Back to the day the dinosaurs died out.

This article is published by Douglas Preston in the New Yorker on April 8, 2019 under the headline “The Day of Death” with anady. Douglas Preston is a writer who has written many novels on paleontology and has written more than thirty books. His latest nonfiction, The Lost City of the Monkey God, tells the story of an archaeological site found in the Honduran rainforest.

Imagine that one night 66 million years ago, when you stood somewhere in North America looking up at the sky, and you’ll soon find something that looks like a star, and if you look at it for an hour or two, it’s increasingly bright and barely moving, and you’ll find that it’s not a star, but an asteroid that’s hitting The Earth at 72,000 kilometers per hour.

Sixty hours later, the asteroid hit Earth.

The atmosphere blew a hole, and the air was compressed and heated violently, creating supersonic shock waves that hit the shallow sea near Mexico’s Yucatan Peninsula today.

At that moment, the Cretaceous period ended, and the ancient era began.

A few years ago, scientists at Los Alamos National Laboratory in the United States used one of the world’s most powerful computers, the so-called “Q machine”, to simulate the impact of the impact, showing that within two minutes of hitting Earth, the asteroid, at least 9.6 kilometers wide, had hit a crater about 29 kilometers deep and threw 25 trillion metric tons of debris into the atmosphere.

Imagine a small stone being dropped into a pond and then zoomed onto the planetary scale. When the local shell rebounded, a mountain higher than Mount Everest briefly appeared, releasing more than a billion times more energy than the Hiroshima atomic bomb, but it did not look like a nuclear explosion with an iconic mushroom cloud.

Back to the day the dinosaurs died out.

Instead, the asteroid’s initial burst formed a huge jet of molten material, spewing out from the atmosphere, some of which spread fanbytorally into North America, most of which was several times the temperature of the sun’s surface, and everything was ignited over a thousand kilometers, in addition, the surface rocks were quickly heated and melted and splashed outwards, forming numerous hot glass meteorites that covered the western hemisphere.

Some of the spewing objects have escaped Earth’s gravity and entered an irregular orbit around the sun, and over millions of years, some of this material has reached other planets and moons in the solar system, and many of these debris appears on Mars — like the one on Earth that was hit high by an ancient asteroid.

A large number of impact fragments may have landed on Titan, Europa and Caristo, and mathematical models show that at least some of the floating debris still contains living microorganisms. As a result, the asteroid may have sowed the seeds of life throughout the solar system, even though it ravaged life on Earth.

The asteroid evaporated after the impact. Its material is mixed with the evaporating Earth rock to form a hot column of smoke that extends to half the distance of the moon before it collapses into an incandescent dust column.

Computer models show that the atmosphere within 2,400 km of the impact point became hot by debris storms, triggering huge forest fires, and as the earth rotates, the earth’s material gathers on the other side of the globe, where it falls and ignites the entire Indian subcontinent, and measurements of the ash and soot that eventually cover the earth show that the fires have engulfed about 70 percent of the world’s forests.

At the same time, the huge tsunami caused by the impact swept across the Gulf of Mexico, tearing the coastline, sometimes pushing hundreds of meters of rock debris inland and then sucking them back into the deep ocean, leaving the clutter of sediments that oil workers sometimes encounter during deep-sea drilling.

The destruction has only just begun.

Back to the day the dinosaurs died out.

Scientists estimate the rate of extinction through computer models, field studies of rock debris, fossils and microfossils, and many other clues, but many details are still being debated.

Overall, it was a devastating shock.

Dust and soot from the impact prevent sunlight from reaching the earth’s surface for months. Photosynthesis was almost completely stopped, with most terrestrial and marine phytoplankton dying, causing oxygen levels in the atmosphere to plummet, the Earth plunged into a cold period, possibly even a deep freeze, the Earth’s oceans and terrestrial food chains collapsed, about 75 per cent of species were extinct, more than 99.9999 per cent of species died and the carbon cycle stopped.

The earth itself has become unfit for life. When asteroids hit Earth, the limestone formation evaporated, releasing a trillion tons of carbon dioxide, 10 billion tons of methane and 100 million tons of carbon monoxide into the atmosphere; The impact also vaporized the hard gypsum rock, spraying 10 trillion tons of sulphide into the sky. Sulfur binds to water to form sulfuric acid and then falls in the form of acid rain. Acid rain may be powerful enough to shed any surviving plant leaves and drain nutrients from the soil.

