I think you are referring to Pangaea. Pangaea was the gigantic single continent that broke into the continents we have today. See the Related Link below for the Wikipedia entry.
The land mass that made up all the continents is called Pangaea. It was a supercontinent that existed millions of years ago before the continents drifted apart to their current positions.
What do you mean with "land mass"? Neptune doesn't have continents like Earth. It is a gas giant - made up mainly of gas.
What is the continents of asia are really parts of the same land mass?
Pangea refers to one land mass made up of all the modern continents.
Antarctica has the least land mass of all the continents.
All the continents used to be a part of one land mass and separated. This supercontinent was Pangea.
Ancient Rome did not control any single continent; it had territories and provinces on all the continents except Australia, but did not control the entire land mass.
The land mass was called Pangaea before the continents split into the continents we know today. Pangaea was a supercontinent that existed about 335 million years ago.
Asia is the biggest in land mass.
The inference is that both continents were once one single land-mass.
Asia and Africa.
Europe and Asia