Edinburgh, Scotland – Research out of the United Kingdom has shed new light on the mysterious giant organism known as Prototaxites that roamed the Earth hundreds of millions of years ago. Scientists have long debated the evolutionary placement of Prototaxites, with recent findings indicating that this ancient creature may belong to a previously undiscovered branch of multicellular eukaryotes. The study, which has not yet undergone peer review, was posted on the preprint server bioRxiv.
The researchers, led by Corentin Loron from The University of Edinburgh’s School of Physics and Astronomy, re-examined fossil remains of a Prototaxites species called Prototaxites taiti. Contrary to previous hypotheses that Prototaxites was a type of fungus, the team concluded that it likely falls within an extinct lineage of multicellular terrestrial eukaryotes. The discovery challenges the conventional understanding of Prototaxites’ place in the tree of life, highlighting its uniqueness.
Through a thorough analysis comparing Prototaxites with ancient fungi found in the Rhynie chert, a significant fossil deposit in Scotland dating back to the Early Devonian period, researchers found distinct anatomical differences. One key observation was the absence of chitin or chitosan molecules in the cell walls of Prototaxites, further separating it from known fungal groups. This led the scientists to suggest that Prototaxites is best classified as a member of an entirely extinct group of eukaryotes.
The study also identified three defining features of Prototaxites: large tube-like structures, lignin-like compounds, and a heterotrophic lifestyle where it consumed other organisms for food. This combination of characteristics sets Prototaxites apart from any known extant lineage, hinting at the possibility of a new kingdom of life. The implications of this discovery could potentially reshape our understanding of ancient organisms and the evolution of life on Earth.