The new finding was made at a controversial dig site that is said by some researchers to hold a pristine record of the day the dinosaurs died.
The image shows the skeletons of tyrannosaurs partially buried in the middle of what has become a desert after the impact of a large asteroid in present-day Mexico. (Getty Images)
A remarkable discovery made in North Dakota suggests that the asteroid impact that wiped out dinosaurs and much of the life on Earth occurred in the springtime.
To reach that conclusion, researchers led by Melanie During, a graduate student at Uppsala University in Sweden, studied the remains of fossilized fish at the Tanis dig site in North Dakota. The team of researchers argued that the growth pattern preserved in the fossilized fish bones suggests that the finned creatures perished during the spring, according to findings published in the journal Nature last week.
According to Nature, fish bones grow rapidly in the springtime as food becomes more abundant and growth slows in winter as the food supply shrinks. With well-preserved fishbones and the aid of some high-powered technology, what is known as ‘line of arrested growth’ (LAG) can be seen preserved in the bone tissue.
A team of researchers was able to create high-resolution micro-computerized-tomography models of six different fish bones and identified LAGs in all six, a fact that suggests the asteroid that killed them, and also the dinosaurs, landed in the spring.
During, the paper's lead author, said a springtime impact would have been particularly devastating.
"I think spring puts a large group of the late Cretaceous biota (animal and plant life) in a very vulnerable spot because they were out and about looking for food, tending to offspring and trying to build up resources after the harsh winter," she said at a news briefing according to CNN.
Illustration of a tyrannosaurus as an asteroid strikes the Earth. Tyrannosaurus was one of the very last dinosaurs, wiped out 65 million years ago during the extinction event that ended the Cretaceous period. Scientists believe that the incident was provoked by the impact of an asteroid or comet with the Earth off the coast of what is now Mexico. (Getty Images)
In another finding that backs up that hypothesis, ecosystems in the Southern Hemisphere recovered nearly twice as fast from the asteroid impact, something that suggests that the asteroid struck during the vulnerable springtime period in the Northern Hemisphere.
Yet, according to Nature, LAGs can be contentious. One qualified postdoctoral researcher, who requested anonymity in order to speak to Nature given the controversy of the site, questioned the spring-impact hypothesis.
“There is no uniform, agreed-upon definition of what a LAG is or how you identify one,” the unnamed researcher said, adding that there is not agreement on how LAGs form.
The Tanis dig site first attracted attention and controversy in 2019 when it was discovered by Robert DePalma, now a PhD student at the University of Manchester, U.K., according to Nature. DePalma said that the Tanis site captured something that had never been seen before -- a picture of what had happened in the minutes to hours after the asteroid that killed the dinosaurs struck Earth on Mexico’s Yucatán Peninsula about 66 million years ago.
DePalma's discovery was met with skepticism as no other place on Earth is believed to store a clear record of the day the dinosaurs died. Additionally, DePalma was accused of restricting access to the dig site, something he denied in an email to AccuWeather, saying that researchers from the American Museum of Natural History in New York City, Stony Brook University and others from European universities have had access to the Tanis site.
A Tyrannosaurus rex skeleton is seen on display biting a Triceratops during the Smithsonian's National Museum of Natural History's "David H. Koch Hall of Fossils-Deep Time" during a media preview in Washington, Tuesday, June 4, 2019. (AP Photo/Carolyn Kaster)
During's results also help to boost DePalma's claims of a well-preserved dig site.
"This deposit literally looks like a car crash frozen in place. It looks like the most violent thing I have ever seen, preserved in pristine condition," During said of the fossil site, according to CNN.
In a 2019 paper, DePalma argued that the massive impact formed 10-meter-high (33-foot-high) seiche waves that killed the fish and other species in the area instantly. That wave deposited dead organisms that became preserved in Tanis, organisms that During excavated for the study.
"I feel that the new study supports multiple lines of evidence previously published by our team on this remarkable site," DePalma wrote in an email to AccuWeather. "The new data adds to the evidence for the chronology of the [asteroid impact]. It is important that data such as this is published, so that other scientists can continue to build a coherent and richer interpretation of the past."
READ MORE:
For the latest weather news check back on AccuWeather.com. Watch the AccuWeather Network on DIRECTV, Frontier, Spectrum, fuboTV, Philo, and Verizon Fios. AccuWeather Now is now available on your preferred streaming platform.
No comments:
Post a Comment