Temperature in Antarctica was a balmy 54 degrees Fahrenheit when dinosaurs roamed the Earth 90 million years ago, traces of ancient rainforest found near the South Pole reveal
- Researchers extracted a core sample from the seabed of West Antarctica
- They found ancient soil containing pollen, spores, roots and flowering plants
- For such plants to grow, temperatures likely reached 66°F (19°C) in the Summer
- The team found that carbon dioxide levels at the time were higher than expected
The temperature in Antarctica was a balmy 54 degrees Fahrenheit — far warmer than previously thought — when dinosaurs roamed the Earth 90 million years ago.
Experts from the UK and Germany modelled the conditions needed to grow the rainforest plants found in an ancient soil sample extracted from under the seafloor.
Their findings also suggest that carbon dioxide levels in the atmosphere were higher than expected at that time during the mid-Cretaceous period.
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Antarctica was covered in rainforest when dinosaurs roamed the Earth, researchers found by studying traces of ancient soil that date back to 90 million years ago. At this time, temperatures at the South Pole averaged a balmy 54°F (12°)
‘The preservation of this 90 million-year-old forest is exceptional, but even more surprising is the world it reveals,’ said paper author and geochemist Tina van de Flierdt of Imperial College London
‘Even during months of darkness, swampy temperate rainforests were able to grow close to the South Pole, revealing an even warmer climate than we expected.’
In their study, the Professor van de Flierdt and colleagues analysed an core extracted from the seabed near the Pine Island and Thwaites glaciers in West Antarctica.
Within the core, the researchers discovered well-preserved forest soil, including plant pollen, spores, a dense network of roots and the remains of flowering plants.
‘The numerous plant remains indicate that 93 to 83 million years ago the coast of West Antarctica was a swampy landscape in which temperate rainforests grew,’ said paper author and palaeoecologist Ulrich Salzmann of the Northumbria University.
These forests, he added, would have been ‘similar to the forests that can still be found, say, on New Zealand’s South Island.’
To get a better idea of what the climate was like at that time, the team assessed the conditions that would have been necessary to grow the plants found in the ancient soil sample.
Simulations showed that summer temperatures would have been around 66°F (19°C) while water temperatures in the rivers and swamps would have reached up to 68°F (20°C).
Meanwhile, the amount and intensity of rainfall in West Antarctica at that time would have been similar to that seen in today’s Wales, the researchers said.
Researchers from the UK and Germany said that preserved roots and other plant remains — including pollen, pictured — in the soil suggest the world at that time was warmer than once thought.
In their study, the Professor van de Flierdt and colleagues analysed an core extracted from the seabed near the Pine Island and Thwaites glaciers in West Antarctica. Within the core, the researchers discovered well-preserved forest soil, including plant pollen, spores, a dense network of roots and the remains of flowering plants. Pictured, the core extractor
The findings also indicated that carbon dioxide levels in the atmosphere were higher than expected at the time of the forest — which was during the mid-Cretaceous period, the age of the dinosaurs.
‘Before our study, the general assumption was that the global carbon dioxide concentration in the Cretaceous was roughly 1,000 parts per million,’ said paper author and climate modeller Gerrit Lohmann of Germany’s Alfred Wegener Institute.
‘But in our model-based experiments, it took concentration levels of 1,120 to 1,680 parts per million to reach the average temperatures back then in the Antarctic.’
However, the researchers are yet to figure out what caused the climate to subsequently cool to form ice sheets in Antarctica.
‘Our climate simulations haven’t yet provided a satisfactory answer,’ Professor Lohmann added.
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