The dinosaurs would have experienced “hell on earth” on the day the asteroid hit Earth 66 million years ago, paleontologists have found.

In a new documentary, Dinosaur Apocalypse from NOVA—narrated by David Attenborough— lead paleontologist Robert DePalma and his team discover a trove of fossils that provide a glimpse into what the last dinosaurs on Earth would have experienced right before their extinction.

The fossils were revealed from a site in the Badlands of North Dakota in the Hell Creek rock formation, which was developed during the Cretaceous period.

In the second part of the documentary, Dinosaur Apocalypse: The Last Day, paleontologists uncover ejecta spherules at the site, which are tiny beads of vaporized rock created by the impact of the asteroid.

Not far from the spherules, they uncovered a three-dimensional leg from a herbivorous dinosaur called Thescelosaurus. While it has not been confirmed, this dinosaur may have been killed by the direct impact of the asteroid—something excavators have never before discovered.

DePalma told Newsweek that these findings provide a snapshot into what the dinosaurs would have experienced, directly after “the massive Mount Everest sized piece of rock” plummeted into the Earth.

“It hit Earth at roughly 20 kilometres (12 miles) a second, that caused that massive impact crater which was formed in the Yucatan,” he said. “Within minutes, the animals would have felt seismic waves rippling through the ground, and at the same time, you would have seen these blobs of impact glass that were blown out of the crater that came back down to the atmosphere as these little red streaks in the air… hell rain would have been raining down.”

DePalma said it would have been “really upsetting” for any animals there. A lot of these animals lived along the river embankments, DePalma said. Back then, the U.S was split in two by a “massive seaway” that ran right up the middle. The Hell Creek Formation, and the site excavated by paleontologists in the documentary, lay right on the banks of that seaway.

And directly after impact, all animals living along the river embankment would have seen a rapidly changing landscape within minutes.

“Any animal that would have been within eyeshot of that river valley would have seen a vista, that would have gone from a tropical paradise to absolute hell on earth,” he said. “They would have seen this massive wall of death… this big wall of water with debris and trees and mud and everything mixed into it. Just racing up that river. The surge came from the direction of the seaway… and that massive wall of water would have been racing up that river embankment…. So you would have had this 10 and a half metre (34 feet) wall of water coming up there. And anything in its path would have been pretty much encapsulated by that.”

What followed was the “second pulse,” of the dinosaur apocalypse. DePalma said this was a period of atmospheric contamination from the heating right after impact, which in turn caused wildfires and later, freezing temperatures.

DePalma said this particular excavation site represents a “perfect storm scenario” as it not only had geographical significance, but held evidence from a key point in time at the end of the Cretaceous period.

“Could there be other sites like this? Absolutely. But try finding them—it’s a needle in a haystack,” he said.

DePalma said that even for people who are not interested in the history of the dinosaurs, the findings from this documentary are relevant to the ecological crisis taking place in the world today.

“You can now perceive what happened in a much more personal way because you can see each of the individual animals’ experience through the effects of that impact,” he said. “The extinction that occurred at the end of the Cretaceous was startlingly close, in time frame and tempo to what the world is seeing today…So of all the mass extinctions that we know about on Earth, one of the closest to that time frame is this particular extinction…Ultimately, my hope and dream is that the impact [from this documentary] is on a broader scale. I hope the take away from this investigation is knowing what the world used to be like, what it’s like, and sort of invokes a sense of pride in taking care of your planet.”

Jurassic Dinosaurs
Dinosaur Apocalypse will premiere on PBS Wednesday, May 11, 2022 at 9pm ET/8CT.