DINOSAUR – A real treasure. This is what paleontologists stumbled upon at the Tanis fossil site in North Dakota, United States. In fact, researchers have made many discoveries, including a herbivorous dinosaur leg with skin found on it, or a pterodactyl (flying reptile) with a particularly well-preserved embryo. An adventure narrated by famed naturalist David Attenborough in a new BBC documentary to be aired this Friday 15 April.
But that’s not all. Paleontologists claim that these discoveries could have been made 66 million years ago, just as the asteroid that caused the dinosaur extinction crashed. If it hasn’t yet been published in a peer-reviewed journal, scientists are amazed at the discovery.
Tanis, fossil gold mine
“The timing accuracy that we can achieve at this point is beyond our wildest dreams…” Phillip Manning, professor of natural history at the University of Manchester, told BBC Radio 4. “Never in my entire career did I dream that I would once had the opportunity to see something (…) so beautiful that also tells such a wonderful story,” he adds, illustrating the excitement surrounding the discoveries being made at the Tanis site.
There are many fossils in a remarkable state of preservation. First, there’s this dinosaur leg, a small herbivore in the ornithopod family called Thescelosaurus. In perfect condition, the leg appears to have been quickly ripped off, with no traces of disease or signs of predation, says Paul Barrett, a dinosaur expert at the Natural History Museum in London.Telegraph.
Other remains found nearby include a fossilized turtle impaled by a wooden stake, small mammals in their burrows, the skin of a triceratops, and a fossilized pterosaur embryo in its egg. Regarding the latter, X-rays found that the pterosaur’s egg may have been buried in the sand by the mother, in a similar way to how modern turtles bury their eggs, according to the BBC.
What all of these discoveries have in common is that they date to the end of the Cretaceous and appear to be at the forefront of the beginning of the end. In fact, the fossils discovered in Tanis have many elements that suggest that these animals participated in the fall of the asteroid that caused the dinosaurs to disappear from Chicxulub, in Mexico.
This was already explained by a study published in April 1, 2019 Proceedings of the American Academy of Sciences (PNAS), the result of the collaboration of eleven paleontologists.
Discoveries from the fall of the asteroid
Many aquatic and terrestrial creatures fossilized together at the site of Tanis seem to indicate that they would have died by the time of the meteorite impact.
In fact, debris was found on the complete leg mentioned above, as well as on an ancient fish. They are in all likelihood tiny bits of molten rock, like bits of glass thrown up by the asteroid and lodged in the gills of the fossilized fish.
These pieces, also called globules, have been linked to the location of the asteroid impact in Peninsular Mexico thanks to radiometric dating (the best known is carbon 14). This gives a measure of the shock when the meteorite struck about 3000 km from what is now North Dakota. Here is a video illustrating this disaster:
In addition, it appears that parts of the asteroid have been found. In fact, fragments were found in amber and after analysis, researchers discovered that they contained iron, chromium and nickel, a composition found in asteroids.
In front of all these elements, paleontologist Robert DePlama (University of Manchester researcher who directs excavation projects at the Tanis site) is admiring. “We have so many details (…). You look at the pillar, you look at the fossils there, and it brings you back to today,” he told the BBC.
If these discoveries astound more than one, some paleontologists are calling for action. In fact, finds at the Tanis site “have not yet been established beyond doubt in the peer-reviewed literature,” University of Edinburgh paleontologist Steve Brusatte tells the BBC.
However, the researcher adds that this is “interesting” research, made credible by the fact that big names in the field like Walter Alvarez (father of the idea in 1980 that an asteroid caused the mass extinction) were involved associated with the study.
“Does it even matter for some of these findings whether these animals died on the day of impact or in previous years?” Steve Brusatte finally wonders, adding that “the pterosaur egg with a pterosaur baby inside is extremely rare ; there is nothing like it in North America”.
Also see on HuffPost: This flying reptile is the largest ever discovered in the Jurassic