Gerald Johnson holding a mastodon bone. (Jackson Landers)

Early on, Gerald Johnson feared he was in the wrong spot. For more than a week this year he dug along a creek in Yorktown, Va., searching for mastodon bones and finding nothing.

Turned out he was in the right spot after all. The excavation has produced dozens of bones and even a pair of tusks from an animal that lived and died about 12,000 years ago.

In 1983, a bricklayer named Lawnell Hart had shown Johnson, a geologist, a tooth the size of a toaster. Together, they found a few more bones eroding from the side of a creek. But the landowners wouldn’t allow them to dig. Hart died in 2011. The land now has a new owner, and Johnson returned to start digging earlier this year.

According to one expert, the marks on this rib were probably made by a large, toothy carnivore such as the extinct saber-toothed cat. Microscopic analysis will be needed to completely rule out human butchering. (Jackson Landers)

For the first week and a half, “we never hit a bone or tusk,” Johnson said. “I don’t know if I showed it or not, but I was getting kind of depressed because I thought this is the wrong place. . . . But it turned out that we were in the right place. We had a crew that really dug into it and did a marvelous job. . . . I was awfully afraid that I’d missed it in some way.”

Johnson personally found a broken tusk, the first of dozens of bones and teeth recovered.

The age of the mastodon bones is unknown. Carbon dating was attempted with one of the toe bones found in 1983, but too little collagen remained and the test was inconclusive. Another attempt will be made using one of the bones unearthed this year.

This molar was worn down to such a small size from use that it was momentarily mistaken for a tooth from a baby mastodon. (Jackson Landers)

About 25 percent of the bones and teeth that a single mastodon would have had were recovered, and they will be studied for years. Some scientists will analyze the growth layers in the tusks to study the animal’s diet, others will look for microscopic evidence showing which species of plants were present.

Pieces of wood found with the bones will also be tested to help determine the age of the site. “We have pollen and spores, and we should have a really good record of them,” Johnson said. “I wish we had more evidence of its sex. We did not find the pelvic girdle, we did not find the skull.”

Johnson has dubbed the remains “the Hart-Fiscella mastodon” in honor of the bricklayer who found the first molar and for a particularly generous pair of donors, Edward and George Fiscella. Not only do they own the land where the bones were found, they have also agreed to pay for radiocarbon dating.

“We’ve got bones over there with all kinds of deformities on them, and I’d like to know what they are,” Johnson said. “We’d like to find out as much as we can about each and every bone. Like that jawbone; it tells a story unto itself. . . . We’re going to turn some of those bones over to people who have medical knowledge of deformities, like that rib,” he said, pointing to a bone that has a series of deep gouges on one end.

Briana Pobiner, a paleoanthropologist at the Smithsonian Museum of Natural History, reviewed photos of the rib and thinks that a predator other than a human is probably responsible.

This fully intact tusk was carefully encased in plaster to prevent it from breaking during transportation from the dig. (Jackson Landers)

“The marks on the rib look intriguing,” she wrote in an email, “but it’s hard to tell what they are without seeing the actual fossils. They could be butchery marks, but to me they look more like tooth marks from a big extinct carnivore like a sabertooth cat, American lion or dire wolf.”

Johnson had already determined that the animal had an impacted tooth and arthritis.

Because the tusks, one of them broken, were found arranged as though they hadn’t moved since the mastodon died, Johnson theorizes that it fell violently to the ground as it met its end in battle with a predator. No arrowheads, stone flakes or other human artifacts were found.

One mastodon expert, Daniel Fisher of the University of Michigan, thinks that the bones found in 1983 came from two different animals because of differences in the size of the toe bones.

This is only the second mastodon skeleton ever found in Virginia. One was unearthed near Saltville, in the far southwest of the state.

Mastodons became extinct about 12,000 years ago, at the end of an ice age. Simultaneously, most of the other large animals in North America died out. Mammoths, camels, giant beavers, ground sloths, dire wolves and saber-toothed cats all disappeared. While many theories have been offered, scientists do not know what caused this wave of extinction. Some have suggested that human hunting was the cause, but there is little direct evidence of such killing in America.

Digs such as this are usually organized and financed through a university or museum. But this one is an independent effort, led by Johnson, a professor emeritus at the College of William and Mary, and supported by private donations of money and labor. Volunteers included members of the Historic Rivers Chapter of the Virginia Master Naturalist Program.

An excavation contractor improved an access road and dug out four feet of soil using heavy equipment. The manual digging for bones was done by volunteers, including Jared Saulman, a 16-year-old Boy Scout who organized other volunteers, helped dig and earned his Eagle badge on the project.

He found one bone fragment. “I was just speechless,” Saulman said. “At first I thought this is a rock. I called Mr. Johnson over and asked if it was a rock, and he said it was a bone! I just couldn’t believe it.”

It may take up to four years to study the bones and other material. Johnson’s role will shift from managing the dig to arranging for scientists to analyze the remains. “Somebody said this caps off your career,” he said. “Well, hell, I want to do something else other than this yet in my life. I’m only two months away from 80, but I’ll be damned if this is going to be the last thing I’ll do.”

Landers is an author and freelance writer in Charlottesville.