what's pangaea?

As the following diagram shows, Earth was once a single land mass called Pangaea. Imagine a ball exploding and breaking into pieces. Now, imagine those pieces as our present continents separated by oceans. The fit between South America and Africa is very clear indeed, but the other continents need a lot more imagination because 'continental drift' - constant movement of the sea-bed plates - has pushed some land masses far away from their original placement.

India, for instance, is now a sub-continent having jammed into Asia; and what is now Australia and the Antarctica once comprised the great southern continent of Gondwanaland. In about 40 million years it is expected that Australia will similarly collide with South-East Asia.