Notes on the origin of inertinite macerals in coal: Evidence for fungal and arthropod transformations of degraded macerals

The role of fungus in the formation of coal macerals, both as a primary contributor in the form of a fungus fossil/maceral funginite, and in their role in degrading wood, thus producing degraded maceral forms, has been established. Fungus, in the course of breaking down the lignin and cellulose in wood, make the wood more digestible for grazers, such as arthropods. In turn, the remnants of the digested wood and anything else eaten but not completely digested are excreted and can be preserved intact; eaten by other fauna with a repeat of the cycle; or colonized by bacteria and/or coprophilous fungi with or without subsequent preservation. Ultimately, the coprolites can be preserved as a form of macrinite.

Research highlights
► Woody tissues are degraded by fungal activity, a path to primary macrinite.
► Some of latter is eaten by arthropods.
► Along with other eaten material, non-digested material is excreted.
► Some of latter can be colonized by fungus or bacteria and/or eaten again.
► If preserved, result is mix of macrinite and other macerals.