About 500 million years ago in the Ordovician period life forms diversified dramatically and gave life to many marine forms familiar today. The fossil record of his period is amazingly intact in the Great Basin of California,Utah, and Nevada and affords an almost unpredicted opportunity to learn about the conditions that favorite innovation in biodiversity.

The Ordovician period lasted almost 45 million years, beginning 488.3 million years ago and ending 443.7 million years ago. During this period, the area north of the tropics was almost entirely ocean, and most of the worlds land was collected into the southern supercontinent Gondwana. Throughout the Ordovician, Gondwana shifted towards the South Pole and much of it was submerged underwater.

How long the period lasted