Pangea represents the state where all living beings where sharing one land (although a pretty big one). As tectonic plates started to drift apart, living beings start to become isolated. This happens through millions of years. So, when we look at fossils of the coasts, an intersting patter emerge, fossils in the Brazilian/Argentine coast are pretty similar to those encounter in the african atlantic coast. This could be explain if we consider this continental pieces as one, in Pangea times, and as tectonic plates started to drift apart, this was the split point. So, living organisms in this split point (south america atlantic coast --- african atlantic coast are pretty similar.