3. Sarcosuchus
Speaking of crocodiles, the Sarcosuchus looked like a modern-day croc.
Sarcosuchus, meaning 'Flesh Crocodile', lived 112 million years ago. These reptiles from the early Cretaceous period were twice the size of the largest saltwater crocs today, and could weigh 8 metric tons. They were so huge that even dinosaurs could become an easy prey for them.