The humble fungus may have been responsible for bringing to an end Earth's period of accumulating coal reserves, say researchers. During the 60 million-year-long Carboniferous period on Earth vast carbon beds were laid down from the burial of ancient forests in marshy swamps. The trees did not decay but were instead converted into peat and under extreme pressure to coal. But 300 million years ago, something changed to stop this deposition of coal.
Scientists now suggest it may have been the rise of fungi capable of digesting the polymer lignin, which among other things keeps plant cell walls rigid. This hypothesis comes from the study of 31 genomes of mainly wood decay fungi - a group called Agaricomycetes. This group includes white rot fungi, which can digest all components of plant biomass - cellulose, hemicellulose and lignin.