Once again, allow me to bore you with my Martian War story.
When we colonize Mars, after generations of great business, a bunch of xenophobic assholes decide that Mars is "manipulating Earth's economy." So they go on several protests and eventually gain the support of billions of Terrans (it's what they call the humans on Earth, because Terran, from Terra, sounds cooler than Earthling to them) and are against the Martians.
So here, as the author I'm showing how there can never be alliance unless there is a real enemy and threat. The humans finally resolve their racial and ethnic differences because racism has been dead for century and only appears in textbooks that it's time for a united earth, under the leadership of the UN, to fight the Martians.
From there I explain how the "planetary" tension between Terra and Mars grows until a war breaks out, but that's another story.
So basically I said that eventually we could very-well become just Earthlings or Terrans or Humans, but that it'll most likely come with the advent of an energetic space program. NOT NASA, but maybe like the International Space Endeavor.
Also, gem, as far as modern findings say, humans weren't around when Pangaea existed. Sorry.