Today, the layers of debris, dust and soot deposited by an asteroid impact are preserved in Earth’s sediments with a black streak, about the same thickness as a notebook. This is the KT boundary layer, which marks the dividing line between the Cretaceous and The Trisophonites (the Third Age has now been redefined as the Ancient Near Age, but the word “KT” is still reserved). In the late Cretaceous period, widespread volcanic activity spewed large amounts of gas and dust into the atmosphere, with much more carbon dioxide in the air than we breathe now, and in a tropical climate, there might have been no ice on Earth, but scientists knew little about the plants and animals of the time, and they were looking for fossil deposits as close to the KT boundary as possible.

One of the most important mysteries in palaeontology is the so-called “three-meter problem”.

In a century-and-a-half-long relentless search, scientists have found few dinosaur fossils in a layer 3 meters below the KT boundary layer, which in itself represents thousands of years of history, so many palaeontologists believe that dinosaurs were extinct long before asteroids hit Earth, possibly because of volcanic eruptions and climate change, and other scientists countered that the “three-meter problem” merely reflected how difficult it was to find fossils, insisting that sooner or later scientists would find dinosaurs closer to the moment of destruction.

The answer to one of the most important questions in the history of life on Earth is locked in the KT boundary layer. If you, like many biologists, see the Earth as a living organism, then the asteroid of the late Cretaceous period, like a bullet, nearly kills the Earth, and deciphering what happened that day is crucial not only to solve the three-meter problem, but also to explain our origins as a species.

Back to the day the dinosaurs died out.德帕玛(右)和他的助手帕斯库奇在发掘现场

Robert Deparma, an obscure palaeontologist and now a doctoral student at the University of Kansas, discovered a fossil site in The Bowman, a small town in North Dakota, without any institutional support or collaborators.

The site is part of the Hell Creek geological formation slot in the Midwest, and in parts of North Dakota, South Dakota, Montana and Wyoming, the Hell Creek geological formation sits to the surface, containing some of the world’s oldest dinosaur fossil layers, and at the time of the impact, the landscape of Hell’s Creek was made up of moist subtropical lowlands and floodplains along the inland coast. The land is full of life and has the conditions that are perfect for fossil formation, with seasonal floods and winding rivers quickly burying dead plants and animals.

Dinosaur hunters first discovered these rich layers of fossils at the end of the 19th century. In 1902, Barnum Brown, a famous dinosaur hunter at the American Museum of Natural History in New York, discovered the first tyrannosaur struck a worldwide sensation, with a palaeontologist estimating that during the Cretaceous period, There were a large number of tyrannosaurs in Hell’s Creek, like the hyenas on the Serengeti prairie, which is also home to the trigonosis and duck-billed dragons.

The formation of hell Creek was formed across the Cretaceous and ancient eras, and at least half a century ago, palaeontologists knew that an extinction had occurred because dinosaur fossils had been found under the KT layer. This applies not only to Hell Creek, but also to the rest of the world. For many years, scientists have thought that the Cretaceous-Third Age extinction is not a big mystery: millions of years of volcanic activity, climate change and other events have gradually killed many life forms.

But in the late 1970s, a young geologist named Walter Alvarez and his father, Nobel Prize-winning nuclear physicist Luis Alvarez, discovered that the KT boundary layer contained the Earth’s rare radon elements and was unusually high.

Back to the day the dinosaurs died out.

They suggest that it is likely that a huge asteroid hit the Earth that triggered a mass extinction, and that the KT boundary layer was the debris of that event, which most paleontologists rejected, but as the years went by, supporting evidence grew, until 1991, when a paper announced conclusive evidence that researchers had found a crater on the Yucatan Peninsula, appropriate in age, the right size, the right geochemical features, and everything suggests that the asteroid caused the global disaster. The crater and asteroid were named Hicksurub, named after a Mayan town near the center of the crater.

David Kline, one of the authors of the 1991 paper, was so shocked by the impact that he later actively called for a system to identify and eliminate threatening asteroids. “There is no doubt that The Earth will again be hit by a Hicksulubo-sized asteroid unless we change its direction,” he said. “

In 2010, 41 researchers from several scientific fields announced in a landmark scientific article that a huge asteroid that hit the Earth had caused the extinction, and that the problem seemed to have been solved, but the opposition to the idea remained high, and the main contradiction facing the hypothesis was the massive eruption of the Dedry dark rock volcano.

