Ordovician Create Talk0 Category page This page needs content. You can help by adding a sentence or a photo! Add to this page! Ordovician-Silurian extinction events “The Ordovician period is the second of the six (seven in North America) periods of the... Ordovician Pages in category "Ordovician" The following 2 pages are in this category, out of 2 total. OrdovicianO Ordovician-Silurian extinction events Retrieved from "http://paleontology.wikia.com/wiki/Category:Ordovician"