The Many Mass Extinctions

Although the Paleozoic Era was a great, prospering period, there were several large extinctions throughout its time.  After each wipeout, new life appeared quickly, even though sixty percent or more of all life was massacred.  The most massive of all, the 'Permian Extinction,' was the last to occur, and wiped out ninety percent of all marine animals, and most of the therapsid species. (Otherwise known as the giant insects)  Scientists have no idea what caused these extinctions, but many believe the Permian Extinction was due to a climatic change.  Other scientists insist the massacre was due to an asteroid impact, but we have no evidence of any kind to give us any hints as to how on Earth these amazing creatures became extinct.  After this great tragedy, the Mesozoic Era rose, better known as The Time of Dinosaurs.