A giant mystery organism more than 350 million years old has finally been identified as a humongous fungus. The enigma known as Prototaxites, which stood in branchless, tree-like trunks up to more than 20 feet tall and a yard wide, lived worldwide from roughly 420 million to 350 million years ago. The giant was the largest-known organism of its day, living in a time when wingless insects, millipedes, worms and other creepy-crawlies dominated, as backboned animals had not yet evolved out of the oceans. ‘That world was a very strange place,’ said researcher C. Kevin Boyce, a University of Chicago paleobotanist. Prototaxites has generated controversy for more than a century. Originally classified as a conifer like a pine tree, scientists later argued that it was instead a lichen, various types of algae or a fungus . ‘No matter what argument you put forth, people say, well, that’s crazy. That doesn’t make any sense,’ Boyce said. ‘A 20-foot-tall fungus doesn’t make any sense. Neither does a 20-foot-tall algae make any sense, but here’s the fossil.’ Strange world Simple vascular plants, the ancestors of the familiar conifers, ferns and flowering plants of today, had established themselves […]