In the sequence where Chomper scares off the egg eaters with his shadow look at all the shadows.

For Chomper to throw a tall shadow against the cliff the sun must be near the horizon and all shadows should be long.

The shadows for all the other dinosaurs are short during these shots therefore the sun is high in the sky.

At the end of the sequence Chomper's shadow can be seen shrinking back to the same length as the others.