The death of the dinosaursThis has fascinated paleontologists for a long time. Their mass extinction following a fiery meteorite strike on Earth 66 million years ago was a dramatic end to their reign.
A new study has found that dinosaurs could have been on their way out of China millions of years earlier than the meteorite struck. This is according to an analysis of more than 1,000 fossilized eggshells discovered in central China.
Qiang Wang of China Academy of Sciences studies that “Dinosaurs died out slowly over millions of generations, rather than suddenly due to sudden disasters.” TelledThe South China Morning Post.
These conclusions will be tested. The study has a weight of approximately a Debates that go on for hours and are often dominated by see-sawingPaleontologists disagree on whether non-avian dinos have ended abruptly or if there was still hope. asteroidTheir fate was sealed.
This new research was done by a team made up of geologists and paleontologists who were working in China. dinosaurThe loss of biodiversity occurred at least two million year before dinosaurs became extinct at the end Cretaceous. Birds were left as their only living relatives.
It is based on a collection containing egg fossils. This includes several incomplete and complete dinosaur eggs. These egg fossils were preserved in layers of 150-meter thickness rock that were deposited between 66.4 and 68.2 millions years ago.
One of the oldest dinosaur records from late Cretaceous is found in Shanyang Basin. And yet the researchers only found three taxa of dinosaurs represented in the fossilized eggshells – a clear drop in biodiversity compared to older fossil records.
Researchers believe that the decline in variation might have affected the ability of dinosaurs to recover collectively from the extinction. Impact of the Chicxulub AsteroidMexico in modern times or to adapt to the The time was turbulent due to the changing environment. They were limited in their evolutionary options and were caught.
“Our results support a slowing down of global dinosaur biodiversity before 66 million years, which most likely set the stage to the end-Cretaceous nonavian dinosaur mass extermination,” Fei Han, China University of Geosciences researcher and his colleagues stated. Send an emailTheir published paper.
They are correct, however. NotesThere are many factors that contribute to the debate about the extinction and reasons for it.
Han and coworkers used a range of techniques to stratify thousands rock samples with fossilized eggshells. Then, they estimated the age and created a timeline from that data, which had a resolution that was 100,000 years.
Two of the three dinosaur eggs oospecies (a species category of dinosaur eggs when you only have eggs) that were identified in the mix came from a group called oviraptors. The third group of egg-laying dinosaurs was identified as herbivorous duckbill hadrosaurids.
Researchers found that there was a low diversity of species in their findings. This matches the skeletal remains from ancient dinosaurs also found in the Shanyang Basin. It is comparable to fossil deposits in eastern and southern China as well as Some bonebedsIn North AmericaThese signs also suggest a decline in dinosaur diversity over the same time period.
Han and his colleagues concluded that this all “points towards a decreased diversity and overall decline of dinosaurs on an international scale.” ArgumentThe decline may have been due to global climate fluctuations and volcanic eruptions, as evidenced by the following:
Similar studies have also suggested that dinosaurs are prone to extinction. However, other studies suggest that their diversity may have begun. As low as 10,000,000 years.Before the meteorite crashed into Earth.
Past studies have shown otherwise. One recent, far-reaching analysis simulating dinosaur speciation – the rate at which new species appear – found that less than 20 percent of dinosaurs were in terminal decline before the asteroid impact, while Other species also thrived.
Han and his coworkers are the only way for these divergent interpretations to be resolved. Final conclusionThis is the ability to sample, analyze, and interpret more fossils, as well as to combine existing data from fossil sites all over the globe to better understand extinction patterns.
This is no easy task but it might help to finally resolve the events of the dinosaurs’ reign.
The researchers said that the study of fossils in Asia is a major step forward in that direction. Send an email.
The study was published in PNAS.
