Question

fossil record
in a section of the grand canyon, scientists have found the fossil remains of several different groups of organisms. the diagram below represents the number and age of the fossils the scientists found. the width of each shaded area in the diagram below indicates the relative number of fossils found.
fossil record
which of the following statements is supported by the fossil record?
group c is now extinct.
group d has been in existence the longest.
group a is the most recent organism to come into existence.
group b was the most numerous organism 10 million years ago.

Explanation:

Step1: Analyze Group C

Group C's fossil record does not extend to the present, so it is now extinct.

Step2: Analyze Group D

Group D's fossil record starts later than Group A's (Group A starts around 30 million years ago, Group D starts later), so it has not been in existence the longest.

Step3: Analyze Group A

Group A is not the most recent. For example, if we assume the present - day is the most recent, Group A's record does not start at the present.

Step4: Analyze Group B

10 million years ago, Group B's fossil width (which represents relative number) is not the largest. Group A has a larger width at some points in the past.

Answer:

Group C is now extinct.