A mysterious slab of sandstone arrives at the St. Louis Science Center. Excavated in Lance Creek, Wyoming, this 2-ton sandstone slab is thought to be a portion of an ancient riverbed and could contain the remains of dinosaurs. Are there really dinosaur bones in there?

Guy brought this specimen to the St. Louis Science Center where he will prepare the fossils. Halfway through the project it is apparent that this boulder is rich in dinosaur remains. Fossil leaves, seeds and small logs begin to show up.

Upon completion, a dramatic cross section of prehistoric life has emerged. This specimen was found to contain over 200 bones of dinosaurs, turtles, and fish. Visitors viewed the entire preparation process which took 3 months. This specimen resides in Guy's private collection.

Do you see a dinosaur skull in this rock? Guy did. In this picture you see a large boulder containing the skull of the dinosaur, Triceratops, at the St. Louis Science Center, "Chip Off the Old Rock" exhibit.

He carefully chipped off the old rock and revealed a portion of a Triceratops skull. Part way through the project the shield and eye sockets are exposed.

Triceratops lived 65 million years ago in the area we now know as Lance Creek, Wyoming. The finished skull is on display at the St. Louis Science Center.

While studying Lower Ordovician fossils, Guy discovered a large chert boulder in Meramec State Park, which contains important fossils. Arrangements are made to provide a spectacular exhibit for the park's Visitor Center. The specimen was found in a hard to reach area of the park, and a helicopter was called in to airlift the boulder off the wooded hillside.

By using a small hammer and chisel, the outer crust is carefully removed. Animals that have been encased in rock for millions of years come to lite. Chert is very brittle, a wrong move could shatter the rare specimens.

After much work, large gastropods and previously unknown marine fossils are exposed. Each fossil is left in place on the boulder, just as they were when they were buried.

On display, the boulder is encrusted with rare and unusual fossils. It provides visitors with an interesting look at life in the area over 450 million years ago.