Today, Antarctica is a huge frozen continent, though it was once temperate enough to be covered in swampy forests. Now, a team of scientists has discovered fossilized tree resin—amber—on the continent for the first time.
The researchers found the amber in a sediment core recovered from 3,103 feet (946 meters) beneath the Amundsen Sea Embayment in West Antarctica. The amber—the first recovered from Antarctica—could help researchers understand the ancient climate and environment on a continent now famous for its inhospitable conditions and many, many penguins. The team’s research describing the find was published this week in Antarctic Science.
“The analyzed amber fragments allow direct insights into environmental conditions that prevailed in West Antarctica 90 million years ago,” says Johann Klages, a marine geologist at the Alfred Wegener Institute and the study’s first author, in a Helmholtz Association of German Research Centres release. “This fascinating find also indicates in more detail how the forest we reconstructed in our Nature study from 2020 could have functioned.”
Indeed, the team’s 2020 Nature paper reconstructed an ancient temperate lowland rainforest environment that existed in Antarctica between 92 million and 83 million years ago. The team developed a climate model simulation of the climate in that ancient past based on a preserved network of 10-foot-long (3-meter-long) fossil roots embedded in mudstone.
The amber samples are small, having been cut down to size when the sediment core was sliced for microscopy analysis. Nevertheless, the amber “likely contains remains of original tree bark as micro-inclusions,” study co-author Henny Gerschel said in the same release.
The new findings build on the 2020 paleo-reconstruction by describing fossilized tree resin, a remarkably valuable tool for paleontologists studying ancient Earth. Tree resin is sticky and viscous; many an unfortunate critter has met its end getting covered in the stuff, and when the resin hardens into amber, it immaculately preserves that organic matter.
In 2020, research in Proceedings of the Royal Society B showcased dozens of amber fossils from the Cretaceous that contained 66-million-year-old insects. The research team’s hope is that more amber finds from Antarctica will clarify what happened to the continent’s forests and, if they’re lucky, turn up an ancient creature or two.
“It was very exciting to realize that at some point in their history, all seven continents had climatic conditions allowing resin-producing trees to survive,” Klages added. “Our goal now is to learn more about the forest ecosystem—if it burns down, if we can find traces of life included in the amber. This discovery allows a journey to the past in yet another more direct way.”
The sediment cores recovered by the team date back 90 million years, putting the amber’s age squarely in the Cretaceous Period, some 25 million years before iconic creatures like T. rex would disappear from the Earth.
The team also found evidence of resin flow in the samples, which trees do when they are protecting damaged bark from pests or fires. It’s a hint at the kind of activity that was happening in the cold continent’s long-lost forests, though more samples would definitely help fill in our portrait of prehistoric Antarctica.
