Manned missions into the cosmos were always going to be a dicey affair, given the multitudes of things we don't know (and the fact that NASA's funding is a fraction of what it should be). But if there are actually hyper-intelligent dinosaurs waiting for us, maybe we should just stay home.
The theory is, the amino acids that formed the building blocks of life came to Earth on an asteroid some 4 billion years ago. And given that those acids came from somewhere else, they also exist somewhere else. Further, if there are an infinite amount of planets in the universe, one must exist with the same conditions that made Earth the perfect incubator. Still further, if life took the same path—again, infinite planets means that everything is possible—then that planet will have dinosaurs.
And, if an asteroid didn't wipe out those dinosaurs the way it happened on Earth, mammals would've never had the chance to evolve and dinosaurs would've remained the dominant lifeform. As scientist Ronald Breslow discusses in a new study that appears in the Journal of the American Chemical Society:
"Showing that it could have happened this way is not the same as showing that it did. ... [But] an implication from this work is that elsewhere in the universe there could be life forms based on D-amino acids and L-sugars. Such life forms could well be advanced versions of dinosaurs, if mammals did not have the good fortune to have the dinosaurs wiped out by an asteroidal collision, as on Earth. We would be better off not meeting them."
All of which sounds moderately terrifying ... until you imagine a T. rex welding a tank with those wee tiny arms.