Posted on 02/24/2022 11:45:38 PM PST by LibWhacker
We’ve long known a disaster took place about 66 million years ago, where in a geological instant, 75% of the plants and animals on Earth were wiped out, including all the land-roaming dinosaurs. But here’s a new detail about that event: Even though we can’t pinpoint exactly what year this disaster took place, we now know it happened during the springtime.
Most scientists agree the disaster was an asteroid impact, where an asteroid at least 10 kilometers wide struck the Chicxulub region in the present-day Yucatán Peninsula in Mexico. The impact released 2 million times more energy than the most powerful nuclear bomb ever detonated.
While previous studies looking at the timing of this event have focused on millennial timescales, a new study from Melanie During and colleagues from the University of Sweden focused on pinpointing seasonal information of fossilized fish found in a site in North Dakota, that perished as a result of the devastating impact.
The devastation created layer of ash sandwiched between layers of rock, known as the Cretaceous-Paleogene (K–Pg) boundary, formerly known as the Cretaceous–Tertiary (K-T) boundary, which is found across the world in the geologic record. It includes a layer of iridium, an element common in asteroids but rare on Earth. It was this ‘iridium anomaly’ that first revealed the extinction event as an asteroid strike to geologists more than three decades ago.
Artistic reconstruction by Joschua Knüppe of the Seiche wave surging into the Tanis river, bringing in fishes and everything in its path (dinosaurs, trees) while impact spherules rain down from the sky. Some dinosaurs are still trying to get away but we know they will not get far. Ants try to get back into their nest as the just blooming dianthus in the foreground are already being impacted by the impact spherules. Credit: Joschua Knüppe
Well-preserved fossil bones of filter-feeding sturgeons and paddlefishes found in the Tanis fossil site in North Dakota had impact debris lodged in their gills, but nowhere further down the digestive system, suggesting an almost-instantaneous death occurred when an impact-triggered seiche –continental water shaken by the impact — caused a sudden upriver surge.
The researchers found distinct growth patterns in the fossils that provided record of seasonal change, of when the fish had reproduced and had developing offspring. In the northern hemisphere, this would have been in the spring.
“We postulate that the timing of the Chicxulub impact in boreal spring and austral autumn was a major influence on selective biotic survival across the Cretaceous–Palaeogene boundary,” the authors wrote in their paper, published in Nature.
The timing of the collision, at least for the Northern Hemisphere, would have come at a particularly sensitive stage in the biological life cycles of many plants and animals.
“I think spring puts a large group of the late Cretaceous biota (animal and plant life) in a very vulnerable spot because they were out and about looking for food, tending to offspring and trying to build up resources after the harsh winter,” Melanie During said at a news briefing.
By contrast, the researchers said that ecosystems in the Southern Hemisphere, where it was fall when the asteroid collided with Earth, appear to have bounced back nearly twice as fast as those in the Northern Hemisphere.
Even though these fossils were found 3,000 kilometers (1,864 miles) away from the impact crater, the details of the dig show the large fish – which are up to a meter (3 feet) long — died dramatically shortly after the asteroid strike. They were buried alive by sediment displaced as a massive body of water unleashed by the asteroid strike moved upstream.
Impact spherules — small bits of molten rock ejected from the crater went high into the atmosphere or even to space where they crystallized into a glass-like material — were found lodged in the fishes’ gills.
“These impact spherules got ejected into space, …and rained back down on Earth,” During said. “This deposit literally looks like a car crash frozen in place. It looks like the most violent thing I have ever seen, preserved in pristine condition.”
This new study coincides with previous studies from as early as 1991 which showed fossils in the same condition, which suggested is happened in June, along with another study from December of 2021, which also concluded the extinction event happened in spring.
🎶 Springtime for Dinosaurs 🎶
🦕🦖🦕🦕🦕🦖🦖🦖🦕🦕
March the 3rd. Kinda messy.
They died on a Tuesday. Shortly after tea time.
Mortimer and Henry were lounging by the pond, just after having feasted on some fish. The two were talking about a ‘hunt’ on the southside of the valley, and entertaining some lady dinosaurs that night....when all hell broke loose.
p
It was a lovely, warm, thoroughly enjoyable spring day. Except for, you know, the everybody dying and stuff.
And they call this science...
I call it science fiction...
“I call it science fiction”
No, this is science. Meticulous collection of data from years of research all presented for review. Unlike the “science” that has been screamed at us for two years.
These "scientists" get paid big bucks for this cr**.
I prefer the more scientific method where they look at the fossilized remains on a dino’s stomach, noted they lunched on a sprintime variety of arugula salad, and then make a claim like this with authority.
>>Springtime for Dinosaurs<<
...and Germany!
Dang it, Spring is coming.
There once was a fellow named Hall
Who died in the spring, in the fall
Twould of been a sad thing, if he’d died in the spring
But he didn’t, he died in the fall
If only the Dinos had listened to Greta Thunbersaurus and her warnings about impending climate change doom.
Or it could have been from the great flood that covered the earth during Noah’s time.
😜🤣
100 million mega tons of tnt,
A six mile diameter rock falls from the sky.
There is about 6 seconds to watch it fall unless you see the shadow first and happen to look up to see.
I wonder what the approach angle was and if it did come from the direction of the sun.
Did the dinosaurs have any advance warning?
Dinosaurs started making fossil fuel in springtime?😎
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.