Study the diagram of the geologic time scale. which method is most likely used to identify what happened before the start of the paleozoic era? a. scientists study fossils from the jurassic period. b. scientists observe index fossil records of the mesozoic era. c. scientists examine fossil evidence during the precambrian time. d. scientists explore the emergence of mammals and humans in the cenozoic era.

The correct answer is option C, that is, scientists examine fossil evidence during the Precambrian time.

In order to simplify the enormous amount of geological data, the scientists or geologists have dissociated the history of the Earth down into different segments that are known as geological eras, periods, and epochs.  

With the help of fossil records it has been illustrated that life prevailed for about 3800 million years, however, complex life originated only about 600 million years. The fossil records permit scientists to date and compare the rocks through the geological time.  

All the geologic time prior to the start of the Paleozoic era is known as Precambrian. This comprises approximately 90 percent of all the geologic time and covers the time from the beginning of the Earth, that is, about 4.5 billion years ago, to 544 million years ago.  

c. is the correct answer