To try to derive what a dinosaur sounds like to have uttered, Dr. Yoshida’s team also looked at the evolutionary relatives of those Cretaceous creatures, including birds and the dinosaurs’ close relatives – crocodiles.
“They kind of bracket the range of sounds that we might expect,” said Victoria Arbor, a paleontologist at the Royal BC Museum in Victoria, Canada, who was not involved in the new study.
The crocodile’s vocal repertoire includes deep rattling and hissing. “The assumption that dinosaurs made crocodile-like sounds is completely safe,” she said. “This is the basic anatomy they will work with. Birds then developed these additional ways of producing sounds as they could modulate the sounds coming out of their throats in a more subtle way. “
Birds and reptiles have very different ways of producing sounds using the organs that surround the bronchi and lungs. In extinct and living relatives of the crocodile, the larynx produces sound. Birds have a different organ, called the syrinx, which is located near their lungs to produce sound. They also have another organ, located near their mouth, to alter those sounds, which allows some birds to create elaborate songs.