(Image Credit: Dallaspaleo.org)

Eighty-two million years ago, the mosasaur terrorized the seas with its imposing size and snake-like jaws that could gobble human-sized prey up in one bite.

Today, the extinct marine reptile is a source of fascination for members of the Dallas Paleontological Society, who have spent the last four years excavating and carefully chipping away at limestone to recover the bones of the vicious animal, which dates back to the Cretaceous period and has been found around the world.

This particular fossil of the 40-to-45-foot-long mosasaur was discovered in a creek in Garland, Texas, in 2008, said Darlene Sumerfelt, a volunteer who has been working on the project.

"Most of the bones were embedded in limestone so they had to be excavated under harsh conditions. We used drill hammers to cut chunks in the limestone and then bring it back to the lab to be prepped," she said. "It's a long process."

The excavation out of the creek took 750 hours, while volunteers from the Dallas Paleontological Society have spent more than 2,000 hours working with slow and steady hands to uncover bones embedded in the limestone, Sumerfelt said.

"You have to go down hour by hour to slowly look for the bone, then you try to figure out what the bone is and slowly bring it out," Sumerfelt said. "We used solidifying agents because the bone is very fragile. It will split, chip and break very easily."

After years of dedication, the group hopes to finish the jaw by 2013, Sumerfelt said. They will then send the estimated 60 percent to 70 percent they have recovered of the sea monster to be displayed at the Heard Museum in McKinney, Texas.