The eruption sprayed large amounts of sulfur and carbon dioxide into the atmosphere, causing climate change. The eruption began before the asteroid hit and continued after the impact for hundreds of thousands of years, one of the largest volcanic eruptions in Earth’s history, with nearly 1.3 million square kilometers of Earth’s surface buried in 1.6 kilometers of lava, and proponents argue that a 3-meter gap beneath the KT boundary line is evidence that mass extinction was underway when the asteroid hit Earth.

In 2004, Depama, then a 22-year-old paleontology undergraduate, began excavating a small site in the Hell Creek formation, once a pond with very thin sediment layers. Typically, a geological layer may represent thousands or millions of years, but Deparma notes that each layer of sediment is formed in a particular storm.

“We can see when the trees germinate, ” he said. ” We can experience these processes in real time. “Looking closely at these rock formations is like looking through an ancient history book, a thin page of which documents decades of ecology. Deparma’s mentor, the late Larry Martin, urged him to look for a similar site, but its formation sits closer to the KT boundary layer.

In 2012, while searching for new pond sediments, Depama heard that a private collector had stumbled upon an unusual piece of land on a ranch near Bowman, North Dakota (most of the land in Hell Creek was privately owned, and ranchers would sell the rights to anyone willing to pay a handsome fee, including paleontologists and commercial fossil collectors), and in July 2012, the collector took Deparma to visit the site and welcomed him to visit.

Back to the day the dinosaurs died out.德帕玛发现的一块鱼鳍化石

At first Deparma was very disappointed, and he wanted to find the same place as he had excavated before: an ancient pond with a fine-grained layer of fossils that spanned many seasons and years, but the opposite was true, and everything was deposited in a flood, but when Deparma looked around, he saw hope that the flood had quickly flooded everything, so the specimen was well preserved, and he found many complete fish, which was very rare in the formation of Hell’s Creek. To get them out of the way, Deparma agreed to pay the rancher a certain amount of money every season he worked there.

In July of the following year, Depalma returned to carry out a preliminary excavation of the site. He began shoveling the soil above the site where the fish fossils were found. This “covering” is usually a substance deposited long after the age of fossil animallife, which is of no interest to paleontologists and is often discarded. However, Deparma notes that these layers contain gray-white spots that look like sand particles, but under the magnifying glass, they are tiny spherical and elongated droplets of water. “I thought, my God, these look like micro-glass meteorites!” Deparma recalls.

Microglass meteorites are glass particles that form when molten rock is sputtered into the air after being hit by an asteroid, solidified and falls back to Earth, and the site appears to contain millions of micro-glass meteorites.

As Deparma carefully excavated, he began to find a series of unusual fossils, all of which were exquisite and well preserved. There are interlaced plants, with pieces of logs, fish trapped between the roots of cypress trees, and tree trunks covered with amber.

Back to the day the dinosaurs died out.

In general, most fossils end up flattened by the pressure of the cladding, but the fossils here are three-dimensional, including fish, which are encased in sediments at the same time that support them. You can see the skin of the fish and see the dorsal fins sticking straight into the sediment.

As he excavated, Deparma came to understand the importance of all this in front of him. If the site is as he thought, it would mean that he had made the most important paleontological discovery of the century.

Deparma grew up in Boca Raton, Florida, and grew up fascinated by the stories behind bones and bones. “When I was three or four years old, I saw visually the individual bones and the beauty of them as a system combined,” he says. “

Deparma’s uncle, Anthony, was a well-known orthopaedic surgeon who had been sheltering Deparma. “I visit him every other weekend and show him my latest findings, ” Deparma said. When he was four years old, a museum in Texas gave him a piece of dinosaur bone fragments that he brought to his uncle. “He told me that all the small knots, rough nodules and protrusions on the bones had names, and the bones had names, ” Deparma said. ” At the age of six or seven, on a trip to Central Florida with his family, he began looking for fossils of his mammalian bones. These fossils date back to the mammals of the Ice Age. At the age of nine, he discovered his first dinosaur bone fossil in Colorado.

In high school, Depama used summer vacations and weekends to collect fossils for the Graves Archaeological and Natural History Museum in Dania Beach, make dinosaur models and install skeletons. He lent the fossils he had collected as a child to the museum for display, but in 2004, the museum went bankrupt and many of the fossil specimens were sent to a community college, de Parma had no documentation to prove his ownership, and the court refused to return his fossils, which were hundreds, mostly locked in warehouses, that could not be publicly displayed and enjoyed.

