This would be a gene to go with the volcanic island suggested here: It would be based off of the Parasaurolophus' head crest. It would give +1 smelling, +2 browsing and + voice reach. The browsing ability can be found here:  The voice reach would be the same as when a nicheling stands on a tree stump or up a tree, only it would be available from any space (except maybe underwater?) It wouldn't have a mane. Instead the females would have short crests like Parasaurolophus cyrtocri