[N] 2006 Duck-billed crests not used for sense or smell
The January (2006) issue of the journal Paleobiology presents a paper of PhD, David Evans of the Department of Zoology on the University of Toronto at Mississauga concerning his research of lambeosaurid crests. Evans concluded in contradiction to what many scientists suspected that the massive but hollow crests had nothing to do with the sense of smell. Using the first-ever cast of the lambeosaurid brain cavity that was reconstructed using well-preserved fragments of fossilized bone, Evans ruled out one historically popular theory: that the crests evolved to increase the animal’s sense of smell.
His research showed no indication that the nerves curled upwards into the crest, as would be expect if the crest was used for the sense of smell. The brain changed very little from their non-crested dinosaur ancestors, and the primary region of the sense of smell was located right in front of the eyes as it is in birds, crocodiles, mammals and basically all four-legged animals. The outcome of his research supports the currently popular theories that the crests were used to create resonant sounds to attract mates or warn of predators, or that they were used for visual display in mate selection or species recognition, similar to feather crests in some birds.