[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 Echinothuroida
see Order Echinothurioida Claus, 1880
Family Echinothuridae
see Family Echinothuriidae Thomson, 1872
Genus Hygrosoma Mortensen, 1903