1. Eons, Eras, Periods, Epochs Monroe

2. Objectives ~ Geologic Column ~ the ordered arrangement of rock in layers, based on age Time frame/segment Eons ~ the very, very longest Eras ~ the almost longest. Periods ~ the middle Epochs ~ the shortest

3. Precambrian Era 1 st Really long. Really, really long. Really

4. Precambrian Era 1 st Really long. Really, really long. Really loooooooonnnnnnnggggggggg 2 nd Not many fossils. Mostly simple life forms, and marine and not land life forms.

5. Precambrian Era 1 st Really long. Really, really long. Really loooooooonnnnnnnggggggggg 2 nd Not many fossils. Mostly simple life forms, and marine and not land life forms. 3 rd Lots of trilobites at the end. 4 th Stromatilites were around to change “bad gasses” in to oxygen and nitrogen atmosphere. Ours.

6. Palezoic Era 1 st Means “ancient life” in Greek

7. Palezoic Era 1 st Means “ancient life” in Greek 2 nd Lots of fossils, land and marine life, and more complex.

8. Palezoic Era 1 st Means “ancient life” in Greek 2 nd Lots of fossils, land and marine life, and more complex. 3Age of fishes 4Ozone (3 oxygen atoms per molecule) is needed to protect life on land from the Sun’s UV rays. In oceans, water does that job.

9. Palezoic Era 1 st Means “ancient life” in Greek 2 nd Lots of fossils, land and marine life, and more complex. 3Age of fishes 4Ends with a really huge mass extinction.

10. Mesozoic Era 1 st Means “middle life”

11. Mesozoic Era 1 st Means “middle life” 2 nd More complex life, like reptiles and birds. Dinosaurs rule the roost. Lots of them.

12. Mesozoic Era 1 st Means “middle life” 2 nd More complex life, like reptiles and birds. Dinosaurs rule the roost. Lots of them. 3 rd Dinosaurs actually turned into birds. Really, I am not kidding you.

13. Mesozoic Era 1 st Means “middle life” 2 nd More complex life, like reptiles and birds. Dinosaurs rule the roost. Lots of them. 3 rd Dinosaurs actually turned into birds. Really, I am not kidding you. 4Angiosperm (flowering plants)

14. Mesozoic Era 1 st Means “middle life” 2 nd More complex life, like reptiles and birds. Dinosaurs rule the roost. Lots of them. 3 rd Dinosaurs actually turned into birds. Really, I am not kidding you. 4Angiosperm (flowering plants) 5Age of Reptiles

15. Mesozoic Era 1 st Means “middle life” 2 nd More complex life, like reptiles and birds. Dinosaurs rule the roost. Lots of them. 3 rd Dinosaurs actually turned into birds. Really, I am not kidding you. 4Angiosperm (flowering plants) 5Age of Reptiles 6First Mammals

16. Mesozoic Era 1 st Means “middle life” 2 nd More complex life, like reptiles and birds. Dinosaurs rule the roost. Lots of them. 3 rd Dinosaurs actually turned into birds. Really, I am not kidding you. 4Angiosperm (flowering plants) 5Age of Reptiles 6First Mammals 7 h Ends with a really huge mass extinction.

17. Cenozoic Era 1 st Means “recent life”

18. Cenozoic Era 1 st Means “recent life” 2 nd Rise of the mammals. Lots of things like Mastadons.

19. Cenozoic Era 1 st Means “recent life” 2 nd Rise of the mammals. Lots of things like Mastadons. 3 rd We win !!!!!!

20. Periods are not as long, and they cut the eras into manageable pieces. Epochs cut the periods into smaller pieces. Our Holocene epoch is only 11,000 years old. Does the future hold an epoch that is “post homo sapien”?

21. Mass Extinctions There have been 5 MASSIVE extinctions. 1.443 million years ago ~ end of Ordovian period. 2.374 million years ago ~ end of Denovian period. 3.251 million years ago ~ end of Permian. The great dying. Death of 90% of ocean dwelling species, and 70% of land animals, even insects. 4.201 million years ago ~ end of Triassic period. 5.65 million years ago ~ end of Mesozoic (and dinosaurs). Biologists believe that plants changed quickly, and that animals could not adapt.

22. Astonomers believe that most (all) of them were caused by asteroids. They believe that the first kill (Ordovian) was a result of a nearby exploding star, but that the others were falling rocks. Geologist have never “called Uncle” in the debate.