Plate tectonics is the theory that Earth's outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core. The plates act like a hard and rigid shell compared to Earth's mantle. This strong outer layer is called the lithosphere (Crust, upper most solid mantle).
Evidence that the plate tectonic were connected
The evidence of flora & fauna matched as the continental were connected was proved by Wegener who realised that fossil plants and animals such as mesosaurs and freshwater reptile which was only found in South America and Africa, could be found on many continents.Rocks on either side of the Atlantic Ocean also matched up like puzzle pieces.
The Appalachian Mountains (United States) and Caledonian Mountains (Scotland) fit together, so does the Karroo strata in South Africa and Santa Catarina rocks in Brazil. Wegener proposed that all of the plate tectonics once fit together like a puzzle piece, all of the pieces seems to fit together when you piece it together. This whole continent was named Pangaea.
Continental drift 3.3 billion