We've spotted strong evidence for a supermassive black hole (of the kind that tend to sit in the center of galaxies like ours, which contains Sagittarius A*) in an extremely distant galaxy - one that formed within the first half-billion or so years of the galaxy.
What makes this important is that we've seen increasing evidence that supermassive black holes (SMBHs) exist earlier than we've expect if they were born from the deaths of massive stars and slowly accumulating mass in the way "typical" black holes today do.
This black hole is apparently very good evidence that these early SMBHs did not form from star collapse but may have formed from gas clouds collapsing directly into black holes. Finding support for this alternative model could lead us to new possibilities in physics.