organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Kingdom Protoctista Hogg, 1860
     Phylum Haptophyta D.J. Hibberd ex Edvardsen & Eikrem (2000) see Subphylum Haptophytina Caval.-Sm. (2015)
       Genus Calcidiscus Kamptner (1950)
       Genus Calciosolenia Gran, in J. Murray & Hjort (1912)
       Genus Calyptrosphaera Lohmann, 1902
       Genus Chrysochromulina J.B. Lackey (1939)
       Genus Coccolithus E.H.L. Schwarz (1894)
       Genus Discosphaera Haeckel (1894)
       Genus Emiliania W.W. Hay & H. Mohler (1967)
       Genus Gephyrocapsa Kamptner (1943)
       Genus Hymenomonas F. Stein (1878)
       Genus Pontosphaera Lohmann (1902)
       Genus Prymnesium J. Massart (1920)
       Genus Rhabdosphaera Haeckel (1894)
       Genus Syracosphaera Lohmann (1902)