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. "history" (Earth) "global geochronologic units" (Eon) Phanerozoic Eon (541.0 Ma - present) (Era) †Paleozoic Era (541.0 - 251.902 Ma) (Period) †Ordovician Period (485.4 - 443.8 Ma) (Epoch) †Early Ordovician Epoch (485.4 - 470.0 Ma) 1 (Age) †Tremadocian Age (485.4 - 477.7 Ma) 2 (Age) †Floian Age (477.7 - 470.0 Ma)