The specific continents that fit together most noticeably are Africa and South America, which form a clear match along their western coastlines. The coastlines of these two continents have a distinctive jigsaw puzzle-like fit, with their shapes appearing to interlock. This observation led to the development of the theory of continental drift and plate tectonics, which states that the Earth's continents were once part of a single supercontinent called Pangaea and have since moved apart over millions of years.
