We can divide the Jurassic Period into three key parts, known as epochs: the Early Jurassic, 201.4 million to 174.7 million years ago the Middle Jurassic, 174.7 million to 161.5 million years ago the ...

During the Early Jurassic period, the area was transitioning from marine sedimentation to inland basins, said Chen Xinyu, a senior engineer with the China Geological Survey. Xing said ...