Explain how index fossils can be used to date newly discovered fossils. Identify another method that could be used to determine the age of the fossil.
Explain why determining the age of the new fossil find is important to scientists.

1) Index fossils are of organisms that lived over a wide area. They lived for a fairly short period of time. An index fossil allows a scientist to determine the age of the rock it is in.

2) Relative dating is used to determine a fossils approximate age by comparing it to similar rocks and fossils of known ages.

Explanation:

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands