plumes

6. Degassing of Methane Hydrates in Early Eocene
Deep-sea plume of methane escaping from the sea floor

7. Climate Change in the Cenozoic
The Great Eocene-Oligocene Cool Down

8. The Great Eocene -Oligocene
Cool Down
Separation of Australia and SA from Antarctica triggers Glaciation and Major Extinction of Warm-climate Species

9. Climate Change in the Cenozoic
Mid-Miocene Cool Down

10. Mid-Miocene Cool Down (15 Ma)
Arctic – Atlantic Connection Established
Miocene
20-15 Ma

11. Cool Down Continues into the Pliocene and into Today

12. Climate Change in the Cenozoic

13. Climate Change Affects the Biosphere
Warm, lush forests/jungles of the Eocene give way to ….
Temperate grasslands and savannas of the Miocene

14. Mammalian Evolution
“In the Late Cretaceous, no mammal was larger than a house cat. By the Eocene (40Ma) all modern orders of mammals had evolved with some the size of a rhinoceros or elephant”

15. Adaptation to the Mid-Cenozoic Climate
Longer–limbed runners Better eye sight
Cud-eaters Hoofs replace toes
High crowned teeth that continue to grow

16. The Gondwanan Continents Natural Laboratories of Speciation

17. Ecological Convergence

18. Great American Interchange When Migration was North to South
South Americans
Isthmus established in Mid-Pliocene (4Ma)
North Americans

19. Fig b

20. Next Lecture The Pleistocene Epoch The Ice Age QUIZ on Chapter 16 p
Next Lecture The Pleistocene Epoch The Ice Age QUIZ on Chapter 16 p and MNaG-Q