Earth Sciences

Paleozoic era

The Paleozoic era, which happened and extended from about 542 million years ago to 251 million years ago, was a time when there were many important changes on Earth. The era began with the rupture of a super continent known as Pannotia, and the formation of a new one. Plants spread and evolved, and the first vertebrate animals that existed colonized the earth.

What is the Paleozoic era?

The Paleozoic era also known as Primary Era, is the division of the geological scale that began with the disintegration of the Pannotia and ended with the formation of the Pangea, the super-continent, which was later divided into several smaller continents.

What happened in the Paleozoic era

The Paleozoic era was an era of transit between the different forms of primitive life that existed, between vertebrate animals and invertebrates, of marine life and land, which was conquered by plants and animals. At this time, invertebrates evolved and grew in number. During the first years, sea life was limited to small animals, but then, vertebrate fish began to appear, which were fish covered with bony shells.

The first vegetables appeared on earth as ferns and conifers, and the atmosphere reached the oxygen levels we have today. Insects, amphibians and reptiles made their appearance, and there was great activity geologically speaking. Pangea began to separate and the lands emerging from the process were surrounded by sea.

Characteristics of the Paleozoic era

Some important characteristics of the Paleozoic era are mentioned below:

Periods of the Paleozoic era

The Paleozoic era is divided into five different periods:


Because plant and animal life had not fully evolved, it has been difficult to find climate information in continental fossil records, so the climate was considered oceanic and temperate, and had almost no seasonal differences. It is believed that at the beginning of the Silurian period there was the first great extinction due to the great glaciation that occurred.

Animals of the Paleozoic era

New aquatic life forms, such as algae, corals, mollusks, sharks, emerged. The first insects emerged at this time as did the echinoderms, although there was a massive extinction in that era. There was the Cambrian explosion, which suggested that animals had evolved by creating improvements in their systems.


During the Ordovician period, temperatures increased, and humidity increased, creating an atmosphere rich in carbon dioxide, facilitating the plant growth and the colonization of the continents by plants. The first vascular plants with rigid stems appeared. Large forests with large trees and swamps also emerged.

Volcanic activity

Volcano activity was very intense during the Paleozoic era, giving rise to new lands through land tectonic plates movement. Through telluric movements, the lands began to elevate giving rise to mountains and large ferns forests.

Written by Gabriela Briceño V.

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