older bound -59.2 Ma Geologic Time Scale (2020) Paleogene Period Thaneti thanetij Thanétien Thanetian Paleocene Epoch Ypresian Age Танет Thanet Thanet Phanerozoic Eon Selandian Age Eocene Epoch 塔内提期 サネティアン期 thanetiano tanet younger bound -56 Ma Thanetian Age Tanet Tanetiano Thanetien Base of Eocene a1.1.1.3.3.1 thaneti Thanetium Base of Thanetian Thanetium Thanetiense Cenozoic Era thanet Tanetis Thanetiën