The world’s coal deposits were roughly formed during a 60-million year period from 360 to 300 million years ago. Then, it stopped at the end of the Carboniferous period. What happened?
It has been postulated that the evolution of a white rot fungal ancestor was linked to the end of coal formation.
White rot fungi from the class of fungi known as Agaricomycetes are capable of degrading the polymer lignin. Lignin is found in plant tissues and is largely responsible for the rigid structure of plant cell walls.
The researchers postulated that fungal degradation of lignin caused plant matter to be broken down into its basic components and eventually released as carbon dioxide. Prior to this, dead matter accumulates as peat that later transforms as coal.