Yes, nice image thx for posting and I agree with subsequent comments. It looks like they have put a grey region as a line between all the basins but I was under the impression that water at the ridge between two basins would fall to one or other sea. I think seeing the rivers on top of those maps would indeed fill in the extra info were looking for. Certainly a river flowing into a desert will dry up, that happens a lot on savanna plains. It evaporates before it reaches the sea. If the climate were more stable and less seasonal then it would probably cut a channel and make a river but it does not get a chance.