[REVIEW] : Discovery of the remains of a fossilized dinosaur with the skin probably dead on the day of the impact of the asteroid!

This is a huge paleontological discovery. A complete dinosaur leg, fossilized with skin, has been found in the US state of North Dakota. In addition to its exceptional preservation, this fossil could be the direct witness of one of the most important catastrophes in the history of the Earth: the impact of the asteroid of Chicxulub 66 million years ago, which would have participated to the mass extinction of the dinosaurs.

Finding the remains of dinosaurs that lived during the few thousand years framing this event is already relatively rare. So when Robert DePalma (University of Manchester) and his colleagues announced that they had discovered fossils of dead dinosaurs on the very day of the impact, the whole scientific community was in turmoil. Some clues indeed suggest that these dinosaurs would have died because of the impact itself.

Fish that swallowed debris from the asteroid

Several have caught the eye of scientists. This magnificent leg of Thescelosaurus, but also the remains of several fish. It is in fact mainly the latter who have put the flea in the ears of the researchers. Because inside their gills, scientists have found small spherules of molten rock, which could be debris from the meteorite impact, projected thousands of kilometers around the crater. As it fell to Earth, the 12-kilometer-diameter asteroid would have pulverized the rock of the Earth’s crust, scattering a rain of debris over a large part of the Globe, where fish would have swallowed them.

The chemical studies of these spherules, as well as their age, show that they would be well linked to the impact of the asteroid. The results, published in 2019 in Pnas, suggest that certain elements composing the spherules of molten rock swallowed by fish are of cosmic origin. These analyzes make it possible to better constrain the composition of the asteroid responsible for the cataclysm, which completely disintegrated during the impact and of which very few traces remain.

A dinosaur died very brutally

If the observations made on the spherules inside the fish seem to have consensus as being a direct marker of the impact, some scientists nevertheless remain skeptical about the interpretation of the scenario of the death of Thescelosaurus.

For the researchers behind this discovery, the main argument in favor of a death directly related to the impact is that the fossil was found in completely reworked and very chaotic sedimentary deposits, in association with many other animal remains, including fish carrying remnants of the asteroid. This type of sedimentary deposit would be characteristic of the arrival of a large wave that devastated the region following the impact. Among other discoveries made at the site, the researchers also unearthed a Pterosaur egg with an embryo in remarkable condition. An extremely rare find.

If it still seems difficult to affirm with certainty that this embryo, as well as the Thescelosaurus, died the same day of the impact, this discovery brings in any case new elements of understanding on the prenatal development as well as on the anatomy of dinosaurs, and more particularly on their skin. However, it will be necessary to wait for the publication of the data, via the current peer-review process, to confirm the hypotheses put forward by the researchers.

Discovery of the leg of a dinosaur killed by the asteroid that hit the Earth 66 million years ago

The leg belonging to a dinosaur victim of the giant asteroid, which hit the Earth 66 million years ago, has been unearthed (North Dakota) in the United States.

“It’s the most incredible object we could imagine here, the best-case scenario, the one thing we’ve always wanted to find on this site and now we have it,” said Robert DePalma, head of research at from the University of Manchester.

Very scaly skin

Until now, scientists had little information on the skin appearance of Thescelosaurus. This discovery made it possible to realize that these small dinosaurs “were very scaly like lizards”, according to Paul Barrett of the Museum of Natural History in London, who examined it.

The latter was able to confirm that the animal was dead on the spot and probably buried the day the devastating asteroid hit the Earth. “There is no evidence of disease on the paw, there is no obvious pathology and no bite mark. There are no pieces that have disappeared either, ”summarizes the specialist.

End of the dinosaurs: remains of the day the giant asteroid hit the earth found

“Dinosaurs: The Final Day”, for which journalists have followed and filmed the teams on site for years. Paleontologists would have discovered animals there that would have been “killed and buried the day the giant asteroid hit the earth”. And this while “fossils of dinosaurs dating from the period preceding the extinction are very rare, finding so many traces of the day of the cataclysm is extraordinary”, marvels Phillip Manning, professor of natural history at the University of Manchester.

An exact picture

For Robert DePalma, a graduate of the same university, who is leading the excavations, “we have so many details on this site that tell us what happened moment by moment, it’s like seeing it unfold in the movies. We look at the rock formations, we look at the fossils here, and it takes us back to that day. »

Came out of the ground, a particularly well-preserved leg of thescelosaurus, but also fish having ingested dust from that day, animals killed by the debris of the celestial body, including a turtle impaled on a wooden stake… And even a fragment of asteroid.

“Incredible”: the leg of a dinosaur killed 66 million years ago found

“It is the most incredible object we can imagine here, the best scenario, the only thing that we have always wanted to find on this site and we have it now”, testified the researcher from the University of Manchester Robert DePalma, Head of Research.

Death on impact

The dinosaur’s leg passed into the expert hands of Professor Paul Barrett of the Natural History Museum in London. “Thescelosaurus comes from a group on which we had almost no information on the skin aspect. This shows conclusively that these animals were very scaly like lizards.”