The distribution of fossils plants (like glossopteris) and animals (like mesosaurus) in different continents gave an indication that there were land bridges connecting these continents. Both Glossopteris and Mesosaurus could not have traveled across the vast oceans that separate the continents today.

Another clue is that there were signs of glaciations that occurred at one particular time, striations and grooves (marks left by the glacier on the rock) indicated that these continental masses were at one point united as one continent and covered by ice.

Mountain belts on different continents seem to "match" in terms of age of formation and geological make up. Wegener's drift hypothesis also provided an alternate explanation for the formation of mountains (orogenesis).

By looking at all of this evidence Wegener had the idea that all the continents were joined together in a single "supercontinent" called Pangea, which means "all lands".