科学家们指出，这些鸭嘴龙的骨骼化石很难随着地层断裂迁移到较为年轻的地层之中。

Scientists point out that the it is very difficult for these duck-billed dinosaur fossil bones to move to more younger strata as of the fracture formation.

这些恐龙都是更大更壮的鸟臀目恐龙，例如剑龙、甲龙和鸭嘴龙的先祖。

These dinosaurs were the forerunners of the bigger and more spectacular ornithischians like stegosaurus, ankylosaurus and the duck-billed dinosaurs.

山东诸城是我国研究白垩纪地层和古生物的经典地区之一，特别以产出晚白垩世鸭嘴龙类恐龙化石群而闻名中外。

Zhucheng City of Shandong Province is one of classic areas for the study on Cretaceous strata and fossils in China, yielding rich Late Cretaceous hadrosaurid dinosaurs famously.

这些纹路能告诉科学家们这些动物可能是怎样咀嚼食物的，而牙齿上并没有坑坑洼洼的小坑，这个迹象告诉我们鸭嘴龙吃什么。

While the scratches told the scientists how the animal may have chewed, the lack of pit marks on the teeth suggested what the hadrosaur was eating.