What is the Paleozoic and its characteristics

Thanks to the geological record that is superimposed on the layers of the soil, we can know what life was like millions of years ago, and based on this, a geological time scale has been formed that allows us to order and understand past times.

One of these times is the Paleozoic era, which is characterized by being the era where marine animals diversified, as well as by the independence of both animals and plants from water. If you would like to take a trip to the past and learn what the Paleozoic is, its stages and animals , we invite you to read this article.

What is the Paleozoic and its characteristics

The Paleozoic is a geological era, whose name comes from the Greek palais for ancient, and zoein meaning life. It is known as the era of ancient life , and occurred 225 to 660 million years ago. Another way it is known is the primary era, or primary, although the term is increasingly out of use.

It has particular characteristics that allow us to identify it, and they are the following.

Paleozoic Geology

In the Paleozoic there were sedimentary rocks of calcareous origin . 30% of the lowlands were covered by low-water seas that washed the continents.

There were considerable uplifts of the Earth’s crust that formed mountains and volcanoes , including the Appalachians, the central Andes, and the Ural Mountains. Volcanic activity was high during this era.

As for the continents, these were separated into small continents . To the south, the continent Gondwana was formed, one of the two continents, and was made up of South America, India, Africa, Australia and Antarctica. The other continent located to the north is known as Laurasia, and the two were separated by the Tethys Sea. At the end of the Paleozoic, most of the continents were together in the famous supercontinent Pangea.

Climate of the Paleozoic era

The climates did not vary much and were quite uniform . The mountains were dry and cold, but generally a tropical to subtropical climate dominated . It was humid, with a lot of rain and warm temperatures. At the end of the Paleozoic era there were large glacial formations.

Stages of the Paleozoic era

The Paleozoic era is divided into 6 periods, which are as follows, from smallest to largest:

  • Cambrian: 600 million years ago.
  • Ordovician: 530 million years ago.
  • Silurian: 470 million years ago.
  • Devonian: 420 million years.
  • Carboniferous: 380 million years ago, it is the longest period of the Paleozoic.
  • Permian: 310 million years.

The event that marked the beginning of the era was the so-called Cambrian Explosion, and the end of the era was marked by the Permian extinction, which has been the largest extinction in the entire history of the Earth, with 95% of disappearance of existing marine species , especially invertebrates. It is suggested that it happened due to climate change and low sea levels.

Paleozoic animals

The Paleozoic fauna is characterized by an explosion and diversification in marine animals . First they started as invertebrates, and then the first fish, amphibians and reptiles appeared, where we can see the step of independence from water. Diversification was so great that 35 new animal phyla were formed.

Although the main animals were marine, there were also terrestrial representatives.

  • Paleozoic animals began in the Cambrian as brachiopods, sponges, crinoids, foraminifera, and trilobites, which are relatively simple invertebrates . The animal considered a representative icon of the Paleozoic is the trilobite.
  • In the Ordovician, corals, gastropods and graptolites appeared . Discover the Coral .
  • In the Silurian, new arthropods such as scorpions appear.
  • For the Devonian , fish arrive , both bony and cartilaginous, among which sharks are classified, as well as an important diversification of sponges and corals.
  • In the Carboniferous, the chordates begin to separate from the water with the group of amphibians to begin the dominance of the fauna on dry land , hence the Carboniferous is also known as the Age of the Amphibians. The first flying animals that dominated the air also appeared , which were insects that developed wings.
  • The Permian already has reptiles independent of water . An important element was the amniote egg, which does not require water. There were two types of reptiles: some similar to lizards and with completely terrestrial habits, and other semi-aquatic reptiles with very slow movements.

Paleozoic flora

Since life was primarily marine, the Paleozoic flora followed the same path. The first plants were algae highly dependent on humidity and the support that water gave them.

An important event in the plant world during the Paleozoic was the evolution towards independence from water. Plants evolved from water-dependent spores to desiccation-resistant spores. Thus mosses and ferns appeared.

Later these plants evolved into gymnosperms , among which are conifers. These are plants without true flower and bare seed. This is the first group of true seeds.

The flora dominated abundantly in the inland, with an immense abundance and variety of plants. Conifers, swamp forests, ferns and giant reeds could be found . This caused an increase in atmospheric oxygen, promoting a joint evolution between plants and animals, and allowing the latter to reach land.

Plants became so abundant at the end of the Paleozoic that they led to the formation of coal in many areas. You may be interested in the Oxygen Cycle: what it is and stages .

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