Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Clade neomura Cavalier-Smith, 1987
             Domain Eukaryota Chatton, 1925 - eukaryotes
               Clade discaria Cavalier-Smith, 2021
                 Clade dorsates Cavalier-Smith, 2021
                   Clade podiates Cavalier-Smith, 2012
                     Clade Amorphea Adl et al. 2012 [Simpson, Medina & Adl 2020]
                       Clade Obazoa Brown, Sharpe, Silberman, Heiss, Lang, Simpson & Roger 2013
                         Clade Opisthokonta Cavalier-Smith 1987 [Simpson & Medina 2020] - animal-fungal clade
                           Superkingdom Holozoa Lang, O'Kelly, Nerad, Gray & Burger, 2002
                             Clade filozoa Shalchian-Tabrizi, Minge, Espelund, Orr, Ruden, Jakobsen & Cavalier-Smith, 2008
                               Kingdom Animalia Linnaeus, 1758 - animals
                                 Clade Planulozoa Wallberg, Thollesson, Farris & Jondelius 2004
                                   Subkingdom Bilateria Hatschek, 1888 - bilaterians
                                     Clade Nephrozoa Jondelius, Ruiz-Trillo, Baguñà & Riutort 2002
                                       Infrakingdom Deuterostomia Grobben, 1908
                                         Clade Ambulacraria Metschnikoff 1881 [Halanych 1995]
                                           Phylum Echinodermata Bruguière, 1789 - echinoderms
                                             Subphylum Eleutherozoa Bell, 1891
                                               Infraphylum Echinozoa Haeckel, in Von Zittell, 1895
                                                 Class Echinoidea (Leske, 1778) - sea urchins and sand dollars
                                                   Subclass Euechinoidea Bronn, 1860
                                                     Superorder Atelostomata von Zittel, 1879 - irregular urchins
                                                       Order Pourtalesioida
                                                         Family Plexechinidae Mooi & David, 1996
                                                           Genus Plexechinusᵀ Agassiz, 1898