314 Million years ago the unassuming North-Welsh village of Brymbo was very, very different….

During work on the Brymbo steel works site in 2003 several large tree-like fossils were uncovered while open-cast mining overlying coal. After initial assessment by Peter Appleton, Professor Barry Thomas and Dr Jacqui Malpas five years of periodic excavation revealed hundreds of fossils and over 20 large tree trunk like structures with rooting networks perfectly preserved, some measuring up to 2.5 meters in height and 1.5 meters in width.

A giant lycopod stump uncovered in the 2008-9 excavations

Coal has been mined on the Brymbo site since the 1400’s, all the while the miners blissfully unaware of the origin of the coal that they were labouring to extract. The coal seams themselves were deposited as thick mats of plant debris approximately 300 million years ago in a period of deep geologic history known as the Carboniferous (derived from the Greek ‘carbo’ – coal and ‘fero’ – bearing). This period of earths history is characterised by high levels of atmospheric oxygen (35% compared to 20% oxygen today, so high that lightning trikes were explosive!) resulting from almost planet-wide tropical forests and swamps.

Costa del Wrexham

At this point in history, North Wales was situated upon the equator, therefore the forest here would have been hot and humid, and the plants and animals unsettlingly unfamiliar.

Palaeocontinental configuration during the mid-late carboniferous

The forest at Brymbo during this time contained no flowering plants. In fact, it would be quite difficult to find many living representatives of the ancient flora preserved at the site. Instead of deciduous trees the forests contained giant relatives of horsetails and club-mosses along with many groups of primitive plants that bore no ancestors that survive today. In-between the layers of coal at the Brymbo are layers of mudstone and sandstone that represent devastating flash flooding events that buried much of the low-lying swampland in the area in sediment. This rapid burial is the reason for the exquisite quality and unusual quantity of in-situ plant fossils at the Brymbo site. Similar conditions have occurred at other points in time and are represented by sites elsewhere in the world but none of this quality from this period. The exposed rock section at Brymbo likely represents some 30,000 years, for context, humans are thought to have created the first cave paintings around 30,000 years ago from the present day. These rocks represent discrete flooding events that have preserved a variety of palaeoenvironments that are uniquely preserved at Brymbo.

The Fossil Forest Project

Excavating, preserving and displaying this geologic marvel is of the upmost importance not only in relation to local history but for global natural history. Such a potential educational resource needs to be protected and utilized to foster a greater appreciation of the earths diverse history, the evolution of ecosystems and, perhaps most importantly, how climate change can impact global environments. The fossil forest at Brymbo represents a truly exciting prospect, an in-situ palaeontological window into a 300 million year old environment, an environment that is intrinsically tied to the local heritage in that it was responsible for producing the coal that allowed the community to thrive during the industrial revolution. But it is also a stark reminder that in the past 200 years humanity has burned hundreds of thousands of years worth of carbon sequestered by these primitive forests. The introduction of huge quantities of carbon into the atmosphere that had been entombed for millions of years is known to be one of the fundamental factors contributing to the climate change that threatens global ecosystems today. The planned excavation of the site and erection of a building to protect and display the fossil forest is the first step in beginning to unlock the potential of this important scientific resource for the public, education and the scientific community.

The Phase-one fossil forest building, due to begin construction spring 2019