WASHINGTON – New research released Friday captures a fossilized snapshot of the prehistoric day when scientists theorize an asteroid smacked Earth, fire rained from the sky and the ground shook far worse than any modern earthquake.
It was the day that nearly all life on Earth went extinct, including the dinosaurs.
The researchers say they found evidence in North Dakota of the asteroid hit in Mexico, including fish with hot glass in their gills from flaming debris that showered back down on Earth. They also reported the discovery of charred trees, evidence of an inland tsunami and melted amber.
Separately, University of Amsterdam's Jan Smit disclosed that he and his colleagues even found dinosaur footsteps from just before their demise.
Smit said the footprints – one from a plant-eating hadrosaur and the other of a meat eater, maybe a small Tyrannosaurus rex – is “definite proof that the dinosaurs were alive and kicking at the time of impact ... They were running around, chasing each other” when they were swamped.
“This is the death blow preserved at one particular site. This is just spectacular,” said Purdue University geophysicist and impact expert Jay Melosh, who wasn't part of the research but edited the paper released Friday by the journal Proceedings of the National Academy of Sciences.
Melosh called it the field's “discovery of the century.” But other experts said that while some of the work is fascinating, they have some serious concerns about the research, including the lack of access to this specific Hell Creek Formation fossil site for outside scientists.
Hell Creek – which spans Montana, both Dakotas and Wyoming – is a fossil treasure trove that includes numerous types of dinosaurs, mammals, reptiles and fish trapped in clay and stone, dated by scientists to between 65 million and 70 million years ago.
Kirk Johnson, director of the Smithsonian National Museum of Natural History who also has studied the Hell Creek area for 38 years, said that the work on the fish, the glass and trees “demonstrates some of the details of what happened on THE DAY. That's all quite interesting and very valid stuff.” But Johnson said that because there is restricted access to the site, other scientists can't confirm the research. Smit said the restrictions were to protect the site from poachers.
For decades, the massive asteroid crash that caused the Chicxulub crater in Mexico's Yucatan Peninsula has been considered the likely cause of the mass extinction often called the “KT boundary” for the division between two geologic time periods. But some scientists have insisted that massive volcanic activity played a role. Johnson and Melosh said this helps prove the asteroid crash case.
http://www.journalgazette.net/news/science/20190330/death-blow-of-dinosaurs-found
2019-03-30 05:05:31Z
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