Phylum Tardigrada Doyère, 1840 - tardigrades
   Order Heterotardigrada Marcus, 1927 see Class Heterotardigrada Marcus, 1927
     Suborder Arthrotardigrada Marcus, 1927 see Order Arthrotardigrada Marcus, 1927
       Family Stygarctidae Schulz, 1951
         1 Subfamily Stygarctinae Schulz, 1951 see Family Stygarctidae Schulz, 1951
         2 Subfamily Neoarctinae de Zio Grimaldi, D'Addabbo Gallo & Morone De Lucia, 1992 see Family Neoarctidae de Zio Grimaldi, D'Addabbo Gallo & Morone De Lucia, 1992