This giant life form resembles nothing else known 🌎

Discovered over 160 years ago, Prototaxites fossils continue to divide scientists. These 400-million-year-old structures may belong to a completely extinct branch of life.


Since their identification in the 19th century, these massive organisms—some reaching 26 feet (8 meters) tall—have been successively classified as algae, conifers, or fungi. A recent study by the University of Edinburgh reignites the debate with a novel hypothesis.

An elusive biological identity

The first hypotheses about Prototaxites date back to the 19th century, when paleontologists saw them as fossilized conifers. This interpretation was quickly challenged, as these organisms predated the appearance of modern trees. The debate then shifted toward a possible fungal nature, supported by certain chemical analyses.

The 2007 study marked a turning point by identifying carbon isotopes typical of saprophytic fungi. Yet, new research on P. taiti reveals major contradictions. The complete absence of chitin, a key molecule in fungal cell walls, and an asymmetrical tubular structure call this classification into question.

Even more puzzling, the Scottish specimens feature nested tubes forming unique patterns in the fossil record. Some segments resemble growth rings, while others show atypical branching. These morphological traits, combined with ambiguous biochemical signatures, make any comparison with modern organisms particularly speculative.

Toward a new category of life?

The exhaustive analysis conducted by the Scottish team compared Prototaxites to all known eukaryotic groups without finding a satisfactory match. Neither plants, with their cellulosic walls, nor fungi, with their chitin, nor even complex protists share all of its unique characteristics. This taxonomic dead end suggests an evolutionary branch with no living descendants.

The singularity of Prototaxites lies in its unprecedented combination of biological traits. Its heterotrophic metabolism, associated with lignin-like compounds and a hierarchical tubular structure, has no known equivalent. Researchers raise the possibility of an "evolutionary dead end"—a case of multicellularity that may not have survived the environmental changes of the Devonian.

This discovery opens dizzying perspectives on lost biodiversity. If Prototaxites truly represents a distinct kingdom, it implies that the tree of life has hidden branches, completely erased by mass extinctions. Its existence reminds us how fragmentary our knowledge of ancient ecosystems remains—and how many other surprises may still lie hidden in the fossil record.