1. The Cenozoic

2. Paleogene Period (65 – 23 MYA)
Mammals diversified into major groups
Began cooling trend from the warm and humid Cretaceous
Silica concentrations rose in the oceans due to mountain building and evolution of grasslands

3. Neogene Period (20.45 – 2.58)
Position of continents about the same as now
Terrestrial life recognizable (mammals, birds, and flowering plants)
Connection between North and South America ~5mya
Periodic desiccation of the Mediterranean basin
Appearance of bipedal hominins