390 Million-Year-Old Fossilized Forest in Somerset is World’s Oldest

Remnants of the world’s oldest fossilized forests and trees, dating back 390 million years, have been uncovered along the Devon and Somerset coast among high sandstone cliffs. The trees likely thrived as part of a vast forest that once blanketed the eastern coast of the Old Red Sandstone continent, which was a part of Europe during that era.

This makes the Somerset forest as being between four and five million years older than the previous record holder, found in Cairo, New York, in the United States. What can this new discovery tell us?

The trees, identified as Calamophyton, bore a striking resemblance to palm trees but boasted thin, hollow trunks. Though they lacked leaves, they featured twig-like structures adorning their branches, reaching heights of 2 to 4 meters (6.6 to 13.1 feet), shedding branches as they matured. This, and a multitude of other discoveries have been unearthed in a new study published in The Journal of the Geological Society.

Early Arboreal Development: The Devonian Period

Discovered by researchers from Cambridge University and identified by experts at Cardiff University, these fossils contain incomplete trunks reaching up to 2 meters (6.6 feet) in length, accompanied by small branches. They belong to an early type of tree known as cladoxylopsids. The team reveals that cladoxylopsids held sway over terrestrial ecosystems for approximately 5 million years prior to the emergence of more contemporary woody trees around 385 million years ago.

The forest would have looked very different from modern woodland (CNN / Peter Giesen/Chris Berry)

This forest dates back to the Devonian Period, spanning from 419 million to 358 million years ago, marking a significant era when life began transitioning onto land. In fact, the Devonian Period is associated with the formation of the first forests on Earth, with remarkable plant diversification occurring, adjusting itself to adaptation.

“The Devonian period fundamentally changed life on Earth. It also changed how water and land interacted with each other, since trees and other plants helped stabilize sediment through their root systems, but little is known about the very earliest forests. The evidence contained in these fossils preserves a key stage in Earth’s development, when rivers started to operate in a fundamentally different way than they had before, becoming the great erosive force they are today,” said the study’s first author Professor Neil Davies of Cambridge University’s Department of Earth Sciences, in a press release.

By the end of the Devonian Period, significant evolutionary milestones had been reached. The emergence of the first seed-bearing plants marked a crucial development in plant evolution, laying the groundwork for the evolution of modern gymnosperms and angiosperms in subsequent geological periods.

The ripple marks in the Somerset cliffs are the fossils of the world’s oldest forest floor (CNN / Neil Davies)

The Devonian Period also witnessed the establishment of the earliest land animals, predominantly arthropods. These early terrestrial arthropods, including insects and arachnids, were well established by the end of the period, marking a significant transition in the colonization of land by animal life.

Oldest Fossil Record and the Passage of Geological Time

“These Calamophyton trees are the oldest fossil trees ever found in Britain and represent an as yet missing part of our vegetational history. The record of fossil forests, where tree bases are preserved where they were living, so far dates back to those discovered in New York State, at Cairo and Gilboa at about 385 million years.”

“Although the area of rock exposure is limited and dangerous to access, our new discovery is the oldest clear example of such a geological phenomenon known to date and it speaks directly to the ecology of the oldest forests 390 million years ago,” explained Dr. Christopher Berry in the same press release. Dr. Berry is a Senior Lecturer at Cardiff University’s School of Earth and Environmental Sciences, who identified the fossils.

The fossils were discovered in the vicinity of Minehead, situated on the southern bank of the Bristol Channel, near the contemporary location of a Butlin’s holiday camp. Scientists had previously assumed that the coastal area along the English coast, including Minehead, lacked significant plant fossils.

However, this finding challenges that assumption, highlighting the important role that early trees played in shaping landscapes and stabilizing riverbanks and coastlines hundreds of millions of years ago, reports CNN.

The fieldwork took place along the highest sea cliffs in England, with some sections only accessible by boat. It uncovered a wealth of plant fossil material from the Devonian period within the sandstone formation.

At that time, the site was characterized as a semi-arid plain, traversed by small river channels originating from mountains to the northwest. The researchers noted that the appearance of the first densely packed clusters of trees likely influenced the flow patterns of rivers across the landscape.

The findings indicate the rapid development of early forests. While the fossils in England depict a sparse forest containing only one type of tree, the previous oldest forest discovered in New York state showcased a greater variety of species, including vine-like trees that grew on the ground, despite being dated just 4 million years later.

According to Davies, comparing the Somerset flora with the New York flora illustrates the swift changes that occurred in terms of geological time. Within a relatively short geological timeframe, there was a notable increase in variety among the flora.

During that era, the cliffs where the fossils were discovered, referred to as the Hangman Sandstone Formation, were geographically connected to regions that are currently part of Germany and Belgium, rather than England. Fossils similar to those found in the Hangman Sandstone Formation, including pieces of wood washed out to sea, have also been unearthed in these neighboring areas.

“People sometimes think that British rocks have been looked at enough, but this shows that revisiting them can yield important new discoveries,” concluded Davies.

Top image: Detail of a fallen tree trunk from the world’s oldest fossilized forest discovered in Somerset. Source: BBC / Chris Berry.

By Sahir Pandey