This evidence can suggest that the continents of South America and Africa were once combined (Pangea). The continents were all combined, then the continents spread apart, through plate tectonics. I hope this helps!
Since the dinosaur could not swim or fly, the only method that they can move from one continent to another is if they migrated by land.
From this fact, we can infer that in the past the lands on top of the world were connected (without sea that separate them). These lands than gradually move away form one another due to some sort of geological process over time.
Madison worries that the small body of legislators may not be as knowledgeable about local issues as they need to be if the area they represent becomes larger