Fossils of dinosaurs which lived on Earth 200million years ago offer glimpse into bleak future if global warming isn't stopped

The conditions would have been something similar to the arid western United States today, scientists say

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The Independent Online

The fossils of dinosaurs that roamed the Earth 200 million years ago have offered a bleak glimpse into what may happen if global warming is not stopped, according to a new study.

Scientists attempting to understand why herbivorous dinosaurs took so long to populate the tropical parts of the planet believe that high level of C02 may hold the answer.

Evidence of long-necked “sauropods” in equatorial regions are have only been documented at least 30 million years after they first appeared on Earth, and the creatures did not move to the tropics until 10 to 15 million years after they had diversified and become travelled closer to the poles.

Experts now believe the dinosaurs were kept from the equatorial regions during the Late Triassic period because of the effects of atmospheric carbon dioxide (CO2), which were at levels four to six times what they are today.

According to findings published in the journal 'Proceedings of the National Academy of Sciences', when C02 levels were high, the tropical climate would change dramatically between wet and dry years.

During the dry periods, vegetation would die off and fuel raging wild fires that burned at temperatures as high as 600C - killing plants and damaging the soil.

 

Such carnage made vegetation was scarce, meaning it was impossible for the huge herbivores to satisfy their appetites.

US expert Dr Randall Irmis, from the Natural History Museum of Utah, warned: “If we continue along our present course, similar conditions in a high CO2 world may develop and suppress low-latitude ecosystems.”

Lead scientist Dr Jessica Whiteside, from the University of Southampton, said: “The conditions would have been something similar to the arid western United States today, although there would have been trees and smaller plants near streams and rivers and forests during humid times.

"The fluctuating and harsh climate with widespread wild fires meant that only small two-legged carnivorous dinosaurs, such as Coelophysis, could survive," she added.

To make their findings, scientists analysed rocks samples containing fossilised bones from Ghost Ranch in New Mexico, that were deposited by rivers and streams between 205 and 215 million years ago.

Researchers were able to study ecosystem changes and measure atmospheric carbon dioxide levels, as well as decipher what creatures ate at different times, and estimate wildfire temperatures.

They found that dinosaurs accounted for less than 15 per cent of the animal fossils found.

The scientists said they hope the findings will improve our understanding of the consequences of human-caused climate change.

Additional reporting by PA

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