Paleontologists in North Dakota has uncovered an incredible stash of fossils that was formed instantaneously after an asteroid struck Earth nearly 66 million years ago.
Excavations revealed in amazing detail fossils of fish and other animals unable to escape the glassy fragments that plummeted from the sky caused by the thunderous impact that obliterated the dinosaurs.
The deposits also contain water, indicating a mammoth sea surge that the collision created.
University of Kansas paleontologist Robert DePalma and colleagues said the excavation site, called Tanis, offered a momentous peek into events that occurred minutes after the asteroid crashed into the planet.
“This is the first mass death assemblage of large organisms anyone has found associated with (the end of the Cretaceous Period),” said DePalma. “At no other (time) on Earth can you find such a collection consisting of a large number of species representing different ages of organisms and different stages of life, all of which died at the same time, on the same day.”
The impact is understood to have generated a huge tsunami, it would have taken many hours for this wave to travel the distance from the Gulf to North Dakota, despite the likely presence back then of a seaway cutting directly across the North American land mass..
Instead, the researchers believe local water could have been displaced much more quickly by the seismic shockwave – equivalent to a Magnitude 10 or 11 earthquake – that would have rippled around the Earth. It is a type of surge described as a seiche, which would have picked up everything in its path and dumped it into the jumbled collection of specimens now being reported by the team.
“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,” said Mr DePalma.
“A tsunami would have taken at least 17 or more hours to reach the site from the crater, but seismic waves – and a subsequent surge – would have reached it in tens of minutes,” he added.
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