Created by Brawndo
The Saurian race appeared on Earth uninvited, claiming that they were the original sapient inhabitants of our world. The truth is that while they did live here at one time, they did not originate on Earth; their species has been marauding across galaxies for eons, moving from one planet to the next as they use them up or outlive them. They planned on staying on Earth for a very long time.
Their entire society fled into space to escape the asteroid that destroyed the dinosaurs, but a warp drive malfunction trapped them in an inert bubble of spacetime for the billions of intervening years.
The bubble has been slowly collapsing over the last couple of decades, releasing elements of the Saurian army in dribs and drabs. To the Saurians, no time has passed; one instant, they were fleeing the solar system and the next, their planet was nearly unrecognizable and peopled with _mammals._Operatives disguised as humans have been infiltrating human society to see what they're up against; one such posing as super-science hero Dr. Tachyon.
The Saurians are still slowly streaming out of the spacetime bubble, and working toward preparing Earth for the remainder of the forces to emerge, even as Doctor Tachyon works to accelerate the collapse of the bubble.