Imagine a time machine that could transport you back to the age of dinosaurs. Suddenly, you find yourself in a dense, swampy forest, buzzing with insects among flowers, ferns, and coniferous trees. Believe it or not, this is what Western Antarctica looked like millions of years ago. It was here that researchers from Germany and the United Kingdom first discovered ancient amber—fossilized resin from coniferous trees that thrived on the southern continent of Earth 83 to 92 million years ago. By drilling into the seafloor of Western Antarctica, scientists uncovered tiny pieces of amber within rock samples. Alongside fossils of roots, pollen, and spores, this amber serves as one of the best pieces of evidence that tropical swamp forests existed near the South Pole during the mid-Cretaceous period. It also indicates that coniferous trees, similar to those found today in Patagonia, dominated this prehistoric environment. The discovery of amber in Antarctica seems to have “pushed back” the current icy shell of the continent, revealing an ancient truth about the region. Once, it was warm and humid enough for resin-producing trees to flourish. During the mid-Cretaceous, these trees would have had to survive months of complete darkness in winter.
Previously, scientists had only found Cretaceous amber deposits in the Otway Basin in Australia and the Tupuangi Formation in New Zealand. “It’s very moving to realize that at some point in history, all seven continents had climatic conditions that allowed resin-producing trees to survive,” noted marine geologist Johann Klages from the Alfred Wegener Institute in Germany.
So, how did researchers stumble upon Antarctic amber? Fossils of wood and leaves have been found in Antarctica since the early 19th century, many of which are hundreds of millions of years old. Their dating coincides with the existence of the southern supercontinent Gondwana. As Antarctica drifted away from Australia and South America toward the South Pole, it remains unclear what happened to its forests. In 2017, Klages’ team drilled into the seafloor near Western Antarctica. After several years of analyzing the extracted rock samples, the scientists announced they had found a network of fossilized roots dating back to the mid-Cretaceous period. Under the microscope, they also discovered fossils of pollen and spores. This drilling provided concrete evidence that trees producing resin once thrived in Antarctica. But the researchers were in for an even more unexpected discovery.
Within a three-meter layer of claystone, the researchers found several tiny pieces of translucent amber, measuring between 0.5 and 1 millimeter. They exhibited yellow and orange hues. On their surfaces, scientists noticed typical scalloped cracks, a sign of resin flow that occurs when sap leaks from a tree, protecting the bark from damage caused by fires or insects. The scientists’ current goal is to learn more about the ancient tropical forest ecosystem, as reported by Science Alert. The amber likely preserved and fossilized because high water levels quickly covered the tree resin, shielding it from ultraviolet radiation and oxidation. It appears that this amber even contains tiny fragments of tree bark, but further analysis is needed to confirm this. Thus, piece by piece, scientists are assembling a picture of what Antarctica’s forests looked like and how they functioned 90 million years ago. The results of the study were published in the journal Antarctic Research.
Alfred-Wegener-Institut