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) †Mississippian Subsystem (358.9 - 323.2 Ma) 1 (Series) †Lower Mississippian Series (358.9 - 346.7 Ma) 2 (Series) †Middle Mississippian Series (346.7 - 330.9 Ma) 3 (Series) †Upper Mississippian Series (330.9 - 323.2 Ma)