Beak evolution in some dinosaurs has been attributed to diet, rather than flight.
A study has examined the skull of Erlikosaurus andrewsi, a 3-4m (10-13ft) large herbivorous dinosaur called a therizinosaur which lived during the Cretaceous Period in what is now Mongolia. Part of its snout was covered by a keratinous beak.
Beaks evolved several times during the transition from dinosaurs to modern birds. It has classically been assumed that beaks evolved to replace teeth and thus save weight, as a requirement for the evolution of flight.
This new study reveals that keratinous beaks played an important role in stabilising the skeletal structure during feeding, making the skull less susceptible to bending and deformation.Read more at University of Bristol