organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain Eukaryota Chatton, 1925 - eukaryotes
     Kingdom Fungi R.T.Moore (1980) - fungi
       Phylum Basidiomycota R.T.Moore (1980) - basidiomycetes
         Class Basidiomycetes G.Winter (1880)
           Subclass Agaricomycetidae Locq. ex Parmasto (1986)
             Order Agaricales Underw. (1899)
               Family Nidulariaceae Dumort. (1822)
                 1 Genus Crucibulum Tul. & C.Tul. (1844)
                 2 Genus Cyathus Haller (1768), nom. sanct. - bird's nest fungi
                 3 Genus Mycocalia J.T. Palmer (1961)
                 4 Genus Nidula V.S. White (1902)
                 5 Genus Nidularia Fr. (1817), nom. cons.