A review of the pilot script here.

Note that they do try to deal with the time-travel paradox, using the "branching timeline" gimmick similar to the one in "Back to the Future." In short, the future world is untouched if someone in the past steps on a butterfly, and the colony in the past will have a future completely different than what would have happened otherwise.

Personally, I don't think humans would find dinosaurs that hard to deal with. The largest late Jurassic meat-eater was Allosaurus. Our own ancestors across the planet dealt with giant cats, giant carnivorous birds, giant lizards (not dinosaurs), giant bears, and a lot of other nasties. They had no guns, tanks, or advanced weapons. The scorecard by the beginning of agricultural civilization showed a lot of human beings all over the world and damn few remaining carnivorous nasties.