Quote Originally Posted by rabek View Post
I showed some friends what I'd done thus far (pictured above) and it was noted that the landmasses kind of end to nowhere... rather than the caps/bands of land you see at the top/bottom of a map of Earth.
There's no reason to think that this is the map of the whole planet! Maybe there's some more land in there that we can't see on this image? And of course not every planet needs to have land or ice covering the poles; after all, for much of our own planet's history it was too warm for polar ice caps, and we may soon be in such a climate again. That said, you do look like you've cut off the ends of this projection.

I highly suggest you jump into the worldbuilding tutorials in the Tutorials section of the board. In particular you're going to want to pay attention to anything about tectonics or climate -- the fact that you've got deserts in the extreme south but not the extreme north suggests that the continents are pretty non-uniformly distributed from north to south. I also suggest the climate maps at scotese.com, since you make particular reference to the breakup of supercontinents. Try the late Cretaceous.