Paleontologists may have found a tiny fragment from the asteroid that killed the dinosaurs when it hit Earth 66 million years ago. It is encased in amber and NASA finds it to be a "mind-blowing" discovery. It was one of the astounding finds in the fossil site in the Hell Creek Formation in North Dakota that preserved the remnants of the asteroid impact that changed the course of the planet.
Its full story was revealed in the documentary "Dinosaurs: The Final Day" on BBC last month and in the "Dinosaur Apocalypse" on the PBS show "Nova," featuring naturalist Sir David Attenborough and paleontologist Robert DePalma.
The Day the Asteroid Hit Earth
DePalma, a postgraduate researcher at the University of Manchester and adjunct professor for the geosciences department at the Florida Atlantic University, started working at the Tanis fossils site in southwestern North Dakota in 2012.
The dusty plains of the fossil site are said to be the exact opposite of what it was before the asteroid impact in the Cretaceous Period, CNN reported. It was a rainforest with an inland sea called the Western Interior Seaway that ran all the way from the Gulf of Mexico to Canada. But now, it has become a wonderland of fossils buried in the aftermath of the asteroid impact, as the 2019 New Yorker article describes the site.
The impact has carved a crater now known as the Chicxulub impact crater, about 100 miles wide and almost 20 miles deep. Molten rock splashed into the air during the impact and cooled into glass spherules. DePalma wrote in his 2019 research paper that impact spherules rained down from the sky and clogged the gills of paddlefish and sturgeon and suffocated them.
But some impact spherules landed on the resin on logs that protected the shards from water and kept them as pristine as the day they were formed. DePalma and colleagues focused on these bits of unmelted rock in their latest findings that are yet to be published in a peer-reviewed scientific journal.
Composition of Asteroid Fragment
DePalma said that finding a well-preserved fragment of the asteroid encased in amber is equivalent to sending someone back in time to gather samples. Most of the rock bits contain strontium and calcium, which indicates that they were part of the limestone crust of the impact site, the New York Times reported.
However, they are a little different inside. The rocks contain higher levels of iron, chromium, and nickel, which point to an asteroid and carbonaceous chondrites. It is similar to Frank Kyte's discovery in 1998 when he found a fragment of the meteor in a core sample drilled off Hawaii, which is more than 5,000 miles from Chicxulub.
There are also some bubbles in the spherules, and scientists believe that they still hold air from 66 million years ago since there are no cracks on them.
Fossil Record Could Give Insight into Current Climate Crisis
Aside from the spherules, DePalma and his team discovered some fossils on the site, like the limb of the plant-eating dinosaur called Thescelosaurus, CNN reported. The limb still has skin on it, which suggests that there was no time for it to decay before it was buried in sediment.
Other fossils found are the fossilized pterosaur egg, which is a piece of evidence that the eggs of the giant flying reptiles were soft like those of today. They also discovered a fossilized turtle with a wooden stick through its body.
Researchers believe that the fossil record gives insights into how a global-scale hazard affected life on Earth and how its biota reacted. Therefore, it gives humans a crystal ball that looks back in time to apply in today's climate crisis.
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