1. Theories of the K-T Extinction by: Gary Motz

2. Theories of the K-T Extinction Asteroid/meteorite impact? –Chixulub crater  Yucatan Peninsula Deccan Traps volcanism? –Southern India Small mammals ate too many dino eggs?

3. Impact Theory Evidence Iridium Concentrations –Ir is a rare element on Earth, but common in extraterrestrial objects The age of the crater corresponds with the time of the K-T extinction event

4. Impact Theory Evidence The crater is HUGE –Gravity map of Chixulub

6. Deccan Traps Volcanism Series of volcanoes and very large basalt flows Large quantities of ash would have contributed to a worldwide dust cloud –Greenhouse effect

7. Mammalian Competition Although mammals and dinosaurs coexisted from the Triassic through the end of the Cretaceous, there is no evidence to support the theory that mammals out-competed the dinosaurs

8. What really killed them off?