KENT CITY, Michigan – It all started with a really big thigh bone.
When Kevin Busscher dipped his backhoe shovel into the soft soil of Michigan last month, he knew the femur he plucked from the ground was far too big to have belonged to a cow or horse. And he knew the diver he was replacing would have to wait.
“My first thought was, ‘Woolly mammoth!'” said Mr. Busscher, who reported his find to the provincial officials overseeing the project, who passed on photos of the bones to scientists.
It turned out that he had found the skeleton of a mastodon, an elephant-like beast that roamed North America during the last ice age. The next morning, a team of university and museum researchers had gathered to extract the rest of the bones. When they pulled out the massive jaw of the mastodon, several bright white teeth were still in place.
That discovery, a few feet underground between a rural road and a hayfield, was the latest in a long tradition of construction workers accidentally becoming paleontologists. Over the years, construction crews in Colorado have encountered horned dinosaurs, millennia-old horse bones in Nevada, and a mammoth graveyard in South Dakota, turning job sites for new homes, backyard pools and government buildings into spontaneous science labs.
“As paleontologists, we wish we could go out with this kind of heavy equipment and cut through it, see through hills and things like that, but we’re not really getting around to it,” said Blaine Schubert, a professor at East Tennessee state. University that oversees the Gray Fossil Site and Museum, which became a research area after workers on a highway project discovered a treasure trove of bones in 2000.
There is a natural symbiosis between paleontology and construction, both professions where digging in the earth is part of the daily work. And because there are so many more construction workers than paleontologists, and because of the powerful machinery used to build, it makes sense that construction workers are often the first to uncover bones.
Joe Sertich, who was until recently the curator of dinosaurs at the Denver Museum of Nature & Science, said he routinely heard from people who thought they’d found remarkable fossils. Sometimes they were false alarms or relatively minor finds, such as ordinary fish fossils or bones so badly damaged by construction equipment that they had limited scientific value. But every now and then, construction workers stumbled upon great discoveries.
He helped excavate thousands of Ice Age fossils, including mammoths, mastodons, camels, plants and insects, at the site of a reservoir expansion in Snowmass Village, Colorado. And in suburban Denver, at two separate construction sites, one for a police and fire station and another for an assisted living facility, workers found remains of horned dinosaurs.
“I’ve organized huge expeditions across the country to go out and dig in remote field areas for eight weeks, looking for things like horned dinosaurs,” said Dr. Sertich. “And it turns out that some of those finds are in our own backyard.”
In Hot Springs, SD, work on a housing development came to an abrupt halt in the 1970s when workers found the skeleton of a mammoth. When Jim I. Mead and other paleontologists went there and started digging, they found another skeleton, and another. The site, said Dr. Mead, turned out to be a long sunken pond where mammoth after mammoth drowned after she was unable to climb out. The housing developer agreed to stop building and, decades later, mammoths are still being discovered there.
“We’re lucky,” says Dr. Mead, now the director of research for the Mammoth Site, which is home to tourists, school groups and scientists. “It’s just phenomenal that this person said, ‘I want this to be preserved.'”
There can sometimes be tension between science and construction. Unlike human remains and Native American cultural artifacts, in the United States there is often no legal requirement to report paleontological finds on private land, meaning that some animal bones are eventually plowed over or sold to private collections rather than handed over for study. And given the tight deadlines faced by many construction projects, enlisting scientists can be seen as an expensive distraction from the task.
Earlier this year, construction equipment in Utah damaged a series of rare dinosaur footprints on federal land, sparking criticism that paleontologists hadn’t been more involved in monitoring the site.
When road workers in Tennessee discovered what became the Gray Fossil Site more than two decades ago, converting the site into a permanent research site required intervention from the governor and money to reroute the highway that was supposed to go there. In the years since, East Tennessee State University has started a paleontology program, thousands of visitors have stopped at the museum, and scientists have unearthed bones dating back about five million years, including red pandas, rhinoceroses, tapirs and alligators, which provided a unique lens in prehistoric times. Appalachian Mountains.
“It tells us what these forests looked like back then, when we had no idea what they looked like on either side for millions of years,” said Dr. Schubert, who oversees the site, where excavations continue. He added: “It was a hugely expensive effort to save this fossil site, and I don’t know if something like that would happen today.”
Scientists generally know where dinosaur bones or ice age remains are most likely to be discovered: in places where sediments or sedimentary rock layers of the correct age are now close to the surface and could be exposed by natural erosion or construction work. Much of North America fits that description, however, and exactly where important new finds may lie is largely a matter of chance.
When fossils turn up, lengthy digs like the Tennessee site are the exception. Often scientists can complete their work in a few days or weeks when construction workers report a remarkable find. In California, which has strict laws warning scientists about paleontological finds, construction crews and scientists have generally coexisted. Peter Tateishi, the chief executive of Associated General Contractors of California, said construction workers were often able to build other parts of a structure when scientists needed to be called in to evaluate a discovery.
“That can be a little annoying, but the laws are written in such a way that we can keep schedules moving,” said Mr. Tateishi.
Dan Wagner, a construction inspector in the Denver area, was helping to oversee the construction of the police and fire station in Thornton, Colorado a few years ago when he found a piece of bone where crews were drilling holes for concrete piers. . The bone came from deep in the ground, suggesting it was probably very old. He wondered, “‘Could this even be a dinosaur?'”
When he dug some more and uncovered a much larger bone, site managers halted work in that area. Over the next few weeks, as work continued on other parts of the new building, Dr. Sertich and other paleontologists found a largely intact Torosaurus in a small, fenced-in area of the job site. Mr. Wagner said he would sometimes check progress during his breaks and go along with some digging at the end of his workday.
“I’ve never been into dinosaurs before, but I was super excited,” said Mr. Wagner, who got a tattoo of the Torosaurus and later took his kids to see it in a museum. “I would go to bed and wonder what the hell it was and how many bones there would be.”
In Michigan, where the mastodon bones were found in August, they never hesitated to allow experts access to the site, where crews were clearing a long-neglected drainage network needed to remove water from farmland.
“You’re in this place on this Earth where a creature has lived that we’ve never seen and will never see,” said Ken Yonker, the Kent County sewerage commissioner, whose office oversaw the construction project. “It’s almost like a gift.”
Mr. Busscher, who found that first femur and owns the construction company, had his employees work in the sand with the scientists the next day. The owners of the land where the bones were found agreed to donate the bones to the Grand Rapids Public Museum, which now performs an extensive cleaning and drying process to prepare the bones for display.
The bones will coexist with other mastodons in the museum, including a partial skeleton known as Smitty, whose bones were found in the 1980s at a housing development site in Michigan.
Cory Redman, the museum’s scientific curator, who used a garden hose to gently remove the dirt from the bones of the newly found mastodon, said it was not yet clear how that skeleton, which likely belonged to a juvenile, next to that country road. north of Grand Rapids. He said researchers can look to see if the bones, which were at least 11,000 years old and dated to a time when glaciers covered parts of Michigan, showed signs of being butchered by humans.
A few days after the discovery, normalcy had largely returned to the construction site. The excavator that exposed the femur was still parked in the ground; water had settled in the hole where the bones had been found; and Mr. Busscher and his crew were hard at work past the “Road Closed” sign.
After all, they still had to finish that drain.
