Answer:
Ferns were dominant plant form during the Paleozolic Era.
Explanation:
The Ferns appeared in times of high carbon and oxygen in the atmosphere because of the condition of the earth. Also, it was a time in which humidity was very high, letting ferns dominate entirely from the mid paleozoic to the late paleozoic. We are talking about one hundred thousand years. After that, the environment changed and many different plants emerged to reign the land and seas. Because the climate was less humid, the oxygen levels fell and other plants found that the ecosystem better to develop. Like gymnosperms and dichroism which were bigger plants with stronger parts to endure the living forms that arrived in that epic time.
