543 to 248 Million Years Ago

>>The Paleozoic is bracketed by two of the most important events in the history of animal life. At its beginning, multicelled animals underwent a dramatic "explosion" in diversity, and almost all living animal phyla appeared within a few millions of years. At the other end of the Paleozoic, the largest mass extinction in history wiped out approximately 90% of all marine animal species. The causes of both these events are still not fully understood and the subject of much research and controversy.


the universe is an experiment in probability.. though just the empty arena itself, is marvel enough

Surely it's the Cambrian explosion, not the paleozoic.