Problem 1) What was the Cambrian explosion? When did it happen? How did increasing oxygen levels contribute to the production of hard parts? What advantages did this provide to organisms? How did this change benefit preservation in the fossil record?
Problem 2) Describe the impact hypothesis for the K-T mass extinction. What was the original evidence used to propose this hypothesis? Summarize the supporting evidence that was discovered. Describe the effects of the impact.
Problem 3) Why do we describe dinosaurs as archosaurs with a permeated acetabulum? How did the unique features of dinosaurs change the orientation of dinosaurs' hindlimbs compared to their ancestors (commonly known as "reptiles")? How did this change allow dinosaurs to be bigger and/or faster? Why do we consider birds to be dinosaurs?
Problem 4) Compare the fossil record of mammals in the Mesozoic Era to the fossil record of mammals in the Cenozoic Era. Why did the fossil record for mammals change so drastically?