YOU hear them before you see them. From out of the dark primeval ooze of the Smithsonian Institution's National Museum of Natural History here come roars, groans, bellows, screams, shrieks, growls, and even a few hisses. We are talking dinosaur audio, a preview of coming attractions as you round the bend and come face to face with ``Dinamation's Dinosaurs Alive and in Color,'' a summer exhibit that the museum has extended through the end of the year.
Little kids with big eyes edge past the giant creatures with their backs to the dark, padded walls as the dinosaurs loom out of their 150-million-year-old habitats.
Most scary is the Allosaurus (late Jurassic period, 140 million years ago). ``Look at his red eyes!'' cries a frightened toddler, burying his face in his father's neck.
The red eyes blink and several dozen teeth gnash. (He grows new teeth in each socket all the time.) Look at his skin, like that of a black rhino, but red under the throat. Look at his claw-like feet, like that of a huge eagle, and the scaly V-shaped ridge on his face.
This dinosaur has the potential for scaring the smallest of children. He is life size - 16-1/2-feet high, 4 tons, with small front legs, giant hind legs, and a huge, long tail that would fell a redwood. He ranged over Colorado, Wyoming, and Utah millions of years ago, but right now he's terrorizing kids on Constitution Avenue. He even gives adults a little frisson, he's so lifelike.
Museum spokeswoman Pamela Baker says ``We've found tiny babies are not frightened at all, don't seem to fear the dinosaurs ... but toddlers are frightened'' at some of the exhibits. She says Dinamation monitors in red aprons roam the exhibit, talking to children who might be scared, showing them pieces of the dinosaurs' fabric skin, but I did not see any.
The Allosaurus owes his realism to the fact that he's an animated, robotic dinosaur created by Dinamation International Corporation of San Juan Capistrano, Calif. Inside this and the other dinosaurs is a computer-operated robot that has the function of a skeleton. With an interior compressed air system, the robot can make the creature move its head around, walk, lurch, stand up, tromp toward viewers.
Among the 18 robot dinosaurs on view are the Stegosaurus, or plated reptile, a two-ton bundle of tiger-like stripes and what are billed as ``radiator spinal plates''; the Pteranodon, one of the largest flying creatures, which looks like a giant brown bat with a swordfish bill but weighed only 35 pounds; the famous Tyrannosaurus, 50 feet long, with teeth like bullets, roaming a volcanic lava turf; and the Apatosaurus, caramel-colored with a tigerish striped tail that could whip around for 50 feet, a giant snake-like head with clacking teeth, and feet like an elephant, 30 tons on the hoof. ``Hi, Dinosaur!'' says one intrepid, tow-headed boy.
The Dinamation show, which fills 5,000 square feet of space on the museum's first floor, is not free, as Smithsonian exhibitions traditionally are. In an experimental departure from standard practice for the financially hard-pressed institution, adults are charged $4 each, while it's $2 for children under 12, and free for the under threes.
Ms. Baker says that so far the director's office has received about a dozen letters protesting the charge for tickets. But she adds that ``Probably they protest by not buying a ticket.''
THE number of people who have seen the show since it opened represents about 12-to-14 percent of the museum's visitors, with the exception of the second and fourth Tuesdays of the month when the show is free and attendance doubles.
The monthly cost of operating the show is $50,000. The museum hopes its profits from September through December will be $100,000 or more, when local school field trips or area residents (who have stayed away because of the summer tourists) buy tickets.
The profit is split 50-50 between the Smithsonian and the exhibit's creators. The ticket experiment has not been a huge financial hit for the museum, which had projected as much as double the present profits.