1. The Shaping of the Modern World
The Cenozoic Era
The Shaping of the Modern World

2. Themes of the Cenozoic Changes in Life
Age of Mammals
Make Way birds
The Ascent of Humans
Mountain Building in Western America continues
Formation of the San Andreas Fault
A Return to the Ice
Several major glacial events
Major Volcanic Eruptions

3. Early Cenozoic North America grows larger
Formed due to a series of collisions between the North American plate and small terranes in the Pacific
The Interior Western Seaway retreats and most of North America is above sea level (very important event)
The Appalachians are eroded

4. Early Cenozoic ( mya)

5. Early Cenozoic
India begins its collision with Asia, causing the Himalayas to be lifted
“Ring of Fire” forms
Australia separates from Antarctica

6. Early Cenozoic Era
The demise of the dinosaurs allows not only mammals, but birds to diversify and flourish
Birds got very large (to 10 feet tall) and were predatory
Songbirds also develop in this time period
First flowering plants develop - angiosperms

7. Giant Birds

8. Early Cenozoic
The climate of the Paleogene was notably drier than previous periods
Also much warmer than it is currently
Lead to more land being above sea level
Allowed for the evolution of first grasses and therefore, grazing mammals (like horses) evolve
Mammals diversify and grow very large
Mammals are an extremely varied group!
All major mammal groups are in place by the middle of the Cenozoic

9. Mammals of the Paleogene

10. Marine Animals The marine mammals evolve at this time
Whales, dolphins, etc
Relative of camels!!!
Lose their visible limbs over time
Sharks take over as the dominant predator in the sea, filling the niche left by extinct mosasaurs and pleisosaurs

11. Marine Animals

12. The Neogene: Middle of the Cenozoic to Present (23 mya – Present)
During the Neogene, the continents take their modern shapes
North and South America join
Iceland emerges from the sea
Polar Ice Caps form
In North America, the San Andreas Fault forms

13. (23 mya – Present)

14. The Pliestocene (1.6 mya – 10,000)
The Pleistocene is often referred to as the “Ice Age”
about 4 major ice advances and 3 retreats
Leads to sea level retreats and advances
Great Lakes form
Other major event includes the eruption of the Yellowstone caldera and (even worse!) the eruption of the Toba caldera
Toba nearly wipes out humans

15. The Ice Ages

16. The Calderas of the Pleistocene

17. Pleistocene Megafauna
Megafauna refers to the extreme large mammals that dominated this time period
Include the Mammoth, Mastodon, Saber-cat, Giant Sloth and Giant Beaver (among others)

18. Pleistocene Extinction
At the end of the last Ice Age (about 18, ,000 ya) most of the large mammals went extinct
This extinction event only affected large mammals
Probable causes include climate changes affecting the web chain and overkill by early humans
Still plenty of room for doubt
One question – is this extinction event a thing of the past, or is it continuing today?????