by Michio Kaku
When I first visited the lab, in April 2014, a block of stone three feet long by eighteen inches wide lay on a table under bright lights and a large magnifying lens. The block, DePalma said, contained a sturgeon and a paddlefish, along with dozens of smaller fossils and a single small, perfect crater with a tektite in it. The lower parts of the block consisted of debris, fragments of bone, and loose tektites that had been dislodged and caught up in the turbulence. The block told the story of the impact in microcosm. “It was a very bad day,” DePalma said. “Look at these two fish.” He showed me where the sturgeon’s scutes—the sharp, bony plates on its back—had been forced into the body of the paddlefish. One fish was impaled on the other. The mouth of the paddlefish was agape, and jammed into its gill rakers were microtektites—sucked in by the fish as it tried to breathe. DePalma said, “This fish was likely alive for some time after being caught in the wave, long enough to gasp frenzied mouthfuls of water in a vain attempt to survive.”
Gradually, DePalma was piecing together a potential picture of the disaster. By the time the site flooded, the surrounding forest was already on fire, given the abundance of charcoal, charred wood, and amber he’d found at the site. The water arrived not as a curling wave but as a powerful, roiling rise, packed with disoriented fish and plant and animal debris, which, DePalma hypothesized, were laid down as the water slowed and receded.
In the lab, DePalma showed me magnified cross-sections of the sediment. Most of its layers were horizontal, but a few formed curlicues or flamelike patterns called truncated flame structures, which were caused by a combination of weight from above and mini-surges in the incoming water. DePalma found five sets of these patterns. He turned back to the block on his table and held a magnifying lens up to the tektite. Parallel, streaming lines were visible on its surface—Schlieren lines, formed by two types of molten glass swirling together as the blobs arced through the atmosphere. Peering through the lens, DePalma picked away at the block with a dental probe. He soon exposed a section of pink, pearlescent shell, which had been pushed up against the sturgeon. “Ammonite,” he said. Ammonites were marine mollusks that somewhat resemble the present-day nautilus, although they were more closely related to squid and octopi. As DePalma uncovered more of the shell, I watched its vibrant color fade. “Live ammonite, ripped apart by the tsunami—they don’t travel well,” he said. “Genus Sphenodiscus, I would think.” The shell, which hadn’t previously been documented in the Hell Creek Formation, was another marine victim tossed inland.
He stood up. “Now I’m going to show you something special,” he said, opening a wooden crate and removing an object that was covered in aluminum foil. He unwrapped a sixteen-inch fossil feather, and held it in his palms like a piece of Lalique glass. “When I found the first feather, I had about twenty seconds of disbelief,” he said. DePalma had studied under Larry Martin, a world authority on the Cretaceous predecessors of birds, and had been “exposed to a lot of fossil feathers. When I encountered this damn thing, I immediately understood the importance of it. And now look at this.”
From the lab table, he grabbed a fossil forearm belonging to Dakotaraptor, the dinosaur species he’d discovered in Hell Creek. He pointed to a series of regular bumps on the bone. “These are probably quill knobs,” he said. “This dinosaur had feathers on its forearms. Now watch.” With precision calipers, he measured the diameter of the quill knobs, then the diameter of the quill of the fossil feather; both were 3.5 millimeters. “This matches,” he said. “This says a feather of this size would be associated with a limb of this size.”
There was more, including a piece of a partly burned tree trunk with amber stuck to it. He showed me a photo of the amber seen through a microscope. Trapped inside were two impact particles—another landmark discovery, because the amber would have preserved their chemical composition. (All other tektites found from the impact, exposed to the elements for millions of years, have chemically changed.) He’d also found scores of beautiful examples of lonsdaleite, a hexagonal form of diamond that is associated with impacts; it forms when carbon in an asteroid is compressed so violently that it crystallizes into trillions of microscopic grains, which are blasted into the air and drift down.
