Climate change seems to have played a significant role in the evolution of early dinosaurs.

As the globe warmed up after the extinction disaster, 201 million years ago, sauropod-like dinosaurs in particular—which evolved into the massive herbivore species of the later Jurassic like Diplodocus and Brachiosaurus—were able to flourish and spread over new lands.

The findings were rather unexpected since sauropods seem to have been quite picky from the start; later in their history, they continued to shun polar regions and remain in warmer climates.

During the Late Triassic and Early Jurassic periods, climate change, not competition, was a key factor in the rise of dinosaurs.

A new study suggests that the Triassic-Jurassic mass extinction, which killed off many large terrestrial vertebrates like the giant armadillo-like aetosaurs, led to changes in the global climate that helped the earliest dinosaurs.

For example, when the Earth warmed following the extinction catastrophe 201 million years ago, sauropod-like dinosaurs, which evolved into the huge herbivore species of the later Jurassic like Diplodocus and Brachiosaurus, were able to flourish and extend over new regions.

An international team of paleontologists led by the Universities of Birmingham and Bristol in the UK, Friedrich-Alexander University Erlangen-Nürnberg (FAU) in Germany, and the University of So Paulo in Brazil published the new evidence in the journal Current Biology.

The team compared computer models of ancient global climate conditions, including temperature and rainfall, with data on the locations of dinosaurs from sources like the Paleobiology Database. They demonstrated how sauropods and similar animals, with their long tails and necks and small heads, were the standout success story during a turbulent period of evolution.

“What we see in the data,” as explained by Dr. Emma Dunne, “suggests that instead of dinosaurs being outcompeted by other large vertebrates, it was variations in climate conditions that were restricting their diversity. But once these conditions changed across the Triassic-Jurassic boundary, they were able to flourish.

“The results were somewhat surprising, because it turns out that sauropods were really fussy from the get-go: later in their evolution they continue to stay in warmer areas and avoid polar regions.”

 “Climate change appears to have been really important in driving the evolution of early dinosaurs,” adds co-author Professor Richard Butler.

“What we want to do next is use the same techniques to understand the role of climate in the next 120 million years of the dinosaur story”.

Source: 10.1016/j.cub.2022.11.064

Image Credit: Jörg Carstensen/picture alliance via Getty Images