Domain Eucaryota
   Subdomain Chlorota Doweld (2001)
     Kingdom Peridiniobiota Starobogatov ex Doweld (2001)
       Subkingdom Parameciobiotina Starobogatov, 1986 [monotypic]
         Phylum Parameciozoa Kussakin & Drozdov, 1998
           Subphylum Oxytrichozoina Doweld, 2001
             Class Spathidiatea Doweld, 2001
               Subclass Isotrichatinea Doweld, 2001
                 Order Isotrichida Doweld, 2001 [monotypic]
                   1 Family Isotrichidae Bütschli, 1889