Annihilation by Aliens

...So any civilization that’s paranoid about competition has had plenty of time to come to Earth and wipe us out. That hasn’t happened.

Newsweek

Well, I'm not quite sure they can say that in all certainty! It occurs to me - it is possible that an alien lifeform may have taken one look at the dinosaurs, and decided they needed to use a tractor beam to fling an asteroid at the planet and wipe everything out!