In some scenes, there's no blood present on the jaws of eating dinosaurs, yet in others, there is.
Tylosaurus is shown to be several times the size of a Tyrannosaurus, with One-Eye fitting into its mouth. This is an immense overestimate of its size, as in reality, Tylosaurus wasn't much bigger than Tyrannosaurus.
The pterosaurs are falsely depicted as scaly, when it has been known for decades that they had a thin coating of fuzz.
Pterosaurs in the movie fold their wings from the sides when on the ground, but this would have been anatomically impossible. They should be folding their wings from the back to the front.
Many carnivorous dinosaurs hold their hands in an incorrect position, even though studies conducted years prior to this movie have shown that they had a limited range of movement and their palms were permanently stuck facing inward.
The ancient mammal Repenomamus are presented as harmless, rodent-like creatures, but in reality, they were surprisingly large and possibly very fierce, known to have eaten small dinosaurs.
Very few of the depicted animals lived in the time this movie takes place in.