Kingdom Fungi R.T.Moore (1980) - fungi
   Phylum Neocallimastigomycota M.J. Powell (2007)
     Class Neocallimastigomycetes M.J. Powell (2007)
       Order Neocallimastigales J.L. Li, I.B. Heath & L. Packer (1993)
         1 Genus Neocallimastix Vávra & Joyon ex I.B. Heath (1983)
         2 Genus Caecomyces J.J. Gold (1988)
         3 Genus Orpinomyces D.J.S. Barr, H. Kudo, Jakober & K.J. Cheng (1989)