An index fossil:
A)is a marker for a specific time period
B)is a fossil species that existed for a long period of time before becoming extinct
C)is a fossil species that was restricted to a small geographic area
D)b and c

Question

Quizplus · Accepted Answer

An index fossil is a species that is used to define and identify geological periods. They are widespread and existed for a relatively short period of time, making them good indicators of the age of the rock layers in which they are found.

An Index Fossil