The Paleozoic era is a rather long stage in the development of the Earth. It lasted 370 million years.
After the formation of significant land areas at the end of the Proterozoic era, the Paleozoic era began with an extensive spill of the seas. According to many geologists, at that time there was one huge continental block called Pangea ("all land" translated from Greek). From all sides it was surrounded by the oceans. Over time, this huge block fell apart. Thus, the Paleozoic era became a time of formation of foundations for future continents. During the further development of the Earth, these parts could increase, unite (due to mountain building processes) or decrease, breaking up again into pieces that could move away from each other until they occupied the position of the present continents.
The first hypothesis of "continental drift" was expressed by Alfred Wenger (German geologist). In his opinion, initially Pangea split into Gondwana and Laurasia.
The periods of the Paleozoic era are divided into Permian, Carboniferous, Devonian, Silurian, Ordovician and Cambrian (the most ancient).
The Cambrian phase began approximately 570 million years ago (according to some sources, somewhat earlier). The duration of this period is 70 million years. The beginning of the stage is associated with an evolutionary explosion on Earth, as a result of which the first representatives of most of the main animal groups that are known today appeared.
The boundary between Precambrian and Cambrian is noted in the rocks, where a huge variety of animal fossils with mineral skeletons suddenly appears. The Cambrian evolutionary explosion is one of the mysteries of the history of the planet. It took two and a half million years to transform the simplest cells into eukaryotic (more complex) cells. After 700 million years, the first multicellular ones appeared. And for another 100 million years, an incredible variety of animals has populated the planet. It should be noted that since that time (in more than 500 million years) not a single animal has appeared on Earth with a fundamentally new body structure.
The Ordovician period began about 500 million years ago, and ended about 408 million years ago.
Most of the southern hemisphere occupied Gondwana. Other large areas of land were concentrated in the equatorial zone. The seas at that time were inhabited by numerous animals, very different from the inhabitants of the Cambrian seas . The land was practically unsuitable for life - there was no soil, no plants, the sun was mercilessly burning, often hurricanes and volcanic eruptions occurred.
Towards the end of the Ordovician stage, they began to climb onto the coastal silt, decomposing it, communities of fungi, algae, and bacteria. Thus, a primitive soil layer was formed.
At the beginning of the Silurian period, the fish took on a look close to modern. At the end of the stage, mountain building processes begin. As a result, the Cambrian, Scandinavian mountains were formed, as well as massifs in East Greenland and Southern Scotland.
The Devonian stage of Earth's development is characterized by the greatest cataclysms on the planet. At that time there was a clash of Greenland, Europe and North America. A huge mainland Laurasia was formed.
The Carboniferous (carbon) period was characterized by a diverse climate - changes occurred from century to century. However, in general, it (climate) was characterized by increased humidity of the temperate, subtropical and tropical zones. This created favorable conditions for the spread of wetland and forest vegetation on land.
Life in the Paleozoic era was formed quite actively until the end of the last stage.
299 million years ago began the final stage of the Paleozoic. On the border with the Triassic period, the largest extinction of species in the history of the planet took place. At that time, about 70% of terrestrial and about 90% of marine organisms disappeared. Thus ended the Paleozoic era.