In the Catskill Mountains of southeastern New York State, scientists have discovered a set of 386-million-year-old fossilized root systems – the world’s oldest known forest.

Fossilized roots dating back to 386 million years ago, in Cairo, New York. Image credit: William Stein & Christopher Berry

The remnants of an ancient forest have been identified in a quarry near Cairo, New York. The fossils have been dated at 386 million years old, making them the oldest we know of. According to scientists, the new site not only teaches us more about how Earth’s climate has changed over time, but it also stands as evidence that forests developed 2 to 3 million years earlier than previously thought. The findings were published recently in the journal Current Biology and reported by New Scientist.

“Charles was just walking across the floor of the quarry and he noticed these big root structures which are very distinctive” Christopher Berry at Cardiff University in the UK said in reference to Charles Ver Straeten at the New York State Museum, who discovered the fossils in 2008.

The researchers found three types of trees at the site – an evidence that ancient forests were comprised of several different tree species. One of them, a member of the Archaeopteris genus, had long roots stretching up to 11 meters (36 ft). This species is similar to modern coniferous trees and was the first known to have evolved flat green leaves.

Aerial view of the root system of Archaeopteris, an ancient tree species similar to modern coniferous trees. Image credit: William Stein & Christopher Berry

“Archaeopteris seems to reveal the beginning of the future of what forests will ultimately become,” William Stein, a biologist at Binghamton University in New York and lead author of the new study, said in a statement. “Based on what we know from the body fossil evidence of Archaeopteris prior to this, and now from the rooting evidence that we’ve added at Cairo, these plants are very modern compared to other Devonian plants. Although still dramatically different than modern trees, Archaeopteris nevertheless seems to point the way toward the future of forests.”

Stein and his team also discovered evidence of “scale trees” belonging to the class Lycopsida – trees that were only thought to exist during the Carboniferous Period millions of years later, at the end of the Devonian Period. Hence, the new findings provide evidence that forests developed much earlier than previously believed.

The first species scientists identified was a palm tree-like plant called

Eospermatopteris, which has short roots that lived for a year or two before dying and growing new ones. The deep water-filled central depression is where the tree base once sat surrounded by preserved roots radiating from the center. Image credit: William Stein & Christopher Berry

Back when this ancient forest flourished, no birds or vertebrates lived on land and dinosaurs wouldn’t appear for another 150 million years. But the forest wasn’t uninhabited. Instead, it was likely home to millipede-like bugs and other insects. “It’s funny to think of a forest without large animals,” Chris Berry, a paleobotanist at Cardiff University and coauthor of the new study, told The Guardian. “No birdsong. Just the wind in the trees.”

Forests and their evolution have played a central role in shaping our planet’s climate and ecology. By capturing carbon dioxide, they brought its levels down similar to modern times, significantly helping to cool the planet. According to Sandy Hetherington at University of Oxford, studying the fossils could help provide clues about the relationship between deforestation and modern climate change.

“Understanding how this happened in the past is crucial for predicting what will happen in the future in light of climate change and deforestation,” she said.