[organisms]
see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
Phylum Echinodermata Bruguière, 1789 - echinoderms
Class Echinoidea (Leske, 1778) - sea urchins and sand dollars
Order Pourtalesioida
1 Family Pourtalesiidae A. Agassiz, 1881
2 Family Urechinidae Duncan, 1889
3 Family Plexechinidae Mooi & David, 1996
4 Family Calymnidae Mortensen, 1907