The Largest Dinosaurs had Embellished Heads
Published: 29th Sep 2016
The biggest carnivorous theropod dinosaurs, such as T rex and Allosaurus, had heads with bony adornments. New research shows that theropod dinosaurs with bony crests, horns and knobs evolved to giant body sizes 20 times faster than those species lacking such ornamentation.
Most large theropods have bony bumps or crests on their heads. Paleontologists hypothesize that these served as display mechanisms allowing dinosaurs to signal to one another for mating, territory or defense purposes.
Using observational data and computer modeling, the researchers found that for theropods weighing under 36 kg bony cranial ornamentation did not evolve. Above that threshold the vast majority had some form of bony head crests.
The research also shows that theropod dinosaurs most closely related to birds – the raptors - abandoned the bony crests of their ancestors and likely used feathers for visual communication. The oonly exception to this being Oviraptor.