Computers Show Triceratops Had Better Posture

Thanks to a computerized facelift, Triceratops is looking good — for a 65-million-year-old.

The wraps come off today as the Smithsonian National Museum of Natural History returns the three-horned dinosaur to public display after more than two years being refurbished.

The new display, a full-size cast of the 23-foot-long animal, shows "how really easily Triceratops could do its job. … It just looks like a very good animal that happens to have a whopping big head," said museum paleontologist Ralph E. Chapman.

Dino Was Deteriorating

When it first went on display in 1905, the museum's Triceratops may have been the first horned dinosaur to be shown publicly. By 1998 the fossilized bones were deteriorating, Chapman explained.

Not only did it need repairs, but over the years scientists had learned more about the dinosaur's posture, and they had realized that the original display contained bones from other animals.

It was time for some restoration.

Triceratops was a 5- to 6-ton plant eater and was one of the last dinosaurs still alive before they all became extinct 65 million years ago.

While the fossilized bones had lasted all that time in nature, the rigors of museum life — heat, cold, vibration, humidity — had not been kind. There were cracks, making them fragile, and pyrite disease, a condition in which the mineral pyrite begins growing inside the fossils and breaks them.

So the giant new skeleton going on display is a polymer casting.

Never fear, though, the real bones aren't hidden away.

The exhibit "is chock full of real material," Chapman said. It's just displayed in plexiglass cases to protect it from changes in heat and humidity.

"We put the real head out there and the real humeri [arm bones] and so forth," he said.

And what a head it is.

Apparently used for protection, and possibly fighting with each other, the museum's Triceratops had a head that would have weighed 700 pounds in real life. It displays two horns on top and a third on its nose, capping a powerful jaw.

They were plant eaters, "and boy, I'll tell you, they had strong jaws … they were overachievers when it came to chomping," he said.

The animal's posture is also changed a bit, with its front legs slightly splayed.

It's what Chapman calls a "best guess" at how they looked. It's a guess that owes a lot to modern technology.

Computer Dino Construction

In the process of developing the new display, the bones were scanned with lasers so they could be reproduced with pinpoint accuracy.

Once the details were in a computer, the researchers used them to construct a one-sixth scale model — a more convenient size for them to study.

When the skeleton was first displayed, the legs were shown widely splayed, much like a lizard, Chapman said. But in the 1960s and '70s scientists decided the legs should be more straight up.

With the one-sixth scale model, Chapman and the other researchers could hold the bones in their hands and see how the joints fit together. They worked out the new slightly splayed posture using rubber bands to simulate muscles and tendons and manipulating the bones to see how each joint could move.

Essentially, they built the new Triceratops from the inside out, "letting the joint talk," he said. You couldn't do that with the full-size bones, he added, or "you'd need a forklift."

The effort cost $2.2 million, all but $250,000 of which was donated, museum officials said.

Triceratops is on display across the aisle from the museum's Tyrannosaurus rex, a predator it may have encountered in real life.