The most colossal mass extinction that the Earth has experienced took place about 250 million years ago. We know it as the “Great Dying” and it wiped out 90% of all living things on our planet. It was a devastating period in the planet’s history. However, a team of paleontologists, led by the University of Bristol (UK), has found that after the Permian Extinction, new predators emerged resulting in prey developing new defences. The animals got smarter and it also made them grow faster in response to the new threat.
Lizards and birds became faster by developing a more upright posture, and mammals and birds developed some form of insulation, either in the form of hair or feathers. Thus this extinction event was followed by a ‘dramatic revival of life’ where animals evolved to be faster and more intelligent than their deceased ancestors.
The natural world bounced back with a vengeance
In their study, published in the journal Frontiers in Earth Science , the scientists reveal that predators became more vicious and prey animals quickly adapted to find new ways to survive. On land, the ancestors of mammals and birds became warm-blooded and could move faster.
The Triassic saw an explosion of life on Earth and in the oceans and was a time of massive increase in energy levels.
“Everything was speeding up,” says Michael Benton of the University of Bristol’s School of Earth Sciences and lead author of the new study. “Today, there’s a big difference between birds and mammals on the one hand, and reptiles on the other. Reptiles are cold-blooded, which means they don’t generate much body heat themselves, and although they can pretty quickly, they don’t have energy and can’t live in the cold.”
Many changes
“It’s the same in the oceans,” says Feixiang Wu of the Institute of Vertebrate Paleontology in Beijing and co-author of the paper. “After the end-Permian mass extinction, fish, lobsters, gastropods and starfish show new hunting styles. They were faster, more agile and stronger than their ancestors.”
The fossils used in the research were discovered in China and feature a variety of predators showing that new hunting styles appeared earlier than previously believed. The scientists found modern-style sharks and the longfish Saurichthys , which was very common around the world (and was an ambush-style hunter ).
“Other Triassic fish from China were adapted to crushing shells,” Wu explained. “Several major groups of fish, and even some reptiles, became shell crushers. We even found the world’s oldest flying fish, and this was probably to escape new predators.”
The last Permian reptiles moved slowly and used a kind of extended posture, like modern lizards, where the limbs protruded to the sides, something that limited their resistance. However, the ones that came after the Great Dying stood more upright, allowing them to move faster and for a longer period of time.
“If this is true, and new fossil discoveries seem to confirm it, all the evidence points to major changes in these reptiles as the world rebuilds itself after the end-Permian mass extinction ,” according to the researchers.
As one side speeds up and becomes more hot-blooded, the other side has to too. This affects competition between plant eaters or competition between predators. “It also refers to predator-prey relationships: if the predator gets faster , the prey does too to escape,” the experts conclude.
” These are not new ideas. What is new is that we are now discovering that they apparently occurred around the same time, through the Triassic. This emphasizes a kind of positive aspect of mass extinctions. Mass extinctions, of course, were news terrible for all the victims. But the massive cleanup of ecosystems, in this case, offered a huge number of opportunities for the biosphere to rebuild itself, and it did so with higher octane than before the crisis ,” says Benton.
Referencia: Michael J. Benton et al, Triassic Revolution, Frontiers in Earth Science (2022). DOI: 10.3389/feart.2022.899541
