Story by Alexandria deRosset
Visuals by Jennifer Tran
On the corner of a street, on the edge of town, there’s a dirt pile that dips and rises. It’s just bigger than two bowling lanes side by side. It’s a little muddy, even on days when the sun beats into the earth.
You probably wouldn’t guess that this rather large pile of dirt is from the same mine where some of the most valuable fossils in the world have been found. You might be even more surprised to hear that the squat, unremarkable building across the street holds some of those fossils.
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Any fossil collector who is decently obsessed might recognize this as Aurora, North Carolina. A town with a population of 490, according to census data from 2021, Aurora is in Beaufort County in the eastern part of the state.
Twenty million years ago, the Aurora Fossil Museum and the fossil pile out front were underwater. Prehistoric sharks, whales and seals swam around what is now the eastern part of North Carolina.
In 1978, the Aurora Fossil Museum opened to the public. Back then, it was one room. Whiting Toler, the museum’s original director, painted the prehistoric animals that used to swim in what is now Aurora based on descriptions from Smithsonian scientists on its walls. He painted the geologic scenes based on interpretations from Stanley Riggs, a geologist at East Carolina University.
Today, the museum has two buildings, two fossil piles and a plan in the works to expand even more.
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The entrance to the fossil museum is long and skinny. On the left side is a glass case filled with dozens of teeth from megalodon sharks, the massive species that went extinct 3.6 million years ago. Megalodon teeth don’t come cheap. Some of the lower-quality teeth in the display case are sold for $350.
Further down, there are other fossils: smaller shark teeth, shells, and trilobites, a species related to shrimp that went extinct about 252 million years ago.
Seven miles down the road is the phosphate mine. It’s been around since the 1960s, just longer than the museum, and is the source of some of the most valuable fossils in the world and the ones in the Aurora museum.
Cynthia Crane has been the museum’s director since 2014. She studied geology at ECU and did her thesis on paleontology. This museum, and the fossils inside it, are her life.
“It’s just like magic up here,” she said. “I like to spread that joy.”
Crane slides into a narrow hallway past a lifesize megalodon jaw into a room filled with shark teeth. Most are from the mine in Aurora, some are from other parts of North Carolina and a few have been purchased for the museum from other parts of the world.
On the back wall, the megalodon teeth are the main attraction. To the casual fossil viewer, the teeth are cool. To a collector, like George Oliver, they are unparalleled.
“Every little serration is perfect and the color is so beautiful,” he said. “All the enamel is still there.”
Oliver is a retired physician turned fossil collector. He missed out on what he calls the glory days of fossil hunting in Aurora because he was busy delivering babies in Morehead City.
The story of the glory days of fossil hunting and Aurora’s reputation for shark teeth begins about 23 million years ago during the Miocene epoch, the age of mammals.
The Miocene lasted from 25 million years ago to 5 million years ago. During that time, water covered the eastern part of North Carolina. Ancient dolphin, whale and shark relatives swam around. Megaloadons began making an appearance.
What is now Cape Lookout stood in the way of ocean currents. The water behind that curve of land swirled in circles, opposite from ocean currents. This is called a back eddy.
Some eddies are slow and gentle. But the eddy that formed behind Cape Lookout was not.
Animals and organisms got caught in the eddy and used up all the oxygen in that part of the water.
“And as [the organisms in the eddy] became abundant, there was basically a big kill zone over the years, naturally,” Crane said.
Skipping a few million years of geologic history, those dead animals sank, became fossilized and turned into one of the richest and purest phosphate deposits in the world.
“The fossils were locked into a clay type of environment where they were fossilized in the almost perfect ideal situation,” Crane said. “[There was] very little influx of other minerals like irons and water and oxygen.”
Today, this deposit of fossils and phosphate is known as the Pungo River Formation. It is 120 to 170 feet below the surface in Beaufort County, where Aurora is located.
When the Miocene ended 5 million years ago, the Pliocene epoch began.
During the Pliocene, the ocean moved east, exposing more of North Carolina as we know it today, and then began moving west, recovering the land. Over the 3 million years it took for this to happen, shark teeth, mammal bones, fish bones and other future fossils were washed inland. This began the creation of the Yorktown Formation, which is 90 to 120 feet below the surface. It is newer and closer to the surface than the Pungo River Formation.
The Pliocene ended 2 million years ago. The ocean receded to expose the modern-day coast of North Carolina. Bones were locked into the phosphate below them and covered with layers of shelly sand full of phosphate. Over the next 2 million years, shell layers, clay, and sand built up, locking the fossils away 100 feet below the surface.
