The Rhynie chert fossils represent one of the most important palaeontological discoveries ever made. This unique Scottish site preserves an Early Devonian ecosystem in astonishing detail. As a result, scientists can learn about an ancient palaeoenvironment.  The biota that existed in a swamp close to hot, mineral-rich springs was like nothing known on Earth today.

Moreover, the Rhynie chert captures life in situ. It preserves hot spring environments, early land plants, arthropods, and microbial communities. Therefore, it provides a rare snapshot of terrestrial ecosystems around 407 million years ago.  As part of a media release concerning a new study into the giant, enigmatic taxon Prototaxites, we received an artist’s impression of the Rhynie chert Devonian landscape.

Artist’s impression of what the environment at Rhynie, Aberdeenshire, where the Prototaxites fossils were discovered, would have looked like 410 million years ago. Picture credit: Matt Humpage.

Picture credit: Matt Humpage

Researching Rhynie Chert Fossils

Recent research has provided additional insight. A recent study suggests that Prototaxites does not belong to fungi or plants. Instead, it may represent an entirely unknown complex life form. This discovery reshapes how we understand early terrestrial life and evolutionary experimentation.

To read our blog post about this research: Beautiful Rhynie Chert Fossils Reveal Their Secrets.

The Rhynie chert fossils continue to challenge long-held assumptions. They demonstrate that Early Devonian ecosystems were already diverse and surprisingly sophisticated. Consequently, this site remains a global reference point for palaeobiology and evolutionary research.

Mike from Everything Dinosaur commented:

“Museum fossil collections are invaluable. Fossils collected decades ago can play a role in new research. Improved analytical techniques allow scientists to re-examine old specimens and uncover fresh insights. We still have so much to learn about our incredible planet and its deep evolutionary history.”

The Rhynie chert fossils continue to transform our understanding of early terrestrial life. They remind us that evolution experimented in unexpected ways during the Devonian.

Everything Dinosaur acknowledges the assistance of the National Museums of Scotland in the compilation of this article.

Visit the Everything Dinosaur website: Models of Prehistoric Animals and Plants.

Newly published research suggests that Early Devonian Prototaxites was a “new” form of life.  This giant organism, represented in the fossil record by columnar fossils up to eight metres tall, is distinct from plants and fungi.  Writing in the academic journal “Science Advances”, scientists from the University of Edinburgh and National Museums Scotland postulate that Prototaxites fossils represent a complex lifeform that is neither a fungus or a plant. Furthermore, the researchers postulate that these novel organisms died out around 360 million years ago.

An artist impression of what Prototaxites would have look like in life. It is surrounded by primitive plants in the Rhynie chert landscape. Picture credit Matt Humpage.

Picture credit: Matt Humpage

Studying Prototaxites Fossils

The fossil at the centre of this investigation comes from the famous Rhynie chert. Named after the nearby village of Rhynie in Aberdeenshire (Scotland), the rocks preserve a terrestrial ecosystem that existed approximately 407 million years ago.  Hot springs saturated with minerals periodically inundated a nearby marsh ecosystem.  The primitive plants and other organisms were preserved in amazingly detail.  Cell walls and pore spaces were replaced by these minerals.  The fossils from this locality provide a unique insight into early terrestrial plant communities.

The fossil material used in this study will be housed and cared for at the National Museums Collection Centre in the north of Edinburgh.

Lead co-author Dr Sandy Hetherington, Research Associate at National Museums Scotland and Senior Lecturer from the School of Biological Sciences at the University of Edinburgh, explained:

“It’s really exciting to make a major step forward in the debate over Prototaxites, which has been going on for around 165 years. They are life, but not as we now know it, displaying anatomical and chemical characteristics distinct from fungal or plant life, and therefore belonging to an entirely extinct evolutionary branch of life. Even from a site as loaded with palaeontological significance as Rhynie, these are remarkable specimens and it’s great to add them to the National Collection in the wake of this exciting research.”

National Museums Scotland Research Associate Sandy Hetherington with a sample of the 410-million-year-old fossil of Prototaxites. Picture credit: Neil Hanna.

Picture credit: Neil Hanna

Prototaxites (P. taiti) Chemically and Structurally Distinct from Fungi

Following an analysis of the Prototaxites fossil material, the research team concluded that this organism was chemically distinct from contemporaneous fungi. In addition, the study demonstrates that it is structurally distinct from all known fungi.

Co-lead and first author Dr Corentin Loron (UK Centre for Astrobiology at the University of Edinburgh) said:

“The Rhynie chert is incredible. It is one of the world’s oldest fossilised terrestrial ecosystems and because of the quality of preservation and the diversity of its organisms, we can pioneer novel approaches such as machine learning on fossil molecular data. There is a lot of other material from the Rhynie chert already in museum collections for comparative studies, which can add important context to scientific results.”

Co-author of the study Corentin Loron from the University of Edinburgh with a slice sample of the Prototaxites fossil. Picture credit: Neil Hanna.

Picture credit: Neil Hanna

A Separate and Entirely Extinct Form of Life

This study casts doubt upon the fungal affinity of Prototaxites, instead suggesting that this enigmatic organism is best assigned to an entirely extinct eukaryotic lineage.

Co-first author Laura Cooper, a PhD student from the Institute of Molecular Plant Sciences at the University of Edinburgh, added:

“Our study, combining analysing the chemistry and anatomy of this fossil, demonstrates that Prototaxites cannot be placed within the fungal group. As previous researchers have excluded Prototaxites from other groups of large complex life, we concluded that Prototaxites belonged to a separate and now entirely extinct lineage of complex life. Prototaxites therefore represents an independent experiment that life made in building large, complex organisms, which we can only know about through exceptionally preserved fossils.”

Dr Nick Fraser, Keeper of Natural Sciences at National Museums Scotland said:

“We’re delighted to add these new specimens to our ever-growing natural science collections which document Scotland’s extraordinary place in the story of our natural world over billions of years to the present day. This study shows the value of museum collections in cutting-edge research as specimens collected over time are, cared for and made available for study for direct comparison or through the use of new technologies.”

Everything Dinosaur acknowledges the assistance of the National Museums of Scotland in the compilation of this article.

The scientific paper: “Prototaxites fossils are structurally and chemically distinct from extinct and extant Fungi” by Corentin C. Loron, Laura M. Cooper, Sean McMahon, Seán F. Jordan, Andrei V. Gromov, Matthew Humpage, Niall Rodgers, Laetitia Pichevin, Hendrik Vondracek, Ruaridh Alexander, Edwin Rodriguez Dzul, Alexander T. Brasier, Michael Krings, and Alexander J. Hetherington published in Science Advances.

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