It is one of many astonishing discoveries at a unique fossil site in Hell Creek Formation in North Dakota that has preserved the remains of the catastrophic moment that ended the age of the dinosaurs – a turning point in the planet’s history.
fossils Discovered there include fish that sucked in explosive debris during The blow, a tortoise impaled with a stick and a leg, probably belonged to a dinosaur that witnessed the asteroid collision.
DePalma, a graduate researcher at the University of Manchester in the UK and assistant professor in the Department of Geosciences at Florida Atlantic University, first began working on Tanis, as the fossil site is known, in 2012.
The exposed and dusty plains contrast starkly With What the site would have looked like at the end of the Cretaceous period. At that time, the American Midwest It was a swampy rainforest, and an inland sea that has since disappeared — known as the Western Inland Seaway — stretches all the way from what is now the Gulf of Mexico to Canada.
Tanis is more than 2,000 miles from the Chicxulub impact crater left by the asteroid that struck off the coast of Mexico, but initial discoveries made at the site convinced de Palma that it provided rare evidence of what led to the end of the age of the dinosaurs.
The site is home to thousands of well-preserved fish fossils that de Palma believes were buried alive by sediments that were displaced when a huge mass of water released by the asteroid strike moved over the Inland Seaway. Unlike a tsunami, which can take hours to reach land after an earthquake at sea, these moving bodies of water, known as an earthquake, rose immediately after the massive asteroid crashed into the sea.
“Piece by piece of evidence began to pile up and change the story,” de Palma said. “It was a series of clues like the Sherlock Holmes investigation.”
“It gives a moment-by-moment story of what happens right after the impact and you end up having such a rich resource for scientific research.”
Many of the recent discoveries revealed in the documentary have not been published in scientific journals.
Although it is “conventional” for new scientific claims to be subject to peer review before they are revealed on television, several other paleontologists have acknowledged that the site Fossils truly represent the “last day” of the dinosaurs.
“Some experts said ‘OK, it could be the next day or a month ago…but I prefer the simpler explanation, which is that it really documents the day the asteroid hit Mexico,'” he said via email.
cosmic origin
“In that amber, we identified a number of balls that were basically frozen over time, because, just like an insect in perfectly preserved amber, when they got into these amber balls, the water couldn’t get into the mud, and they are perfectly preserved.”
It’s “like getting a sample vial, going back in time and getting a sample from an impact site and then saving it for science,” DePalma She said.
They were able to locate a number of small, unmolten rock fragments inside the glass spheres. Most of these small rock fragments are rich in calcium — most likely from limestone under the Yucatan Peninsula, de Palma said.
“But two of those were very different in composition. You had elevations in chromium, nickel and some other elements that are only common in meteorites and those fragments based on our initial analysis… are almost certainly of cosmic origin.”
said Jim Garvin, chief scientist at Goddard, who has studied collision crashes on Earth and Mars.
Searching for buried amber spherules have not been published in a refereed journal. During peer review, scientists provide rigorous notes about each other’s work to ensure it faces scrutiny. DePalma said to peer review A paper on the preliminary results will be published “in the coming months”.
dinosaur leg
An exceptionally preserved dinosaur leg with patchy skin is another discovery from the Tanis site that was featured in the documentary, which first aired in the UK in April, and has racked up the limelight in the paleontologist.
Very few fossils from the Cretaceous period have been found in the upper rocks of the geological record, and it is possible that the tip — which belonged to Thescelosaurus, a small plant-eating dinosaur discovered by DePalma and his colleagues — would have died on the same day the asteroid impacted. Preservation of soft tissues such as skin indicates that her body did not have any time to decompose before it was buried in the sediment.
“The only two scenarios supported here are that he died during the surge or that he died just before (the asteroid strike) but it’s so close in time that it didn’t really have time to disintegrate. That’s not something that died years ago and then paraphrased. This doesn’t happen with soft tissues. Like this “.
Detailed analysis of dinosaur leg bones can shed light on conditions before the impact.
Other fascinating finds from the site include a fossilized pterosaur egg, the first egg found in North America. It appears that the eggs of the giant flying reptiles were as soft as the eggs of many reptiles today. A petrified turtle with a wooden stick across its body is evidence that the creature was impaled during the wave of water released by the asteroid impact.
Not only does the work done at Tanis bring to light the astonishing details of what happened on the day the asteroid hit, it also provides great insight into In an event that caused a mass extinction and how that extinction occurred later. DePalma hopes this provides a framework for thinking about today’s climate crisis.
“The fossil record gives us a window into the details of the global threat and the response of living organisms on Earth to this threat,” de Palma said. “It gives us…a crystal ball that looks back in time and enables us to apply that to today’s ecological and ecological crisis.”
“This is amazing, but it is also beneficial for us. Because by studying this event in more detail, we can be better prepared to take care of our world at the moment.”