Three new species of walnuts have been found above the Arctic Circle, remnants of a time when the North and South Poles were covered in forests. Credit: Florida Museum photo by Jeff Gage =============================================================================== The discovery of extinct walnuts in the Arctic suggests a warmer historical climate with dense forests, extending our knowledge of walnut evolution and geographic spread. Scientists have discovered three new species of extinct walnuts on an island above the Arctic Circle. The fossils were discovered further north than any known walnut species, living or extinct, and represent some of the oldest-known records of this group. A...