The Good Dinosaur will be out in theaters in 2016. What we know from the trailers is that it will take place in a time way before Brave. The Earth is a land of the dinosaurs. We also see a human child who behaves sort of like an animal. The dinosaurs are quite intelligent, even more than the humans of that time. How do all of these facts fit into the Pixar Theory? Let's take a look...
In Cars 2, it has been hinted that dinosaurs went extinct.
"Fossils, as in dead dinosaurs. And we all know what happened to them." -Sir Axlerod
One theory suggests that the humans eventually killed the dinosaurs for food or as a threat after gaining intelligence. This is the reason why we don't see any dinosaurs in other movies. We can't really say whether the humans gained intellect from the dinosaurs or by themselves.
Another theory is that Boo wanted to revive understanding in the animals and thus started her experimentation on animals. As the first theory suggests, the humans wipe out an entire species of animals. The animals became upset because of the treatment of the humans towards them and thus began the conflict between humans and animals.
The movie may also have something to do with Dinoco- the oil company/gas station seen in Toy Story, and the oil company that sponsors the Piston Cup in Cars. However, nothing can be said for sure until the movie comes out.