Why aren’t fungi as tall as trees?

The earth was once populated by actual mushrooms as tall as trees, which have since shrunk to their current size.

About half a billion years ago, there were barely any plants on the surface of the Earth, which was instead populated by huge fungi called Prototaxites.

They were able to thrive thanks to the abundance of bacteria as well as lichens, algae and dead fungi in the soil.

Most of the Earth looked like this.

The fact that the fungi of the time did not have their characteristic hats (also called pileus), however, left a lot of light (and therefore free energy) unused, a resource that plants began to exploit until they took over the surface of the entire planet.

Fungi lost their predominance, but continue to this day to live in symbiosis with animals and plants, to whom they provide food and minerals in exchange for the energy they produce through photosynthesis. Even today, intricate mycelium networks distribute nutrients and essential elements over vast areas.