The Paleozoic Era was from 542-251 million years ago, roughly 300 million years. Within this era are several different periods, including; Cambrian, Ordovician, Silurian, Devonian, Permian, and Carboniferous. This Era is known for its two most important events in animal history. In the beginning, there was a large explosion that changed the diversity in almost all multi celled animals; and at the end, there was a mass extinction that wiped out about 90% of the marine species. During the era, there were 6 main landmasses.
Cambrian Period
During this period, the climate was mild because there were no glaciers. Also, it was very tropical; this supported the extensive shallow-water. There were several reefs in Sibera. Even though the Cambrian period is between two periods that always were cold and icy. The sea level rose and new marine animals thrived.
Ordovician Period Throughout this period, marine invertebrates thrived. Some of them include, brachiopods, trilobites, and graptolites. In parts of the period, the climate was warm and humid; however, several glaciers formed which caused sea levels to drop. 60% of marine invertebrate genera and 25% of all families went extinct because of a mass extinction.
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Silurian Period
The Silurian period consisted of a lot of new beginnings for the world. Coral Reefs were first introduced during this period. Also, the first clear evidence of life was found. The climate was much warmer during the Silurian Period. This caused the glaciers to melt and the seas to rise. 65% of shallow seas flooded during this period because of low continental elevations. Vascular plants also evolved during the Silurian period.
Devonian Period
The Devonian period was a crucial time for the evolution of life: this was when the first vertebrate tetrapods climbed out of the primordial seas and began to colonize dry land.The first tetrapods (land-living animals) appeared during this period as well as the first wingless insects. The climate of the Devonian period was mild. At the end of this period, there was a mass extinction that was believed to be cause by meteorites.
Carboniferous Period The carboniferous period had a very mild climate with shallow warm waters which usually flooded the continents. More modern fish started to evolve during this period. Also, there were two large ice sheets that locked up the water as ice dropping the sea levels. Seedless plants thrived in forests, and basic tetrapods and ammonites evolved.
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Permian Period
This period is marked by the largest mass extinction in the history of Earth. The extinction affected
several different environments, but the most affected was the marine environment. Some species survived the extinction, however, they never
regained their population. The continents were usually dry, and with the decrease in glaciers; the temperature rose. The Permian period was the last period of the Paleozoic Era.
several different environments, but the most affected was the marine environment. Some species survived the extinction, however, they never
regained their population. The continents were usually dry, and with the decrease in glaciers; the temperature rose. The Permian period was the last period of the Paleozoic Era.