Learn more about the time period that took place 488 ... group-living animals that built coral-like structures. Ordovician reefs were also home to large sea lilies, relatives of sea stars.

The group includes the more famous animals such as whale sharks and great whites ... ancestors are a few scales dating to 450 million years ago, during the Late Ordovician Period. “Shark-like scales ...

The Paleozoic era's Silurian period saw animals and plants finally emerge on land. But first there was a period of biological regrouping following the disastrous climax to the Ordovician.