By comparing the genetic characteristics of modern snakes with a large sample of fossils, an international research team led by scientists from the University of Bath determined that all currently living species (around four thousand) are derived from the few survivors of chicxulub impact. , the asteroid that wiped out non-avian dinosaurs and countless other groups of animals 66 million years ago.
The approx four thousand species of snakes currently living all derive from a handful of survivors to the catastrophic impact ofasteroide chicxulub, that 66 million years ago, at the end of Cretaceo, determined themass extinction of the non-avian dinosaurs and many other groups of animals. It was a real blank slate, as happened in previous massive extinctions, allowing the survivors to conquer new ecological niches, occupy new habitat and differentiate into new species, renewing the biodiversity previously annihilated.
To determine that modern snakes are “children” of a few species surviving the devastation of chixulub, which generated a monstrous tsunami 1.5 kilometers high and able to propagate at a speed of 143 kilometers per hour, was an international research team led by British scientists from the University of Bath, who collaborated closely with colleagues from the School of Earth Sciences and the School of Biological Sciences of the University of Bristol, of the Department of Science of the Terra of the University of Cambridge and the GeoZentrum Nordbayern of the Friedrich-Alexander University (Germany). The researchers, coordinated by Dr Catherine Klein and Professor Nick Longrich of the Milner Center for Evolution, came to their conclusions after comparing a large sample of fossil records and the genetic characteristics of modern snakes, coming to reconstruct the evolutionary history of these splendid reptiles step by step.
As pointed out by the researchers, the ability of snakes to survive underground and to be able to stay for a long time without eating allowed some of the hardiest species to survive the devastation of chicxulub. Not only to the tsunami and the very violent fires which were unleashed almost everywhere in the globe after the impact, but also atdarkening of the sun (for years) due to the rise of an immense cloud of debris, which in a short time killed a huge number of plant and with them the herbivores, dragging i predators. It is estimated that around the 75 percent of living species was blown away during theCretaceous-Paleocene mass extinction. But as mentioned, some snakes made it, and without the competition of other similar ones, dinosaurs and other animals that occupied the same niche, have been able to evolve into multiple shapes and sizes, occupying a large part of the globe over time.
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Illustration of a prehistoric snake that survived the asteroid impact. Credit: Joschua Knüppe
Although the snakes originated in the southern hemisphere, researchers believe that after extinction they began to spread again from theAsia. Only after the dramatic event of the late Cretaceous were born vipers, cobras, pythons, boas and all the great variety we know today, including sea snakes, some of which in the past reached gigantic dimensions, reaching 10 meters in length. During this evolutionary process theirs also changed vertebrae. “It’s remarkable, because not only are they surviving an extinction that wiped out so many other animals, but within a few million years they are evolving, using their habitats in new ways,” said Dr. Klein in a press release. . Today several of the 4 thousand living species are threatened by climate changes and from destruction of the natural habitat man-made, which effectively triggered the sixth mass extinction. The details of the research “Evolution and dispersal of snakes across the Cretaceous-Paleogene mass extinction” have been published in the scientific journal Nature Communications.