Rock formations in the western United States are a good place to find dinosaur fossils. Many fossils have been found in Colorado and Wyoming. Malcolm Bedell works at the Wyoming Dinosaur Center. His team is digging up what he believes to be the remains of a large, plant-eating creature.

MALCOLM BEDELL: We are still in the process of continuing to prove that this is a Diplodocus Carnegiei, basically. We havent found any bones that contradict it yet. Some skeletons with some types of dinosaurs, some areas come out in three weeks. Some take three years. Some never come out completely. This one has been ongoing for twelve years. These bones have been sitting here for over 1,500,000 centuries. We get one shot at it. If you fail, thats it!

These rocks were made when dinosaurs ruled the Earth. Dean Lomax is a student from England. He says the American West is the place to be for people interested in fossils.

DEAN LOMAX: Theres so much more fossils to be discovered and there are so many more actual dinosaur museums and paleontology museums.

Every year, forty thousand people visit the Wyoming Dinosaur Center. The center has rare treasures like this fossil of a flying dinosaur called Archeopteryx. Scott Hartman is the science director of the center.

SCOTT HARMAN: In terms of real highlights, the Archeopteryx, which is the only one here in North America at all, is probably our most famous fossil worldwide.

The center has high-quality display areas and its own laboratory. William Wahl is preparing a Camarasaurus fossil. The Camarasaurus ate plants, but weighed almost twenty tons.

WILLIAM WAHL: This is the distal condyle of a femur that we were working for a Camarasaurus, a large Camarasaurus specimen. What is interesting about this is that as we were prepping on this, we ended up noticing there is a series of very parallel marks across the surfaces. Those are bite marks. From whatever, maybe not from the predator that killed this animal, but definitely something that was feeding on it.

This Camarasaurus bone probably will be shown to the public after it is cleaned. The Wyoming Dinosaur Center has more than two hundred displays. Im Bob Doughty.