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Fossils Of Fish Killed By Asteroid That Wiped Out Dinosaurs

kamalktk

Antediluvian
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Scientists may have found fossils of fish directly killed by the asteroid that killed the dinosaurs

Scientists Find Fossilized Fish That May Have Been Blasted by Debris From Asteroid That Ended the Dinosaur Age

https://gizmodo.com/scientists-find-fossilized-fish-that-may-have-been-blas-1833671176

"But the rocks at Tanis preserve a mixture of both freshwater fish, like paddlefish and sturgeon, and marine mollusks called ammonites—implying that around this time, the ocean had mixed with freshwater rivers. And lodged inside the fossilized paddlefish’s gills were more of the glass spherules. It appeared that waves containing shocked glass from the impact over 3,050 kilometers (1,895 miles) away had inundated the area, and in their dying breaths, the fish had inhaled some of them. "
 
There is a lot of back-channel chatter going on with paleontologists about this. It's being sold as the "dinosaur graveyard". The evidence hyped in the media stories are apparently not in the PNAS paper. Note this from the New Yorker splash:

https://www.newyorker.com/magazine/2019/04/08/the-day-the-dinosaurs-died
"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."

Update: I've now gone through the paper's supplement. Only a single dinosaur bone is mentioned: a partial ceratopsian ilium that was 'extensively transported' before deposition. This is an awesome site, but I don't see any evidence for a dinosaur graveyard! Something is weird.

That doesn't mean the find isn't real but science via media is poor form, hurts your rep, and usually turns out to be oversold.
 
Maybe we can edit the thread to change the fish reference, because there are claims that it is fish and very likely dinosaurs:

On August 5, 2013, I received an e-mail from a graduate student named Robert DePalma. ... I called, and he told me that he had discovered a site...which contained, among other things, direct victims of the catastrophe.

DePalma discovered a large feather. “Every day is Christmas out here,” he said. He exposed the feather with precise movements. It was a crisp impression in the layer of mud, perhaps thirteen inches long. “This is my ninth feather,” he said. “The first fossil feathers ever found at Hell Creek. I’m convinced these are dinosaur feathers. I don’t know for sure. But these are primitive feathers, and most are a foot long. There are zero birds that big from Hell Creek with feathers this primitive. It’s more parsimonious to suggest it was a known dinosaur, most likely a theropod, possibly a raptor.” He kept digging. “Maybe we’ll find the raptor that these feathers came from, but I doubt it. These feathers could have floated from a long way off.”

It's a very promising site - but as so often, we will have to wait for the outcome. However, the whole article gives you an idea of what they are finding there. If true, totally amazing.

https://www.newyorker.com/magazine/2019/04/08/the-day-the-dinosaurs-died
 
The controversy continues.

Astonishment, skepticism greet fossils claimed to record dinosaur-killing asteroid impact
By Colin BarrasApr. 1, 2019 , 10:50 AM

A fossil site in North Dakota records a stunningly detailed picture of the devastation minutes after an asteroid slammed into Earth about 66 million years ago, a group of paleontologists argue in a paper due out this week. Geologists have theorized that the impact, near what is now the town of Chicxulub on Mexico’s Yucatán Peninsula, played a role in the mass extinction at the end of the Cretaceous period, when all the dinosaurs (except birds) and much other life on Earth vanished.

If the team, led by Robert DePalma, a graduate student in paleontology at the University of Kansas in Lawrence, is correct, it has uncovered a record of apocalyptic destruction 3000 kilometers from Chicxulub. At the site, called Tanis, the researchers say they have discovered the chaotic debris left when tsunamilike waves surged up a river valley. Trapped in the debris is a jumbled mess of fossils, including freshwater sturgeon that apparently choked to death on glassy particles raining out of the sky from the fireball lofted by the impact.

“That’s the first ever evidence of the interaction between life on the last day of the Cretaceous and the impact event,” says team member Phillip Manning, a paleontologist at the University of Manchester in the United Kingdom. The deposit may also provide some of the strongest evidence yet that non-bird dinosaurs were still thriving on impact day.

https://www.sciencemag.org/news/201...ly_2019-04-02&et_rid=394299689&et_cid=2747366
 
More finds at Tanis.

When a massive asteroid struck Earth some 66 million years ago, were dinosaurs around to experience the cataclysm?

