Oligozän Geologic Time Scale (2019) Chattian Age older bound -33.9 Ma Rupelian Age Oligoseeni oligocén oligocén Oligocène Cenozoic Era Oligocen Oligocen Paleogene Period Priabonian Age oligocene younger bound -23.03 Ma Oligocénico Oligoceno Oligotseen Oligocæn 渐新世 Miocene Epoch Олигоцен Oligocenas oligocen oligocen 漸新世 Phanerozoic Eon Eocene Epoch Oliogoceen a1.1.1.3.1 Base of Oligocene Aquitanian Age Neogene Period Oligocene Oligocene Epoch Oligocén Base of Neogene