DENVER — FOR a great part of the American public, the name "dinosaurs" still means "terrible lizards." Those who labor under such delusions are being set straight in a four-part documentary series on television's Public Broadcasting Service, "The Dinosaurs!" (Nov. 22-25).
Last night's program, "The Monsters Emerge," focused on the history of dinosaur discovery.
Tonight's program, "Flesh on the Bones," looks at where the dinosaurs lived, what they ate, how fast they moved, their migration patterns, and whether or not they were cold-blooded, like reptiles, or hot-blooded, like birds. Evidence from various sciences feeds into the hot-blooded theory.
"The Nature of the Beast" (Tuesday) describes persuasive evidence of the dinosaurs' birdlike qualities: Gastroliths used to grind food internally like birds and cared for their babies much as birds do today.
The final segment, "The Death of the Dinosaur," on Wednesday night presents a compelling argument for the dinosaurs' sudden extinction in a conflagration when a giant asteroid or comet collided with the earth about 65 million years ago. This theory for the dinosaurs' demise is not the only one. Paleontologist Robert Bakker of the University of Colorado at Boulder says dinosaurs could have fallen victim to widespread disease.
Mr. Bakker, who was intimately involved in the series, is often quoted in each program. He says one of the things that makes this series unique is the animation.
"In the very first story conference two years ago, the animator [David Alexovich] was included. All of the storyboarding was planned around both the live action sequences and the animation. Usually they shoot the live action and then buy a little animation, which is thrown around."
But the storytelling itself makes the program so convincing. "In geology, if you know how to read layers of rocks, you are reading a story," Bakker says. "It does have patterns, tensions, times of crises and denouement. Evolutionary history is a story.... There are characters who are very rich, and they do interact with each other.... Dinosaurs were big, smart, hot-blooded, fast-running, and colorful characters."
The ability to read and tell the stories of science helps break down biases. Stereotypes about dinosaurs prevailed for a long time, even though the evidence that they were intelligent creatures was available as early as 1917 with the discovery of skulls.
"If they had been thinking `big bird' instead of `big lizard' they would have known. The huge brain cases show that the brains were wired like birds' brains, which are neurologically very sophisticated," says Bakker.
THE perception that dinosaurs were dull, gray, and bad mothers was so ingrained that scientists weren't looking objectively at the evidence, he adds. "Dinosaurs' eyes were wired like birds' eyes, which means they were color sighted. Birds see a wider range of colors than we do. Animals that are gray (hippos, rhinos, and elephants) are colorblind. So the idea that dinosaurs had to be gray because they were big is wrong." They had eyes like a parrot's, so they would have attracted each other with color as birds do, he says.
Bakker says the series puts the dinos in historical perspective (although not the oldest animals, they ruled for a longer time than any other species has). The fact that they were hot-blooded creatures is important in understanding their lifestyles. And we still live in an age of dinosaurs. There are 400 species of mammals and 8,400 species of birds. Birds, he insists, are dinosaurs.