What did Alfred Wegener study about Pangaea?

Alfred Wegener was the first to propose the concept of Pangaea, that all the continents were once one super continent. He noticed mountain ranges that seemed to continue past the ocean. He noticed that there were the same species of fossils on two different continents, of animals that would have had no way to travel over oceans. With these and other facts, he concluded that the continents must have at one time been connected to each other, and had moved away from each other, by a process he called Plate Tectonics.