This article first appeared in the St. Louis Beacon, Nov. 6, 2009 - If you still think of dinosaurs as overgrown lizards, the spectacular new exhibit at the St. Louis Science Center will update your conceptions in a most entertaining fashion. "Dinosaurs Unearthed" is an educational extravaganza, with more than 20 life-size models, many of which move and roar on their own, and some of which the visitor can control. Also on display are 39 fossils and five life-size skeletons, including a long necked plant eater, the Omeisaurus, that is 62 feet long.
After "Jurassic Park," most of us know that at least some of the predatory dinosaurs were fast moving. But did you know that scientists now believe that at least some of them were warm-blooded?
Did you know that some of these ancestral birds already had feathers 120 million years ago?
And that while some of the feathers -- like the down thought to keep juvenile Tyrannosaurus Rex from losing too much body heat -- were functional, others like the topknot on the velociraptor were probably used to attract the opposite sex?
Dinosaurs were the most successful creatures ever on Earth, points out Stephanie Kuster, paleo-ecologist and geologist for the Science Center's Paleotrek program. They persisted for 164 million years, beginning about 230 million years ago (Triassic) and dying out about 65 million years ago (Cretacious).
"People tend to concentrate on their disappearance," says Kuster, who recently completed her doctorate at Washington University in the Department of Earth and Planetary Sciences. "But geologists and paleontologists work on a different time scale from everyone else. The dinosaur's rapid extinction actually took place over 10,000 years."
In terms of the time dinosaurs ruled the Earth, 10,000 years is short. But as we look back 10,000 years from today, mastodons were still roaming Missouri.
Kuster, who conducts her own dig in Montana, looks upon dinosaurs as a unique kind of animal. They had tremendous variety -- crests, horns, feathers, plates, tail clubs, etc. But to be formally classified as a dinosaur, they have to fit 59 skeletal criteria. These technical criteria are concerned with such characteristics as sutures in the skull and the number of sacral vertebra.
Most of the dinos featured in this exhibit were found in China, many within the past 15 years.
An example is the Confucius Bird. This very bird-like dinosaur lived about 125 million years ago. It probably wasn't a very good flier, because its shoulder structure is not optimal, but it had a beak like modern birds. And its fossil, well preserved in a lake bed, showed body and leg feathers.
Archeopterix, the well known bird ancestor from 140 million years ago in Germany had wing feathers, but still had teeth and no beak.
A velociraptor with preserved quill points was found in Mongolia just a couple of years ago. So if "Jurassic Park" is ever redone, those pack-hunters will have to be feathered instead of scaled.
A cast of a 16.7 foot foreleg from the "Titan of Huanghe" towers over the exhibit. The first of this species was discovered in Henan province by paleontologists in 2004. However, the local villagers knew it well. Thought to be a flying dragon, its fossilized bones had been used in traditional medicine for years. Only 40 percent of the skeleton of this giant remained.
This is one of the first traveling exhibits to feature casts taken directly from the feathered dinosaurs of China. Apparently these fossils that are being taken out of Chinese lake beds were preserved under ideal conditions: After death they were quickly silted over with volcanic ash, allowing very little oxygen to promote decay.
"It's so hard to become a fossil," said Kuster. You have to be in the right place at the right time.
Jo Seltzer is a freelance writer with more than 30 years on the research faculty at the Washington University School of Medicine and seven years teaching tech writing at WU's engineering school.