Bigyra Cavalier-Smith, 1998 Subphylum Opalozoa Cavalier-Smith, 1992 Infraphylum Placidozoa Cavalier-Smith, 2013 Superclass Wobblata Cavalier-Smith, 2013 [paraphyletic] Class Placididea Moriya, Nakayama & Inouye, 2002 [monotypic] 1 Order Placidida Moriya, Nakayama & Inouye, 2002 [monotypic]