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) †Mesozoic Erathem (252.17 - 66.0 Ma) (System) †Cretaceous System (145.0 - 66.0 Ma) (Series) †Upper Cretaceous Series (100.5 - 66.0 Ma) (Stage) †Santonian Stage (86.3 - 83.6 Ma) (Substage) †"lower Santonian Substage"