Dinosaurs became extinct due to climate change millions of years before the meteorite hit
Herbivorous dinosaurs became extinct first, which upset the balance in the ecosystem and paved the way for the extinction of meat-eating species (Getty Images)
Those reptiles, which are better suited to warm weather, could not tolerate the increasing coldness with a temperature drop of 7 degrees Celsius
It is believed that the number of dinosaurs declined as a result of a climate change that occurred on the planet 10 million years before a meteorite 12 km in diameter hit the Earth, causing their extinction, according to a recent study.
While paleontologists (a science that studies ancient living species) have for several years agreed on what led to the complete extinction of the dinosaurs, experts' opinions have so far been divided over the extent to which this group of ancient reptiles disappeared or flourished, before the sudden end of the "epoch of Mesozoic Era (also called the age of reptiles) 66 million years ago.
Now, an international team of scientists, including experts from the University of Bristol in Britain, has announced that the existence of dinosaurs faced a sudden decline 76 million years ago, when their extinction rates were escalating.
Scientists attributed this to a period of global cooling in the Earth, when the average temperature dropped by seven degrees Celsius, which harmed the dinosaurs that the warm climate brought.
In the details, the researchers found that plant-eating (herbivorous) species of dinosaurs faced extinction first (before their meat-eating counterparts), which upset the stability of ecosystems, and put the existence of other dinosaur families at risk of extinction.
In this regard, Professor Mike Benton of the "School of Earth Sciences" at the University of Bristol, who is one of the researchers involved in the study, indicated that he and his colleagues discovered "in the analyzes different types of possible reasons that led to the decline of the dinosaurs."
He added, "It became clear that there were two main factors, the first of which was the general coldness of the climate at that time, which made life more difficult for dinosaurs that most likely relied on warm temperatures. After that, the demise of the herbivorous dinosaurs resulted in disruption of ecosystems and their exposure to a series of extinctions. We found Also, the longest-lived species of dinosaurs were under greater threat of extinction (than those that did not live long), and this may reflect their inability to adapt to new conditions on Earth,” according to Professor Benton.
In a related context, Fabian Condamine, principal author of the study from the Institute of Evolutionary Sciences in Montpellier, France, said, "Our research dealt with the six families of dinosaurs that were the most abundant throughout the Cretaceous period, which spanned between 150 and 66 million years ago, And we found that they all began to develop and increase, and it seemed clear that they succeeded in continuing.
According to Komen, "76 million years ago, those dinosaurs faced a sudden decline. Their extinction rates escalated, and in some cases the rate of emergence of new species decreased. It marked a defining moment in the evolution of life. Dinosaurs dominated the world for more than 160 million years, As their numbers declined, other groups began to dominate, including mammals.
"Dinosaurs were often so huge that they probably didn't know that small, furry mammals were lurking there in the bushes," Condamine continued. "But mammal species started increasing before the dinosaurs died, while after that extinction, they found the opportunity to build new species of the ecosystems we see today.
In their study, the researchers considered uncertainties in palaeontology, including incomplete fossil records and inconsistencies in the emergence and extinction histories of each species, by running digital software to create virtual models. They repeated these models millions of times before agreeing on the most likely date for the dinosaur population's decline.
Among other details provided by researcher Phil Currie, who co-authored the study from the University of "Edmonton" in Alberta, Canada, it turns out that the study "used more than 1,600 highly accurate fossil records related to the dinosaurs of the Cretaceous period . "
He added, "For a long time, I have been collecting dinosaur fossils in North America, Mongolia, China and other regions. I have noticed huge advances in our knowledge about the ages of the rock formations that hold the remains of dinosaurs."
In closing words from Currie, "This indicates that information is constantly becoming more abundant and accurate. It makes sense for the decline in dinosaur numbers over the 10 million years of their existence. In fact, that feature is the best part of their fossil record, given their abundance." What the samples are based on, according to what our study showed.
The results of the study have been published in the journal Nature Communications.
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