 In "Anaeromyces", the presence of putative resting spores has been observed  but the way in which these are formed and germinate remains unknown.Neocallimastigomycota lack mitochondria but instead contain hydrogenosomes in which the oxidation of NADH to NAD+, leading to formation of H2.Neocallimastigomycota play an essential role in fibre-digestion in their host species.