Imagine a time machine that could take you to the age of dinosaurs. Suddenly you find yourself in a dense swamp forest, where insects buzz among flowers, ferns and conifers. Believe it or not, you’re standing in West Antarctica. Scientists from Germany and England discovered amber here for the first time; This amber was the fossilized “blood” of ancient conifer trees that once grew on the Earth’s southernmost continent between 83 and 92 million years ago.

Amber, along with root, pollen and spore fossils, is one of the best pieces of evidence to show that a swampy rainforest existed near the South Pole in the mid-Cretaceous period, and that this prehistoric environment was “conifer-dominated” like the forests of New York. Today it is Zealand and Patagonia.

Amber excavations in Antarctica are restoring the continent’s current icy appearance, revealing an ancient habitat that was once warm and moist enough to grow resin-producing trees. In the middle of the Cretaceous period, these trees would have had to survive months of pitch darkness in winter. But they clearly managed to survive. Even if they have to rest for a long time. Before this discovery, scientists had only found deposits of Cretaceous amber as far south as the Otway Basin in Australia and the Tupuangi Formation in New Zealand.

“It was very exciting to realize that at some point in their history, all seven continents had climatic conditions that allowed resin trees to survive,” says marine geologist Johann Klages of the Alfred Wegener Institute in Germany.

“Our goal now is to learn more about the forest ecosystem; Can we find traces of life in amber if it burns? “This discovery allows us to travel back in time more directly.”

Scientists have been excavating petrified trees and leaves in Antarctica since the early 19th century, but most of these discoveries date back hundreds of millions of years, when the southern supercontinent Gondwana existed. It’s not entirely clear what happened to their forests as they moved from Antarctica, Australia, and South America towards the South Pole.

In 2017, researchers dug into the seafloor near West Antarctica and found remarkably well-preserved evidence of these long-lost habitats. After several years of analysis, Klages and a team of researchers announced in 2020 that they had found a network of fossilized roots dating back to the mid-Cretaceous period. They also found signs of pollen and spores under the microscope. The same drilling now provides concrete evidence that resin-producing trees once existed in Antarctica.

Klagen and the new team identified several small pieces of translucent amber measuring just 0.5 to 1.0 millimeters in the 3-meter mudstone layer. Each contains a variety of yellow to orange colors with typical scalloped surface fractures. This is a sign of resin flow, which occurs when sap leaks from the tree to protect the bark from fire or insect damage.

The Cretaceous period was one of the hottest periods in Earth’s history, and volcanic sediments found in Antarctica and nearby islands show that forest fires were frequent during this period.

Amber was probably preserved and fossilized because high water levels quickly covered the tree resin, protecting it from ultraviolet radiation and oxidation. The amber even appears to contain small pieces of tree bark, but further analysis is needed to confirm this.

Scientists are slowly building a picture of what forests in Antarctica once looked like and how they functioned 90 million years ago. The study was published on: Antarctic Research.