Smithsonian Magazine has a story about a new dinosaur that gives us clues on how dinosaurs sounded. Pulaosaurus qinglong lived about 163 million years ago in what is now Qinglong, a Chinese county in Hebei Province. The nearly complete animal was described in a paper in the journal PeerJ.  The fossil includes its bony vocal organs, which are rarely preserved.  These organs are similar to the vocal anatomy of modern birds.  

Today’s reptiles, in general, make sound using a larynx that contains cartilage. But modern birds’ vocal organ, called the syrinx, has both bone and cartilage components, allowing them to make complex sounds. But these tiny bones are extremely hard to preserve in the fossil record, leaving dinosaurs’ vocal anatomy largely a mystery.

The newly discovered Pulaosaurus is only the second known non-avian dinosaur with a bony voice box preserved—the first, an ankylosaur called Pinacosaurus grangeri, was described by scientists in 2023. While the bony vocal organ of Pinacosaurus was not exactly like the syrinx of extant birds, its large and mobile anatomy may have nevertheless allowed the iconic armored dinosaur to make bird-like noises.

Xing Xu, a paleontologist at the Chinese Academy of Sciences and a co-author of the paper, tells the New York Times’ Asher Elbein that Pulaosaurus may have had a similar, though less developed, vocal organ arrangement.