A new study by Connecticut College provides strong evidence that palm trees once thrived in subarctic Canada, reshaping scientific understanding of past Arctic climates.

Siver’s team identified fossilized phytoliths—microscopic silica structures formed in plant tissues—from palm trees in ancient lakebed sediments extracted from the Giraffe kimberlite pipe locality in Canada’s Northwest Territories. These fossils, alongside preserved remains of warm-water aquatic organisms, indicate a climate far warmer than previously thought, challenging assumptions about when and where ice first formed in the Northern Hemisphere.