7. Which animal species lived for the shortest amount of time? 8. Which time periods only had one species of animals present?
9. Let’s say you want to find a fossil
of a ray-finned fish. In the picture
of rock layers below, which rock
“formation” or “member” would
be the best for you to start digging
in?
10. What is the first formation or
member would you be able to find
jawless fishes in?