Science Adviser reports on the discovery (or rediscovery) of a fossil that is not just a new species, not just a new class, order, nor phylum of life. It’s so different from animals, vegetables, and even fungi that it’s being considered an entirely new kingdom — that died out 400 million years ago:
Ever since its discovery in 1859, paleontologists have argued about the identity of this log-shaped giant, known as Prototaxites. Was it an ancient conifer, a mass of algae, a rolled-up mat of liverworts, or even “the Godzilla of fungus”? Now, scientists propose something else entirely—and far weirder than Godzilla. After analyzing a new and extremely well-preserved specimen, researchers argue that Prototaxites is an unknown type of multicellular life.
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microscope revealed the ancient creature had masses of interwoven small tubes typical of Prototaxites fossils. While some have suggested such tubes resemble the hyphae of a fungus, the tubes in the new fossil help rule out that possibility. For one, they branch and merge in decidedly nonfungal ways, the team noted, and some have banded walls that resemble structures seen in modern vascular plants.
Many Prototaxites fossils also have dark spherical spots, which some researchers have suggested are evidence that it was a symbiotic organism like a lichen—but the new fossil looked nothing like a lichen up close. Instead, the spots might have been sites for exchanging gases or nutrients with water, just as the air sacs in our lungs allow oxygen to diffuse into our blood. Traces of biomolecules also indicate Prototaxites was unique.