Mushrooms For All

You've probably seen this image, and heard of the huge fungal "Trees" of the late Silurian and Devonian period.
What if I told you this was probably not what they were like?
When fossils of these organisms were first discovered they were thought to be early trees. After all they were HUGE, up to 8 meters long and a mater wide. They had concentric growth rings like trees after all, and even branching points. But later microscopy showed a structure more similar to hyphae. Millions of long, hollow tubes collected together to make this structure possible. And recent infrared spectroscopy of the fossils we have has revealed a structure most likely composed of chitin polymer.
That's likely a fungus!
So why are they so tall?
You'd be tall to disperse spores or escape predation.
Early plants were barely 6cm at their largest. And early trees didn't appear until the late devonian, about when prototaxites start disappearing from the fossil record. Being a meter tall would still make you tower above all these tiny Bryophytes. And the only predators are tiny. The current most likely theory is that Prototaxites weren't tall, they laid on the ground like an extremely large rhizomorph. Not only have their fossils not undergone compaction like many fossilized logs do, but as a fungus this would benefit them hugely. Spreading out across the ground, covering more surface area means more food. Especially since as far as we're aware they were still saprotrophs.
We have also never found anything resembling a "stump" of one of these so called fungus trees. Which have all been found more or less laying on their side. The idea that they stood upright is a wonderful image, huge, alien looking trees that are actually fungus? Awesome!
It's looking more and more like that was probably not the case. It's true that they were the largest organisms on land for a time, massive structures that dominated their plant peers around them. But most likely they didn't stand large, phallus like above the landscape.
We still have this image because we thought of them this way for so long, at first they were trees. Then we corrected and went "Actually they were fungi." But we still had the idea of trees, because they look like a tree trunk. There are other theories but they also have little evidence, such as them being rolled up mats of lichen.
It's possible that they grew upright at times, but the idea of a forest of mushrooms is unfortunately, likely a fantasy born of the scientific process of ideas being superseded by other ideas.