One of the prehistoric animals which serve as not-huntable background creatures is the Dimetrodon (you know, that big lizard with the fin on it's back) which lived in the premian period. In the game, he shown as a peaceful herbivore, but he is actually a meat-eater, and feeding in small animals.
Another mistake of Carnivores 2 is about the Brachiosaurus, one of the largest dinosaurs ever. He's shown in the game walking in swamps, and diving to eat soft water vegetation. But the Brachiosaurus is a land feeder, and eats leaves from the treetops.Information also contributed by