Original photo by Science History Images/ Alamy Stock Photo

Landscape of the Earth during the Devonian Period

Long before trees, Earth was home to towering organisms called Prototaxites, which lived during the Late Silurian through the Devonian periods, roughly 420 million to 350 million years ago. Fossil evidence shows they could reach up to 24 feet tall and 3 feet wide, making them the largest land organisms of their time. 

Most plants back then measured only a few inches, forming low mats of mosses, liverworts, and early vascular species. Land animals — millipede-like arthropods, primitive insects, and early amphibians — were also relatively small, and the first treelike plants would not appear until millions of years later, making Prototaxites the giants of their prehistoric world.

Mushrooms can survive in space.

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Certain fungi have shown remarkable resilience in extreme conditions. Scientists are exploring fungi as tools for future space missions, with potential uses including breaking down waste, contributing to biomanufacturing, and even serving as natural shields against radiation.

For more than a century, scientists debated whether Prototaxites were plants, fungi, algae, or lichens, since nothing comparable exists today. Their fossil “trunks” were composed of tightly packed microscopic tubes, unlike vascular tissues in plants, and they lacked roots, leaves, or wood. Isotope studies suggest they lived as heterotrophs, absorbing nutrients from decaying organic matter rather than producing their own food.

They may also have played a role in shaping primitive soils and nutrient cycles, and some researchers speculate their massive columns offered shelter to small arthropods. Although scientists are still investigating how Prototaxites lived and precisely what role they played in early ecosystems, evidence now points to them being either fungi or an otherwise unknown fungus-like branch of life.

Numbers Don't Lie

Numbers Don't Lie

Number of edible mushroom types that can be commercially mass grown
10
Known species of mushrooms worldwide
16,000
Year the first Prototaxite fossils were discovered
1843
Height (in feet) of the tallest living tree, a California coast redwood named Hyperion
380

In the 1959 adventure film “______,” explorers find a subterranean world filled with towering prehistoric mushrooms.

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In the 1959 adventure film “Journey to the Center of the Earth,” explorers find a subterranean world filled with towering prehistoric mushrooms.

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Some mushrooms can glow in the dark.

Bioluminescent fungi, such as Panellus stipticus and Mycena chlorophos, emit a soft green light through chemical reactions involving enzymes and oxygen. This glow serves multiple ecological purposes: It may deter predators, attract insects to help spread spores, or even protect the fungi from harmful oxidative stress. In dense forests at night, patches of these glowing mushrooms can make the forest floor shimmer as if dotted with tiny lanterns.

Interestingly, more than 130 fungi species are known to exhibit bioluminescence, making it more common among fungi than among animals. In Japanese folklore and among Indigenous cultures in Central and South America, bioluminescent mushrooms were often thought to be the spirits of the dead. Today, their glow reminds us even seemingly ordinary organisms hold hidden wonders, quietly illuminating the ecosystems we may otherwise overlook.

Kristina Wright
Writer

Kristina is a coffee-fueled writer living happily ever after with her family in the suburbs of Richmond, Virginia.