Corryn Wetzel is a writer.

Artistic reconstruction of the reptile adaptive radiation in a terrestrial ecosystem during the warmest period in Earth?s history. Image depicts a massive, big-headed, carnivorous erythrosuchid (close relative to crocodiles and dinosaurs) and a tiny gliding reptile at about 240 million years ago. The erythrosuchid is chasing the gliding reptile and it is propelling itself using a fossilized skull of the extinct Dimetrodon (early mammalian ancestor) in a hot and dry river valley. Image created by Henry Sharpe.

During this time, global temperatures were very hot.

There is a man named Henry Sharpe.

Warming may have caused a boom in reptile abundance and diversity around 250 million years ago instead of filling the gap left by a mass extinction of mammals.

Two volcanic eruptions caused global temperatures to increase by 30C. The global warming effect was caused by the large amount of greenhouse gases released by the volcanoes. The ocean was very hot in the tropics.

The eruptions were one of the most destructive mass extinction events in our planet's history, wiping out 86 percent of the species.

The eruptions caused a 20-million-year-long hot streak on the planet. The evolution of reptiles was rapid as early mammal ancestors began dying in large numbers.

Simes and his colleagues spent eight years comparing museum fossils of extinct amniotes that lived 70 million years before and 70 million years after the extinction event. He compiled skull dimensions and tail lengths for 1000 fossils. He and his team compared the data with global temperatures.

According to their analysis, reptiles were increasing in number and diversity around 40 million years ago, and this was due to a warming climate.

Simes says that reptiles were already evolving fast as they reached the peak of the changing climate. It was already under way.

Christopher J. Raxworthy is the director of the American Museum of Natural History. He says that new climates could be stimulating evolution.

Raxworthy notes that, compared with the rapid pace of climate change, this stretch of warming was relatively slow. He says that the evolutionary implications of the climate change will not be seen. It could be huge.

Science Advances was published in the journal.

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