Early dinosaurs benefited from changes in global climate

According to a recent study published in the journal Current Biology, the ascendancy of dinosaurs through the Late Triassic and Early Jurassic periods was primarily driven by climate change, rather than inter-species competition.

The experts argue that changes in global climate linked to the Triassic-Jurassic mass extinction – which wiped out many large terrestrial vertebrates such as the armadillo-like aetosaurs – in fact benefited the earliest dinosaurs.

For instance, sauropod-like dinosaurs, which later on evolved into the giant herbivore species of the late Jurassic (such as Diplodocus or Brachiosaurus) were able to thrive and expand their territories as the Earth warmed substantially after the mass extinction event, about 210 million years ago.

By comparing computer models of prehistoric global climate conditions like temperature and rainfall with data on the different locations of dinosaurs, the scientists showed how the sauropods and related creatures ended up being the success story of a turbulent period of evolution.

“What we see in the data 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,” said study lead author Emma Dunne, a lecturer in Paleontology at Friedrich-Alexander University Erlangen-Nürnberg (FAU).

“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. 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,” concluded study co-author Richard Butler, a professor of Vertebrate Paleontology at the University of Birmingham.

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By Andrei Ionescu, Earth.com Staff Writer

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