The researchers say the scratches reveal that the movements of hadrosaur teeth were complex and involved up and down , sideways and front-to-back motion .
研究者们认为，这些纹路显示了这种鸭嘴龙的牙齿运动很复杂，包括了上下、左右、前后的运动。
Although its name identifies it as a small duckbill , it is based on juvenile remains , and the size of the adult hadrosaur is unknown .
虽然从它的名字就可知它是小型的鸭嘴龙科，但其实发现的只有幼体遗骸，而成体的大小就不得而知了。
So far , they have determined that the hadrosaur 's hindquarters are 25 percent larger than previously thought for the species , meaning that it could run up to 28 mph -- faster than previously estimated .
