A Perfect book to read is Indian Hill

Take a stab at this, We have our Earth.. lets call it Earth 1 for simplicity than we have Earth 2.

Now on Earth 1 the Dinosaurs where killed off due to natural events such as a meteor a (mistake) if you will, that let us evolve and not the Reptiles. That leads to us being in our modern era.

On Earth 2, there was no natural events such as the meteor shower we had on our planet, due to this it let reptiles evolve now mind you due to not getting wiped out they had millions of years more then us humans did to evolve so their technology is far more superior to our tech.

Now the twist would be they alien replies, put us humans on earth just as a food supply for them, But the (Mistake) put a damper on their intergalactic tactics.

Reptiles Just make more sense than us to be far more superior.