England’s highest sea cliffs have revealed the world’s oldest known fossilized forest. This ancient ecosystem, featuring palm-like trees known as Calamophytons, dates back 390 million years. This discovery edges out the previous oldest known forest, located in New York State, by three to four million years.
In the southwest of England, the discovery was made on a red sandstone cliff. Initially thought to be devoid of any fossils, this site has now provided a remarkable glimpse into life during the Devonian Period. This era was marked by falling sea levels, which exposed land and formed two massive continents, Gondwana and Euramerica.
The newly exposed lands were quickly colonized by animals and primitive plants. The earliest trees, including the Calamophytons, lacked roots, leaves, spores, seeds, and a vascular system, which made them reliant on proximity to water sources like coastlines and rivers. However, the Calamophyton trees found near Minehead on the Somerset coast had evolved to have roots and vascular tissue in their stems. Despite these advancements, they were relatively small, reaching heights of only two to four meters with thin, hollow trunks.
Similar trees have been found in fossil form in Germany, New York, and China. Given that Germany and this part of England were once connected when the Gondwana supercontinent existed, it’s logical they shared similar vegetation.
Christopher Berry from the University of Cardiff, with 30 years of experience studying these trees worldwide, recognized the significance of these fossils immediately. He found it amazing to discover such ancient trees close to home.
What sets this fossilized forest apart is the preservation of some trees in their original growth or fallen positions, offering a first look at the forest’s layout. Unlike the fossil forest in New York, the trees in this ancient floodplain were shorter and grew closely together.
Described as a “pretty weird forest” by Neil Davies from the University of Cambridge, there was little to no undergrowth, and grass had not yet appeared. The densely packed trees dropped a significant number of twigs, impacting the landscape dramatically. Over their lifetime, Calamophyton trees could shed up to 800 branches.
This shedding contributed to the forest floor being covered in an abundance of plant debris, marking the beginning of organic matter accumulation in the soil. This was a critical development for the Earth’s ecosystem.
The forest was surrounded by rivers and channels, with seasonal floods likely being common. The trees adapted by evolving deeper roots to survive periods of water scarcity. These roots helped stabilize the land, forming slopes and channels that would support other plant life.
As water flowed through the floodplain, it left behind mud ripples around the vegetation. These were later fossilized, preserving the plants and their positions for millions of years.
The Devonian period is often referred to as the ‘age of fishes,’ but with the discovery of plants like Calamophyton and their significant impact on the landscape, it could also be considered the age of trees. This study, published in the Journal of the Geological Society, sheds light on the earliest forests and their role in shaping life on Earth.