Chunky the "Macawnivore" started out as a bit of a joke in the art department. Artist Leighton Hickman was bored with the drab colors intended for creatures in the desert scenes, and painted the saber-tooth tiger with bright "parrot" colors. The filmmakers liked the look for the "Macawnivore" so much that it made it to the final film.
The direction the sun sets changes from the beginning of the movie to the end. Initially the sun sets in the direction of the Croods' hunting grounds (two knuckle warning). But, they spend the majority of the movie heading towards a mountain in the opposite direction, which is where the sun sets for the remainder of the film.