Our understanding of the origins of species has been in constant flux ever since the theory of evolution was proposed by University of Edinburgh alumni Charles Darwin, in the mid-19th century. Today, brand new research focusing on fossils from the Early Devonian period (around 400 million years ago), adds new complexity to the picture.
Enter Prototaxites, said to be the first giant organisms on earth. Estimated to have once towered up to eight meters tall, these unusual entities have been variously described as primitive plants or fungi. Fossil records have been found at precious few paleontological sites, one such being Rhynie chert in Aberdeenshire, Scotland.
Recently, a team of researchers from the University of Edinburgh have re-examined the anatomy of these Scottish fossils in microscopic detail, alongside systematic chemical analysis. In doing so, they have reached a ground-breaking conclusion: Prototaxites must be excluded from every known domain of complex life. The organism is neither fungus, plant, nor animal. It is an alien species — which cannot be classified according to classical biological definitions.
So, where does it belong? Evolutionary theorists are no strangers to understanding the extinction of species, even families of species. However, the existence and subsequent disappearance of a completely unique life-form is a rare conundrum to encounter.
With a scant fossil record, describing Prototaxites as a fully distinct and separate form of life will spark controversy for years to come–as it has done for the past 165 years. Only time — and research — will tell if it will eventually come to roost on an entirely new branch on the tree of life.
A few weeks ago, a 410-million-year-old, rare Prototaxites fossil entered the possession of the National Museums Scotland, alongside other valuable Rhynie chert specimens. Once it is put up for display, you will be able to witness a life form no longer found on earth.
“prototaxites section” by Sabrina Setaro is licensed under CC BY 2.0.