A phylum of filamentous, microscopic fungi that undergo sexual reproduction by the formation of a zygospore. The Zygomycota are often referred by the common names “pin molds” or “sugar molds” and are ubiquitous fungi though rarely observed by humans because of the diminutive size of their reproductive structures. Zygomycota grow as a network of interconnected filaments (hyphae) that grow on or inside their substrate and acquire nutrients through absorptive, heterotrophic nutrition. Zygomycota usually have coenocytic (multinucleate) hyphae lacking septa (cross-walls) between cells, but may also be regularly septate. The Zygomycota have a large diversity of ecological roles: as saprophytes on various substrates, especially sugary substrates and dung, as parasites of animals or plants, as commensualistic (both nonpathogenic and nonbeneficial) associates of arthropods, as parasites of other fungi, and as mycorrhizal symbionts with plant roots.