Longer ago then you will get away with knowing, the world wanted to see dinosaurs and dragons in the same place.
Today we give a scenario as to what would happen if they where in the land before time. But to understand this, we would have to remember the difference between a dragon and a dinosaur. In other words, I am not going to animalize the dragons, I am going to go according to the legends.
Now, dragons are not animals, they are intelligent beings. No not like humans, don't be disrespectful. But like humans dragons could talk, think, and ponder. They are people. A mythological race like elves orcs and goblins.
Does this mean they would be able to talk to little foot you wonder. The answer is no, not anymore then you could talk to a cow. Brace your self, this is going to be very dark.
What would dragons their for see dinosaurs as? Prey? Predator? The answer is far worse, they would see the dinosaurs, as animals. Allow me to explain why that is worse. See, the herbivores of the great valley.... wait hold on, I am getting ahead of my self. Lets start before that.
Being both intelligent and able to breath fire dragons would have the supreme advantage. It has been scientifically proven that a sentient species who has just begun do not need to stay in the stone age for over a decade. Dragons would be swift, swift as a fighter plane in ww2, strong enough to keep up with half or more then the dinosaurs, survival would be to easy to stay stone age for very long. They would see volcanos and in that moment be inspired to craft with metal and glass, creating implements such as the javelin which they could use as a projectile to conserve their fire for a more strategic time to use it.
Now can I mention what effects it would have on the great valley?
Yes.
Ok.
The great valley would be easy to find, as it would be fertile, perfect for plants to grow, herbivores to eat them. In less then an hour the herbivores would be conquered, in the opinion of the audience and fan base they would be enslaved, they wouldn't stand a chance, as they would be seen as animals.
Does this mean it is all over for our favorite characters? No, not at all, this is just the beginning of the beginning of the beginning.
Animals such as duckies mother would be favorite, as having so many children means having so much more live stalk, the more the better, it is only once she is to old to lay eggs that she would be eaten. In fact, practically anyone who is young stands a better chance, especially little foot and his friends. Though males would be slightly less necessary as they would only require enough to make sure the females eggs hatch.
However unlike humans dragons have something called honor, they would see cowards such as wild arms and emedeantly kill him out of disgust for his existence. (your welcome.)
So they see herbivores as their live stalk, how then do they see carnivores? Their are 2 scenarios, they will either see the carnivores as a nussince, which could lead to events such as the wolf genocide of yellow stone but with raptors, or, they will find use for them, making them pets, for example Chomper may turn into the family dog. (I think we know which one gets the vote.)
Food is not all they would see the dinosaurs of the great valley as, their skin for example would become leather armor, light weight for flight to not be made slower, enough to stop a sword or spear in clan to clan wars. They would be put to work with yoks, expanding the great valley by planting fertilizing and watering out side the great valley to make it bigger, greater, so more herbivores can eat, breeding more herbivores to feed them selves, their population rises.
Rather then enjoyed by the great valley dinos the cave of shimmering stones will turn into a mine.
Rather then the great valley dinos falling into tar the tar pits will be fenced off to protect them, the tar harvested to put stone together with stone, building store houses and watch towers.
Ships would be built merely as a floating storage to make fishing easier, dragon ships would be the worlds first air craft carriers.
Then, would come war.
With the growth of power comes the greed for more power, a clans lord or chieftain will want more people to rule, being smart, strong, and he will have victory. At the end of this war the clans of the areas seen in the movie have been united, civilization has begun. End of chapter one.