Kingdom Chlorobiota C.Jeffrey ex Doweld (2001) - plants see Subkingdom Viridiplantae Caval.-Sm. (1981)
   Subkingdom Bryobiotina Campb. (1890)
     Division Anthocerotophyta Stotler & Crand.-Stotl. (1977) see Phylum Anthocerotophyta Stotler & Crand.-Stotl. (1977)
       Class Anthocerotopsida Jancz. (1872) - hornworts
         Subclass Notothylatidae Duff, J.C. Villarreal, Cargill & Renzaglia [monotypic]
           Order Notothyladales Hyvönen & Piippo [monotypic]
             Family Notothyladaceae Müll.Frib. ex Prosk. (1960)
               Subfamily Phaeocerotoideae Hässel
                 Genus Mesoceros Piippo