PORIFEROS  _
               + CNIDARIOS
                                PLATELMINTOS
                                                     NEMÁTODOS
                                                                        ANÉLIDOS
                                                                                      MOLUSCOS
                                                                                                       ATROPODOS
                                                                                                                          EQUINODERMOS
                                                                                                                                                      PECES
                                                                                                                                                               ANFIBIOS
                                                                                                                                                                           REPTILES
                                                                                                                                                                                        AVES       +
                                                                                                                                                                                          _   MAMÍFEROS