Construction workers digging in a peat bog discovered the nearly complete skeleton of a 10,000 to 12,000-year-old mastodon, scientists said Tuesday.

The mastodon, an early ancestor of the elephant, lived in the southern Great Lakes region until the end of the Ice Age.While remains of the animal have been found at hundreds of sites, only a handful of complete skeletons have been recovered, said Bob Anemone, an anthropologist at the State University of New York at Geneseo.

"The whole skeleton was lying out as it was when it died," he said. "All the neck vertebrae were in line."

The skeleton was discovered about two weeks ago when workers at a construction site in Livingston County brought up the skull in an excavation bucket, said geologist James W. Scatterday, director of the mastodon project.

Almost 90 percent of the skeleton has been recovered so far. A team is still looking for the animal's hip bone, one or two lower leg bones and some small hand and foot bones. Also missing is the left tusk and the root of the left tusk.

The exact location of where the skeleton was found was withheld to protect the privately owned site, where field teams continued to search for bones.

Some of the skeleton pieces originally went home with the workers as souvenirs, but rumors of the find quickly got out and reached the university, which arranged with the owners of the land to excavate the mastodon.

Since Jan. 23, teams of faculty members, researchers from other universities and museums and high-school teachers have been working with the construction workers to dig up the remains.

The skeleton was about 5 feet underground, beneath layers of peat and mired in a bed of sticky, wet clay. The moisture of the clay helped preserve the bones, Anemone said.

Project workers believe the creature was an adult male weighing 5 to 6 tons and measuring 8 to 9 feet at the shoulder - about the size of a modern-day Indian elephant.