Palm phytoliths in subarctic Canada imply ice-free winters 48 million years ago during the late early Eocene.

Background And Aims: Phytoliths are microscopic siliceous structures produced in specific tissues by many plant families. The morphological features of phytoliths are diagnostic for many plant taxa, and given their inorganic composition often become part of the fossil record. We use phytolith remains from lacustrine sediments to document the conclusive presence of Arecaceae (palms) in subarctic Canada during the late early Eocene (48 Ma).