A flurry of paleobotanical research published in 2024 and early 2025 is reshaping how scientists understand the deep evolutionary history of plants, including the discovery of one of the world’s oldest fossilized forests in southwest England, dated to roughly 390 million years ago. The find — announced by researchers from the University of Cambridge and Cardiff University in the journal Journal of the Geological Society — pushes back the known origin of complex woodlands and offers a vivid window into the moment Earth’s continents first turned green.
The Discovery That Pushed Back Forest History
The fossilized forest, located along the high sandstone cliffs of the Hangman Sandstone Formation between Minehead and Combe Martin in Somerset and Devon, was identified through clusters of fossil tree stumps and fallen trunks belonging to a primitive plant group called the cladoxylopsids. These early trees stood between two and four meters tall, with hollow centers and densely packed branch-like fronds in lieu of leaves. The age of the deposits — placing them squarely in the Middle Devonian period — makes the site approximately four million years older than the previous record-holder in New York State, as documented in the original Journal of the Geological Society publication.
Lead researcher Professor Neil Davies described the find as transformative, noting that the fossil landscape preserves not only the plants themselves but also evidence of how their roots stabilized sediment and altered river systems. That insight matters: the rise of forests in the Devonian is widely considered one of the great turning points in Earth history, comparable in scale to the later evolution of flowering plants or the emergence of grasslands.
Why Devonian Forests Matter
Before the Devonian, Earth’s land surface was an alien place — barren rock and microbial crusts punctuated by low-growing mosses and small vascular plants. The arrival of tree-sized vegetation changed the planet permanently. As detailed in coverage by the BBC science desk, the appearance of forests drew down atmospheric carbon dioxide, cooled global climates, and built the first true soils. Roots fractured bedrock, accelerating chemical weathering, while leaf litter introduced organic carbon to terrestrial ecosystems for the first time.
These changes also reshaped rivers. Pre-forest rivers tended to be broad, shallow, and braided, sweeping across unconsolidated sediment. Once roots arrived, riverbanks held firm, and the meandering, single-channel rivers familiar today began to dominate. The Somerset fossils show this transition mid-stride, with sediment patterns suggesting plants were actively engineering their environment.
A Cascade of Evolutionary Consequences
Forests also indirectly enabled the evolution of large terrestrial animals. By the Late Devonian, the first tetrapods were crawling onto land, exploiting habitats made possible by plant-driven oxygen enrichment and complex three-dimensional vegetation. Researchers writing in Nature’s paleontology coverage have long argued that without the cladoxylopsids and their successors, the trajectory of vertebrate evolution would have looked radically different.
What Experts Are Saying
Professor Davies told reporters the team was struck by how “recognizable” the ancient forest floor felt, despite the absence of modern flowering plants or grasses. Co-author Dr. Christopher Berry of Cardiff University, who has spent decades studying cladoxylopsids, emphasized that the new site preserves a community of plants in growth position — a rarity in paleobotany, where most fossils are transported and disarticulated before burial. Such in-situ preservation allows researchers to reconstruct forest density, canopy structure, and even sediment dynamics with unusual precision.
Looking Ahead
The Somerset discovery is unlikely to remain the oldest for long. Paleobotanists are now systematically re-examining Middle Devonian sandstones in Norway, Germany, and the Canadian Arctic, where similar fossil forests may be hiding in plain sight. Each new site refines our understanding of how quickly forests spread and how their ecological influence accumulated. As climate scientists increasingly look to deep-time analogs to understand modern carbon cycles, these ancient woodlands offer more than curiosity value — they are natural experiments in how vegetation reshapes a planet.
For readers interested in more deep-dive coverage of botanical science, paleontology, and environmental research, visit science.wide-ranging.com for related articles and ongoing reporting.
