By far the most spectacular devices for sex intimidation were evolved by the duckbill dinosaurs. (life size dinosaur)Some duckbills evolved large, display tails, but in general, they reserved the most vigorous expression of their evolutionary changes for their heads. The duckbills actually divided into four different subclans evolving ever greater cranial specialization. Perhaps the most primitive display was Kritosaurus’s Roman nose. This animal had enlarged compartments around its nostrils and probably amplified its bellows and snorts through resonating nasal chambers. (animatronic dinosaur factory)A bit more complex was Saurolopbus, which combined sight with sound: A solid spike of bone jutted backward from its head and probably supported a wide flap of skin; meanwhile its nasal compartments were huge, implying great resonance when it snorted. A strictly audio approach was favored by Edmontosaurus. Its head was large and its nasal compartments comparatively huge. The most complex headgear of all among the duckbills belonged to Parasaurolophus. Each nostril started with a separate trombone-shaped tube leading from the nose up to the top of the skull, then out and behind the very long crest, a sharp Uturn and back down the crest, then down along the head, and through to the windpipe. Since each nostril had a complete tube of its own, a crest in section reveals four separate chambers two ingoing and two outgoing.
Hollow-crested duckbills are widely regarded certainly with good reason as head-hooters, amplifying and modulating their cries through their crests. All of the varied, hollow cranial ornaments were specialized outgrowths of the normal air tract. (dinosaur costume)In a primitive duckbill, like Kritosaurus, as the animal inhaled, the air would pass through the nostrils, then through a short passage in the snout, to the rear of the throat into the windpipe at the base of the tongue. A hollow-crested duckbill complicated the course the air had to follow: in through its nostrils, up and back through special bony tubes growing backward from the nose, up and above the eyes into a huge bony compartment, then down and forward into the throat and windpipe. With all their loops and extra chambers, the hollow-crested duckbills could reproduce in bone some of the qualities instrument makers seek to design into brass and wood today. Duckbill springtime choruses may well have been the loudest and richest cacophony evolution has ever produced. Being large conferred great lung power. (dinosaur factory)A male Parasaurolophus would have weighed three or four tons. In the fossils of the Judith Delta in Alberta, six different duckbills were found within a small area, each with its unique nasal amplifier. If all started playing their sexual overtures together, the din must have been thunderous.