Frustrated by the “wasteful mismanagement” of his collection, Depama has adopted some unusual collection practices. Usually, palaeontologists would leave the management and care of specimens to the institutions that preserve them, but Deparma insisted that he oversee the terms of the contract for the management of specimens, and that he was never digging on public lands because he thought the government was too cumbersome, but without federal support, he had to pay for almost all of the costs of the Hell Creek site alone, at a cost of tens of thousands of dollars. He helps pay for it by installing fossils, reconstructing scenes, casting and selling copies for museums, private collectors and other clients.

Sometimes, parents offer some money. “I barely got it,” Deparma said. “If I’m going to have to choose between getting more PaleoBond, an expensive liquid glue used to stick fossils together, and replacing air conditioning filters, I’m going to choose the former.” “Now Depama is single and lives in a three-bedroom apartment with a variety of dinosaur models. “It’s hard to have a life outside of work, ” he says.

Back to the day the dinosaurs died out.

Deparma’s control over his own research collection is controversial. Fossils are a big deal; wealthy collectors can pay hundreds of thousands of dollars, if not millions, for a rare specimen. In 1997, at a Sotheby’s auction, a tyrannosaur specimen nicknamed “Sue” sold to Chicago’s Field Museum of Natural History for more than $8.3 million, and the U.S. market was filled with illegally smuggled fossils.

But in the United States, it is legal to collect fossils on private property, and it is also legal to buy and sell fossils. Many scientists see the deal as a threat to palaeontology and call for important fossils to be placed in museums, but DePalma insists that he retains “the best of both worlds” and keeps some of his collections in several nonprofits, including the University of Kansas, the Palm Beach Museum of Natural History and The Atlantic University of Florida;

In 2013, a paper published in the Proceedings of the National Academy of Sciences made news. Four years ago, he and field assistant Robert Feeney discovered a strange multi-knot fossil in Hell’s Creek, identified as two fusion vertebrae on the tail of a Cretaceous platypus. Deparma believes the bone may have grown around a foreign object and wrapped it up. He took the fossil scan to Lawrence Memorial Hospital in Kansas, where a CT technician scanned the fossil for free when the machine was idle at midnight, only to find that it contained a broken king dragon tooth; the duck-billed dragon escaped after being bitten by the king dragon.

The discovery helped overturn an old hypothesis re-runby by paleontologist Jack Horner that the tyrannosaur was just a percarn-eating animal. Horner believes that the tyrannosaurs are too slow, slow to move, too thin arms, poor vision to prey on other animals. When Deparma’s discovery was reported in state media, Horner dismissed it as “guesswork” and merely “a data point”, and he offered another hypothesis: the tyrannosaur might have accidentally bitten the tail of a sleeping duck-billed dragon, thought it was dead, and then “backed away” when he realized his mistake, which Deparma thought was absurd. At the time, he told the Los Angeles Times: “A rotting animal doesn’t suddenly realize that it’s alive when it discovers food.” Horner later admitted that the tyrannosaur sat sedits alive.

Deparma recalls the moment he discovered. Earlier that summer, the first fossil he had removed was a 1.5-meter-long freshwater spoon kiss, which is still alive, and has a long bone kiss to search for food in the murky water, and when DePalma came up with the fossil, he found the tooth of a giant marine carnivorous reptile dragon under neath.

He was curious about how freshwater fish and marine reptiles could appear in the same place, at least a few kilometers from the nearest inland sea (at the time, a shallow sea known as the “Western Inland Seaway” stretched from the Gulf of Mexico to parts of North America), and the next day he found a 60-centimetre-wide sea fish tail that looked like it had been pulled from a fish for a while, usually if it had been dead for a while, it would have rotted and broken almost intact.

So Deparma believed that it had been transported from other places at the time of death or shortly after death. Like the teeth of a dragon, somehow it finally left the sea of origin and moved to the interior miles away, Deparma said. “These findings suggest an unusual conclusion that he is not ready to accept, “I was 98% confident at the time.”

The next day, Di Palma noticed that there was a small ripple in the sediment. It is about 8 cm in diameter and looks like a crater, formed by an object falling from the sky into the mud. A similar phenomenon has been found in previous fossil records, caused by hail falling on to muddy surfaces. As Deparma cut through the cross-section of the shallow pit, he found something at the bottom — not hail, but a small white ball.

