Paleozoic era


The Paleozoic era , which happened and spanned from approximately 542 million years ago to 251 million years ago, was a time when a host of major changes occurred on Earth . The era began with the breakup of a supercontinent known as Pannotia and the formation of a new one. The plants spread and evolved and the first vertebrate animals that existed colonized the land.


What is the Paleozoic era?

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

  • What happened in the Paleozoic era
  • Characteristics of the Paleozoic era
  • Paleozoic era periods
  • Weather
  • Paleozoic era animals
  • Floors
  • Volcanic activity

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 , marine life and the land , which was conquered by plants and animals. At this time the invertebrates evolved and grew in number. During the first years, the life of the sea was limited to small animals, but then the vertebrate fish began to appear , which were fish covered with bony shells. The first vegetables appeared on earth such as ferns and conifers and the atmosphere reached theoxygen levels we have today. Insects, amphibians and reptiles made their appearance and there was great activity geologically speaking. The Pangea began to separate and the lands that emerged from the process were surrounded by sea.


Characteristics of the Paleozoic era

Some important characteristics of the Paleozoic era are mentioned below:

  • In the Paleozoic Era, the life of the seas grew and changed.
  • Plants evolved, but they did not yet have leaves or the vascular tissue to extract water and nutrients.
  • Ferns appeared, as did the first trees.
  • Many of the animals began to develop skeletons and shells.
  • The animals and plants managed to conquer the land leaving their marine life.

Paleozoic era periods

The Paleozoic era is divided into five different periods:

  • Cambrian Period : Life in this stage occurred in the sea and did not exist on land . The seas were shallow and large invertebrates and multicellular animals with exoskeletons, such as shells and snails, emerged. Algae and lichens predominated on the land. Thanks to the oxygen in the atmosphere, there was a proliferation of plants.
  • Ordovician Period : The seas withdrew and with it the land was exposed, approaching the continents and forming mountains . There was great volcanic activity and the first vertebrates emerged .
  • Silurian Period : There was life on land and water , and the first animals emerged. The first plants with vascular systems emerged and oxygen in the atmosphere reached today’s levels. Ferns and seed plants existed.
  • Devonian Period:  The warm climate and the rains predominated in this period. Fish acquired adaptability to fresh and salty waters and the first primitive sharks, starfish, and sponges emerged. The plants began to have roots and stems and reproduced by means of spores . The first forests originated in this period.
  • Carboniferous Period : There were great movements of the earth’s crust , the climate became more humid creating swamps where the plants began to diversify and grow. Amphibians spread and reptiles were born.
  • Permian Period : Lizard-like reptiles emerged that were entirely land animals and some semi-aquatic . The vegetation was abundant and there were great earthquakes causing the continents to emerge from the seas.


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

Paleozoic era animals

There was the emergence of new forms of aquatic life , such as algae, corals, mollusks , sharks. The first insects arose at this time as did the echinoderms , despite the fact that there was a mass 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 rose and humidity increased creating an atmosphere rich in carbon dioxide, facilitating the growth of plants and the colonization of the continents by them. The first vascular plants with stiff stems appeared. Large forests with large trees and swamps also emerged .

Volcanic activity

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

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