The Day the Dinosaurs Died:

[beecee]

The following is probably a well known, scientifically based story, about a time when the Earth suffered an almighty blow. It is lengthy, very lengthy, and at the same time detailed, very detailed.

I actually followed it by the audio reproduction, which I recommend to others. As I said, very detailed and descriptive, and for an amateur novice such as myself, some of it quite revealing. Hope all take the time to listen and/or read.....

https://www.newyorker.com/magazine/2019/04/08/the-day-the-dinosaurs-died?itm_content=footer-recirc

The Day the Dinosaurs Died:

 

By Douglas Preston

March 29, 2019

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a small extract:

On August 5, 2013, I received an e-mail from a graduate student named Robert DePalma. I had never met DePalma, but we had corresponded on paleontological matters for years, ever since he had read a novel I’d written that centered on the discovery of a fossilized Tyrannosaurus rex killed by the KT impact. “I have made an incredible and unprecedented discovery,” he wrote me, from a truck stop in Bowman, North Dakota. “It is extremely confidential and only three others know of it at the moment, all of them close colleagues.” He went on, “It is far more unique and far rarer than any simple dinosaur discovery. I would prefer not outlining the details via e-mail, if possible.” He gave me his cell-phone number and a time to call.

I called, and he told me that he had discovered a site like the one I’d imagined in my novel, which contained, among other things, direct victims of the catastrophe. At first, I was skeptical. DePalma was a scientific nobody, a Ph.D. candidate at the University of Kansas, and he said that he had found the site with no institutional backing and no collaborators. I thought that he was likely exaggerating, or that he might even be crazy. (Paleontology has more than its share of unusual people.) But I was intrigued enough to get on a plane to North Dakota to see for myself.

DePalma’s find was in the Hell Creek geological formation, which outcrops in parts of North Dakota, South Dakota, Montana, and Wyoming, and contains some of the most storied dinosaur beds in the world. At the time of the impact, the Hell Creek landscape consisted of steamy, subtropical lowlands and floodplains along the shores of an inland sea. The land teemed with life and the conditions were excellent for fossilization, with seasonal floods and meandering rivers that rapidly buried dead animals and plants.

Dinosaur hunters first discovered these rich fossil beds in the late nineteenth century. In 1902, Barnum Brown, a flamboyant dinosaur hunter who worked at the American Museum of Natural History, in New York, found the first Tyrannosaurus rex here, causing a worldwide sensation. One paleontologist estimated that in the Cretaceous period Hell Creek was so thick with T. rexes that they were like hyenas on the Serengeti. It was also home to triceratops and duckbills.

The Hell Creek Formation spanned the Cretaceous and the Paleogene periods, and paleontologists had known for at least half a century that an extinction had occurred then, because dinosaurs were found below, but never above, the KT layer. This was true not only in Hell Creek but all over the world. For many years, scientists believed that the KT extinction was no great mystery: over millions of years, volcanism, climate change, and other events gradually killed off many forms of life. But, in the late nineteen-seventies, a young geologist named Walter Alvarez and his father, Luis Alvarez, a nuclear physicist, discovered that the KT layer was laced with unusually high amounts of the rare metal iridium, which, they hypothesized, was from the dusty remains of an asteroid impact. In an article in Science, published in 1980, they proposed that this impact was so large that it triggered the mass extinction, and that the KT layer was the debris from that event. Most paleontologists rejected the idea that a sudden, random encounter with space junk had drastically altered the evolution of life on Earth. But as the years passed the evidence mounted, until, in a 1991 paper, the smoking gun was announced: the discovery of an impact crater buried under thousands of feet of sediment in the Yucatán peninsula, of exactly the right age, and of the right size and geochemistry, to have caused a worldwide cataclysm. The crater and the asteroid were named Chicxulub, after a small Mayan town near the epicenter.

One of the authors of the 1991 paper, David Kring, was so frightened by what he learned of the impact’s destructive nature that he became a leading voice in calling for a system to identify and neutralize threatening asteroids. “There’s no uncertainty to this statement: the Earth will be hit by a Chicxulub-size asteroid again, unless we deflect it,” he told me. “Even a three-hundred-metre rock would end world agriculture.”

In 2010, forty-one researchers in many scientific disciplines announced, in a landmark Science article, that the issue should be considered settled: a huge asteroid impact caused the extinction. But opposition to the idea remains passionate. The main competing hypothesis is that the colossal “Deccan” volcanic eruptions, in what would become India, spewed enough sulfur and carbon dioxide into the atmosphere to cause a climatic shift. The eruptions, which began before the KT impact and continued after it, were among the biggest in Earth’s history, lasting hundreds of thousands of years, and burying half a million square miles of the Earth’s surface a mile deep in lava. The three-­metre gap below the KT layer, proponents argued, was evidence that the mass extinction was well under way by the time of the asteroid strike.

In 2004, DePalma, at the time a twenty-­two-year-old paleontology undergraduate, began excavating a small site in the Hell Creek Formation. The site had once been a pond, and the deposit consisted of very thin layers of sediment. Normally, one geological layer might represent thousands or millions of years. But DePalma was able to show that each layer in the deposit had been laid down in a single big rainstorm. “We could see when there were buds on the trees,” he told me. “We could see when the cypresses were dropping their needles in the fall. We could experience this in real time.” Peering at the layers was like flipping through a paleo-history book that chronicled decades of ecology in its silty pages. DePalma’s adviser, the late Larry Martin, urged him to find a similar site, but one that had layers closer to the KT boundary.

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Again, I advise listening to the "pleasing" audio of this lengthy story. A story that impressed me as a non scientist novice, on the beauty and logic of science and the scientific method. The story may be well known today [the article is from 2019] but the detailed description of the before time,the  effects and after time are awe inspiring.

Edited July 29, 2021 by beecee

[studiot]

Thank you for the link. +1

I will listen when I have more time.

A running time of the presentation would be handy for others though.

 

You may like to look out this book by Professor Benton of Bristol University, who was a key player in some of this work.

It is very readable by the lay person, but offers much useful information as well.

It also treats all 5 of the recognised major mass extinctions, not only the dinosaurs.

Do not confuse the title with when the earth nealy died or the day the eath died, which are different (lesser) books.

 

[beecee]

35 minutes ago, studiot said:

Thank you for the link. +1

I will listen when I have more time.

A running time of the presentation would be handy for others though.

It is around 67 minutes long narration...please don't let that put any one off! Extremely awesomely interesting in its detailed description, that signifies what science in general is all about.

Edited July 29, 2021 by beecee

[beecee]

6 hours ago, studiot said:

You may like to look out this book by Professor Benton of Bristol University, who was a key player in some of this work.

It is very readable by the lay person, but offers much useful information as well.

It also treats all 5 of the recognised major mass extinctions, not only the dinosaurs.

Thanks for that. If its half as interesting and detailed as the original article I posted, it will be worth it. "The greatest story ever told", maybe a better title! [not to be confused with the 60's movie of the same name 😉]