K-T Extinction

Question 1

K-T Extinction is also called…

Answer 1

Cretaceous-Tertiary Extinction or end-Cretaceous extinction

Question 2

What were affected?

Answer 2

Both Land and Marine organisms (75% of plant & animal species)

Question 3

What went extinct?

Answer 3

100 family groups of marine invertebrates, Dinosaurs, Pterasaurs, Mosasaurs, Plesiosaurs

Question 4

Catastrophic Extinction:

Answer 4

Many species go extinct at the same time.

Question 5

Stepwise Extinction:

Answer 5

Groups of species go extinct at particular, closely spaced times.

Question 6

Graded Extinction:

Answer 6

Species go extinct one at a time over a continuous time interval.

Question 7

Biotic Causes vs Physical Causes for extinction

Answer 7

Biotic causes are due to the organism itself (decrease in sexual activity, hormone problems) and Physical Causes are due to the environment (Climate, Volcanic Emissions)

Question 8

What are the 2 main hypotheses?

Answer 8

Impact & Volcanism

Question 9

Evidence for Impact:

Answer 9

Shocked Quartz, Microtectites, Iridium Layer, Tsunami Deposits, Smoking Gun?

Question 10

Evidence for Impact:

Answer 10

Shocked Quartz, Microtectites, Iridium Layer, Tsunami Deposits, Smoking Gun?

Question 11

Evidence for Volcanism

Answer 11

Deccan Traps