SCIENTIFIC EDUCATIONAL CENTER science idea

The transition from the Cretaceous Period to the Paleogene was marked by the loss of approximately 76 percent of all species that inhabited the Earth, as well as 80 percent of plants. Studies have shown that the Cretaceous-Paleogene extinction event, which occurred about 66 million years ago, coincided with the impact of an asteroid that formed the Chicxulub crater in Mexico. It caused a tsunami and the release of billions of tons of sulfur, sulfates, dust and soot into the atmosphere-all this significantly reduced insolation and led to global cooling, the collapse of photosynthesis and, as a result, mass death on the planet.

Among others, non-avian dinosaurs, pterosaurs and mosasaurs have become extinct. Although other vertebrate clades-birds, mammals, and scaly-have generally survived the disaster, they have faced a decline in biodiversity, as have insects. But, despite the scale of the cataclysm, ecosystems quickly recovered.

The consequences for snakes — a suborder of the reptile class of the scaly order, which today has more than 3,7 thousand species and is found on all continents except Antarctica-remain poorly understood. Traditionally, scientists believed that scaly reptiles went through extinction with minimal losses, but an analysis of the transition from the Cretaceous to the Paleogene in western North America showed a high rate of death of these reptiles.

At the same time, it was not clear what was happening to them on a global scale. Taking into account all the uncertainties, researchers from Friedrich-Alexander University (Germany), the Milner Center for Evolution at the University of Bath, as well as the University of Bristol (UK) tried to improve our understanding of the evolution of snakes.

After studying the fossils and analyzing the genetic differences, the authors of the study came to the conclusion that all modern snakes descended from several species that survived the Cretaceous-Paleogene extinction. After the asteroid hit, they hid underground, as well as in the water and on the forest floor, going without food for a long time.

Their prosperity was made possible by the disappearance of the dinosaurs. In the absence of competition, snakes began to increase in size and spread around the world, mastering new habitats and occupying territories where they had not previously lived: according to scientists, the ancestor of modern snakes lived in the Southern Hemisphere, and after the extinction they first began to meet in Asia.

New groups have appeared, including giant sea snakes up to ten meters long, venomous vipers and cobras, huge boa constrictors and pythons. Thus, the catastrophe allowed these reptiles to diversify into new niches previously occupied by their rivals. And the second peak of the evolution of snakes occurred around the time when the Earth moved from a warm climate to a colder one and the ice age began.

The article was published in the journal Nature Communications
PHOTO: Komodo wood viper (blue kufiya) — the rarest species of kufiya found on the island of Komodo in the heart of the Indonesian Archipelago © Getty Images

Source: naked-science.ru, sci-dig.ru