| 古生代 | Gǔ shēng dài | Paleozoic, geological era 545-250m years ago, covering Cambrian 寒武紀|寒武纪, Ordovician 奧陶紀|奥陶纪, Silurian 志留紀|志留纪, Devonian 泥盆紀|泥盆纪, Carboniferous 石炭紀|石炭纪, Permian 二疊紀|二叠纪 |
| 二叠纪 | Èr dié jì | Permian (geological period 292-250m years ago) |
| 二迭纪 | Èr dié jì | Permian (geological period 292-250m years ago) / also written 二疊紀|二叠纪 |