Gosh yes, imagine a species transporting creatures that could potentially predate upon them across the ocean. When has that ever happened?
You are comparing a species and a civilization that has every weapon imaginable, which will leave a thousand or a million times as much of a footprint to archaeologists from the next tens of millions of years as the dinosaurs ever did, with a species who (in your mind) did nothing more than a few boats.
Lions and big predators pose almost no danger to humans. Small dinosaurs were in permanent danger from the larger ones. There is a reason why archaeologists are now finding a few Deinonychus in very limited locations on Earth, but future archaeologists will find humans everywhere. Humans are so powerful that they do not have any predators of importance, while Deinonychi were hunted by other dinosaurs and suffered from lots of dangers, to the point where they never were an important percentage of the living dinosaurs.
Other carnivore dinosaurs not just "could potentially predate upon them", other dinosaurs did predate on them.