This is a micro-glass meteorite, about 3 mm in diameter, is the ancient asteroid hit the Earth produced by the dust, continue to dig, he found many small craters, the bottom has micro-glass meteorites. After millions of years of glass turned to clay, these microglass meteorites are now clay, but some still have glass-like cores, and the micro-glass meteorites he discovered earlier may have been carried by water, but these micro-glass meteorites were trapped where they fell – a day that Deparma believes must have been the day the disaster occurred.

Back to the day the dinosaurs died out.在一个半世纪的不懈搜寻中,科学家在KT界线层以下3米深的地层中几乎没有发现恐龙化石

“When I saw this, I knew it wasn’t an ordinary flood deposit,” Depama said. “By mapping the formations, DePalma speculated that a huge inland surge flooded a river valley and flooded the low-lying areas where they were located, possibly as a result of an asteroid impact triggering a tsunami sweeping the inland sealanes in the west.

When the water slows down, everything it captures during its journey accumulates on the surface of the water and is quickly buried in silt and preserved: dead and dead creatures, including marine and freshwater organisms; plants, seeds, trunks, roots, polo, pine needles, flowers and pollen; shells, bones, teeth and eggs; micro-glass meteorites, mineral shocks, tiny diamonds, dust, ash, wood, and amber wood hanging from amber. As the sediment slowers, the glass particles fall in the mud like raindrops, first the largest, then getting smaller and smaller, until they fall like snowflakes.

“The whole KT event was preserved in these sediments, ” Depama said. ” “Scientists have never found an ancient site like this before, and if Depama’s hypothesis proves to be correct, the scientific value of the site will be enormous.

When Walter Alvarez visited the site, he was stunned. “It’s really an unparalleled site,” he said, adding that “it’s undoubtedly one of the best sites ever found that tells us what happened on the day of the crash.” “

The fossil bed consists of dozens of thin layers of mud and sand. Further down, it evolved into a more chaotic gravel belt, containing heavier fish fossils, bones and larger micro-glass meteorites, beneath which were hard sandstone surfaces, the site’s original Cretaceous bedrock, most of which were washed away by the flood.

Paleontology is a maddening job, and its progress is usually in millimeters. Deparma and assistant Rudy Pascoe lay in the scorching sun, eyes only a few centimeters away from the earthen wall, and began digging.

Depama occasionally finds small plant fossils, including petals, leaves, seeds, pine needles and bark fragments. Many of them are marks on the dirt that crack and peel when exposed to the air, and he quickly sprays PaleoBond, soaking the fossils and sticking them together. Sometimes he would use another technique to pour the plaster up before it disintegrates, preserving the fossil’s pattern.

Then he found a perfect leaf, next to a seed of pine already , a similar discovery — and three small craters with micro-glass meteorites, and he used a blade to dig out a small piece of brown bone – a jaw less than a quarter of an inch long. He held it with his finger and looked it in detail with a magnifying glass.

“Mammals,” he said. “It was dead when it was buried.” A few weeks later, he confirmed in the lab that the jaw may belong to distant relatives of primates, including our humans.

Back to the day the dinosaurs died out.德帕玛的发现可能填补了化石记录中的空白

Half an hour later, Deparma found a large feather. For him, it’s Christmas every day. He exposed his feathers with precise movement. This is a clear mark on the mud layer, about 33 cm long. “This is my ninth feather, ” he said. ” I think these are dinosaur feathers, but I’m not sure yet.

But these are primitive feathers, most of which are a foot long. Hell Creek is not such a big, feathered bird, more conservatively speaking, this is a known dinosaur, probably the animal-footed sub-species, or it may be a rapid dragon. He continued to dig. “Maybe we can find the birds of prey that these feathers belong to, but I doubt it.” These feathers may have floated from far away. “

Depama dug out the edge of a fin fossil. It was later confirmed that the fish was almost 1.8 metres long. Depama probed the sediment around it and determined its location to better remove it. As more fish fossils were unearthed, it was clear that the fish’s 60cm-long kiss had broken, possibly when it was washed underwater by floodwaters, and hit the branches of the southern fir, which had sunk in the water, and Deparma noted that every fish on the site died with their mouths open, which may indicate that they had suffocated in sediment-filled water.

