(Redo! Cuz I beefed something up!) Why not visit the Ordovician period? The Ordovician period began about 486 mya, at the end of the Cambrian. While the Cambrian critters are a hard show to follow, fossil evidence tells us that life on earth diversified even more than during the cambrian explosion! Unfortunately, it all came crashing down, as the end of Ordovician is marked by one of the first of the 5 big mass extinctions. The event was even more deadly than the one that killed non-avian dinosa