Finally, he showed me a photograph of a fossil jawbone; it belonged to the mammal he’d found in the burrow. “This is the jaw of Dougie,” he said. The bone was big for a Cretaceous mammal—three inches long—and almost complete, with a tooth. After my visit to Hell Creek, DePalma had removed the animal’s burrow intact, still encased in the block of sediment, and, with the help of some women who worked as cashiers at the Travel Center, in Bowman, hoisted it into the back of his truck. He believes that the jaw belonged to a marsupial that looked like a weasel. Using the tooth, he could conduct a stable-isotope study to find out what the animal ate—“what the menu was after the disaster,” he said. The rest of the mammal remains in the burrow, to be researched later.
DePalma listed some of the other discoveries he’s made at the site: several flooded ant nests, with drowned ants still inside and some chambers packed with microtektites; a possible wasp burrow; another mammal burrow, with multiple tunnels and galleries; shark teeth; the thigh bone of a large sea turtle; at least three new fish species; a gigantic ginkgo leaf and a plant that was a relative of the banana; more than a dozen new species of animals and plants; and several other burrow types.
At the bottom of the deposit, in a mixture of heavy gravel and tektites, DePalma identified the broken teeth and bones, including hatchling remains, of almost every dinosaur group known from Hell Creek, as well as pterosaur remains, which had previously been found only in layers far below the KT boundary. He found, intact, an unhatched egg containing an embryo—a fossil of immense research value. The egg and the other remains suggested that dinosaurs and major reptiles were probably not staggering into extinction on that fateful day. In one fell swoop, DePalma may have solved the three-meter problem and filled in the gap in the fossil record.
* * *
By the end of the 2013 field season, DePalma was convinced that the site had been created by an impact flood, but he lacked conclusive evidence that it was the KT impact. It was possible that it resulted from another giant asteroid strike that occurred at around the same time. “Extraordinary discoveries require extraordinary evidence,” he said. If his tektites shared the same geochemistry as tektites from the Chicxulub asteroid, he’d have a strong case. Deposits of Chicxulub tektites are rare; the best source, discovered in 1990, is a small outcrop in Haiti, on a cliff above a road cut. In late January 2014, DePalma went there to gather tektites and sent them to an independent lab in Canada, along with tektites from his own site; the samples were analyzed at the same time, with the same equipment. The results indicated a near-perfect geochemical match.
In the first few years after DePalma’s discoveries, only a handful of scientists knew about them. One was David Burnham, DePalma’s thesis adviser at Kansas, who estimates that DePalma’s site will keep specialists busy for at least half a century. “Robert’s got so much stuff that’s unheard of,” Burnham told me. “Amber with tektites embedded in it—holy cow! The dinosaur feathers are crazy good, but the burrow makes your head reel.” In paleontology, the term Lagerstätte refers to a rare type of fossil site with a large variety of specimens that are nearly perfectly preserved, a sort of fossilized ecosystem. “It will be a famous site,” Burnham said. “It will be in the textbooks. It is the Lagerstätte of the KT extinction.”
Jan Smit, a paleontologist at Vrije University, in Amsterdam, and a world authority on the KT impact, has been helping DePalma analyze his results, and, like Burnham and Walter Alvarez, he is a co-author of a scientific paper that DePalma is publishing about the site. (There are eight other co-authors.) “This is really a major discovery,” Smit said. “It solves the question of whether dinosaurs went extinct at exactly that level or whether they declined before. And this is the first time we see direct victims.�
� I asked if the results would be controversial. “When I saw his data with the paddlefish, sturgeon, and ammonite, I think he’s right on the spot,” Smit said. “I am very sure he has a pot of gold.”
In September of 2016, DePalma gave a brief talk about the discovery at the annual meeting of the Geological Society of America, in Colorado. He mentioned only that he had found a deposit from a KT flood that had yielded glass droplets, shocked minerals, and fossils. He had christened the site Tanis, after the ancient city in Egypt, which was featured in the 1981 film Raiders of the Lost Ark as the resting place of the Ark of the Covenant. In the real Tanis, archeologists found an inscription in three writing systems, which, like the Rosetta stone, was crucial in translating ancient Egyptian. DePalma hopes that his Tanis site will help decipher what happened on the first day after the impact.
