Bundled up in parkas to brave negative temperatures, fierce winds, and blinding days of 24-hour sunlight, Gulbranson, Isbell, and an international team of researchers searched for fossil fragments. Between November 2016 and January 2017, they scaled the snow-capped slopes of the McIntyre Promontory high above the ice fields and glaciers, sifting through the Transantarctic Mountain’s gray sedimentary rocks for clues. By the end of the expedition, they had uncovered 13 fossil fragments from trees dating back more than 260 million years, around the time of the world’s greatest mass extinction event.
“The continent as a whole was much warmer and more humid than it currently is today,” says Gulbranson, a professor at University of Wisconsin – Milwaukee. The landscape would have been densely forested with a low-diversity network of resilient plants that could withstand polar extremes, like the boreal forest in present-day Siberia.
The fossils preserved the biology and chemistry of the …