Question Detail
Question
What is the longest part of Earth's history trace fossils appeared? a. Paleozoic Era b. Precambrian Era c. Mesozoic Era d. Cenozoic Era
Correct Answer
Option B is the correct answer.
Detailed Explanation
The Precambrian is the longest part of Earth's history. While trace fossils (like microbial mats and burrows) do appear in the late Precambrian, abundant and diverse fossil life, including most trace fossils, appears in the subsequent Paleozoic Era.
Hint
This is the longest stretch, covering the time before complex life exploded.