The scientists believe that dinosaurs were doomed to extinction without falling asteroid Bashny.Net

About 66 million years ago, a giant asteroid fell on the Yucatan peninsula, causing spewed large amounts of soot and carbon monoxide into the atmosphere, causing extreme climate change, which 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 brink of extinction before the fall of Chicxulub, which changed forever the Earth's ecosystem, according arstechnica.

Scientists interested in two parameters - the rate of appearance of new species and the rate of disappearance of the existing dinosaurs. If the first parameter exceeds a second, then one can say that dinosaurs thrived and expanded its presence in the world, and in the reverse situation it is their slow extinction.

The researchers published their findings in the journal PNAS. They found that the population of dinosaurs declined before asteroid fell on our planet. Research shows that the number of three major suborders of dinosaurs - ornithischian, sauropodomorpha and theropods began to fall. This is indicated by calculations extinction rates and the emergence of new species. Simply put, the new dinosaur species have not evolved to replace those that have died.





"All the available evidence indicates that dinosaurs, which existed at that time and dominated terrestrial ecosystems for over 150 million years, somehow lost the ability to rapidly form new species. Most likely, it was one of the reasons why they could not endure the environmental crisis caused by the fall of an asteroid, "- said Michael Benton, one of the scientists who conducted the study

. Scientists came to this conclusion by constructing a so-called "tree of extinction" of different species, genera and families of dinosaurs that lived in the past few million years before the disaster. For this it was prokatalogizirovano and mapped more than 600 different species of dinosaurs.

This scenario is "gradual decline" suggests that the Chicxulub disaster was not so much the cause of the extinction of the dinosaurs, as the last fatal blow to the already weakened group of animals.

The truth is that a mass extinction is always a long and messy process. A standard definition for the mass extinction, when 75 percent or more of the Earth's species is dying out, there is a reservation: this process usually takes more than a million years. In fact phenomenally hard to kill so many kinds. Earth itself, with its tectonic shifts, killing dinosaurs long before the fall asteroid, who just finished the job.

Source: geektimes.ru/post/274578/