Corrected entry: Just after Littlefoot and the others get stuck in the tar, we see Cera being chased by a group of Pachycephalosaurus. They act like they want to eat Cera, which is the error because the Pachycephalosaurus was an herbivore, not a carnivore.
Corrected entry: Ducky was the first of the eggs to hatch, yet later it was stated that Cera was the oldest of all them, and Ducky was youngest.
Correction: Age is probably done by when the eggs were laid, not when they hatched.
Correction: The pachycephalosauruses may be simply driving off a stranger from their territory, since they are not attempting to bite or maul her as much as just intimidate and headbutt her.