How to build a dinosaur

The Brachiosaurus lowers its long neck, creased with wrinkles, and briefly surveys the human crowd staring back at it.

“That thing looks so realistic,” says a young voice from the audience. The dinosaur settles back on its massive haunches and lets out a low bellow — “I sure do," it seems to say.

This dino is a high-tech puppet and one of the stars of "Walking With Dinosaurs," a live production that grew out of a BBC television series by the same name. The show is currently on a six-month North American tour. 

The show's only human character — based on the British biologist Thomas Henry Huxley — time-travels through prehistory, starting with the Triassic period. Over the course of two hours, the theatrical equivalent of 165 million years of evolution, 10 types of dinosaurs make appearances.

There's the plant-eating Plateosaurus, the armored Ankylosaurus and, of course, the iconic Tyrannosaurus rex.

“We wanted to find some emblematic, representative creatures in each of the three major periods of dinosaur evolution,” says Sonny Tilders, the creative director of The Creature Technology Company.

Tilders' company designed and constructed the 20 dinosaur puppets, which are approximately life-sized. For inspiration, the company's team pored through scientific and popular science literature to understand, generally, what various dinosaurs might have looked like. They also observed how large, living animals like elephants and giraffes move.

Constructing the puppets required working “from the inside out,” as Tilders puts it. Inside one of the behemoths you’ll find architecture somewhat similar to a real animal’s. The larger puppets have a skeleton made of steel, complete with points of articulation that allow their bodies to move in a way that seems natural.

The dino’s bulk consists of a system of custom-made muscle bags, constructed from netting and filled with styrene beads. “They stretch and contract like real muscles would,” says Tilders, “so you get all this subtle movement that transfers through the creature.”

On top of their bulging muscles, the puppets wear a special skin made of lycra — “but with a trick that I can't tell you about,” Tilders says. Hand painting lends a prehistoric veneer.

But for these dinosaurs to really convince audiences, they’ve got to walk like they’re flesh and blood. The puppets’ lifelike movements are based on a critical illusion: a sense of hefty mass. Many of the dinosaurs we know and love weighed tons, so “every puppet has to look balanced and grounded,” says Tilders, otherwise “we would lose that sense of mass.”

Performers handle the smaller dinos, including Utahraptors, but larger ones — like the big, carnivorous Allosaurus — are motorized.

And while those creatures appear to plod, their limbs don’t actually bear weight. In the case of the larger puppets, a sturdy rod anchors each body to a motorized chassis, and a driver inside steers the creature around the stage. The puppets’ steps are preprogrammed to coincide with the speed and direction of the vehicles’ speed and direction.

The drivers also communicate via radio with so-called “voodoo puppeteers,” who stand out of sight in a balcony and control multiple aspects of dino dynamism. A puppeteer wearing something like a robotic arm can operate up to 25 axes of mobility, while a colleague manipulating a joystick controls sounds and finer movements like eye blinking or teeth gnashing, as well as sounds.

And hydraulics make the puppets even more lifelike. “You can actually go up to one of our creatures and grab his nose and push [it] out of the way, and [it’ll] slowly come back to position,” says Tilders — none of the typical amusement park animatronics that shudder and shake. “That's probably one of the things that I’m proudest of,” Tilders says.

Paleontological nitpickers might quibble with certain dino details. For instance, the puppets roar, growl and grunt, even though scientists can’t definitively say what sounds real dinosaurs made — or if they uttered any at all, according to Lindsay Zanno, a paleontologist at the North Carolina Museum of Natural Sciences who was hired by the show to promote its educational merits.

But, she admits, “how could they not [make sounds] in a show?”

The show did update the look of some puppets in response to consensus from the paleontological community. For their North American tour, the T. rexes, Liliensternus and Utahraptors all sported feathers.

While the new ’dos may look a bit kitschy, they’re a nod to our ever-evolving picture of dinosaurs, based on more than 150 years of research. And all of the complex, painstaking work pays off.

The puppets are literally jaw-dropping, as I found out when a curious Liliensternus stepped on stage during a show at the Barclays Center in Brooklyn. No one’s seen a live dinosaur, of course, but these puppets evoke a convincing “dino-ness.” And they're plenty scary, too.

“I've worked with gators, crocodiles — all manner of beasties,” says Phil Manning, a professor of natural history at the University of Manchester. He saw the show in Northern Ireland about a year ago, where he got up close and personal with one of the T. rexes. “[The puppet] installed the same fear as an 800-pound gator did in me in Florida a few years ago.”

This story is based on a blog post from PRI's Science Friday with Ira Flatow.