Caledonian stage

例句：

1. 1. The researcher found that the Caledonian stage was a crucial period in the evolution of life on Earth.
   研究人员发现，凯尔多尼亚阶段是地球上生命演化的关键时期。
2. 2. During the Caledonian stage, the climate was characterized by warm and humid conditions.
   在凯尔多尼亚阶段，气候特点是温暖湿润。
3. 3. The discovery of fossils from this period has shed light on the early history of our planet.
   这一阶段的化石发现为我们星球的早期历史提供了线索。