We've killed off everything big except for a few. We've killed off lots of the small (passenger pigeon, dodo, etc).
We're the meanest, nastiest species in the solar system.
Venus is a burning wreck. Mars is a freezer.
We have opposable thumbs, gunpowder, the lever, and nukes.
Hell, we have carnivores for pets. Dogs, catz, ferrets etc...
I've killed and eaten an alligator that weighed twice what I do (not at one sitting).
I'm not seeing reptiles winning.
When we run out of other stuff to kill, we kill each other, just for practice.
/johnny
Just wait until it gets cold and they den up, then gas them like we do rattlers.