Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       Astra Plinius - celestial bodies
         Universe
           (Supercluster) Virgo-Hydra-Centaurus Supercluster
             (Supercluster) Virgo Supercluster
               (Cluster) Local Group
                 (Galaxy) Milky Way Galaxy veter.
                   (Spiral arm) Orion Arm
                     (Region) Local Bubble
                       Local Interstellar Cloud
                         (Planetary system) Solar System
                           (Planet-satellite system) Earth System
                             (Planet) Earth veter.
                               "spheres" (Earth)
                                 (Sphere) Lithosphere (Earth) - layer of rock
                                   "strata"
                                     "chronostratigraphic units"
                                       "global chronostratigraphic units"
                                         (Eonothem) Phanerozoic Eonothem (541.0 Ma - present)
                                           (Erathem) †Paleozoic Erathem (541.0 - 251.902 Ma)
                                             (System) †Carboniferous System (358.9 - 298.9 Ma)
                                               (Subsystem) †Pennsylvanian Subsystem (323.2 - 298.9 Ma)
                                                 1 (Series) †Lower Pennsylvanian Series (323.2 - 315.2 Ma)
                                                 2 (Series) †Middle Pennsylvanian Series (315.2 - 307.0 Ma)
                                                 3 (Series) †Upper Pennsylvanian Series (307.0 - 298.9 Ma)