At the new Dinosaur Hall at the Natural History Museum of Los Angeles, visitors are greeted with the simulated sound of a dinosaur’s roar. Some 300 dinosaur specimens are on display. It’s also a hands-on show, with interactive games where kids can become paleontologists. The centerpiece of the revamped exhibit are three Tyrannosaurus rex skeletons, including the youngest known T. rex fossil in the world.

The three T. rexes are all different sizes to demonstrate growth, says curator and paleontologist Luis Chiappe, who directs the museum’s Dinosaur Institute. He says the baby is estimated to have died at 2 years old and is about 10 feet long. The juvenile, 14, is about 20 feet long, and the 17-year-old T. rex is about 30 feet long. The dinosaurs are arranged around the carcass of a duck-billed dinosaur, which Chiappe says is known as something T. rexes would eat.

“We use this display to talk about both growth on the one hand and behavior on the other,” he says.

The exhibit has a modern sensibility. The hall is washed in natural light. Fully articulated dinosaur skeletons are mounted atop sleek, black platforms in poses that are both intimidating and breathtaking.

Most of the dinosaur skeletons on display are real; they aren’t casts, and Chiappe collected some of them himself in the Utah desert.

He says instead of organizing the exhibit chronologically, he wanted to present the fossils in a way that highlights what’s know about dinosaurs and what’s left to learn.

“It’s a series of case studies that illustrates the questions that both the public and the scientists ask about these animals: How did they behave? Or how did they grow? Or how did they walk? And it’s really all about, how do we know what we know?” Chiappe says.

He hopes highlighting the unknown will inspire children who visit to become the ones who later find the answers. There are plenty of children who visit for whom these near-mythical, prehistoric animals are a point of fascination, like 10-year-old Dante Lewis Jr. He says his favorite dinosaur is the T. rex and that he wants to be a paleontologist when he grows up.

The exhibit is also geared toward breaking down common misconceptions.

“I think one of the big misconceptions that people have about dinosaurs is that essentially every animal, or every large reptile that lived during the age the dinosaurs, was a dinosaur, and that’s not really the case,” Chiappe says, “and this gallery really illustrates a number, say the ancient marine animals, marine reptiles, that lived during the age of the dinosaur and were not dinosaurs.”

He says another false idea about dinosaurs is that they all lived and died at the same time. The exhibit shows that dinosaurs actually became extinct at different times.

“For example, take two iconic dinosaurs: triceratops and stegosaurus. They lived 85 million years apart,” Chiappe says. “We only live 65 million years apart from the triceratops. So in a time context, a triceratops is closer to us … than a triceratops to a stegosaurus.”

Humans may not have walked among the T. rex, as some movies indicate, but Chiappe says people have lived with dinosaurs — in a way.

“We live with 10,000 species of dinos, but they’re not the dinos that lived during the age of the dinosaur millions of years ago — they’re the birds,” Chiappe says. “Throughout this exhibit we highlight very clearly that there’s plenty of evidence indicating that birds are the descendents of dinosaurs, that therefore dinos are not extinct, and that birds are living dinosaurs.”

Copyright 2011 National Public Radio. To see more, visit http://www.npr.org/.