Q2061593

Prototaxites is an extinct genus of large macroscopic eukaryote dating from the Late Silurian until the Late Devonian periods. Prototaxites formed large trunk-like structures up to wide, reaching in height, made up of tiny interwoven tubules around in diameter, making it by far the largest land-dwelling organism of its time.

The taxonomy of Prototaxites has long been the subject of debate. It is widely considered a fungus, but the debate is ongoing. Its exact relationship with extant fungus lineages is uncertain. It was almost certainly a perennial organism that grew over multiple years. Several ecologies have been proposed, including that it was saprotrophic like many modern fungi, or that it was a lichenised autotroph. Recent research that analyzed fossils of a prototaxite species comparing them with arthropods, plants, bacteria and fungus fossils of the same location found prototaxite fossils lacks quitin derived chemical assignature that is preserved in fungi fossils of the same location and condition, challenging this claim and proposing that Prototaxites is not a fungus, but belongs to a new kingdom of eukaryotic life.