The talk, limited though it was, caused a stir. Kirk Cochran, a professor at the School of Marine and Atmospheric Science at Stony Brook University, in New York, recalled that when DePalma presented his findings there were gasps of amazement in the audience. Some scientists were wary. Kirk Johnson, the director of the Smithsonian’s National Museum of Natural History, told me that he knew the Hell Creek area well, having worked there since 1981. “My warning lights were flashing bright red,” he told me. “I was so skeptical after the talk I was convinced it was a fabrication.” Johnson, who had been mapping the KT layer in Hell Creek, said that his research indicated that Tanis was at least forty-five feet below the KT boundary and perhaps 100,000 years older. “If it’s what it’s said to be,” Johnson said, “it’s a fabulous discovery.” But he declared himself “uneasy” until he could see DePalma’s paper.
One prominent West Coast paleontologist who is an authority on the KT event told me, “I’m suspicious of the findings. They’ve been presented at meetings in various ways with various associated extraordinary claims. He could have stumbled on something amazing, but he has a reputation for making a lot out of a little.” As an example, he brought up DePalma’s paper on Dakotaraptor, which he described as “bones he basically collected, all in one area, some of which were part of a dinosaur, some of which were part of a turtle, and he put it all together as a skeleton of one animal.” He also objected to what he felt was excessive secrecy surrounding the Tanis site, which has made it hard for outside scientists to evaluate DePalma’s claims.
Johnson, too, finds the lack of transparency, and the dramatic aspects of DePalma’s personality, unnerving. “There’s an element of showmanship in his presentation style that does not add to his credibility,” he said. Other paleontologists told me that they were leery of going on the record with criticisms of DePalma and his co-authors. All expressed a desire to see the final paper, which will be published next week, in the Proceedings of the National Academy of Sciences, so that they could evaluate the data for themselves.
* * *
After the GSA talk, DePalma realized that his theory of what had happened at Tanis had a fundamental problem. The KT tsunami, even moving at more than 100 miles an hour, would have taken many hours to travel the 2,000 miles to the site. The rainfall of glass blobs, however, would have hit the area and stopped within about an hour after the impact. And yet the tektites fell into an active flood. The timing was all wrong.
This was not a paleontological question; it was a problem of geophysics and sedimentology. Smit was a sedimentologist, and another researcher whom DePalma shared his data with, Mark Richards, now of the University of Washington, was a geophysicist. At dinner one evening in Nagpur, India, where they were attending a conference, Smit and Richards talked about the problem, looked up a few papers, and later jotted down some rough calculations. It was immediately apparent to them that the KT tsunami would have arrived too late to capture the falling tektites; the wave would also have been too diminished by its long journey to account for the thirty-five-foot rise of water at Tanis. One of them proposed that the wave might have been created by a curious phenomenon known as a seiche. In large earthquakes, the shaking of the ground sometimes causes water in ponds, swimming pools, and bathtubs to slosh back and forth. Richards recalled that the 2011 Japanese earthquake produced bizarre, five-foot seiche waves in an absolutely calm Norwegian fjord thirty minutes after the quake, in a place unreachable by the tsunami.
Richards had previously estimated that the worldwide earthquake generated by the KT impact could have been 1,000 times stronger than the biggest earthquake ever experienced in human history. Using that gauge, he calculated that potent seismic waves would have arrived at Tanis six minutes, ten minutes, and thirteen minutes after the impact. (Different types of seismic waves travel at different speeds.) The brutal shaking would have been enough to trigger a large seiche, and the first blobs of glass would have started to rain down seconds or minutes afterward. They would have continued to fall as the seiche waves rolled in and out, depositing layer upon layer of sediment and each time sealing the tektites in place. The Tanis site, in short, did not span the first day of the impact: it probably recorded the first hour or so. This fact, if true, renders the site even more fabulous than previously thought. It is almost beyond credibility that a precise geological transcript of the most important sixty minutes of Earth’s history could still exist millions of years later—a sort of high-speed, high-resolution video of the event recorded in fine layers of stone. DePalma said, “It’s like finding the Holy Grail clutched in the bony fingers of Jimmy Hoffa, sitting on top of the Lost Ark.” If Tanis had been closer to or farther from the impact point, this beautiful coincidence of timing could not have happened. “There’s nothing in the world that’s ever been seen like this,” Richards told me.
