Brigham Young University paleontologists have discovered a massive fossil of a pelvis and several vertebrae they believe is from a supersaurus - the second-largest dinosaur to roam the earth.

On Aug. 18, workers at the Dry Mesa Quarry in western Colorado noticed two bone tips protruding from a partially excavated sandstone wall."When we realized the tips were part of the same fossil, we knew we had something big," Clifford Miles, bone preparator, said Wednesday.

The fossil is believed to be about 133 million years old. At the widest point, it's 6 feet long. When surrounding rock is removed, the fossil will weigh about 1,500 pounds, officials said.

Supersauruses were plant eaters that grew up to 130 feet long - longer than a tennis court. They had very long necks and tails, and their hind legs were longer than their front legs. Paleontologists believed that build enabled them to eat leaves from high tree branches.

The dig is an annual event sponsored by BYU.