Well, what was Pangea?

http://volcano.und.nodak.edu/vwdocs/vwlessons/lessons/Pangea/Pangea4.html Heres the link to help explain this to you...

Just before the days of the dinosaurs the Earth's continents were all connected into one huge landmass called Pangaea . This huge supercontinent was surrounded by one gigantic ocean called Panthalassa

Here's a great site about it.

http://www.scotese.com/earth.htm

Click each link on the left.