Dinosaurs disappeared 65 million years ago, so we don't really know what they sounded . Of course, there are many movies with dinosaurs making all kinds  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  the kinds of sounds dinosaurs made. The scientists examined a rare fossil. It was  a spiky, armoured dinosaur called an ankylosaur. The fossil is  78 million years old. It includes a record  the ankylosaur's voice box. It is the world's oldest fossil  a voice box. The scientists believe the shape  the creature's voice box means it probably made bird-like sounds.
The research was led  Professor Junki Yoshida, a dinosaur researcher  the Fukushima Museum in Japan. Dr Yoshida did many tests  the shape of the fossilized voice box. He compared it  the voice box of dozens of birds, crocodiles, lizards and turtles. They now have a good idea  what the muscles around the voice box looked . The muscles controlled the windpipe and sounds  the voice box. Yoshida's research may mean that movies  Jurassic Park got it wrong. Millions of years ago, the Tyrannosaurus rex probably made more  a tweeting sound,  a bird. Hollywood may have to change its scary roars and growls  future dinosaur films  a tweet-tweet sound.