Imagine trying to piece together a puzzle 60 feet long and 13 feet wide with no box-top picture to guide you.

That's the challenge facing a team of four Brigham Young University researchers who, at long last, are putting together the skeletal remains of a sauropod dinosaur discovered in the Dominquez/Jones Quarry in western Colorado in 1967.James A. Jensen, curator of BYU's Earth Science Museum at the time the dinosaur was discovered, took just one summer to unearth the giant dinosaur's fossilized bones and cart them to BYU. The bones then sat on shelves at the museum for 21 years because of time and money constraints.

Researchers began the painstaking processing of working the bones out of their rock tombs three and a half years ago.

In 1988, Jensen identified the dinosaur as a new genus and species of sauropod, which he named Cathetosaurus lewisi, a member of the Camarasauridae family that lived during the Upper Jurassic period.

As a member of the Camarasauridae family, the dinosaur is related to such giants as diplodocus, brontosaurus and brachiosaurus - with common traits of long necks and long tails.

Researchers hope their detailed study of Cathetosaurus lewisi will determine whether it is indeed a new genus and species of sauropod dinosaur. They are now piecing together the dinosaur skeleton behind the museum's exhibition room.

Involved in the project are Wade Miller, museum curator; Ken Stadtman, assistant museum curator; David Gillette, state paleontologist; and Jack McIntosh, a physics professor at Wesleyan University in Connecticut.

McIntosh spent the past two weeks at BYU measuring each bone and looking for differences that distinguish Cathetosaurus from other dinosaurs. He describes that as similar to looking for the differences between a "lion and a tiger or like a lion and a dog."

Reconstructing a dinosaur is not easy, but luckily some of the bones were linked together when discovered in the quarry. And five similar dinosaur skeletons exist in the country, offering researchers clues on reconstruction.

Unfortunately, some of the other skeletons are only partially complete, while others are pieced together incorrectly.

To make matters worse, the skeleton pieces are 140 million years old and often crumble at the slightest touch.

Still, the researchers are making progress. "We have decided that it is a new species but not a new genus," Miller said.

BYU's Cathetosaurus was apparently very old and, like many older humans, suffered from an arthritic condition. That condition caused skeletal formations that at first made the dinosaur appear structurally different from other sauropods.

This particular dinosaur apparently came to a violent end. The position of the skeleton and deep teeth marks found on the left side of the dinosaur's hip bone suggest a large carnivorous dinosaur killed and then fed upon this Cathetosaurus.