PART 1. What is good science?

1. Go to the website ucmp.berkeley.edu/diapsids/buzz/dinoscience. Review the discussion "What is Good Science?".

2. What is the difference between an opinion & a scientific fact?

3. What is a falsifiable scientific hypothesis?

4. Visit the webpage ucmp.berkeley.edu/diapsids/extincthypo. Review "The Invalid Hypotheses". Your textbook presents many similar hypotheses in Box 15.1 (232-3). What makes most of these hypotheses invalid?


PART 2. Can scientists prove what caused dinosaur extinction?

1. Review the webpage entitled "The Great Mystery" at ucmp.berkeley.edu/diapsids/extinction. Then search the term "Hell Creek Formation" & pay a virtual visit to the best fossil record of dinosaur extinction. List your favorite virtual visit website(s). 

2. Why are even the best fossil localities only imperfect records of extinction?

3. Why is it so difficult to reconstruct global paleoecology at the end of the Cretaceous?

4. Why are "why" problems in paleontology so difficult to answer?


PART 3. How well does the pattern of extinction indicate the process of extinction? 

1. Review the webpage entitled "Extinction Theories" at ucmp.berkeley.edu/diapsids/extinctheory. 

2. Briefly describe the pattern of dinosaur extinction predicted by each of the two major hypotheses for the cause of end Cretaceous extinction.

3. Familiarize yourself with the Signor-Lipps effect by going the the Wikipedia page (wikipedia.org/wiki/Signor-Lipps_effect). How does this effect complicate our picture of extinction pattern?

4. So far, you have considered patterns in the timing of extinction. Victims & survivors of the end Cretaceous event also exhibit patterns. Go to the Wikipedia page entitled "Cretaceous-Paleogene extinction event" (Wikipedia.org/wiki/Cretaceous-Tertiary_extinction_event) & review the "Extinction Patterns" section. 

5. How well does the pattern of extinction at the best fossil localities (see Part 2) reveal the process of extinction?

6. How can scientists get a clearer picture of extinction pattern?


PART 4. What killed the dinosaurs?

1. Return to the ucmp.berkeley.edu/diapsids/extinctheory & review "The common ground" & the 2 hypotheses. 

2. What scientific facts do scientists know & agree upon about the end Cretaceous extinction? Categorize this knowledge under the following headings:

A. Climatic & Tectonic Changes
B. K-T Boundary Layers
C. Victims & Survivors
3. What are the two main scientific hypotheses about end Cretaceous extinction? Briefly summarize these hypotheses under the following headings:

A. Intrinsic Gradualism ("Earthly Whimperers")
B. Extrinsic Catastrophism ("Cosmic Bangers")


4. Now is your chance to weigh in on the subject. What do you think killed the dinosaurs? Cite your evidence.