Once upon a time, there was a rainforest near the bottom of the world. Buried sediment extracted from the seafloor off West Antarctica contains ancient pollen, fossilized roots and chemical evidence of a diverse forest that flourished millions of years ago, less than a thousand kilometers from the South Pole. The sediment offers the southernmost glimpse yet into just how warm Earth was during the mid-Cretaceous Period, between 92 million and 83 million years ago. By analyzing traces of vegetation in the sediment, researchers reconstructed climate conditions at the site. Average annual temperatures were about 13° Celsius (about 55° Fahrenheit), with summertime temperatures reaching as high as 20° or 25℃, the team reports in the April 2 Nature.
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