Flexi Says: Wegener found fossil evidence that the continents were once joined. The same type of plant and animal fossils are found on continents that are now widely separated. Wegener suggested that when the organisms were alive, the lands were joined and the organisms were living side-by-side. Wegener found rocks of the same type and age on both sides of the Atlantic Ocean. He thought that it could not be a coincidence! He said that the rocks must have formed side by side. These rocks then drifted apart on separate continents. Wegener also matched up mountain ranges across the Atlantic Ocean. The Appalachian Mountains were just like mountain ranges in eastern Greenland, Ireland, Great Britain, and Norway. Wegener concluded that they formed as a single mountain range. This mountain range broke apart as the continents split up. The mountain range separated as the continents drifted.