The song of Parasaurolophus

Jeff Poling

Using a supercomputer and a CT scan of the hadrosaurid Parasaurolophus, scientists in New Mexico have recreated a sound not heard in 75 million years: the low-pitched song of a species of dinosaur. After two years of hard work, the song of the dinosaur was played at the New Mexico Museum of Natural History and Science Friday, December 5, 1997.

The skull used for the experiment was found near Farmington, New Mexico, by Tom Williamson of NMMNH and Robert Sullivan of the State Museum of Pennsylvania. The specimen was the second-most complete Parasaurolophus skull ever found, lacking only a segment below the eyes.

Parasaurolophus is distinctive in that it had a four foot long crest extending from the back of the skull. Scientists have long known that complex network of nasal passages run through it, and have speculated that it could have been used to produce sounds.

Williamson and computer scientist Carl Diegert of the Sandia National Laboratories took the skull to a hospital in Albuquerque, where they performed a series of some 350 CT scans at 3mm intervals. The scans, along with a recreation of the missing beak and nostrils, were used to create a three-dimensional computer reconstruction of the structure of the air chambers within the skull and crest. Biological knowledge and some imagination were used to add soft-tissue to the head and throat. The computer model was then used to produce possible sounds bouncing through air passages of the skull and crest.

"It sounds a little out of this world, like a giant clearing is throat," said Williamson. "It's the kind of sound that would easily be heard by other animals through a thick rain forest." The scientists believe the sounds would have been distinctive enough that the animals could have identified individuals by their voices.

Because paleontologists currently do not know whether Parasaurolophus had vocal cords, the scientists simulated the sounds the dinosaur could have made both with and without vocal cords.

Hear the sound of the Parasaurolophus from NMMNH's website in a 640k .wav file. The first set of sounds are without vocal cords, the third set are with vocal cords. I don't know about the second set. The sounds are copyright © 1997 by New Mexico Museum of Natural History Foundation, Inc.