26-Foot Mystery Giant: Scientists Discover an Entirely Lost Form of Life

The organism, known as prototaxites, stood an astonishing 26 feet tall and thrived around 410 million years ago, before vanishing roughly 360 million years ago.

Scientists have discovered a towering form of ancient life that once loomed over Earth’s early landscapes, rewriting what we know about evolution on land. The organism, known as prototaxites, stood an astonishing 26 feet tall and thrived around 410 million years ago, before vanishing roughly 360 million years ago.

For more than a century, prototaxites baffled researchers, with most believing it to be a giant prehistoric fungus. Now, a groundbreaking fossil analysis led by scientists from National Museums Scotland has shattered that assumption.

The new study concludes that prototaxites were neither plant nor fungus, but instead belonged to an entirely extinct evolutionary branch of life—a form of complex organism unlike anything alive today.

“It's really exciting to make a major step forward in the debate over prototaxites, which has been going on for around 165 years,” said Dr Sandy Hetherington, co–lead author of the study.

“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.”

The fossil was discovered in the Rhynie chert, a deposit near Rhynie in Aberdeenshire - one of the most important prehistoric sites on Earth.

“The Rhynie chert is incredible,” said Dr Corentin Loron, co–lead author of the study. “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.”

Researchers examined both the chemical makeup and internal anatomy of the fossil, an approach that ultimately confirmed prototaxites did not fit into any known biological category.

“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,” explained Laura Cooper, co–first author of the study.

“Prototaxites, therefore, represents an independent experiment that life made in building large, complex organisms, which we can only know about through exceptionally preserved fossils.”

The rare fossil has now been added to the collections of National Museums Scotland in Edinburgh, marking a significant milestone for both science and heritage.

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.”