A really long time ago, there was a huge landmass named Pangea. Pangea broke apart into our present day continents. Scientist Alfred Wagner noticed that our continents could fit next together, like in a puzzle, that could form a supercontinent. That was when the idea of Pangea first existed. To this day, evidence supports the huge landmass's existence, such as same type of fossils on different continents. There were even fossils from different continents on Antarctica. So the short answer to your question is Pangea.