(ORDO NEWS) — A petrified turtle pierced by a piece of wood, fish with fragments in their gills, and mammals buried in their own holes are just a few of the first victims of the Chicxulub meteorite. All of them were found near Tanis in North Dakota and vividly illustrate the very first stage of the great extinction.
From year to year, we learn more and more about the causes of the great extinction that put an end to the Mesozoic era and the dominance of dinosaurs on Earth. There is no doubt that the huge Chicxulub meteorite played the main role in this tragedy.
Its fall led to a cascade of global consequences for the Earth and its population. Some of them were stretched out in time, but for those who lived close enough to the epicenter of the impact, it turned into an instant drama, which, like the infamous Pompeii, was well preserved in the rocks.
It is believed that the fatal meteorite was about 12 kilometers across and fell into the sea near the Yucatan Peninsula, at a distance of as much as three thousand kilometers from Tanis, an excavation site in North Dakota (USA). Despite this, fatal consequences for the locals came immediately.
“We see a lot of details here that help to reconstruct the sequence of events, as if watching this scene in a movie,” says Robert DePalma (Robert DePalma), head of the excavation and graduate student from the University of Manchester (UK). “You look at the rock cut, you see the fossils, and it’s like you’re transported back to that day.”
Fossils dating back to the time of the fall are a real mess. The destroyed fragments of the bodies of animals and plants, the inhabitants of the river and its banks were mixed and washed away by the streams of river water – this created a monstrous earthquake.
Among other victims of that terrible day, paleontologists were especially interested in the remains of sturgeon fish that lived in the local river. Small particles stuck in their gills turned out to be spherules. They were formed from rocks melted by an explosion of monstrous force, flew thousands of kilometers and only then fell into the water.
Chemical analysis and radioisotope dating made it clear: they really got here at the time of the meteorite fall. Two of these spherules contain remnants of tree resin, as well as material of extraterrestrial origin.
“When we noticed that there were some inclusions inside these little glass balls, spherules, we studied their chemical composition using the Diamond X-ray synchrotron, which is located near London,” said Professor Phil Manning, scientific director Robert DePalma. Scientists are convinced that particles of the meteorite itself also got into the gills of these fish.
In the neighborhood of the unfortunate fish, there are many other victims of that tragedy, which have turned into its own monuments. Recently, scientists have learned that the fall took place in the spring – the time when all living things were preparing for another long warm season, one of those that had been seen many millions of times in the Mesozoic.
Here, in Tanis, scientists stumbled upon a huge rarity – a pterosaur egg with an embryo remaining inside. A turtle killed with a wood chip. Skin torn off a Triceratops. A severed leg posed a separate forensic task to paleontologists .
“It’s a Thescelosaurus . It belongs to a group of dinosaurs whose skin remains have not been found before, and this sample very convincingly shows that they were covered with advanced scales – like in lizards, – said another scientist and professor Paul Barrett (Paul Barrett). “They didn’t have feathers like those of their predatory contemporaries.”
Paleontologists suggest that the limb of the Thescelosaurus was torn out instantly. There were no traces of disease or carrion teeth left on it.
Looking back at the whole tragic picture in Tanis, paleontologists conclude that all the animals found died almost simultaneously.
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