Catastrophic change

Continents break up, move away and rejoin again. Such unsteady phenomenon on the Earth has been happening for ages. Recently, scientists have predicted that in 50 million years from now, the continents that broke away from one large landmass and formed Asia, Africa, Europe and Americas, would merge back. According to them, the last time a break-up occurred was 200 million years ago. But what happened before that, how many times the