Beginnings, Cenozoic Era (66 mya-Present), Evolution of Life (4600 mya-Present), Neogene Period (66-2.58 mya), Oligocene Epoch (33.9-23.0 mya) Beginnings, Evolution of Life: Oligocene Epoch (33.9-23.0 mya), Ruminants September 28, 2025 — 0 Comments