living organisms
 see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
  
 Superkingdom Eukaryotae
 see Domain Eukaryota Chatton, 1925
    
 Kingdom Animalia Linnaeus, 1758 - animals
      
 Subkingdom Eumetazoa Butschli, 1910
 see [unranked] Eumetazoa Bütschli, 1910
        
 Phylum Echinodermata Bruguière, 1789 - echinoderms
          
 Subphylum Echinozoa von Zittel, 1895
 see Infraphylum Echinozoa Haeckel, in Von Zittell, 1895
            
 Class Holothuroidea (de Blainville, 1834) - sea cucumbers
              
 Subclass Aspidochirotacea
                
 Order Elasipodida Théel, 1882
                  
 Family Pelagthuriidae
 see Family Pelagothuriidae Ludwig, 1893