Long Before Trees, Earth Was Covered by Giant Mushrooms

From around 420 to 350 million years ago, when land plants were still the relatively new kids on the evolutionary block and “the tallest trees stood just a few feet high,” giant spires of life poked from the Earth. “The ancient organism boasted trunks up to 24 feet (8 meters) high and as wide as three feet (one meter),” said National Geographic in 2007 . With the help of a fossil dug up in Saudi Arabia scientists finally figured out what the giant creature was: a fungus. (We think.)

The towering fungus spires would have stood out against a landscape scarce of such giants, said New Scientist in 2007 . “A 6-metre fungus would be odd enough in the modern world, but at least we are used to trees quite a bit bigger,” says Boyce. “Plants at that time were a few feet tall, invertebrate animals were small, and there were no terrestrial vertebrates. This fossil would have been all the more striking in such a diminutive landscape.” Fossils of the organisms, known as Prototaxites , had peppered the paleontological findings of the past century and a half, ever since they were first discovered by a Canadian in 1859 .

But despite the fossil records, no one could figure out what the heck these giant spires were. The University of Chicago : For the next 130 years, debate raged. Some scientists called Prototaxites a lichen, others a fungus, and still others clung to the notion that it was some kind of tree. “The problem is that when you look up close at the anatomy, it’s evocative of a lot of different things, but it’s diagnostic of nothing,” says Boyce, an associate professor in geophysical sciences and the Committee on Evolutionary Biology.

And here is a little factoid video from Amazing Planet about the HUMONGOUS FUNGUS (AKA Armillaria solidipes)! The world’s BIGGEST living ORGANISM!

Scientists who aimed to disprove the fungus theory suggested that the massive Prototaxites spires were actually large mats of liverworts that had somehow curled up. However, in a subsequent study, the researchers who originally put forward the fungus theory remained steadfast in their belief. Science is a complex process, and despite over 100 years of research, we are still uncertain about the true nature of these colossal spires and giant mushrooms that once dominated the ancient Earth.