@Qwertise #1
I think it is rather safe to say that we are the most intelligent species on earth today (unless there are some hyper intelligent beings hiding at the bottom of the oceans where we haven't explored yet, though I find that very unlikely, try discovering or working with electricity underwater, let's see how that goes for you).
As for the past: The dinosaurs in fact "ruled" the earth. But this mainly means that they were a set of dominant species, able to survive nearly everywhere on the globe. It does not mean that they must have been very intelligent. Just fit enough to survive. They didn't "rule" in the human sense, they didn't form societies as far as we know. Technically we can't know for sure, but I'm quite convinced that the advent of human like intelligence was a singular event in geological history. For earth, I think we are the first. That's simply because it seems so unlikely for intelligent life to emerge, since we've seen it with no other species except our own (so far). And also because there's no sufficient evidence (well, we shouldn't expect any) to support the proposition that there might have been societies on earth before humans.
As for the rest of the universe: I'm quite convinced that there are other intelligent beings out there, far away. Intelligent life might be very rare, but given the enormous size of the universe, it seems likely that there are (and were) others. We are probably not the first and probably not the last. And it's somewhat doubtful we'll ever meet extraterrestrial intelligent beings (maybe we'll be able to communicate with them though). But finding evidence indicating extraterrestrial (primitive) life? This might happen within our lifetimes (e.g. through the James-Webb-Space-Telescope). Interesting questions, interesting time to be alive!
