part of the Paleozoic era, produced the most intense burst of evolution ever known. The Cambrian Explosion saw an incredible diversity of life emerge, including many major animal groups alive today.

“like the imprint of some animals’ fingertips and belly skin.” The Permian period, the last part of the Paleozoic Era, ended with the largest mass extinction in the history of life on Eart ...

3 min read During the Ordovician period, part of the Paleozoic era ... of the Ordovician remained confined to the seas with new animals evolving in place of those that didn't survive the Cambrian.

revealed a significant rise in marine oxygenation during the Late Paleozoic era (400 million years ago), hundreds of millions of years after the emergence of animal-life. These findings suggest ...