Scientists Discovered a Fossilized Forest in England
At over 390 million years old, it's the newest, oldest forest ever found.
Hiya!
I’m a Pacific Northwest native, which means I’m a child of the forest. It’s where I grew up exploring, playing, and learning. There’s no place in the world I feel more connected to Nature than in a forest. The vast deserts, oceans, and soaring mountains all leave me in wonder, but they also instill a different sort of energy.
All the other natural entities feel immense but singular. Meanwhile, forests are like us. They have communities made of individuals that depend on relationships and diversity. Perhaps that’s why I was so excited to learn that scientists recently stumbled upon the newest, oldest known forest.
The Discovery
Expert in field-based sedimentary geology and University of Cambridge professor in the Department of Earth Sciences, Neil Davies and colleagues at Cardiff University set out to the Hangman Sandstone Formation along the coastline of southwest England intending to examine sediment but ended up finding far more than they expected.
There, on the dramatic sandstone cliffs — the highest sea cliffs in England, some only accessible by boat — were fossilized trees belonging to the planet’s oldest-known forest. Davies and his team published their discovery in the Journal of the Geological Society in February 2023.
The Devonian Period
The Hangman Sandstone Formation, where the forest was discovered, is located close to Devon and the Somerset coastline and dates back to the Middle Devonian period — between 393 million and 383 million years ago.
Back then, what we call the United Kingdom today (England, Scotland, Wales, and Northern Ireland) was part of a landmass called Laurentia, which existed just below the equator with a warmer and drier climate. During this time, the area where Davies and his team located the fossils didn’t connect to the rest of England as it does today but was attached to Belgium and Germany, where similar fossils have also been found from the same period.
Earth looked very different during the Middle Devonian. Besides the various positions of continents, this was when animals became established on land, and the first plants began using seeds to reproduce. In addition to producing seeds, plants had another important function.
As landmasses shifted, plants helped stabilize the soil the same way they do now. By using their roots to hold the ground together, which helps prevent erosion. Davies, the lead author of the new study, explained in a statement:
“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 stabilise sediment through their root systems, but little is known about the very earliest forests.”
That’s beginning to change thanks to their fortuitous find. The researchers identified fossilized plants and plant debris throughout their fieldwork, including traces of roots and sedimentary structures, tree logs, and even tracks belonging to small Devonian animals, all beautifully preserved in the cliffside sandstone. Although, Davies told New Scientist writer Sascha Pare:
"At this time, there's nothing much bigger than lots of little arthropods knocking around on land. You might find some more amphibian-type things and fish in some of the lakes and rivers nearby."
Through analysis, the scientists determined that when the forest existed, the area was a semi-arid plain with small river channels spilling from the northwest mountains and crisscrossing the site. The forest helped direct the water’s flow.
A Single Tree Species
Remarkably, the entire fossilized forest the researchers found consisted of trees from a single species known as Calamophyton. They kinda looked like palm trees, but the scientists think they were more closely related to sphenopsids (horsetails) and ferns. Davies explains:
"They look like palm trees, but they're in no way related to palm trees. They've got a long central stem and what look like palm fronds coming off, but those palm fronds aren't really leaves — they're actually just lots of twiglets."
The trees the research team found weren’t very tall either, compared to a forest today. These trees would have only grown between 6.5 and 13 feet (2 to 4 meters) high. For reference, most trees on Earth these days are around 100 feet (30 meters) tall, but about 5 percent can grow over 164 feet (50 meters).
Some of the largest living trees are the giant sequoias of California’s Redwood Forest, which can grow to around 22 feet (7 meters) wide at their base and up to 367 feet (112 meters) high.
Also, while most trees we’re familiar with today have trunks made of solid wood, the Calamophyton trunks were hollow. Paleobotanist and senior lecturer at the University of Cardiff in the U.K. and the study’s co-author, Christopher Berry, said in a statement by Cambridge:
"When I first saw pictures of the tree trunks I immediately knew what they were, based on 30 years of studying this type of tree worldwide. It was amazing to see them so near to home. But the most revealing insight comes from seeing, for the first time, these trees in the positions where they grew."
While some of the fossils were fallen logs flattened over eons, some hollow trunks were preserved thanks to sediment filling them. The fossilized trees also bear visible scars showing where branches used to attach to the tree trunks. These branches were covered in hundreds of twiggy thistle-like structures. Davies said:
“This was a pretty weird forest – not like any forest you would see today.”
The image below is an illustration the researchers composited based on their findings of the fossilized trees the team found. To me, they look a bit like trees Dr. Seuss might have drawn or as though they’d exist in the children’s book Where the Wild Things Are.
Anyway, the debris on the floor in the image is the accumulation of branches the trees shed as they grew, which littered the forest floor. Davies went on to explain:
“There wasn’t any undergrowth to speak of and grass hadn’t yet appeared, but there were lots of twigs dropped by these densely-packed trees, which had a big effect on the landscape.”
During the Devonian period, plants evolved to live closely together on land for the first time. As the forest of tightly packed Calamophyton trees grew, they dropped an abundance of branches, leading to the buildup of sediment layers that also impacted how water moved across the landscape.
This marked the first time that the flow of rivers could be affected in such a way.
Bridging the Gap
While the Calamophyton forest in today’s England is the oldest known forest, its trees are not the oldest ever discovered. Individual trees that were much older have been found worldwide, some dating back to when plants first colonized land around 500 million years ago.
Before Davies and his colleague’s fortunate discovery, the Gilboa Fossil Forest, first found in 1870 in New York state, was the oldest known forest, dating back to 386 million years ago.
More than beating the previously held record, scientists are intrigued by the stark differences between the two forests. A big one is that the Gilboa forest appears to have had a diverse range of plants, while only the Calamophyton species formed the cliffside forest Davies and his colleagues found.
This difference can (hopefully) help scientists better understand the evolution of ecosystems. Davies says they can already see that forests evolved from being “relatively primitive to becoming well-established over just a few million years.”
Perspective Shift
Discoveries like this one remind us that our planet is always changing and has gone through many phases before looking as it does now. Earth 300 or 500 million years ago would have seemed alien-like compared to what we’re familiar with today.
Climate and landmass formations aside, Nature’s favorite tool is diversity. It’s literally everywhere, in every shape and form available: diversity of species, climates, currents, colors, senses, ideas, and on and on it goes. Now, between the Calamophyton and Gilboa forests, scientists have narrowed down the timeline for when Nature started utilizing it — and it’s never stopped.
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Became well established “in just a few million years”. That kind of helps give perspective. Interesting info. Thanks