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Mon Sep 9, 2019, 07:53 PM

Last day of the dinosaurs' reign captured in stunning detail

Inch by inch, the team pulled up the skinny core of ghostly white limestone from the ocean floor, gazing at the compressed remains of ancient organisms that died tens of millions of years ago. But then a stark divide appeared as the layers abruptly darkened

“It was nothing like the stuff above,” recalls Sean Gulick, a co-chief scientist of the expedition and a researcher at the University of Texas at Austin.

This change in the rock marks one of the most catastrophic events in Earth’s history, some 66 million years ago, when an epic asteroid slammed into the sea just offshore of Mexico’s Yucatán Peninsula. The impact triggered a nightmarish sequence of events that sent some 75 percent of plant and animal species spiraling to extinction—including all the nonavian dinosaurs.

Now, by subjecting the rocky core to a battery of tests, including geochemical study and x-ray imaging, the research team has assembled a meticulous timeline chronicling events on that fateful day—sometimes down to the minute. As they report today in the Proceedings of the National Academy of Sciences, the dark layers reveal stunning details, including the sheer amount of material that piled up mere hours after the strike, along with bits of charcoal later left by raging wildfires.


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Reply Last day of the dinosaurs' reign captured in stunning detail (Original post)
mfcorey1 Sep 9 OP
FirstLight Sep 9 #1
CaliforniaPeggy Sep 9 #2
friendly_iconoclast Sep 9 #5
JudyM Sep 10 #6
customerserviceguy Sep 9 #3
OAITW r.2.0 Sep 9 #4

Response to mfcorey1 (Original post)

Mon Sep 9, 2019, 07:59 PM

1. fascinating...

wish I had access to the actual academic text!

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Response to mfcorey1 (Original post)

Mon Sep 9, 2019, 08:02 PM

2. Fascinating article! I don't have time to read it now, but I will later!

These historical bits have always fascinated me.

Thanks for posting the article.

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Response to CaliforniaPeggy (Reply #2)

Mon Sep 9, 2019, 10:29 PM

5. Recommended read "The Rise and Fall of The Dinosaurs: A New History of A Lost World"...

...by Stephen Brusatte:


Also recommended:


A young paleontologist may have discovered a record of the most significant event in the history of life on Earth.

By Douglas Preston

March 29, 2019

If, on a certain evening about sixty-­six million years ago, you had stood somewhere in North America and looked up at the sky, you would have soon made out what appeared to be a star. If you watched for an hour or two, the star would have seemed to grow in brightness, although it barely moved. That’s because it was not a star but an asteroid, and it was headed directly for Earth at about forty-five thousand miles an hour. Sixty hours later, the asteroid hit. The air in front was compressed and violently heated, and it blasted a hole through the atmosphere, generating a supersonic shock wave. The asteroid struck a shallow sea where the Yucatán peninsula is today. In that moment, the Cretaceous period ended and the Paleogene period began.

A few years ago, scientists at Los Alamos National Laboratory used what was then one of the world’s most powerful computers, the so-called Q Machine, to model the effects of the impact. The result was a slow-motion, second-by-second false-color video of the event. Within two minutes of slamming into Earth, the asteroid, which was at least six miles wide, had gouged a crater about eighteen miles deep and lofted twenty-five trillion metric tons of debris into the atmosphere. Picture the splash of a pebble falling into pond water, but on a planetary scale. When Earth’s crust rebounded, a peak higher than Mt. Everest briefly rose up. The energy released was more than that of a billion Hiroshima bombs, but the blast looked nothing like a nuclear explosion, with its signature mushroom cloud. Instead, the initial blowout formed a “rooster tail,” a gigantic jet of molten material, which exited the atmosphere, some of it fanning out over North America. Much of the material was several times hotter than the surface of the sun, and it set fire to everything within a thousand miles. In addition, an inverted cone of liquefied, superheated rock rose, spread outward as countless red-hot blobs of glass, called tektites, and blanketed the Western Hemisphere.

Some of the ejecta escaped Earth’s gravitational pull and went into irregular orbits around the sun. Over millions of years, bits of it found their way to other planets and moons in the solar system. Mars was eventually strewn with the debris—just as pieces of Mars, knocked aloft by ancient asteroid impacts, have been found on Earth. A 2013 study in the journal Astrobiology estimated that tens of thousands of pounds of impact rubble may have landed on Titan, a moon of Saturn, and on Europa and Callisto, which orbit Jupiter—three satellites that scientists believe may have promising habitats for life. Mathematical models indicate that at least some of this vagabond debris still harbored living microbes. The asteroid may have sown life throughout the solar system, even as it ravaged life on Earth.

The asteroid was vaporized on impact. Its substance, mingling with vaporized Earth rock, formed a fiery plume, which reached halfway to the moon before collapsing in a pillar of incandescent dust. Computer models suggest that the atmosphere within fifteen hundred miles of ground zero became red hot from the debris storm, triggering gigantic forest fires. As the Earth rotated, the airborne material converged at the opposite side of the planet, where it fell and set fire to the entire Indian subcontinent. Measurements of the layer of ash and soot that eventually coated the Earth indicate that fires consumed about seventy per cent of the world’s forests. Meanwhile, giant tsunamis resulting from the impact churned across the Gulf of Mexico, tearing up coastlines, sometimes peeling up hundreds of feet of rock, pushing debris inland and then sucking it back out into deep water, leaving jumbled deposits that oilmen sometimes encounter in the course of deep-sea drilling...


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Response to friendly_iconoclast (Reply #5)

Tue Sep 10, 2019, 07:27 PM

6. That's some vivid description. Absolutely yikes.

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Response to mfcorey1 (Original post)

Mon Sep 9, 2019, 08:39 PM

3. Asteroid, shmasteroid

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Response to mfcorey1 (Original post)

Mon Sep 9, 2019, 09:05 PM

4. Very interesting.

75% of all plantlife and animals died almost immediate. All dinosaurs, except some avian dinosaurs died (including all land based dinosaurs
Wow, so the flying dinos beat wings, so to speak and some survived morph into birds, evolutionary speaking.

If there were a higher, cósmic consciousness, what better way to reprogram a planet.

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