Some Dinosaurs May Have Reared Back and ... Cooed

Specialized sounds birds make with mouths closed may have been made by dinosaurs too.

Published On 07/12/2016
5:07 PM EDT
An X-ray image shows a ring dove (Streptopelia risoria) producing cooing sounds with a closed mouth. Birds push air into an esophageal pouch to make the sounds. Credit: TOBIAS RIEDE