During the Paleozoic Era there was explosion of life in the oceans. Most of the continents were covered in warm, shallow seas. What is true about life on Earth at this time?

This event may have caused the climate changes that led to mass extinction event

The Appalachian Mtns were formed during this time

Invertebrates were dominate

Fish emerged

Fish led to the arrival of amphibians

At the end if the Paleozoic, the largest mass extinction in history wiped out approximately 90% all marine animal species and 70% of land animals.