The Paleozoic Era The History Of The Geologic And Evolutionary Changes That Began Over 500 Million Years Ago Charles River Editors by Charles River Editors B0BPVZ4HC8 instant download after payment.

The early history of Earth covers such vast stretches of time that years, centuries, and even millennia become virtually meaningless. Instead, paleontologists and scientists who study geochronology divide time into periods and eras.

The current view of science is that Earth is around 4.6 billion years old, and the first 4 billion years of its development are known as the Precambrian period. For the first billion years or so, there was no life in Earth. Then the first single-celled life-forms, early bacteria and algae, began to emerge. It’s unclear where they came from or even if they originated on this planet at all, but this gradual development continued until around four billion years ago when suddenly (in geological terms) more complex forms of life began to emerge.

Scientists call this time of an explosion of new forms of life the Paleozoic Era, and it stretched from around 541-250 million years ago (Mya). In the oceans and then on land, new creatures and plants began to appear in bewildering variety, and by the end of this period, life on Earth had diversified into a myriad of complex forms that filled virtually every habitat and niche available in the seas and on the planet’s only continent, Pangea.