A team of researchers found the oldest known vocal organ of a bird in Antarctica’s Vega Island. The Mesazoic era vocal organ, known as syrinx, demonstrates that dinosaurs did not make the same sounds as present-day birds do.

The syrinx came from a bird called Vegavis iaai that lived more than 66 million years ago during the age of dinosaurs. According to the study published in Nature on Oct. 12, the organ could have originated late in the evolution of birds.

“This finding helps explain why no such organ has been preserved in a nonbird dinosaur or crocodile relative,” says lead researcher Julia Clarke, a palaeontologist at The University of Texas at Austin Jackson School of Geosciences. “This is another important step to figuring out what dinosaurs sounded like as well as giving us insight into the evolution of birds.”

The bird’s fossil was actually discovered by the Argentine Antarctic Institute research team in 1992. However, it was only in 2013 that the syrinx, which is made of stiff cartilage rings, was found.

The asymmetrical syrinx supports soft tissues that vibrate to emit complex sounds from modern birds. Based on the team’s analysis, the organ’s shape shows that the bird made honking noises through the right and left parts of the syrinx.

Further research is still needed. The researchers tried to look for a syrinx in other dinosaur fossils but they did not find any. They also studied the syrinxes of other birds.

Nevertheless, the study’s co-author Franz Goller, a physiologist at the University of Utah, believes that the organ can bring more understanding about the sound early birds made. Now, the research team is working with engineers to model sound-producing organs to study the sounds up close.

In July this year, Clarke and other researchers also revealed that dinosaurs made closed-mouth vocalizations, which are similar to the booms ostriches make. This did not require a syrinx.