Stegosaurus and Triceratops were hunting for food but bumped into a crying Tyrannosaurus Rex. Ankylosaurus heard Stegosaurus scream and came to fight the Tyrannosaurus Rex, who had whacked a Pteradactyl with his tail. Ankylosaurus then killed the Tyrannosaurus Rex with one hit from its tail, allowing Stegosaurus and Triceratops to resume searching for food without threat.