One impatient 4-year-old girl broke away to run down the ramp - toward the noise, not away.

The Children's Museum of Indianapolis' $25 million dinosaur experience is the largest display of real juvenile and family dinosaur fossils in the United States. So exacting is the detail of the exhibit that the night sky has the star patterns of the Cretaceous Period that was the climax of the age of dinosaurs 144 million-165 million years ago.

The impressive thunder and lightning effects greeting visitors are part of a cycle of day and night that plays across the sky of the expansive sphere, repeating about every 22 minutes.

The centerpiece of Dinosphere is Bucky, a teenage Tyrannosaurus rex, the first juvenile T. rex on permanent display in a museum.

Other specimens include:

• A hypacrosaur family of adult, juvenile and infant examples.

• Maiasaura, a plant-eating duckbill dinosaur.

• Kelsey, one of the most complete Triceratops skeletons.

• Baby Louie, the only articulated dinosaur embryo fossil found in the world.

"It can take 10 man years of work to get one skeleton to display status," says museum Paleo Prep Lab scientist Shane Zimmer as he cleans some bones and answers questions from the children.

"Getting everything in place is quite a feat. Just the skull of a Triceratops can weigh close to 600 pounds."

World-famous paleontologists and dinosaur experts are part of an advisory board that ensures that the 13-acre museum's exhibits are lifelike and truthful to known science.

Children enjoy their time in the Paleo Lab by fitting together bone fragments and trying to identify what bone they have "discovered."

On the opposite side of Dinosphere, the Dinosaur Dig Site is less scientific but great fun as kids borrow "dig equipment" to unearth their finds.