Continuity mistake: Throughout the movie, the size comparisons between the 5 kids keeps changing. Example: During the scene when Cera and Littlefoot are popping bubbles in the pond, Littlefoot is twice the size of Cera, but just before they started popping the bubbles, they were closer in size.
Continuity mistake: In the scene in which they all spend the night in Sharp Tooth's footprint, when they fall asleep, they are under a large tree, but when they awake, as Sharp Tooth is coming, the tree has disappeared. (00:48:00)
Continuity mistake: Sharptooth's eyes are red, but when it wakes up from the coma one of them is yellow.