What if all the continents fit together perfectly?

In a world where the continents fit together perfectly, without exposed sea floor, how does that change the Earth? Imagine the Atlantic Ocean simply getting smaller with no oceanic or sea floor in the way, just a large land bridge that connects two adjacent continents. I'm not looking for a Pangaea or Gondwana, just simply all continents juxtaposed and the Atlantic Ocean shrinks to essentially nothing.