* * *
One day 66 million years ago, life on Earth almost came to a shattering end. The world that emerged after the impact was a much simpler place. When sunlight finally broke through the haze, it illuminated a hellish landscape. The oceans were empty. The land was covered with drifting ash. The forests were charred stumps. The cold gave way to extreme heat as a greenhouse effect kicked in. Life mostly consisted of mats of algae and growths of fungus: for years after the impact, the Earth was covered with little other than ferns. Furtive, ratlike mammals lived in the gloomy understory.
But eventually life emerged and blossomed again, in new forms. The KT event continues to attract the interest of scientists in no small part because the ashen print it left on the planet is an existential reminder. “We wouldn’t be here talking on the phone if that meteorite hadn’t fallen,” Smit told me, with a laugh. DePalma agreed. For the first 100 million years of their existence, before the asteroid struck, mammals scurried about the feet of the dinosaurs, amounting to little. “But when the dinosaurs were gone it freed them,” DePalma said. In the next epoch, mammals underwent an explosion of adaptive radiation, evolving into a dazzling variety of forms, from tiny bats to gigantic titanotheres, from horses to whales, from fearsome creodonts to large-brained primates with hands that could grasp and minds that could see through time.
“We can trace our origins back to that event,” DePalma said. “To actually be there at this site, to see it, to be connected to that day, is a special thing. This is the last day of the Cretaceous. When you go one layer up—the very next day—that’s the Paleocene, that’s the age of mammals, that’s our age.”
TIM REQUARTH
The Final Five Percent
from Longreads
When the motorcycle accident dealt my brother’s brain an irreversible blow, he and his wife were living in their newly purchased farmhouse on the fringes of suburban Chicago. Conway* had been waiting to move out of the city’s inner-ring suburbs for years, and each morning on the forested property he woke up exuberant. Shortly after moving in, he built an extraordinary tree house some sixty feet in the air, spanning two trees, with sliding joists under the floor to accommodate sway and a hammock to lie in during sunsets. He loved riding his motorcycle, and before work he’d sometimes take his bike out for a spin on the open
roads just a few miles away. His wife, Caroline, loved antiques, and the area was full of shops. They were in their fifties and living in a house they planned to grow old in together. Then, after dinner on a fall day in 2007, Conway hopped on his Harley Softail Classic to go buy ice cream and cigarettes. A drunk driver barreled into him. Conway’s left femur snapped and his skull struck the traffic-warmed asphalt, splattering blood all the way to the road’s shoulder.
Conway’s body was battered, but the real threat, the injury warranting a helicopter ride to the closest hospital with a neurosurgeon on call, was a hemorrhage beneath the subarachnoid membrane, a thin sheath of triple-helixed collagen fibers intertwined with blood vessels that protects the brain’s private chemical harbor of cerebrospinal fluid from the open waters of the body’s blood. The sons of a doctor ourselves, my brother and I had heard stories about neurosurgeons called in at midnight, and those stories didn’t have happy endings.
In the weeks after the accident, I watched Conway wake, recognize familiar faces, and begin to walk. Some signs of progress were cause for celebration; other developments were more worrisome. He’d rarely ever raised his voice at Caroline, but now he called her a “worthless cunt” and a “bitch.” He was lewd to the nurses, exposing himself and laughing. When a speech therapist gently reminded him that she would return for another session later that afternoon, Conway retorted, “No you won’t, because I’ll be fucking you in my van outside!”
