This is because the formation kept walking in the land is rich in dinosaur fossils, and pterosaur fossils are very scarce and rare, in our country are scarce and rare.

• 这是因为地层中保存的行走在陆地的恐龙化石十分丰富，而翼龙化石却格外贫乏和稀少，在我国更是稀缺和罕见。