Extinction
Either due to war or being assimilated into the brood lairs of Sun dragons, Moon Dragons eventually disappeared from this world.
Only accounts from this Era exist within the Queen of Air dragons lair. According to them, Sun dragons, their predecessors caught and captured Moon Dragons females, killed off their mates and decimated their entire species. The resulting hybrids hatched from the union between Sun dragons and Moon dragons eventually came to be today's Mud dragons, Fire dragons, Water dragons and Jungle dragons. It is difficult to believe such a great variance of dragons came to be from hybrids of the two proto draconic species, but one part of the story is definitely true. No Moon Dragons have been seen on the continent ever since.