Dr. Stephan Lautenschlager and Dr. Emily Rayfield of the University of Bristol, Dr. Perle Altangerel from the National University of Ulaanbaatar in Mongolia, and Professor Lawrence Witmer from the University of Ohio presented new evidence that dinosaur beaks evolved for eating prior to the development of flight in the Dec. 2, 2013, edition of the journal Proceedings of the National Academy of Sciences.
Keratin-covered beaks have been found in a variety of dinosaurs from the Cretaceous Period. Keratin is a fibrous structural protein that is the basic material in the beaks of modern birds.
The researchers examined the skull of Erlikosaurus andrewsi, a herbivore that lived in what is now Mongolia about 90 million years ago with high-resolution X-ray computed tomography (CT scanning) and computer simulations that examined the engineering of the dinosaur’s mouth.
The researchers found that part of the snout of Erlikosaurus andrewsi was covered with keratin. The dinosaur had lost some teeth as a result of the development of a beak compared to other herbivores that existed during the same time period. The beak provided stability to the dinosaur during biting and feeding.
Therizinosaurs like Erlikosaurus andrewsi were one of the ancestors of birds.
This new research indicates that beaks developed earlier in dinosaur evolution as a tool for eating. Beak development and loss of teeth to reduce weight as an evolutionary adaptation that led to flight may also be responsible for early beak development in dinosaurs.