12.09 Why did dinos die?

Question 1

What causes extinction?

Answer 1

• Out-competition by other organisms. (Specialist preferred).
• Environmental change (Generalists preferred).
• Chance!

Question 2

Big Five mass extinctions

Answer 2

• Permian/Triassic
• Ordovician/Silurian
• Triassic/Jurassic
• Cretaceous/Paleogene
• End-devonian

Question 3

Two Types of Extinction

Answer 3

• Normal background extinction, accounts for most extinctions.
• Mass extinction, has greater effect.

Question 4

Cretaceous Mass Extinction

Answer 4

• 75% of marine invertebrate life go extinct.
• Non-avian dinosaurs go extinct.
• Few mammals affected? Patterns of selectivity.

Question 5

CMN Theory 1: Outcompetition

Answer 5

Mammals outcompete dinosaurs.

Disproven, mammals did not become dominant after.