A mushroom weighing more than 20 kilograms, picked in a forest in Mexico's southernmost state of Chiapas in 2007.

My hypothesis is that both species evolved a mutualism with colony forming insects. Termitomyces titanicus is a specialist that only can function with its termite counterpart while Macrocybe titans has a more generalist ecology, and can carry out an interaction with leafcutter ants as well as live a solitary saprophytic lifestyle. Again, I’m left shook that researchers have not looked more closely at this interaction. These are the two largest mushrooms on the planet. Although possible, there’s no way Macrocybe titans grows from leafcutter ant mounds by chance. I think this is the species ancestral trait. Let me explain.