In a dusty Wyoming town, swimming in fossils
KEMMERER, Wyo. — Just shy of 4 inches long, these fish on the end of a hook would not have been keepers. And with slightly contorted, upturned mouths and torsos sporting forests of prickly-looking bones, they were not about to win any beauty prizes.
But for 55 million years old, they were not looking bad at all as they cluttered a sheet of limestone like anchovies on a pizza.
They were Diplomystus fossils, a distant cousin of the herring and testament to the fact that when conditions are right you can make a lasting impression for a burgeoning tourist trade.
“We never intended to start an industry,’’ said Shirley Ulrich, who cofounded Ulrichs Fossil Gallery with her husband, Carl, in 1988. “We just kept getting more and more excited as we dug up different things. Word of mouth did the rest.’’
Ulrichs and a handful of neighboring private quarries are located in Kemmerer, a mining town 7,000 feet high in the southwest corner of Wyoming. Shortly after its founding in 1897, Kemmerer boasted a population of 5,000 residents — almost all of them coal miners. One was a haberdasher, James Cash Penney, who figured out how to cheaply clothe miners in rugged coveralls shipped in bulk from the East. In 1902 he opened the first JCPenney, a modest building that still stands on Pine Avenue, and still offers JCPenney products.
Time has been good to the folks here. It fashioned them coal, natural gas, and most recently a thriving fossil collection business.
Four decades ago, Shirley Ulrich was shocked to learn that fossil hunters were arriving in town with dynamite to blow the tops off mountain ridges. This was Wyoming; no laws prohibited it. When a US Senate candidate at a political rally mistakenly left a microphone on, Ulrich stepped to the podium to plead with the candidate for federal protection of the state’s fossil treasure — knowing she was also speaking to the entire audience. So was sown the seed that, in 1972, became Fossil Butte National Monument.
Fossil Butte protects 13 square miles of rock that once sat below the long-gone Fossil Lake. It was one of a series of freshwater lakes covering what is now the Wyoming/Utah boundary. Visitors to the monument are welcome to tour exhibits and walk the trails, but not to dig. For souvenirs, collectors must book at one of at least four private quarries in the region.
It’s a symbiotic relationship between these quarry owners and the federal government. Visitors by the thousands come each summer to sift through tons of dirt on private lands that the government would never have the resources to comb, according to Arvid Aase, the paleontologist at Fossil Butte. Quarry owners are held to their word that if something rare appears, the artifact gets loaned to researchers at either the National Monument or the University of Wyoming for further study.
“The quarries allow access, they spark public interest, they move the earth, and we get to analyze the occasional rare find,’’ says Aase. The pickings have included crocodiles, boa constrictors, giant palm leaves, insects, and tens of thousands of small fish. Billions of fauna and flora specimens remain pressed between layers of limestone as frozen statements to a period of dramatic climate upheaval.
To condense several tens of millions of years into three paragraphs, Fossil Lake was born at the dawn of the Eocene, an epoch that may have set the record — to date — for the speed at which the planet warmed. Epochs begin and end with abrupt, sometimes cataclysmic events told by the fossil record. About 58 million years ago, the carbon dioxide levels rocketed to twice, perhaps six times, normal levels, according to climatologists.
The cause might have been changing ocean currents or a huge release of carbon-rich gas that escaped as continents shifted. The resulting dense layer of atmospheric carbon dioxide trapped the earth’s radiant heat and warmed the planet so quickly that many species simply could not adapt. In geologic time, it was but a blink — perhaps 100,000 years. The Eocene brought trees to the poles and crocodiles and stingrays to ancient Wyoming, which was inundated with all the rainfall created as a byproduct of melting ice.
So how did all the fossils of fish that died and settled in the lakebed get 7,200 feet high? Fossil Lake lasted for only the first 3 million of the Eocene’s 32 million years. Earthquakes and geologic lifting dispensed with the lake and pushed the lakebed sky high. The fossils were then exposed to erosion, and finally — for a few of them — to me.
I wish I could claim that the aforementioned Diplomystus, replete with gloriously delicate bone structure and finely preserved fins, was the result of masterful spade work. I wish a fellow tourist had mistaken me for an Indiana Jones.
Truth is, “Diplos’’ and the even more numerous Knightia, another herring ancestor, populate the limestone layers like fabric patterns. They are here in the billions. You just need to know where to look. Or better yet, be shown.
That job fell to Michael Snively and brothers Casey and Courtney Bluemel, all residents of Kemmerer and guides at the Ulrich quarries.
“Hey, guys, look here. This is sweet indeed,’’ said Casey, 22, who works in the oil fields when the winter freeze closes down fossil hunting. He had just pried loose a cardboard thin sandwich of limestone to expose an 8-inch-long Mioplosus, a toothy ancestor of the perch fish.
The thin bones in Casey’s specimen resembled filament spun by a spider. He handed me a splitting tool, a machete-sized blade as dull as a butter knife. I inserted the end gingerly between the layers of limestone. The blade easily penetrated. Then with a gentle twist of the tool, the seam opened. At least a half-dozen fish appeared, each a crisp line drawing drafted in black carbon. We were suddenly looking at the remains of life that had been buried for more than 50 million years. I felt like a voyeur.
I also felt greed. So I did what any newly addicted fossil hunter would do. I dug for more.
David Arnold can be reached at firstname.lastname@example.org.