<em><u>The Silurian Period was a third period of the Paleozoic Era that occurred from 443 million to 416 million years ago. This period occurred after the Ordovician Period and was then followed by the Devonian Period.</u></em>
Silurian period is the period that many biologically significant events took place. There was a widespread radiations of crinoids, continued priliferation and expansion of the brachiopods and also the oldest known fossils of coral reefs.
