Okay some evidence that supports this is that they continents seem to fit together like puzzle pieces. Which is the theory of continental drift. The continents all together they call it pangea. So more detailed empirical evidence is that fossils being found in areas of several continents which leads us to believe it was one big land mass. Climate change and glaciers are another indicator. The rock/mountain types that tend to match indicating they were once connected. Coal fields also show there could have been one big coal field but was broken due to the continental drift theory