Beaver dams are walls made out of branches and mud. Their construction is nothing like that of a boat, and their integrity comes from repairs made by the beavers and, over time, the growth of plants on them.
But they are constructed to an extremely high standard, and by a relatively small animal. I bet most of us here would fail if given the same task.
The vessels you speak of have been built by humans, yes. But once again we have no evidence of any such craft existing in the time of the dinosaurs, and we don't see birds building them, either.
But we don't have any physical evidence of them existing among humans of that time either. We're totally reliant on written accounts, and even they only go so far back. Nevertheless, we posit that such boats existed long before the surviving textual evidence was written.
I should also point out that all the dinosaur nests we've found have not been similar to bird nests. They've been pits dug into the ground, some with mud piled up around the side. They're like reptile nests.
And I should point out that the oldest fossils of birds' nests we have found are (to my knowledge) only a few thousand years old. Yet no-one is suggesting that birds did not have nests before then, or that prehistoric species of bird (now extinct) did not build nests.
An intelligence that would be remarkable when compared to their EQ measurements. It would be larger mismatch than any we see in modern species.
The subject of EQ measurements has been a source of dispute in this thread and others, and I am satisfied that it does not serve as an accurate measure of intelligence. I suggest doing a few searches, as there have been extensive discussions on the subject.
In anthropology we'd say it's a civilization once people start getting into specialized jobs and the population exceeds a certain amount. At this point, the governance has to become more formalized to deal with the lack of personal ties between people. The distinction between civilizations and chiefdoms is fuzzy, though, and it's a word I believe both you and James have used.
The point is that we don't have remains of dinosaur cities and villages, no fabric that they made, writing, or any artifacts of any sort.
But we do have fossil evidence that supports the contention that they migrated over huge distances. As the geography necessitates that they would have done so by sea, the requisite technological advancement can be inferred.
As for anthropology, it goes without saying that it is by definition an anthropocentric discipline, so I feel it may be difficult to make 1:1 comparisons between our standards of civilisation and that of any other species. In any event, I am not particularly tied to the word civilisation - chiefdom would be fine, or even a term which encompassed technologically sophisticated nomads/herders.