 We're back to an intelligent descendant of the dinosaurs, and I kind of explored this idea in a science fiction novel, a horror novel I did, called Vampire. They might be the remains of a very ancient human civilization that survived some catastrophic event and may remain hidden from us. And finally, they suggest some sort of supernatural beings, maybe fairies or elves, that are hidden from us, which, given our warlike nature, can't be seen as much of a surprise.