More and more feathers, leaves, seeds and amber are being excavated. Depama even discovered a mammalian cave. He later wrapped the cave in the sediment and removed it intact. By analyzing the jaw fossils, he believes it is a kangaroo. Maybe it survived the asteroid impact and flooding, dug a hole in the mud to escape the cold darkness, and died.

There are also two impact particles in a piece of amber, another landmark discovery, as amber preserves their chemical composition. The elements of all other micro-glass meteorites have been exposed for millions of years and have undergone chemical changes. He also found many beautiful blue silkdale stones, a six-sided diamond associated with an asteroid impact. This material is formed when the carbon on an asteroid is intensely compressed, crystallized into trillions of tiny particles, then sprayed into the air and falling down.

Back to the day the dinosaurs died out.德帕玛在遗址中采集的岩心样品,该遗址可能保留着白垩纪末期小行星撞击的地质记录

Gradually, DePalma came together a possible picture of the disaster.

By the time the floodwaters flooded the site, the surrounding forest had been engulfed in flames, as a large amount of charcoal, charred wood and amber had been found at the scene. The water arrives not as a pure wave, but as a powerful, rolling ascent, filled with disoriented fish, plants and animal debris. Deparma speculated that the debris would be deposited as the water slowed and receded.

Depama also cites other discoveries at the site: several submerged nests, drowned ants still inside, some caves filled with micro-glass meteorites; a possible bee cave; another mammalian cave with multiple tunnels and corridors; shark teeth; the femurs of large turtles; at least three new species of fish; a giant ginkgo leaf and a plant close to bananas; and a dozen new plants and animals.

At the bottom of the sediment, among the heavy gravel and micro-glass meteorites, Depama identified the broken teeth and bones of almost all of the dinosaur groups known to be in the Hell Creek structure, including hatching remains, and pterosaurs previously thought to have been found only below the KT boundary level. He found a complete, unhatched egg containing an embryo-bearing dinosaur, a fossil of great research value. The dinosaur eggs and other remains suggest that the dinosaurs and other major reptiles may not be endangered by the time of that disastrous day. Deparma may have solved the three-meter problem in one fell swoop, filling a gap in the fossil record.

At the end of the 2013 field trip season, Deparma was convinced that the site was caused by flooding caused by an asteroid impact, but he lacked conclusive evidence that it was the Hicksulub impact 66 million years ago. All this could also be caused by another asteroid impact at the same time. “Extraordinary discoveries require extraordinary evidence,” Deparma said.

If the micro-glass meteorite he found had the same geochemical properties as the micro-glass meteorite from the Hicksulube asteroid, he had strong evidence. The Hicksurubo microbo meteorite deposits are scarce; the best source of fossils discovered in 1990 was a small outcrop in Haiti, on a cliff on the edge of a highway.

In late January 2014, Depama traveled to Haiti to collect micro-glass meteorites and sent them to an independent laboratory in Canada with the micro-glass meteorites from Hell’s Creek, using the same equipment while analyzing samples. The results show that the two have near-perfect geochemical matching.

Back to the day the dinosaurs died out.

In the first few years after Deparma’s discovery, only a few scientists knew about it. One of them is David Burnham, A depama’s paper director at the University of Kansas. Burnham believes the depama site will keep scientists busy for at least half a century.

Deparma briefed the discovery at the annual meeting of the American Geological Society in Colorado in September 2016. He referred only to the sediments he found in the KT flood, which contained glass droplets, shock minerals and fossils, and named the place Tanis, named after the ancient Egyptian city.

In the 1981 film “The Warriors”, Tanness was mentioned as the place where the covenant cabinet was placed. In the real ancient city of Tannis, archaeologists have discovered inscriptions from three text systems, like the Rosetta stone, which played a crucial role in the translation of ancient Egyptian, and Deparma hopes his discovery will also help explain what happened the day after the crash.

The report, though limited in content, caused a stir. Kirk Cochran, a professor at Stony Brook University’s School of Ocean and Atmospheric Sciences in New York, recalled that when Deparma showed off his findings, the audience was surprised to take a breath of cold air. Some scientists are cautious. Kirk Johnson, director of the Smithsonian’s National Museum of Natural History, is familiar with the Hell’s Creek area, where he has been working since 1981.

“After that speech, I very much suspected that I thought it was a forgery, ” he said. Johnson has been mapping the level of the Hell’s Creek KT boundary. He points out that his research shows that the Tannis site is at least 13.7 meters below the KT boundary level, probably 100,000 years earlier than the KT layer.