Two years ago, a paleontologist claimed to have found evidence at a fossil-rich North Dakotan site called Tanis that dinosaurs were alive until moments after the impact, when floodwaters surged over them. But many paleontologists were skeptical, especially because the dinosaur data were first discussed in a magazine story rather than a peer-reviewed journal. Last week, at the annual meeting of the Geological Society of America (GSA) in Portland, Oregon, paleontologist Robert DePalma and colleagues added detail to their claims. They presented evidence of fossils from Tanis—including stunningly well-preserved bones, skin, and footprints from what’s probably a Triceratops—that suggest dinosaurs were indeed witnesses to the asteroid that ushered them out of existence.

“This is a good example that shows a healthy ecosystem in the Dinosauria prior to the extinction,” says Sean Gulick, a geophysicist at the University of Texas, Austin, who attended the talk. But some paleontologists are reserving judgement. The work is “a step in the right direction,” says Kay Behrensmeyer, a vertebrate paleontologist at the Smithsonian Institution’s National Museum of Natural History. But she says that although the claims by DePalma and his colleagues “are dramatic and compelling, especially to nonpaleontologists,” they haven’t clearly outlined their argument or fully considered alternative interpretations that might complicate the dating of the site’s sediment layers.

The fateful asteroid that struck what is today Mexico’s Yucatán Peninsula near the town of Chicxulub Pueblo left behind a crater 150 kilometers in diameter, sending violent shock waves across the globe, kicking up widespread plumes of hot dust and ash, and triggering volcanic eruptions and roiling tsunamis. The apocalyptic spectacle marked the end of the Cretaceous period, during which terrestrial dinosaurs had dominated the landscape, and the beginning of a new Paleogene era.

But despite its reputation as a “dino killer,” a few paleontologists have questioned whether the asteroid actually killed off the dinosaurs or the mighty reptiles were by that point already extinct or in serious decline. ...

https://www.science.org/content/art...eroid-hit-excavators-controversial-site-claim
 
Springtime For Mammals! Winter For Dinosaurs! More on this story,

On a spring day 66 million years ago, as flowers bloomed and baby birds hatched in what is now North Dakota, a ball of fire streaked across the sky and wiped out nearly three-quarters of life on Earth.

So says a new high-resolution study of fossilized fish bones, which pinpoints the season of the Cretaceous-Paleogene mass extinction to the Northern Hemisphere spring.

“It’s amazing that this is an event that happened 66 million years ago, and we’re talking about the season,” says Kenneth Lacovara, a paleontologist at Rowan University who wasn’t involved with the paper. “It’s a remarkable degree of resolution.”

When it struck Mexico’s Yucatán Peninsula, the 10-kilometer asteroid tossed debris into the atmosphere and literally shook Earth. Gases and rock filled the air, kicking off a nuclear winter and leading to the extinction of 75% of Earth’s species, including all nonavian dinosaurs.

Some creatures died on the day the asteroid struck. At a site called Tanis in present-day North Dakota (more than 3500 kilometers away from where the asteroid hit), a tsunamilike wave called a seiche sloshed out of a river and swept up all life in its path, depositing sediment, trees, and animal carcasses in a jumbled heap. Now, paleontologists are analyzing the pile of ancient bones frozen among Cretaceous tree trunks and stacks of rock. “[The site] looked incredibly violent, like a car crash,” says Melanie During, a paleontologist at Uppsala University and lead author of the new paper, who visited Tanis in 2017.

During wasn’t part of the discovery of Tanis, which generated controversy after an article in The New Yorker revealed details about the find that were not included in the first research paper, released several days later in the Proceedings of the National Academy of Sciences (PNAS). Since then, the team that discovered Tanis has released more data in subsequent papers and at scientific meetings. “It’s a really remarkable site that captures this short window of time immediately after impact,” says James Witts, a paleontologist at the University of Bristol who has visited Tanis. ...

https://www.science.org/content/art...n-dinosaurs-died-ancient-fish-fossils-suggest.
 
There is a link in the TV & Radio reminders thread, "Dinosaurs:- The Final Day", with David Attenbrough.
 
....The Yucatan impact ... probably the greatest ever “ What If”.... in history?
And covered very well imho by Harry Harrison’s “West of Eden” series of novels...
 
its a great documentary...though maybe a little sensationalist.

(but maybe the K-T event is sensationalist)
 
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