For over 165 years, the enigmatic, colossal fossilized remnants attributed to an organism named Prototaxites have resisted all attempts at definitive classification.
A recent investigation conducted by researchers in the United Kingdom, detailed in a recently published study, posits a compelling explanation for why these peculiar formations do not seamlessly integrate into our current understanding of life’s evolutionary tree: they represent a distinct lineage, entirely devoid of any living counterpart.
Approximately 400 million years prior, the marshy landscapes of the late Silurian period were host to a flora comprising primitive horsetails, ferns, and other primordial plant analogues that appear strikingly alien by today’s standards.
Interspersed among these early plant forms stood towering structures, reaching as high as 8 meters (26 feet), whose identification remains elusive. These broad, unbranched organisms, researchers hypothesize based on scant remaining evidence, could have been a type of algae or an ancestral conifer.
The petrified specimens unearthed along the coast of Gaspé Bay in Quebec, Canada, were initially interpreted by geologist John William Dawson as the decomposed remains of trees. This led him to christen the fossil ‘first conifer‘ during the 1850s.
While the designation persisted, ambiguity surrounding the fossil’s taxonomic placement endured until 2001, when Francis Hueber, a paleontologist at the National Museum of Natural History, presented evidence strongly suggesting that Prototaxites was, in all likelihood, a colossal fungus.
This assertion received further corroboration several years later, in 2017, following a subsequent examination of a fossil fragment purportedly originating from the outer periphery of a smaller Prototaxites species, designated P. taiti.
The 2017 investigation purported to identify structural details reminiscent of the reproductive organs found in extant Ascomycota fungi.
However, this interpretation has not achieved universal consensus, particularly given the possibility that the distinct structural components might not have been interconnected.
“Within the extensive literature on extant fungi, no analogous structures are described,” stated Alexander Hetherington, a paleobotanist from the University of Edinburgh, in an interview with Erik Stokstad for Science Magazine.
Hetherington, who jointly led a study focusing on three distinct P. taiti fragments, concluded that the available evidence is insufficient to definitively classify Prototaxites as a fungus.
Through a meticulous review of its microscopic anatomy and a chemical analysis of its tubular formations, the research team systematically ruled out every potential classification group. This process revealed no extant organism with which it might share an evolutionary link.
Fungi? Eliminated due to its distinct anatomical connectivity.
A plant or alga? Unlikely, based on its chemical makeup.
A composite organism, such as a lichen? Ruled out by its specific anatomy.
An animal? Implausible, given the presence of cell walls.
“Our investigation offers no basis for assigning Prototaxites to any existing lineage, thereby underscoring its singular nature,” the researchers assert.
“We conclude that the morphology and molecular signature of P. taiti are unequivocally distinct from those of fungi and other organisms fossilized alongside it in the [Devonian deposit]. We therefore propose that it is best categorized as a member of a hitherto unknown, entirely extinct group of eukaryotes.”
The fate of this long-vanished group of organisms remains a subject of speculation. Future investigations might even lead to its eventual reclassification among ancient fungi.
Our paper on the mysterious Devonian organism Prototaxites has now finally been published! See the paper here (www.science.org/doi/10.1126/…) and our explainer thread below!
Prototaxites reconstruction by Matt Humpage— Laura Cooper (@transitionalform.bsky.social) January 22, 2026 at 5:55 AM
In the absence of comparable specimens for correlation, Prototaxites may persist as a paleontological enigma—a testament to evolution’s continuous experimentation, a process marked by a multitude of evolutionary cul-de-sacs that likely far exceed our current comprehension.
This research was disseminated in the journal Science.