“I’m skeptical of these findings, ” said a prominent West Coast paleontologist and authority on the KT event. They put forward various unusual ideas at the meeting in various ways. He may have stumbled upon something amazing, but he’s known for making a fuss. He cites Deparma’s paper on dakota dragons as an example, pointing out that the skeletal fossils were basically collected in the same area, some of them dinosaur fossils, others were part of a turtle, and Deparma put them together as bones of the same animal. The scientist also believes that the Tannis site is too secretive, making it difficult for outside scientists to assess Deparma’s claims.

After a lecture by the American Geological Society, Deparma realized that there was a fundamental problem with his Tanness theory. Tsunamis triggered by an asteroid impact, even at a speed of more than 160 kilometers per hour, can take hours to reach the site of the site 3,200 kilometers away, but rain-like micro-glass meteorites were supposed to hit the area less than an hour after the impact, but micro-glass meteorites appear to have fallen into an active flood.

Back to the day the dinosaurs died out.德帕玛说,整个KT事件都保存在这些沉积物中,有了它们,我们可以描绘出白垩纪大灭绝那天发生了什么

The timing was completely wrong.

This is not a question of palaeontology, but of geophysics and sedimentology. Deparma’s co-author Jan Smit is a sedimentologist and another researcher who shared the data with him, Mark Richards, a geophysicist at the University of Washington. After calculating, they realized that the tsunami caused by the asteroid impact had come too late to capture the falling microbos, and that the waves would weaken sharply because of the distance they moved, unable to explain the 10-meter rise in the Water Level in Tannis.

They suggest that the wave may have been caused by a peculiar phenomenon, the “false tide”. In a major earthquake, the shaking of the ground sometimes causes the water in the pond, swimming pool and bathtub to shake back and forth. Richards recalls that 30 minutes after the 2011 earthquake in Japan, a strange 1.5-meter-high tide was created in the norwegian fjords, which were absolutely calm and inaccessible by the tsunami.

Richards had previously estimated that the global earthquake caused by the KT asteroid impact could be 1,000 times stronger than the largest earthquake ever experienced in human history. He estimates that strong seismic waves reach the Tannis site six, 10 and 13 minutes after impact (different types of seismic waves travel at different speeds). A violent tremor is strong enough to trigger a strong earthquake, and in a matter of seconds or minutes, the first micro-glass meteorites will begin to fall.

As the false tides move in and out, the micro-glass meteorites continue to fall, and layers of sediment seal these micro-glass meteorites. In short, the Tanness site did not form on the first day after the impact, but may have recorded the first hour of the impact. If this assumption is true, the site will be more incredible than previously thought. It is incredible that the most important 60-minute accurate geological record in Earth’s history still exists tens of millions of years later. This beautiful time coincidence would not have happened if Tanis had been closer to the impact point or farther away. It’s like a high-definition video recorded in a fine rock formation, after which it’s presented to humans after the Bohai Sandfields.

Back to the day the dinosaurs died out.德帕玛和助手正在用石膏保存化石痕迹

One day, 66 million years ago, life on Earth came to an end almost completely. The world after that impact was much simpler, and when the sun finally broke through the haze, it lit up a hellish landscape. The sea is empty, and volcanic ash floats on the ground. The forest was charred. Because of the greenhouse effect, the cold becomes extreme heat. Life consists mainly of seaweed mats and fungi. In the years after the impact, there were few plants on land other than ferns. Ghostly, mouse-like mammals live in dark underlying vegetation.

However, life eventually emerged in new forms and flourished again. The Cretaceous-Third Age extinction event continues to attract the interest of scientists in large part because it leaves a philosophical reminder of The Earth’s survival that mammals had very few mammals in the hundreds of millions of years before the asteroid hit the earth and had to flee at the feet of dinosaurs.

But when the dinosaurs died out, the mammals were freed. In the ensuing era, mammals experienced outbreaks of adaptive radiation, evolving into a variety of dazzling life forms, from tiny bats to giant thunderous beasts, from horses to whales, from the dreaded primitive carnivorous mammals to the primates of super-brain capacity, which evolved a gripable hand and the ability to think through time.

“We can trace the origins of humanity back to that event, ” Deparma said. ” This is the last day of the Cretaceous period, the next day, the ancient Sine, that is the time of mammals, our human era. “