Which accurately describes a chart developed 20 years after a historical event?

effective secondary source document

too biased for historical evidence

too focused for historical evidence

unreliable narrative source

useful primary source document

Which of the following statements proves that scientific knowledge changed due to the discovery of the fossil of a hadrosaur in north dakota? hadrosaurs were better runners than earlier thought. hadrosaurs had no pattern on their skin as expected. the length of the hadrosaur was shorter than previously thought. the muscular structure of hadrosaurs was less developed than expected.