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Home https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ Science https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ Mowing fossils show mammals racing to fill the void of dinosaurs

Mowing fossils show mammals racing to fill the void of dinosaurs



About 66 million years ago, mammals were lucky. An asteroid bumped into what is now Chicxulub, Mexico, and launched a catastrophic chain of events that led to the destruction of non-bird dinosaurs. That day began his hairy climb to the top of a brave new world, the one from which our species would one day emerge . But little is known about the period immediately after the disappearance of the Cretaceous-Paleogene or the K-Pg event, because there is no fossil.

A team of paleontologists has discovered in Colorado a trail of thousands of fossils that provides an in-depth look at the first millions of years after the K-Pg mass extinction event. The discovery provides an insight into the interactions between animals, plants and the climate that emerged in the earliest days of the mammalian era, and allowed them to grow from the size of large rodents in the diverse wildlife we ​​can begin to recognize today.

"We provide the brightest picture of restoring the drought ecosystem after any mass extinction," says Tyler Leeson, a paleontologist on vertebrate animals in Nature and Science in Denver. His team document was published Thursday in Science.

Dr. Leeson has been hunting fossils since the age of 10. Although he has discovered many dinosaurs, he has discovered fossils of species that appeared immediately after the extinction of dinosaurs proved to be quite elusive in his field of study. [19659005] "You can only find so many Trikeratop skeletons and partial skeletons of T. rex and stuff, until you want a bigger challenge," Dr. Lison said. "Finding fossils right after the K-Pg disappears is a huge, huge challenge."

In the spring of 2016, he and some colleagues explored a fossil site near Colorado Springs called Corral Bluffs. He knew years earlier Sharon Milito, a fan of fossil hunting, had discovered a mammal's skull, which was confirmed to be from the K-Pg border. He went looking for mammalian bones protruding from the ground. But his search proved fruitless.

While wandering through the bluff, he returned to his time as a graduate student working in South Africa. There he had learned to spot certain rocks, called concrements, that hold fossils in captivity, like pearls in oysters. He shifted his focus from the bones to the rocks.

"I found this ugly, white-looking rock that looked like a small mammalian jaw," Dr. Lison said. He opened it and found it inside a fossilized crocodile. "That was the moment when the bulb went out. If there is one fossilized concrete inside, there should be more more . "

"You are going from a very small dog that you will see on the streets of New York to a very large wolf within these hundreds of thousands of years," says Dr. Chester.


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