Snakes experienced an ecological boom 66 million years ago

66 million years ago, the extinction 75% of species, including all non-avian dinosaurs, ushered in an era (the Cenozoic) in which primarily mammals and birds found infinitely empty ecological niches in which to survive. However, other survivors have also survived to this day.

Snakes have evolved to specialize in earthworms, fish, frogs, slugs, snake-shaped eels, and even other snakes.

Michael Grundler

A new study, published in the journal PLoS Biology, reveals that snakesThe most elusive and rarest in the fossil record on such a broad phylogenetic scale, they also diversified rapidly after mass extinction, reaching nearly 4,000 species today.

Those reptiles “They tapped into every aspect of their diversity,” he tells SINC Michael C. Grundler, first author of the work and researcher at the Department of Ecology and Evolutionary Biology of Rio de Janeiro. University of California In Los Angeles. “They evolved to specialize in earthworms, fish, frogs, slugs, snake-shaped eels and even other snakes,” continues Grundler.

As part of this process, these animals developed a whole series of behaviors and morphologies. “Poison and constriction, which allow snakes to subdue prey much larger than themselves, are two important examples”, emphasizes the biologist.

In search of new ecological opportunities

the scientist, along with Daniel L. Rabosky, a co-author at the University of Michigan, focusing on diet of these reptiles to understand their evolution. Both collected published data on the feeding of 882 species of live snakes. Thanks to the use of sophisticated mathematical models, they were able to reconstruct this food diversification.

Sometimes these opportunities are generated by extinctions, like the one that wiped out the dinosaurs. Others are caused by the dispersal of an ancestor to another land

Michael Grundler

The results therefore show that the most recent common ancestor of modern snakes was insectivorous. However, after the disappearance of the dinosaurs, the diet of these animals quickly expanded to include birds, fish and small mammals, that is, groups of vertebrates that also flourished at that time.

“Our work shows how ecological opportunities can shape evolutionary fortunes. In this case, the opportunity for the snakes was to find many vacant ecological niches that needed to be filled”, Grundler tells SINC. And it was this opportunity that seems to have triggered the evolutionary explosion.

“Sometimes these opportunities are generated by extinctions, like the one that wiped out the dinosaurs. Others are caused by the dispersal of an ancestor to another land, as happened with the colubrids when they arrived in South America”, adds the specialist. So when they arrive in new places, they often experience similar bouts of diversification in their diet.

In fact, after the event that eliminated most species, the diversification of snakes declined, but some bloodlines they kept trying new ones booms of evolution and adaptation.

To detail the snakes’ dietary change, the scientists used ecological information from the analysis of the stomach contents of specimens preserved in museums. “Until now, it was almost impossible to directly use this type of data in evolutionary analysis. This allows us to capture much more variation and complexity in the snakes’ diet and thus better understand how they have changed”, says Grundler, who points out that there is still a long way to go.

“Although our sample includes all the main snake families, it covers less than a quarter of the species described. And a considerable number of them are represented by a handful of observations”, he concludes. “The reality is that many snakes remain ecologically little known.”

Source: SYNC

Rights: Creative Commons.