Question

What is one example of index fossil

Answer 1

Ammonites were common during the Mesozoic Era (245 to 65 mya), They were not found after the Cretaceous period, as they went extinct during the K-T extinction (65 mya).

Step-by-step explanation:

Answer 2

Answer: below

Step-by-step explanation:

Examples of index fossils include: Ammonites were common during the Mesozoic Era (245 to 65 mya), They were not found after the Cretaceous period, as they went extinct during the K-T extinction (65 mya).

index fossil: The trilobite is in all three outcrops (it is widespread) and in only one layer per outcrop (it is short lived.)