World’s oldest forest discovered in the U.S.

Fossil forest in Cairo, New York

Scientists have discovered remnants of the world’s oldest fossil forest — an extensive network of trees around 386 million years old — in a sandstone quarry in Cairo, New York, in the foothills of the Catskill Mountains. The fossil forest would have spread from New York all the way into Pennsylvania and beyond.

The research shows that the forest was home to at least two types of trees: Cladoxylopsids was a primitive tree-fern-like plants, lacked flat green leaves, while Archaeopteris, a conifer-like woody trunk with frond-like branches with green flattened leaves, is related to modern trees. All these trees reproduced using only spores rather than seeds. The team also reported a ‘spectacular’ and extensive network of roots, more than eleven metres in length in some places, belonging to the Archaeopteris trees.

At the time this ancient forest existed, no birds or vertebrates lived on land. Dinosaurs wouldn’t appear for another 150 million years. Instead, the forest was likely home to millipede-like bugs and other insects.

This forest reveals a key milestone in Earth’s climate history. As plants developed thick, carbon-rich wooden roots, they pulled carbon dioxide out of the atmosphere, changing the global composition of the planet’s air. Plants themselves became significant carbon sinks.

Researchers believe the forest was eventually wiped out by a flood, due to the presence of fish fossils that were also visible on the surface of the quarry.