That is, until 1955.
That’s the year that the phosphate deposit was discovered by Texas Gulf, a sulfur mining company from Texas. By 1963, Texas Gulf had the rights to more than 30,000 acres of land and was testing their mining operations. In 1965, the mine was up and running.
Phosphate is used primarily in fertilizer. In 2022, the United States produced $1.9 billion worth of phosphate, according to the U.S. Geological Survey.
The mine has gone by many names over the years. First, it was the Texas Gulf Sulphur mine. In 1995, PotashCorp, a company based in Saskatchewan, Canada also known as PCS Phosphate, bought the mine. In 2018, it became Nutrien, after PotashCorp merged with another Canadian company.
Locals and old-timers call it the Lee Creek mine, after the creek that was bulldozed to dig the giant open pits that phosphate mining requires.
Here’s how the mine works:
Phosphate hides beneath 23 million years of geologic history, at least 100 feet below surface level. To find it, backhoes and draglines, the souped-up mining version of construction excavators, remove everything in between.
Regular backhoe excavators, the diggers often seen at construction sites, remove 35 to 50 feet of clay and sand. This exposes a shell bed, 20 to 30 feet thick, where the draglines sit and do their digging.
The draglines dig back through time until they reach the phosphate ore. All of the shells, clay and sand that are removed are called overburden. Dragline operators dump the overburden around the sides of the shell bed. This is where fossil hunters like Clyde Swindell did their collecting.
“The best thing I could do as a dragline operator was take that fossil layer and spread it along the top [of the shell bed],” Swindell said. He especially loved to pick out pumice, amber, megalodon teeth and whale vertebrae.
His hearing’s shot from 40-odd years working in the mine. He worked his way up from laborer to dragline operator. In his spare time, he became a pretty big deal in the fossil collecting world.
“You found vertebrae as big as stools you could sit on all the time,” Swindell said. “That was on a normal day.”
Swindell has more than a few teeth on display in the Aurora museum. Others are in the Smithsonian’s collection. He sold most of his tooth collection and used the money to put his daughter through college at UNC Wilmington and buy a new car.
He never went to college himself. He started working in the mine straight out of high school, when minimum wage was $1 per hour.
“I went over there because they were paying $1.55 cent an hour,” Swindell, who is 78, said.
Over the years, he developed a relationship with researchers at the Smithsonian. They sent him pictures of animals with the bones he had found colored in. In return, Swindell sent them the fossils they were looking for.
One of Swindell’s most significant finds was a set of teeth from a rare shark species that lived 53 million years ago called the Parotodus benedeni, also known as a false Mako.
One 2-inch tooth from this shark goes for over $1,000 online. Swindell not only found an entire set, but an entire set from the same shark. Paleontologists refer to this as an associated set.
“[Associated sets] are extremely rare,” Crane, the museum director, said. Most of the sets on display in the museum are made up of teeth from different sharks in the same species.
Finding an associated set from any shark is remarkable, but an associated set from a rare shark like the Parotodus benedeni is exceptionally uncommon.
Swindell worked with other fossil collectors and a researcher from the Smithsonian to unearth the whole set. Over the course of a year, they collected 114 teeth, almost a full set.
The original teeth were donated to the Smithsonian in 1996. A replica of the set is on display in Aurora.
Even to the untrained eye, the differences between Lee Creek fossils and fossils found in oceans or rivers are clear.
The Lee Creek fossils are shiny and perfect. The outside is scratch free and the roots are fully intact. Ocean and river fossils, on the other hand, have been tumbled around by the water movement. They tend to be more chipped, more worn and less shiny.
Since 2009, members of the public have not been allowed to fossil hunt in the mine. The increasing rarity of Lee Creek teeth makes them even more valuable.
“Just the fact that [a shark tooth] is from Aurora doubles the price, at least,” Oliver, the fossil collector, said.
These days, Nutrien sends some of their overburden to the fossil pile outside the museum in Aurora.
It sits there on the corner, on the edge of town, while people of all ages pick their way through the gravel, searching for teeth.
“I’ve got one!” A little girl in red rainboots shows off the shark tooth she’s just found in the pile.
Swindell remembers that feeling of triumph, although he hasn’t been fossil hunting in ages.
“I mean, you always want to holler and jump up and down, it’s like winning a trophy,” Swindell said. “You win the trophy, and [say] I got it right here. This is the best feeling in the world.”
