Scientists have discovered amber fragments near the South Pole, revealing that Antarctica once supported vast and expansive resin-producing Cretaceous forests. Crucially, the new findings confirm, for the first time, that up to 90 million years ago, all seven continents once had vast resin-producing forests at the same time.
That is according to Germany’s Alfred Wegener Institute (AWI), which published First Discovery of Antarctic Amber in the Antarctic Science journal yesterday.
Wood Central understands that the amber was discovered in sediment retrieved near the Amundsen Sea – an arm of the Southern Ocean in Western Antarctica – using seabed drilling aboard the 2017 icebreaker Polarstern expedition. For analysis, the source material was carefully air-dried and sliced into pieces to extract the amber.
“The amber fragments provide direct insights into the environmental conditions that prevailed in West Antarctica 90 million years ago,” according to Dr Johann P Klages, an AWI marine geologist who was the lead author in the research. “It was very exciting to realise that, at some point in their history, all seven continents had climates that allowed resin-producing trees to survive.”
Why dinosaurs and mammals once roamed great forests
Wood Central understands that atmospheric carbon dioxide was high during the Cretaceous age, making the world a much warmer place. Moreover, the lack of an Antarctic Circumpolar Current meant the climatic difference was most significant on the southern continent, where dinosaurs and mammals inhabited great forests.Â
There are, however, significant gaps in our knowledge of the nature of these forests and their inhabitants because it is so hard to access any fossil beds that preserve them. One way around this is to drill the sea floor off the Antarctic Coast, with Dr Klages leading a team of scientists who hit paydirt off Pine Island in the Amundsen Sea.
Within a 5-centimeter (2-inch) thick layer of lignite (moist coal), Dr Klages found pieces of hardened tree resin, better known as amber. Â Based on the lignite’s age and composition, the amber was estimated to be between 92 and 83 million years old and came from a swampy forest mostly composed of conifers.
Resin is released by many tree species when bark is damaged. Many resins, particularly those from conifers, fossilised under the right conditions, preserving insects, feathers, and a dinosaur tail. We already have amber fossils from the same era in southern Australia, attached to Antarctica at the time, so it is no surprise specimens like this were preserved, but finding them is a different matter.
“This fascinating find indicates in more detail how the forest we reconstructed in our Nature study from 2020 could have functioned,” Dr Klages said. “Our discovery is another piece of the puzzle and will help us better understand the swampy, conifer-rich, temperate rainforest environment identified near the South Pole during the mid-Cretaceous.”
- For more information: Johann P. Klages, Henny Gerschel, U. Salzmann, G. Nehrke, J. Müller, C.-D. Hillenbrand, S. M. Bohaty, and T. Bickert: First discovery of Antarctic amber; Antarctic Science (2024). DOI: 10.1017/S0954102024000208
