Researchers Explain Story Of Ancient Invasive Species In North America Brett Smith for redOrbit.com - Your Universe Online A new study from researchers at Ohio State University tells the story of an invasion and domination that took place around 450 million years ago in North America. During the Ordovician period , a dramatic ecological shift occurred near what are now the Appalachian Mountains, as represented in the fossil record. In the study , which was ...
Aug. 22, 2013 - redOrbit