How much of that topology is speculation? I get that geologists can estimate the latitude of a location at a given time because of climate and chemical signals, plus some contemporary tectonic shift vectors. I don't get how paleomagnetism is reliable when the magnetic field can wander in the timespan of some thousand years. I'd expect the resulting equations to yield a multitude of solutions or even be unsolvable.
Not an expert at all but I would expect there to be shared fossil record on coasts that used to be joined up until they are no longer joined. So probably based on that data we can make good estimates of time periods and joined up coastlines.
