Big Changes During The Paleozoic Era

3. The Paleozoic Era was from 542 million years ago to 251 million years ago; at this time big changes began to happen on Earth. The era began with the disintegration of a supercontinent and the creation of another. Plants began to grow all over the place. Also at this time the first vertebrate animals conquered the land. Also Paleozoic appeared with the Cambrian Period, 53 million years is when life started to burst on Earth. The Cambrian period again gave way to the beginning of arthropods.

Furthermore during the Paleozoic Era, life blossomed in the ocean. 45-million- years later the Ordovician Period arrived after the Cambrian Period. This is recorded in the fossils by a large amount of marine invertebrates. One of the well-known

Tetrapods began to lay eggs on land around this period, which allowed them to separate from an amphibious environment. Trilobites were starting to disappear as fish became diversified. The beginning of the conifers was starting to appear. Tetrapods were starting to become unique, after animals from two groups appeared. The marine reptiles were the, which included lizards and snakes. The second was the archosaurs, which became crocodiles, dinosaurs and birds. This era was also referred to as the "Age of the Cockroaches," on occasion, because this is when the roaches’ family started to appear in quite a few places during the Carboniferous. The oceans were taken over by trilobites, inarticulate brachiopods, monoplacophoran molluscs, hyolithids.

The Permian Period was the last of the Paleozoic era, which started 299 million years ago and was completed around 251 million years ago. This period also became the time of the largest mass extinction that has ever happened. Besides the mass extinction, it was the time that the warm water in the ocean and life itself started to develop Coral reefs. The reef provided the regular fish and shelled a little shelter. Ginkgo trees and conifers also developed on land. The terrestrial vertebrates became