Question

Can y’all help me with this (picture down below)

Answer 1

1. A 1,000 Different Index species

2. The Cenozoic Era

3. The Cambrian Period

4. Younger than 5 million years

5. The Cambrian Period (same question but worded differently)

6. Because they existed for only a small period of time

7. because without the fossils in the rock layers they wouldn't know much about the animals during that time period