I was watching Life After People on the History Channel a few hours ago. As I watched it, I came up with a new theory about those Rainbow Faces from LBT 7. It's complex, but interesting.
Basically, this theory states that the Rainbow Faces, as a race, are not aliens but were once just like the rest of the dinosaurs on Earth. At one time, they became so intelligent, they began to develop civilization. Eventually, the dinosaur world resembles the human world, in place of humans are the Rainbow Faces. They eventually realize that by building civilization, they are severely damaging the planet. It soon becomes clear that the only solution is to end civilization. Instead of dieing off, they choose to leave the planet and become citizens of space. Nearly everything they leave behind disappears after only a few hundred years. Some Rainbow Faces chose to stay behind and abandoned civilization, explaining their appearances in LBT 9 and 11. Many dinosaurs become determined to not end up like the Rainbow Faces, so they limit their area of thought.
Like I said, this theory is very complex, but quite interesting. This theory might even inspire some fanfiction. What do you think of this theory?