Scientists believe that dinosaurs were doomed to extinction and without the fall of an asteroid

    About 66 million years ago, a giant asteroid fell on the Yucatan Peninsula, which resulted in the release of large amounts of soot and carbon monoxide into the atmosphere, causing extreme climate changes that destroyed most of the dinosaurs. However, this is not the whole story. A new study by a group of scientists from the UK shows that most dinosaurs were on the verge of extinction even before the fall of Chiksulub , which changed the Earth’s ecosystem forever, reports arstechnica .

    Scientists were interested in two parameters - the rate of appearance of new species and the rate of extinction of existing dinosaurs. If the first indicator exceeds the second, then we can say that the dinosaurs flourished and expanded their presence on Earth, and in the opposite situation, we are talking about their slow extinction.

    Researchers published their findings in PNAS . They found that the dinosaur population had declined even before the asteroid fell on our planet. The study shows that the number of dinosaurs of the three main suborders - poultry , sauropodomorphs and theropodsbegan to fall. This is indicated by calculations of the rate of extinction and the emergence of new species. Simply put, new species of dinosaurs did not evolve to replace those that became extinct.

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    “All available evidence indicates that the dinosaurs that existed at that time and dominated terrestrial ecosystems for more than 150 million years, somehow lost the ability to quickly form new species. Most likely, this was one of the reasons why they could not survive the environmental crisis caused by the fall of the asteroid, ”said Michael Benton, one of the scientists who conducted the study.

    Scientists came to this conclusion by constructing the so-called "extinction tree" of various species, genera and families of dinosaurs that lived in the last several million years before the disaster. For this, over 600 different species of dinosaurs were cataloged and compared.

    This “gradual decline” scenario suggests that the Chiksulub catastrophe was not so much the cause of the extinction of the dinosaurs as the last fatal blow to an already weakened group of animals.

    The truth is that mass extinction is always a long and chaotic process. The standard definition for mass extinction, when 75 or more percent of the Earth’s species dies, has a caveat: this process usually takes more than a million years. It is actually phenomenally difficult to kill so many species. Earth itself, with its tectonic shifts, was killing dinosaurs long before the asteroid fell, which simply completed the work that had begun.

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