Research that had been kept secret for years that captured a fossilized snapshot of the day nearly 66 million years ago when an asteroid hit Earth, wiping out nearly all life on the planet, including the dinosaurs, has finally been released, shocking the scientific community.
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.
Additionally, University of Amsterdam professor Jan Smit said he and his colleagues found footsteps from dinosaurs moments before they met their untimely death.
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." Despite the incredible finds, other experts in the field have concerns about the work, 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 from 65 to 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." Johnson said the restrictions are preventing confirmation by other researchers, while Smit says it due to protecting the site from poachers.
Johnson also raised concerns about claims made by the main author, Robert DePalma, a University of Kansas doctoral student, that appeared in a New Yorker magazine article published last week but not in the scientific paper.
“A tangled mass of freshwater fish, terrestrial vertebrates, trees, branches, logs, marine ammonites and other marine creatures was all packed into this layer by the inland-directed surge,” Robert DePalma said in a statement. “Timing of the incoming ejecta spherules matched the calculated arrival times of seismic waves from the impact, suggesting that the impact could very well have triggered the surge.”
The University of Kansas has not yet responded to a request for comment from Fox News.
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. A study published in January suggests that the asteroid also caused a worldwide tsunami that reached more than 5,000 feet in the air.
Other researchers believe that volcanic activity played a role in the demise of the dinosaurs.
Johnson and Melosh said this helps prove the asteroid crash case. There were only a few dinosaur fossils from that time, but the footsteps are most convincing, Smit said.
There was more than dinosaurs, he said. The site includes ant nests, wasp nests, fragile preserved leaves and fish that were caught in the act of dying. He said that soon after fish die they get swollen bellies and these fossils didn't show swelling.
The researchers said the inland tsunami points to a massive earthquake generated by the asteroid crash, somewhere between a magnitude 10 and 11. That's more than 350 times stronger than the 1906 San Francisco earthquake.
Purdue's Melosh said as he read the study, he kept saying "wow, wow, what a discovery."
The details coming out of this are "mind-blowing," he said.
The North Dakota fossils are the latest in a series of fascinating dinosaur discoveries. Paleontologists recently confirmed that the world's largest T. rex has been discovered in Canada. In China, an incredible 110-million-year-old bird fossil was found with an egg inside.
Separately, duck-billed dinosaurs were recently discovered in the Arctic, a find that raises new questions about biodiversity among dinosaurs during the late Cretaceous period.
The Associated Press and Fox News’ Christopher Carbone contributed to this article.