1. Which layer is the oldest? Which layer is the youngest? How do you know?
2. What are some characteristics of the organisms in layers 1-6?
3. What are some characteristics of the organisms in layers 7-12?
4. Develop a theory as to how the organisms in this area changed over time.

1 Which layer is the oldest Which layer is the youngest How do you know 2 What are some characteristics of the organisms in layers 16 3 What are some characteri class=