Dinosaurs disappeared 65 million years ago, so we don't really know what they sounded like. Of course, there are many movies with dinosaurs making all kinds of roars, screeches and screams. However, these noises are just guesses that movie directors make about how dinosaurs sounded. A new discovery has given scientists a better idea of the kinds of sounds dinosaurs made. The scientists examined a rare fossil. It was from a spiky, armoured dinosaur called an ankylosaur. The fossil is around 78 million years old. It includes a record of the ankylosaur's voice box. It is the world's oldest fossil of a voice box. The scientists believe the shape of the creature's voice box means it probably made bird-like sounds.

The research was led by Professor Junki Yoshida, a dinosaur researcher at the Fukushima Museum in Japan. Dr Yoshida did many tests on the shape of the fossilized voice box. He compared it with the voice box of dozens of birds, crocodiles, lizards and turtles. They now have a good idea of what the muscles around the voice box looked like. The muscles controlled the windpipe and sounds of the voice box. Yoshida's research may mean that movies like Jurassic Park got it wrong. Millions of years ago, the Tyrannosaurus rex probably made more of a tweeting sound, like a bird. Hollywood may have to change its scary roars and growls in future dinosaur films to a tweet-tweet sound.